BIOL 321 Part II Flashcards
(613 cards)
1
Q
Bryozoa lifestyle
A
colonial, sessile, suspension feeders
2
Q
Individual bryozoan
A
zooid
very tiny (mm’s)
lophophore
3
Q
lophophore
A
funnel of ciliated tentacles used for suspension feeding
4
Q
Bryozoan exoskeleton
A
zooecium
often calcified
5
Q
Bryozoan digestion
A
u-shaped digestive tract
6
Q
why is u-shaped digestive tract appropriate for exoskeleton enclosed organisms
A
if posterior end is closed feces would accumulate
7
Q
Bryozoan compartments
A
2 coelomic compartments - lophophoral coelom, perivivsceral coelom
8
Q
Bryozoan organs
A
no specialized organs for gas exchange, excretion/osmoregulation, internal fluid circulation
9
Q
How do Bryozoans accomplish gas exchange/fluid circulation without organs
A
ciliated mesothelium circulate fluids/gases
10
Q
Bryozoan colony form diversity
A
stoloniferous
encrusting
erect
11
Q
encrusting bryozoan colonies
A
zooids lie flat on substrate w/ dorsal surface attached to substrate
12
Q
stoloniferous bryozoan colony
A
creep over rocks, zooids bud up from stolon
13
Q
erect Bryozoans
A
flat blades
branched fronds
14
Q
solitary bryzoan
A
Monobryozoan
solitary, motile, infaunal- interstitial fluids of sand grains, extensions hold on to sand grains, contact to pull organism down
15
Q
Bryozoan polymorphs
A
heterozooid
autozooid
16
Q
Heterozooid
A
usually defensive, non-feeding
e.g. avicularium, operculum snaps shut to deter predators/organisms settling
17
Q
Autozooid
A
feeding, reproducing
18
Q
Vibraculum
A
type of heterozooid (Bryozoan)
elongate ‘whips’ swarm around colony, dislodge settling/predators/used as ‘legs’ for movement
19
Q
Bryozoan reproduction
A
larva -settles -metamorphosis -initial zooid (founder)- aseuxal budding - more individuals = colony
sexual reproduction to form new colony
20
Q
Bryozoan circular colony
A
founder cell in middle
budding takes place around circumference
21
Q
periphery of encrusting bryozoan colony
A
budding zone
22
Q
brown body
A
degenerated mass of zooid tissue, only epidermis +mesothelium, regressed zooid
23
Q
what happens with brown body
A
regenerate whole new zooid w/ brown body in stomach - defacate it out
24
Q
why do zooids regress and regenerate?
A
possibly method of dealing with toxin/waste build up
25
Bryozoan defense
```
heterozooids
colonialism
chemical defense
induced defences
calcification of frontal membrane
```
26
colonial defense
strength in numbers, genome maintained - unlikely predator will eat whole colony, can regenerate
27
what are chemical defenses
secondary metabolites
deter predators
antibiotics
28
Bryozoan secondary metabolites
bryostatin - appears to have anti-cancer, anti-alzheimer properties, synthesized by symbiotic bacteria
29
why is it important to calcify frontal membrane of Bryozoan
flexible frontal membrane leaves them vulnerable to predation
e.g. nudibranch slices frontal membrane w/ radulae and sucks out bryozoan
30
Induced defense, bryozoa
initially put all E into reproduction, predator comes, w/i 48hrs of predator feeding zooids form calcareous spines on corners of zooecia
31
Bryozoan frontal membrane calcification
frontal surface inflexible to protect against predators
32
how can lophophore retreat with inflexible frontal membrane
sac inside of perivisceral compartment is filled w/ fluid, ejects fluid out pore to make room for lophophore
33
periversceral fluid-containing sac in Bryozoans with frontal membrane calcification
Ascus
34
how is lophophore moved out in Bryozoan w/ frontal membrane calcification
parietal muscles expand balloon and water is sucked back in - forces lophophore out of way
35
how is lophophore retracted in a Bryozoan
lophophore retractor muscles
36
Bryozoan sexual characteristics
gametes arise from mesothelium
hermaphroditic (sequential or simultaneous)
sperm spawn through tentacular pores
external or internal fertilization
37
Bryozoan external fertilization
both gametes spawned externally
| long-lived feeding larvae
38
Bryozoan internal fertilization
eggs maintained internally, brooded for short period, short-lived non-feeding larvae
39
Bryozoan egg brooder
ovicell (heterozooid)
40
Mollusca subphyla
Conchifera
| Aculifera
41
Aculifera groups
Polyplacophora
| also Chaetodermomorpha, Neomeniomorpha which we are not studying and are placaphora
42
Conchifera groups
```
Monoplacophora
Cephalopoda s.g.
Scaphopoda s.g.
Bivalvia s.g.
Gastropoda
```
43
Mollusca primitive characteristics
dorso-ventral differentiation
CaCO3 shell
mantle cavity, gills, osphradia
shell-attached muscles
44
chiton shell
8 articulating shell valves w/ 8-pairs dorsal ventral shell-attached muscles (from shell-foot)
45
Mollusc dorso-ventral differentiation
visceropallium
| cephalopodium
46
Chiton osphradia
2 sensory organs - on either side of anus
47
Mollusca gill
ctenidium - central axis w/ gill lamella, afferent/efferent blood vessels
48
Mollusca circulation
hemal fluid in to afferent blood vessel, through each gill lameli, out efferent blood vessel
49
Mollusca water circulation
in between each lameli - countercurrent to hemal flow to maximize efficiency of gas exchange
50
Mollusca reduced coelom
pericardium
| containing heart, attached to metanephridia, gonads, associated with gut
51
metanephridia, Mollusca
heart contraction = ultrafiltration
| fluid down metanephridial ducts = selective reabsorption
52
Mollusca gonads
derived from mesothelium
| most extant organisms do not retain connection between gonad-pericardium
53
Mollusca digestion
mouth, radular cartilage, foregut, radular sac
54
radular sac
secretes riot of radular chitinous teeth on ribbon
55
radular cartilage
rods, support radular teeth
56
how radula works
muscle protrudes radular cartilages out of mouth carrying radular teeth - pull teeth back in scraping substrate
57
Mollusc radula + cartilages
buccal mass
58
Mollusc nervous system
```
circum-esophogeal nerve ring (cephalopodium)
visceropallial nerve cords
pedal nerve cords
pleurovisercal ganglia
cerebral ganglia
pedal ganglia
```
59
distinctive characteristics of chitons
```
minimal cephalization
dorso-ventral flattening
dorsal shell w/ 8 articulating valves
mantle assisted substrate adhesion
radula with magnetite caps
```
60
Chiton cephalization
non-ganglionated
| non-active, head non-specialized
61
Why chitons have dorsoventral flattening
low profile helps avoid being washed away - adaptation to wave swept shores
62
Chiton substrate adhesion
very muscular foot + mantle periphery for clinging
| lift mantle roof = negative pressure = suction
63
Chiton radula caps
Mollusc teeth are replaced but chitons cap w/ magnetite (Fe containing bxomineral) to reduce wear
64
Chiton reproduction
dioecious, broadcast spawn (m and f), external fertilization, gametes from gonad mesothelium, ciliated non-feeding larvae
65
largest metazoan phyla
Arthropoda
66
2nd largest metazoan phyla
Mollusca
67
Class Monoplacophora
very rare, deep sea, only known from fossils, single dorsal shell, ventrally similar to chiton, sister clade to rest of conchifera
68
Monoplacophora ventral
mouth, anus, lateral mantle cavity w/ ctenidia, 8 dorsal shell muscles
69
Gastropod shell
isometric coiling -coils in same plane, only see one from front view -asymmetric coiling
70
Accommodating coiled shell, gastropod
visceroplallial elongation and coiling
71
gastropod shell central pillar
columella, CaCO3, central coiling axis
72
shells are designed to be
protective retreat
73
gastropod shell-attached muscles
single or single paired
hold on to columella
run down to foot/head to pull head in, close operculum
74
changes from monoplacophoran to hypothetical intermediate gastropod
```
Shell coils (exogastric) and elongate dorsoventrally,
reduced shell aperture, mantle cavity, # shell muscles, #ctenidia
```
75
changes from hypothetical intermediate gastropod to derived gastropod
Torsion (180ºrotation) of visceropallium relative to cephalopodium, rotation of shell (endogastric shell coil)- anus + mantle cavity over mouth
76
evidence of torsion
anatomy of living gastropod
| development of basal gastropod
77
asymmetries in gastropods
1. asymmetric coil of shell (goes to the left or right)
2. torsion
3. non-bilateral organs/structures (majority of gastropods have left ctenidium/osphradium)
78
extant gastropod anatomy as evidence of torsion
cross-over of visceropallial nerve connectives
79
gastropod veliger larva
tiny calcareous shell swimming side down, 2 velar lobes, modified trochophore (prototroch, metatroch for feeding)
80
torsion advantages
mantle cavity and therefore ctenidia are moved anterior - water that is brought in is less disturbed by movement
81
torsion advantage to developing gastropod
mc below foot = pull foot in first, velum in last; velum is more valuable and vulnerable than foot, advantageous to have mc above head and pull foot in last
82
development of basal gastropod as evidence of torsion
ontogenetic torsion
| see foot on both sides of shell in developmental stage
83
torsion hypothesis test, abelone
1 batch pre-torsional larvae, 1 post-torsional; both have predators; found no difference in # survivors- no evidence of torsion being advantageous
84
1 problem of torsion
results in deeper anterior mantle cavity - water needs to be frequently circulated for aeration and removing waste
85
solutions to fouling
restricted mantle cavity
shell perforations
shit of anus to right side
86
all gastropods with shell perforations
have 2 ctenidia
87
shifted anus, gastropod
Majority of gastropods; loss of right ctenidium, osphradium;
shift anus to right;
oblique current through mantle cavity; pick up fecal material last on way out
88
gastropod snorkle
siphon
| right side, highly mobile, muscular, samples water and picks up chemical signatures
89
alternative hypothesis for gastropod body
unilateral enlargement of mantle cavity- 2 mc's and one expands in different ways
90
types of gastropod MC enlargement methods
monotocardian
diotocardia
heterobranchia
91
monotocardian
enlarged MC, ctenidia on left, anus on right
92
diotocardian
enlarged MC, 2 ctenidia (L/R), anus in middle
93
heterobranchia
MC not enlarged, reduced to 1 ctenidia
94
gastropod cephalization
fast moving, A-P axis = need for receptors, ganglionization: 1+ tentacle sets, eye spots, series of ganglia
95
Class Gastropoda main features
protective shell - single plate into coiled cone
torsion
pronounced development of head
96
Class Gastropoda groups
Patellogastropoda s.g.
Vetigastropoda s.g.
Caenogastropoda s.g.
Heterobranchia
97
Old Class Gastropoda phylogeny
Prosobranchia (Patellogastropoda, Vetigastropoda, Caenogastropoda) s.g. Opisthobranchia (Heterobranchia) s.g. Pulmonata (Heterobranchia)
98
Vetigastropoda
keyhole limpets, abelone
99
Caenogastropoda
majority of marine gastropods, well developed shells
100
Gastropoda primitive feeding method
herbivorous grazing using radula
101
radula
ribbon of teeth secreted by radular sac, protruded out of mouth to scrape rock
102
buccal cavity
area of gut that radula opens in to
103
vetigastropod feeding
many herbivorous grazers, retain primitive method
104
Caenogastropod feeding
many herbivorous grazers, retained primitive feeding method (radula); many predators with proboscis
105
Proboscis
right side, normally tucked in, used for feeding
106
herbivorous gastropod foregut
mouth - buccal cavity- anterior esophagus- mid-esophageal gland; salivary glands attach to buccal cavity
107
predatory gastropod foregut
deep in-pocket in anterior end = proboscis sac, buccal cavity = proboscis, esophagus greatly lengthened, mid-esophageal gland is enlarged and connected to esophagus by narrow gut
108
evidence of predatory gastropods
shell drills, leave bevelled edged hole on preys shell
109
how predatory gastropod makes shell drills
tip of proboscis has accessory boring organ - raps on shell = mechanical abrasion; also chelate shell = chemical dissolution
110
Cone snail
highly derived gastropod feeding, mostly tropical/subtropical, predatory caenogastropod, feeds on worms/molluscs/fish
111
Cone snail feeding
very long proboscis, w/ harpoon tooth and venom
112
cone snail harpoon tooth
apex of radular tooth is shaped like hollow harpoon, snail takes 1 tooth and places it at end of proboscis, tooth is connected to venom gland
113
cone snail venom gland
midesophogeal gland highly elongated ending in muscular ball specialized to synthesize and secrete conotoxins
114
conotoxin
neurotoxins, peptide that bind to Fe channels and neurotransmitters, rapidly immobilize prey, any 1 species may have 100's
115
Heterobranchs
elaborated dorsal surface, secondarily deflected anus to posterior end (detorsion); loss of larval shell during metamorphosis
116
Heterobranch loss of shell
do have shell in juvenile form (and torsion), crawl out of shell and discard it and operculum
117
Heterobranch defense
chemical defense
escape behaviour
sequester nematocysts
autotomy
118
chemical defense, Heterobranch
dorsal chemical glands - unpallatable/toxic
119
where do Heterobranchs get chemical defense
some make own
| many steal from prey (sponges, bryozoans) and put in dorsal gland sacs (cerata/papillae)
120
escape behaviour, heterobranch
touched by predator -- lift off seafloor - d/v body undulations - catch current and float away
121
sequestering nematocysts, Heterobranchia
feed on cnidarian- sequester nematocyst- carried up to cerata and deposited- phagocitized - utilized
122
where are nematocysts stored in heterobranch
cnidosac - special sac at time of cerata lined by epithelium
123
how are heterobranchs able to utilize nematocysts?
secrete mucus that makes them not trigger (like clown fish) - may get stung at first until they learn the right formula (species specific)
124
Nudibranch autotomy
rapidly release body part, mainly cerata
125
terrestrial heterobranchs
snails, slugs; terrestrial; threats include desiccation, T changes
126
terrestrial heterobranch, breathing
closed mantle cavity = 'lung', pneumostome = pore, opening to lung (able to close)
127
adaptations for life on land (Heterobranchia
mantle cavity forms internalized lung
conversion of ammonia to uric acid
asetivation
128
Aestivation, heterobranchs
metabolic slow-down, hide in humid location,
tolerance of desiccation
ability to rapidly rehydrate
129
freshwater snail w/ air breathing adaptation
Caenogastropods, pneumostome + long siphon opening in to lung
(convergence w/ heterobranchs)
130
how gastropods can rehydrate
open spaces between epithelial cells
131
Vetigastropoda reproduction
broadcast spawn gametes, external fertilization
132
Caenogastropoda, Heterobranchia reproduction
internal fertilization, encapsulated eggs, juvenile crawls out of egg capsule
133
Class Bivalvia
```
dv flattened body
2 shell valves
spacious lateral mantle cavity to house ctenidia
minimal cephalization
no radula
```
134
Bivalve falttening
including foot, facilitate digging
135
why bivalves need 2 valves
life in substrate - need to remain open for circulation, need to shells to remain open - pressure would collapse mantle
136
Bivalve radula
none in extant members, feeding by suspension or deposit
137
bivalve water flow
along edge of shell or restricted to siphons
138
bivalve adductor muscles
pull valves together, cause tension in ligaments, when released ligaments pull shells open
139
Bivalve shell secretion
secreted by outer mantle lobe, sequential layers of bxomineral CaCO3 w/ crystals oriented in opposite directions - cross-hatched for strength
140
Bivalve mantle margin
sensory structures on periphery of mantle fold (middle lobe)
141
bivalve middle lobe
most exposed to environment, may contain photoreceptors, tentacles
142
bivalve outer lobe
secretes shell
143
bivalve inner lobe of mantle fold
'muscle lobe'
| has pallial muscles connected to shell valve to pull and tuck all soft tissues in side shells
144
Diversity of feeding in Bivalvia
prosobranch
lamellibranch
septibranch
145
Protobranchs
deposit feeder; use palp tentacles; gills for gas exchange only, ancestral feeding strategy, long paired siphons
146
palp tentacles
ciliated, deposit feeding in protobranchs
147
Protobranch ctenidium
gas exchange only
| non-elaborate gill filaments on sides of gill axis
148
Lamellibranch
ctenidia for gas exchange and feeding, suspension feeders
149
lamellibranch ctenidia
elongate filaments, folded back to fit, highly ciliated to carry particles
150
lamellibranch folds
demibranchs
| outer demibranch = closest to shell
151
Lamellibranch cilia
each 'limb' is surrounded by 3 types of cilia: lateral cilia, laterofrontal cilia, frontal cilia
152
lateral cilia, lamellibranch
short, on the 'top/bottom', create water current
153
laterofrontal cilia, lamellibranch
longer, point diagonally, intercept particles
154
Septibranch feeding
rare, predators, suction feeding, enormous inhalant siphon used for sucking in small organisms
155
septibranch ctenidia
modified gill = muscular, perforated diaphragm; closed shell, elevated muscular shelf = increased volume in inhalent chamber = suction
156
Bivalvia habitatlifestyle diversity
burrowers (majority; deeper = longer siphon)
attached to solid substrate
boring
157
example of shallow burrowing bivalve
cockle
158
e.g. of bivalve attached to solid substrate
mussels
159
Mussel attachment
secrete byssal threads
160
frontal cilia, lamellibranch
short, face out, frontal surface, carry particles down filament to elbow-like area of gil filament
161
example of deep burrowing bivalve
geoduck
162
how to use byssal threads
byssal gland by foot secretes fluid-- fluid runs down foot, forms puddle-- starts to harden - lift foot- move foot and repeat
163
oyster substrate attachment
cement w/ CaCO3
164
boring bivalve
shipworms
| free-swimming larva, settle, metamorphose, feed/create tunnel
165
Class Scaphopoda
tusk shells, see text book ch 12
166
Class Cephalopoda
active, pelagic, predatory, smartest, largest, fastest molluscs, 3 subclasses, 1 extinct
167
Cephalopod molluscan characteristics
radula
molluscan-style gill (but not ciliated)
shell-secreting mantle (but reduced/lost in most extant)
168
Cephalopod unique characteristics
septate shell
| highly modified foot
169
Cephalopod foot modifications
```
prehensile appendage (arms, tentacles)
funnel
```
170
Cephalopoda groups
Nautiloidea - extant, since Palaeozoic, first known group (540Ma)
Ammonoidea - extinct end of Mesozoic, known from mid Paleo
Coleoidea - extant, known from end of Paleo
171
Nautilus
primitive cephalopod, tentacles have no suckers, external shell, hood, funnel
172
Nautilus shell
external, gas-filled chambers, chambers separated by septa, septa perforated for siphuncle
173
Squid
active, agile swimming, predatory feeding
174
squid example
Loligo
175
squid predation
visual predators- image-forming eyes, eye morphology convergent w/ vertebrates
176
Coleoidea metabolics
high metabolic rate, ventilate gills by pumping muscular mantle, closed circulatory system, systemic and branchial hearts
177
Coleoid branchial hearts
booster pumps to force blood through gills
178
Protostomia groups
Lophotrochozoa
| Exdysozoa
179
Exdysozoan groups
Nematoda, Onychophoran, Arthropoda
180
Ecydsozoa shared morphological characteristics
Ecdysis
| no motile cilia/flagella
181
Ecdysis, ecdysozoa
periodically moult exoskeleton/cuticle for growth
182
Phylum Nematoda basic characters
multilayered collagenous cuticle, 4 moults, longitudinal muscles only, pseudocoel, syncytial epidermis, anterior nerve ring, longitudinal cords, aberrant cilia, eutely
183
Nematode cilia
non motile, restricted to sensory function
184
eutely
embryo hatches w/ set # of somatic cells and never produces any more; growth only by enlargement of cells
185
Nematode body movement
thrashing motion; dorsoventral contractions; only useful for forward motion in dense medium
186
Needed for nematode locomotion
stiff cuticle;
fluid maintained under high pressure in pseudocoel;
longitudinal muscles
187
Nematode feeding
triradiated pharynx, muscle contraction opens lumen, have to actively open gut by muscular means b/c high pressure of gut, must drink water to actively push food down
188
Nematode reproduction
Asexual and sexual
189
nematode asexual reproduction
very rare - parthenogenesis (no budding or fission)
190
nematode sexual reproduction
dioecious, internal fertilization, males w/ copulatory spicules, ameboid sperm (aflagellate)
191
nematode developments
4 moults to adult stage; egg - 4 juveniles - adult; eutely
192
Dauer larva
Nematode facultative diapause, triggered by enviro. cues, age arrest (reduced metabolic rate), occurs at L2 (juvenile #2)
193
parasitic nematode examples
hookworm, wuchereria, golden nematode
194
Hookworm
intestinal parasite, 1 host, cuticle around mouth forms tooth/hook-like projections, consume blood from intestinal wounds, leads to anemia
195
Hookworm life cycle
adult worm in human intestine - eggs passed in feces - juv. 1 hatches - 2 moults - juv. 3 burrows into skin, often foot - moves to circulatory system - heart - lungs - trachea - pharynx-- intestine
196
Wuchereria bancrofti
Nematode, Elephatiasis, microfilariae larvae clog lymphatic vessels, causes grotesque swelling, 2 hosts - human, mosquito
197
Wuchereria bancrofti life cycle
microfilariae - mosquito - moult - move to salivary gland - transmitted to human
198
Golden nematode
1 host, damaging potato parasite, cysts on roots are dead swollen fm bodies filled w/ eggs
199
Golden nematode distribution
Europe, Asia, Africa, Canada (Nfld, Central Saanich)
200
What golden nematode does
burrow in to roots, feed on root tissues, cause death/stunted growth
201
Caenorhabditis elegans
model organism for developmental genetics- tiny (few mm's), short generation times (3days), hermaphroditic (self-fertilize), eutely (959 somatic cells)
202
why C elegans is a model organism
cell lineage known for all cells - map
synaptic connections btw neurons mapped
entire genome sequenced
203
ratio of animals that are arthropods
4/5
204
Phylum Arthropoda importance
```
high successful by any metric
important food web component
medical importance
economic importance
model organisms
```
205
Arthropods success
most specious, most individuals, ability to invade almost all habitats, etc.
206
Arthropods in food webs
important component - 1º and 2º consumers, removal of arthropods would collapse any ecosystem
207
e.g. Arthropod medical importance
mosquitos are disease vector
208
e.g. Arthropod economic importance
positive and negative
| pollination, crop destruction
209
Arthropod phylogenetic controversies
monophyletic or polyphyletic?
sister groups?
relations amongst major groups?
one of the most extensively debated subjects in evolutionary biology
210
Arthropod metamerism
convergent with Annelida
211
consolidations of multiple adjacent metameres into coherent morphological units with specialized functions
tagmosis
| unit = tagmata
212
Arthropod exoskeleton
chitin (polysaccharide) + crosslinked proteins (sclerotization) secreted by epidermal epithelium
213
Arthropod exoskeleton functions
support
protection (predators, mechanical abrasion)
facilities movement
214
exoskeleton movement function
transmits force of muscle contraction
215
Parts of arthropod exoskeleton
epicuticle (lipids, waxes)
Protocuticle (exocuticle + endocuticle)
Epidermis
216
axial arthropod skeleton
4 hardened plates (sclerites): top = term, bottom = sternum, sides = pleuron
217
appendicular arthropod skeleton
articles - thin hollow tubes connected to form appendages
218
arthropod jointed appendages
joints formed by thin, flexible exoskeleton (articular membrane)
219
movement of arthropod appendages
antagonistic muscle bands
condyle
many appendages/articles
220
Arthropod antagonistic muscles
extensor and flexor muscles
221
condyle
one article fits precisely into the other - only permits movement in 1 direction
222
Benefit of many articles in arthropod appendages
movement in different directions/planes = large range of motion
223
Adaptive potential of arthropod appendages
versatile raw material:
- can be sculpted into diff. shapes/functions
- each article can be precisely moved by muscles
224
exoskeleton tools
sensory, mouthparts, prey capture, crawling, swimming, escape behaviour
225
arthropod secondary body compartment
hemocoel separated by diaphragm in to pericardial and peravisceral
226
Arthropod nephridium
epithelial tubes capped by epithelial sac = metanephridium
excretory tubes homologous to metanephridium
saccule homologous to shrunken coelom(?)
227
extra consequences of exoskeleton
moulting
| sensilla
228
Arthropod growth
periodic moults under hormonal control- secrete inactive chitinases
229
moulting process, cellular
glandular cells secrete inactive chitinase (proenzyme) - new epicuticle secreted - proenzyme activated - digest endocuticle - split out at areas of weakness
230
new exoskeleton
week/soft, not cross linked - pump up with air/water -make bigger before hardening - harden - shrink back down - have room
231
sensilla
sensory, ball and socket joint, neurons w/ dendrites, lower exoskeleton cover
232
What is Arthropod sister group
Onychophora
233
Phylum Onychophora
velvet worm, low species #s compared w/ arthro. (180), very humid terrestrial, chitinous cuticle, metameric, non-jointed appendages, annelid/arthropod, distinct terminal ends (claws)
234
earliest known Arthropod
Hallucigenia, Burgess Shale, Field BC, early Cambrian
235
Arthropoda subphyla
Trilobitomorpha
Chelicerata
Mandibulata
236
Chelicerate tagmata
2 tagmata
Prosoma
Opisthosoma
237
Chelicerate # of appendages
Prosoma - 6 pr.
| Opisthosoma - variable
238
Chelicerata first pr appendages
chelicerae
239
Chelicerata 2nd pair appendages
pedipalps
240
Chelicerata classes
Merostomata
Arachnida
Pycnogonida
241
Merostomata
1 genus (4spp.) extant, marine, horseshoe crab
242
Merostomata e.g.
Limulus sp.
| horse shoe crab
243
Merostome morphology
2 tagmata: prosoma (A), opisthosoma (P);
| telson, compound eye (unique)
244
Merostome prosoma
shovel-shaped to facilitate sediment burrowing
245
telson
not true metamere, hinged to body, d-v movements, aids in 'righting' flipped over body
246
Merostome appendages
Prosoma: chelicerae, pedipalp, (mouth), 4 walking legs
247
chelate
pincer-like appendage
248
article
podomere (segment of appendage)
249
Merostome posterior appendages
not chelate
'pusher legs'
push off sediment
clean out gills
250
Merostome opisthosome
6pr appendages fused in to flaps = gill opercula
251
Merostome gill opercula
thicker exoskeleton protecting book gills (very thin exo.)
| wave to oxygenate gills
252
gnathobase
proximal joint/ process of arthropod appendage, modified to aid in carrying/ masticating food
253
Class Arachnida
scorpions, spiders, ticks, mites
terrestrial, largest group of chelicerata, few opisthosome appendages, predators, malpighian tubules, book lungs/tracheae, spermatophores
254
Arachnid feeding
mostly predatory, mostly on other arachnids
255
How to feed on arachnids
must get in to exoskeleton - rip up, vomit digestive enzymes, suck up sap
256
malpighian tubules
lined tubules extend from gut and float in hemocoel, take up rates and crystallize- move down tubule - removed from anus - save water
257
Book lung
internalized book gill
| delicate epidermis layers covered by thin exoskeleton
258
tracheal tubules
tubular, branched, invagination of epithelia w/ exoskeleton floating in hemocoel
259
Arachnid reproduction
internal fertilization
| spermatophores - protected bundles of sperm
260
scorpion appendages
Prosoma: chelicerae (small), 1 pr pedipalps (large, chelate), 4 pr walking legs
telson: stinger w/ neurotoxin glands
261
Scorpion pedipalps
prey capture, ambush predator (only use stinger for big prey)
262
pectine
comb-like sensory structure - high density of mechanoreceptors to detect substrate movements, opens to book lung, ventral side of prosoma
263
Spider characteristics
no compound eyes, unique pedipalps, pedicel, spinneret
264
Spider pedipalps
fm - sensory appendages
m- deliver sperm
not chelate, daggers
265
Spider waist, between opisthosome and prosome
pedicel
| narrow for movement = flexibility of spinneret
266
spinneret
many spigots release strands of silk
267
spider fertilization
no spermatophores, extrude sperm on to silk, pedipalp sucks it up in to chamber, fits in to fm gonopore like lock&key
268
functions of spider silk
```
sperm transfer
egg cases
prey capture
aqualung
ballooning
```
269
ballooning
move through the air by releasing threads to catch the wind
270
mites/ticks
huge diversity- aquatic, predator/ herbivorous/ parasites
271
mites/ticks appendages
hypostome
chelicera
pedipalp
4 pr walking legs
272
mites/ticks parasitic feeding
attach to host - slice open host w/ chelicera - insert hypostome to anchor and hold position - use pedipalps to support body and for sensory
273
Class Pycnogonida
sea spiders
| ectoparasites, very small, puncture hole in host and suck out body fluid
274
Pycnogonid body parts
Prosoma: proboscis, chelicera (chelifore), pedipalp, ovigerous leg, 4 prs legs
Opisthosoma great reduced, bears anus
275
pycnogonid proboscis
forced through body wall of host to suck body fluid, chelicera help open wound for insertion
276
pycnogonid oviparous leg
often only in m, used to carry eggs, males carry and brood eggs until hatching
277
Arthropod groups
Chelicerata
| Mandibulata
278
Mandibulata groups
Myriapoda
| Pancrustacea
279
Pancrustacea
Crustaceans = Hexapoda
| Ostracodes, Cirripedia, Malacostraca, Copepoda, Branchiopoda, Hexapoda, Remipedia
280
Is crustacea monophyletic
no, paraphyletic
281
mandibulata tagmata
2 or 3
head + trunk
or head+ thorax + abdomen
282
Mandibulate head + thorax
cephalothorax (secondarily consolidated)
283
tagmata in majority of Mandibulates
3
| head+ thorax + abdomen
284
Mandibulate appendages
head: 1-antennae, 2-antennae or X, 3-mandibles, 4-maxillae I, 5- maxillae II
(3prs mouthpart appendages)
285
grasshopper mouthparts
```
disarticulated
upper lip (labrum), 2 mandibles, 2 maxillae, lower lip (labium)
```
286
biramous arthropod appendages
epipod, protopod
287
biramous appendage protopod
2 basal articles made of multiple articles - exopod, endopod
288
compound eyes
common in mandibulate
| many hexagons = ommatidium
289
ommatidium
single photoreceptor cartridge: each one samples section of visual field at different angle than neighbour, detecting slightly different visual field
290
after ommatidium detects image
crystalline cone focuses incoming light - reticular cells covered in microvilli are receptors - open ion channels - membrane polarization - propagate action potential - brain -information
291
Myriapoda tagmata
2:
head
thorax
292
Myriapoda appendages
head: pair antennae, mandible, 2 pr maxillae
293
What are myriapods
centipedes, millipedes
294
centipedes
predators, poison claws, fast
295
centipede poison claw
first trunk appendage
296
centipede movements
fast effective stroke, slow recovery stroke, high speed, high gear, low power, not many legs on ground at once
297
Millipede
herbivorous, slow, diplosegments
298
diplosegment
2prs legs/segment
299
millipede movement
slow effective stroke, fast recovery stroke, slow movement, low gear, high strength, most legs on ground at once pushing - strong walking
300
What is hexapoda sister group
Remipedia - primitive body plan - annelid like, not very successful
301
Hexapoda terrestrial adaptations
Minimize water loss
Avoid/tolerate temperature extremes
Wings/flight
302
Hexapoda water loss
minimized via: waxy epicuticle (myriapods lack waxes in epicuticle), mapighian tubules, water reabsorption (specialized rectum), tracheal tubules
303
Hexapod malpighian tubules
tubules in hemocoel take up urates, precipitate uric acid (non-soluble), pass w/ feces
304
glow worm
glow produced w/ malpighian tubules - sticky silk threads ensnare prey
305
Hexapod tracheal tubules
hollow cylindrical invaginations of body wall, dendritically branched, end on cell body, O2 delivered directly to cell via tube, lined inside by exoskeleton
306
opening of hexapod tracheal tubule
spiracle with filter hairs
307
tracheal tubule support
Taenidia - circular thickenings of exoskeleton along length of tube to prevent collapsing
308
Myriapod spiracles
not closable (dry out quicker)
309
Hexapod temperature tolerance
behavioural
morphological
physiological
310
behavioural temperature tolerance, hexapod
basking, stilting, crouching
311
stilting
extend legs, lift body off of hot ground
312
crouching
ground heats/cools slower than air, crouching close to rock to absorb heat
313
morphological temperature tolerance strategies, hexapoda
insolating cuticler hairs, layer of hair around body prevents heat loss, e.g. bumblebee
314
physiological temperature tolerance strategies, hexapoda
shivering, antifreeze proteins
315
dangers of freezing
sharp crystals rupture cells
316
AFP
Antifreeze Proteins
317
Insect AFP
surround small ice crystals and prevent them from growing
318
Hexapoda wings
mesothoracic, metathoracic wings
| from 2nd, 3rd thoracic segments
319
wingless insects
apterygotes
320
insect wing morphology
largely exoskeleton, reinforced by wing veins (tracheal tubules), nerves, sensory receptors, tissues
321
Advantage of flight
new niche space, dispersal to new resources, reach resources inaccessible to others, escape predators, find mates, migration, find suitable mating locations
322
origin of wing hypotheses
Tergal lobes
| Appendage derivatives
323
Tergal lobe theory
tergum (top sclerite lobe) draw out laterally
324
problems with tergal lobe theory
```
no hinge (wings are hinged)
would require elaborate modification
```
325
Appendage derivative hypothesis
epipods are hinged and fn in gas exchange
326
testing appendage derivative hypothesis
Drosophila gene rubbin (Tc factor) is essential for wing development; mutated rubbin = little nub wings; look for homologues of rubbin in pancrustacea - mark - follow development
327
results of appendage derivative hypothesis testing
rubbin traced to epipod in crayfish and brine shrimp- consistent with epipod-wing theory
328
Hexapoda mouthpart diversification
chewing, sponging, piercing, sucking
329
ancestral hexapod mouthparts
chewing type
| e.g. grasshopper
330
grasshopper mouthparts
heavily sclerotized, chewing:
| labrum, 2 mandibles, 2 maxilla, labium (2nd pr maxillae), hypopharynx
331
winged insects
pterygotes
332
hypopharynx
tongue
| salivary glands
333
sponging mouthparts, hexapoda
labium (2nd pair maxillae)
| tubules for sponging liquid food
334
cutting + sponging mouthparts
sponging labium + cutting mandibles (cut open prey to sponge up fluids)
335
piercing and sucking mouthparts
labium =protective sheeth, supports stiletto-like mouthparts - labrum, mandibles, maxillae = elongate spheres;
mandibles puncture, labrum forms sucking tube, salivary secretions make us itchy
336
butterfly mouthparts
sucking; 1st pr maxillae curve together to form elongate sucking straw
337
Hexapod development patterns
ametabolous
hemimetabolous
holometabolous
338
exopterygote development
=external wing development
hemimetabolous development
larva similar to adult minus wings
339
Ametabolous development
apterygotes
nymphs hatch from eggs that look exactly like adult, live in same habitat, feed on same material
stages of moults all look same
no major transitions in development (except reproduction)
340
how are hemi/holometabolous youth different than adults
mainly they do not have wings
341
holometabolous development
endopterygote development
larva very different than adult
internal wing development
342
example of hemimetabolous development
grasshopper, locusts, mayfly larva, dragonfly larva
343
what do hemimetabolous wings develop from
wing pads
344
what do holometabolous wings develop from
imaginal discs
345
holometabolous specialties
differential specialization
larva specialized for feeding
adult specialized for reproduction
346
holometabolous metamorphosis
body rearrangement
| exclusively adult features develop internally (wing, antennae, mouthparts)
347
imaginal discs
nests of stem cells that differentiate in to various adult structures
348
pupa stage, holometabolous development
rearrangement
larval structures destroyed
adult structures everted
349
aquatic larva, Hexapoda
2 life history stages, major development, differential specialization
350
mosquito life cycle
adult - eggs in water - larva (w) - pupa (w) - adult emerges in to air
larva has posterior siphon for breathing
pupae has anterior snorkle
351
Hexapoda defensive strategies
morphological
behavioural
chemical
physiological
352
Hexapod morphological defensive stratgies
shape and colour matching
| e.g. stick bug
353
hexapod behavioural defensive strategies
flight
projectile defecation
petiole clipping
behavioural crypsis
354
projectile defication
release feces in projectile motion to hide location
355
petiole clipping
fill up on leaf, chop off stem so hole-y leaf is not so visible
356
example of behavioural crypsis
woolly aphid, ant, lacewing larvae
357
example 2 of behavioural crypsis in hexapoda
leaf beetle larva
| hold mass of own feces containing defensive chemicals from plant on back - disguise as something not tasty
358
chemical defensive strategies, hexapoda
venomous stings (bees, wings)
sticky threads to entangle
(termites)
reflex bleeding (ladybug)
359
relex bleeding
toxic hemal fluid released from self-directed rupturing of articular membrane between leg articles
360
articular membrane
thin area of exoskeleton 'joints'
361
bombardier beetle chemical defence
abdominal reaction chamber - explosively eject hot, toxic fluid from anus
362
bombardier beetle reaction
secrete hydroquinone and H2O2, catalaze reduces H2O2, O2 oxidizes hydroquinones (exothermic), hot quinones released (toxic)
363
Non-hexapod pancrustacean characteristics
2 pair antennae (hexapods have 1)
biramous appendages (hexapods have uniramous)
nauplius larvae
364
Nauplius larva
no cilia
3 pr muscle-operated appendages
single median eye
2 pr antennae, 1 pr mandibles = swimming
365
Pancrustacea clades we focus on
Copepoda
Cirripedia
Malacostraca
Hexapoda
366
generalized Malacostracan body plan
3 tagmata - abdomen (6 segments), thorax (8), head (5)
367
Malacostracan head appendages
2pr antennae, 1 pr mandibles, 2 pr maxillae
368
Malacostracan thorax appendages
thoracopods
8 prs appendages
maxillipeds, pereopods
369
Malacostracan maxillipeds
1+ pairs often modified accessory mouthparts
370
Malacostracan pereopods
walking legs
371
Malacostraca abdomen appendages
6pairs
pleopods (swimming)
uropods
372
Malacostracan head/thorax consolidation
tergal sclerites fused in to cephalothorax = carapace
| lateral carapace flaps form chamber
373
carapace gill chambers, Malacostracans
branchiostegites
374
Euphausiacea
Malacostraca, krill
| incomplete branchiostegite, no maxillipeds, specialized thoracopods
375
Euphausiid thoracopods
setose biramous feeding appendages = feeding basket/sieve
376
setose
exoskeleton elaborated in to bristle like extensions
377
Pericarida, Malacostraca
Amphipoda, Isopoda
| no carapace, 1pr thoracopods = maxilliped, eggs brooded in marsupium formed by oostegite
378
Amphipoda
laterally compressed
379
Isopoda
dorso-ventrally compressed (form ball)
380
coxa
basal most article
381
basal
bottom layer, closest to body
382
Caprellid amphipod
skeleton shrimp, Malacostraca
383
stomatopod
```
mantis shrimp (Malacostraca)
tropical/semitropical, benthic, carapace does not cover entire length of thorax, functional telson, very aggressive
```
384
Stomatopod appendages
5prs maxillipeds, 2pr raptorial appendages
385
spearing appendages, stomatopod
species that burrow in soft substrate
386
smashing appendages, stomatopods
species that live in rock crevices
387
"most complex visual organ on the planet"
stomatopod compound eye
388
Stomatopod eye
mounted on moveable stocks = 360ºrotation = large visual field
eye divided in half = stereo vision = broad focal range
12-19 photoreceptors w/ different photopigments
389
human photoreceptors
3
390
what is the different in having more photoreceptors if they cover the same spectral range
more sensitive to subtle difference in colour, and extremes (UV, polarized)
less 'windows' (missing coverage areas)
391
Stomatopod telson functions
wide flat defense shield
| reflect polarized light -signaling?
392
Decapoda groups
Caridoa
Astacidea
Anomura
Brachyura
393
Decapod general characteristics
(Malacostraca)
well-developed carapace (entire thorax)
3 pr maxillipeds
394
Caridea
```
Shrimp
delicate, slender pereopods
large muscular abdomen
well developed pleopods
holopelagic or pelago-benthic
```
395
Caridea pereopods
delicate perching appendages
| unique amongst the decapods
396
Caridea pleopods
well developed, swimming
397
Astacidea
Crayfish, lobsters (Decapoda, Malacostraca)
| massive pereiopods, large muscular abdomen, pleopods, chelipeds
398
Astacidea pleopods
swimming (but don't swim a lot)
399
Astacidea chelipeds
1st pair of pereopods - prey capture, defense, offence
400
Brachyura
```
true crabs (Decapoda, Malocastraca)
broad flat cephalothorax, heavy robust pereopods, chelipeds, reduced tucked in abdomen, closed gill chambers
```
401
Brachyura appendages
```
robust pereopods
1st pr pereopods = chelipeds
uropods - secondarily lost
pleopods - reduced/lost, retained in fm to hold eggs between thorax and abdomen
4 pr walking legs
```
402
Anomura
```
squat lobsters, hermit crabs (Decapoda, Malacostraca)
most diverse group of decapods
very reduced 5th pr pereopods
3 prs walking legs
abdomen well developed
```
403
hermit crab
abdomen has spiral asymmetry to fit gastropod shell
pleopods only developed on one side
uropods have grippers to hold on to columella
404
Porcelain crab
Anomuran
carcinization
3 prs walking legs
405
carcinization
anomurans that have converged body morphology with brachyuran crabs (reduced abdomen, carapace over cephalothorax)
406
gill bailer
decapod elaboration of second pair of maxillae, aerate gills, moves in a wave-like fashion
407
why do decapods need gill bailer
to clean out gill filaments - no motile cilia!!
408
Caridea gill cleaning
chelate pereopods - reach in to gill chambers w/ delicate pinchers
(no chelopeds)
409
Anomuran gill cleaning
5th pair of pereopods = little 'stub' on posterior dorsal end of carapace, insert in to gill chamber for cleaning, setose tip
410
Brachyuran gill cleaning
3pr maxilliped epipods = elongate, setose, gill cleaning combs
extend back in to gill chambers
gill scrubbing whenever maxillipeds move
411
Brachyuran, carbonized Anomurans
closed gilled chambers
| lateral rim of branchiostagites fused to abdominal surface
412
Anomuran tail fan
telson + 2pr biramous uropods
| used along w/ abdominal muscles for movement = tail flip
413
Tail flip, jump backwards
flexion of posterior abdomen segments - pulls body backwards
414
Copepoda lifestyle, habitat
Pancrustacea
extremely abundant, diverse aquatic habitats - freshwater/marine- puddles, hot springs, enormous number of individuals, largest animal biomass on the planet, holopelagic, pelago-benthic, parasitic
415
Copepod body size
1-2mm
416
Copepod importance
transfer organic carbon from producers to higher trophic levels
417
tail flip, jump up
flexion between abdomen and cephalothorax -bend middle of body -- body move upwards
418
Copepod body
torpedo-shaped
2 tagmata - head/thorax, abdomen
single medial eye
419
copepod appendages
```
1st pr antennae - sensory
2nd pr antennae- swimming
pr mandibles, 1st pr maxillae
2nd pr maxillae - food capture
1pr maxillipeds - assist feeding
4-5prs thoracic app. - hop swim
forked telson - 2 caudal rami
```
420
distinctive copepod features
forked telson
421
copepod swimming appendages
2nd pr antennae (biramous, bristled)
| 4-5prs thoracic appendage (hop swim) coupled together along median line
422
copepod feeding appendages
2nd pr maxillae
| 1 pr maxillipeds
423
Planktonic copepod environmental factors
```
pull of gravity
depth-dependent light intensity
nowhere to hide
dilute resources
small Re #
```
424
Maintaining position in water column, copepods
1st pr antennae long,bristled increase drag
2nd pr antennae- swim
store nutrients as lipid globules for buoyancy
425
Reynolds number
describes viscous : inertial forces for characterizing behaviour of fluids flowing past an object
426
Re =
(velocity x size x density) / viscosity
427
Copepod feeding
flow lines disrupted by particle - 1st antennae detect disrupted flow while swimming on back- 2nd pr maxillae move apart rapidly - negative pressure, particle drawn in - close maxillae rapidly to capture particle
428
Re dominated by
velocity, size
| density/viscosity relatively unchanging within water column
429
Re less than 10
flow lines move past object in orderly fashion, maintain trajectory, at low speed fluid dominated by viscous forces
430
Re above 20,000
Turbulent flow
dominated by inertial forces
flow lines severely disrupted past object
431
copepod swimming
very active movement, no gliding when movement stops
| small size = low Re = viscosity dominant
432
Why do copepods move maxillae rapidly to feed
to increase Re (increased velocity)
433
boundary layer
non-moving fluid around object
| low Re = thick boundary layer
434
flow dominated by viscous forces
small Re
435
how do copepod detect changes in flow lines
1st antennae covered in mechanoreceptors and setose bristles have thick boundary layer (paddle-like)
436
Copepod evasion and escape
```
transparent w/ few tissue pigments
loss of compound eyes (pigmented)
hop swim
diel vertical migration
1st antennae sensory axons have myelin sheath
```
437
copepod myelin sheath antennae
action potentials travel more rapidly if axon is enlarged (vertebrates), inverts use myelin sheath to speed potential
438
Copepod mate finding
Pheromones
| Behaviour patterns
439
how copepod mating strategies work
male swim back and forth across top of column, fm swim up and down releasing pheromone, when pheromone detected m swims down
440
thin boundary layer
large Re
441
copepod reproduction
eggs brooded in egg sacs
| nauplius larva
442
parasitic copepod example
salmon louse
ectoparasite
huge, cling to external surface, feed on mucus/epidermis/ blood, detrimental to fish health
443
giant parasitic copepod
family Pennellidae
ectoparasite of marine mammals
up to 30cm long
444
Class Cirripedia
sessile in post-metamorphic stage (unique)
carapace as calcified plates
suspension feeding
free-living or symbiotic
445
main Cirripedia groups
acorn barnacles
| stalked (gooseneck) barnacles
446
acorn barnacle
calcified cone directly attached to substrate
447
stalked barnacle
calcified plate mounted on fleshy stalk
448
Cirripedia morphology
opercular plates
wall plates
cirri
449
Cirri
6 pairs thoracic appendages, biramous and setose, very small = low Re, feeding paddles
450
flow dominated by inertial forces
Large Re
| generate turbulent flow
451
Gooseneck barnacle environment
high flow -incapable of sweeping cirri, can't raise Re
| passive feeding
452
Gooseneck barnacle morphology
peduncle (stalk)
adhesive gland
ovary, gut, cecum, muscle, mouth, mantle cavity, cirri
453
Cirripedia moulting
partial moult, only exoskeleton of cirri
454
Cirripedia growth
CaCO3 added to basal rim and up sides - grow in diameter, height
455
barnacle reproduction
most hermaphroditic
very long penis
gregarious settlement, metamorphosis
456
gregarious settlement
larval stage attracted to settle near other members of the species - need to be nearby each other
457
benefit of hermaphroditism in barnacles
as long as there is neighbour fertilization can take place
458
barnacle life cycle
Nauplius larvae - cyprid larva
459
Cyprid larva
2nd larval stage, non-feeding, must find suitable settling place, crawl around on rocks w/ 1st pr antennae
460
symbiotic barnacles
commensal
| parasitic
461
commensal barnacles
dwarf, complemental males in some species
when density low
settle out of copulation range
462
barnacle on crab under anemone
decorator crab with anemone on top to protect itself against cephalopods - barnacle reaches up and rips off anemone tentacles
463
Rhizocephalan barnacle
endoparasite of decapod malacostracan
highly derived adult morphology
manipulation of hosts behaviour
464
Rhizocephalan life cycle
dioecious - naplius metamorphoses to cyprid - fm swim around looking for decapod - settle - slice hole- insert cells - grow in to series of branched root-like structures that invade all tissues of host (interna) -derive nutrients from host - break through as mass of tissue to exterior (externa) - 'mate'
465
Rhizocephalan mating
fm forms externa, male cyprid finds externa, metamorphosis into dwarf male - essentially a sperm sac
466
where does externa go
breaks out where egg mass would normally be, alters hosts behaviour to treat it like eggs (aerate, clean) - even male hosts!
467
Phylum Echinodermata major characteristics
```
'spiny skin'
Deuterostome
Eucoelomate
WVS
calcareous endoskeleton
pentamerous radial symmetry
mutable collagenous tissue
```
468
Echinoderm body compartments
coelom
endoderm derived mesoderm
3 sets of compartments formed in development
469
Echinoderm coelom development
enterocoely
470
WVS
water vascular system
coelomic compartments
operates tube feet
471
tube feet
highly flexible, muscular, tubes filled d w/ fluid, moved by hydrostatic mechanism, unique
472
pentamerous radial symmetry
pentaradial
at least in adult stage
bilateral + 5 point
bilateral in juvenile stage
473
mutable collagenous tissue
connective tissues that can change response to tension between extensible and rigid, under control of nervous system
474
Echinoderm skeleton
```
calcareous endoskeleton
spines are skeleton covered w/ living tissue
secreted by embryonic mesoderm
ossicles
microporosity
```
475
do all echinoderms have mutable collagenous tissue
yes, but not all collagenous tissues are mutable
476
normal connective tissues
lots of collagen fibres
| form in keeping things together (skin to muscle) - generally not active
477
Echinoderm subphylum
Crinozoa
Asterozoa
Echinozoa
478
Crinozoa groups
Class Crinoidea
479
Asterozoa groups
Class Stelleroidea - Subclasses Asteroidea, Ophiuroidea
480
Echinozoa groups
Classes Echinoidea, Holothuroidea
481
Asteroidea
sea stars, mostly predatory
| spines, disk, ambulacra, madreporite, arms, ossicles, pedicellariae
482
ambulacra
where tube feet extend to environment (oral surface)
483
Asteroid endoskeleton
latticework of interconnected ossicles, laced together w/ collagen fibres
spines
484
Asteroid pedicellariae
2 jaws formed by specialized ossicles
| cleaning, removing settlers
485
Pedicellariae morphology
epidermis
2 jaw ossicles
basal ossicle
attached by opener/closer muscles
486
Echinoderm canals
```
fluid-filled tubes
ring canal around esophagus/ mouth
radial canal down arm
lateral canals out from radial to tube feet
stone canal - from ring to madreporite
```
487
movement of tube foot
close valve - contact muscle surrounding ampulla- force water down in to tube foot- foot extended - reach out- contract tube foot muscles to bend
488
tube feet are like
flexible pipettes
489
polian vessicle
filled with fluid
| fluid reservoir
490
stone canal
reaches up to specialized ossicle (madreporite)
491
madreporite
very coarse ossicle
| replenish fluid in WVS by taking in sea water
492
Tiedmann's body
manufactures phagocytes to phagocitize invading particles that come in madreporite
493
Echinoderm coelomic compartments
WVS
perivisceral coelom
perihaemal coelom
genital coelom
494
Echinoderm nervous system
ring nerve + 5 radial nerves
intra-epithelial
no centralization
same organization as WVS
495
sea star feeding
tube feet pry open shell- evert cardiac stomach- digest and ingest
496
specialized echinoderm ossicles
madreporite
spines
pedicellariae
497
Asteroid reproduction
Asexual - fission and regeneration, autotomy
Sexual
planktonic, feeding larva
catastrophic metamorphosis
498
Asteroid fission
central disk breaks in two then regenerates missing parts
499
Asteroid autotomy
arm is shed and lives independently as a 'comet', eventually regenerating missing parts
500
Asteroid sexual reproduction
dioecious
broadcast spawn
external fertilization
501
respiratory out foldings of sea star body
papulae
502
'no arm' Echinoderms
Echinozoa (Echinoidea, Holothuroidea)
503
Echionoidea
no arms
endoskeleton
aristotles lantern
504
echinoidea endoskeleton
flat ossicles that fit tightly together
5 ambulacral plates, 5 interambulacral areas, 2 rows of plates in each
spines, stalked pedicellaria
505
ambulacral plates, echinoidea
2 rows of double pores for tube feet
506
sea urchin spines
attach via ball-and-socket joints, moved by muscles, function in bracing, manipulating food, defense, may extrude toxin
507
Echinoid pedicellaria
stalked
calcareous support rods
three opposing jaws
508
Aristotles Lantern
complex system of ossicles and muscles surrounding esophagus
teeth can be protruded from mouth and moved in various directions to eat or scrape
509
regular echinoids
sea urchin
radial symmetry
rocky substrates
510
irregular echinoid symmetry
superimposed bilateral symmetry
| e.g. sand dollar
511
regular echinoid locomotion
spines and tube feet
512
regular echinoid feeding
scarpe algae from rocks
shred kelp
capture drift algae with tube feet
513
Irregular echinoids
sand/mud substrate
locomotion by spines only
deposit feeding (tube feet)
514
Irregular echinoid respiration
petaloid tube feet specialized for gas exchange
515
Holothuroidea body
no arms
elongation along oral-aboral axis
bilateral symmetry
516
Holothuroidea endoskeleton
microscopic ossicles
| not connected flexible, muscular body wall
517
Holothuroidea WVS
5 ambulacra
buccal podia
suspension/deposit feeding
internal madreporites
518
Holothuroid ambulacra
bivium ('dorsal')
| trivium ('ventral')
519
buccal podia
circle of 10-30 tentacles around mouth, may be same
size, or some dwarfed, may be branched (dendritic / arborescent), may be pinnate, peltate or digitate, retractile and the body wall can close over them
520
cuvierian tubules
toxic structures attached to left respiratory tree, used for discouraging and entangling potential predators
521
evisceration
expelling internal organs, cuvierian tubules or entire digestive system, respiratory trees, and gonads; liquify and rupture connective tissue attaching viscera to inner body wall, eventually regenerated
522
Holothuroidea distinctive characteristics
```
sausage shape
microscopic ossicles
muscular body wall
spacious perivisceeral coelom
buccal podia for feeding
respiratory trees
```
523
ophiuroid suspension feeding
bury central disk and stick arms up (kind of looks like whip coral)
524
Basket star
ophiuroid w/ branched arms - suspension feeding, coil around prey (zooplankton)
525
bursal slit
narrow slit along inner arms of Ophiuroids, leading into large thin-walled sac (the bursa) which has a respiratory function
526
Ophiuroidea characteristics
```
central disk w/ highly flexible arms
locomotion by arm rowing
arm autotomy (MCT)
no anus
tube feet lack suckers and ampullae
bursa for gas exchange
```
527
MCT
mutable collagenous tissue
| soften body wall before autotomy
528
brittle star respiration
cilia-lined sacs called bursae; each opens between the arm bases on the underside of the disk
529
Crinoidea
'sea lily', 'feather star'
arms with pinnules and podia
stalk or cirri
530
Crinoidea feeding
suspension feeding w/ pinnule podia
531
Crinoid endoskeleton
disc or vertebrate-shaped ossicle
| allow long term extension of arms
532
crinoids as representatives of primitive echinoderm state
body orientation - mouth up
endoskeleton -articulating discs
WVS for suspension feeding (not locomotion)
MCT for long-term maintenance of posture w/ no E expenditure
533
Deuterostomia phylogeny
[Echinodermata s.g. Hemichordata]
s.g.
Chordata (Cephalochordate s.g. Urochordata s.g. Craniate)
534
Chordates
perforated pharynx
notochord
dorsal hollow nerve cord
muscular post-anal tail
535
Subphylum Urochordata groups
Class Ascidiacea
Class Larvacea
Class Thaliacea
536
Urochordata characteristcs
also Tunicata
Tunic
no metamerism
eucoelom as pericardium
537
tunic
tunicin cellulose-like fibrous material
538
Class Ascidiacea
sea squirts
sessile suspension feeders
solitary and colonial forms
539
Ascidian tunic
epidermis secreted tunicin + protein
hemal channels w/ wandering blood cells
spicules, fibrous material
540
branchial basket
cartilaginous structure supporting the gills in protochordates and lower vertebrates
buccal siphon, atrial siphon
w/ pharyngeal mucus net to catch particles that go through perforated pharynx
541
colonial ascidians
zooids interconnected by stolons
zooids rise from basal mat of shared tunic
zooids entirely embedded in shared tunic
542
Didemnum sp.
invasive species of colonial tunicate, aggressive space competitior
543
Ecteinascidia turbinata
Ascidian, source of anti-cancer drug 'yondelis' - PharmaMar, now synthetically manufactured
544
Ascidian reproduction
hermaphroditic
broadcast spawn
eggs w/ self/non-self recognition
tadpole larva
545
Ascidian larva
```
tadpole
short-lived, non-feeding
tail w/ notochord, dorsal hollow nerve chord, muscles
adhesive papillae
start of branchial basket
```
546
Ascidian metamorphosis
tadpole attaches to substrate w/ adhesive papillae (anterior end)
retraction of tail (apoptosis)
90º rotation of viscera
547
viscera
internal organs in the main cavities of the body, especially those in the abdomen
548
Class Larvacea
planktonic, 1-2mm
disposable gelatinous house
pharynx w/ 2 stigmata, mouth, anus, gut all in 'head'
tail w/ notochord and dorsal hollow nerve chord
549
larvacean house
```
secreted by epidermal epithelium (4-8/day)
blown up by tail thrashing
captures food particles
escape opening
pre-filters
food-concentrating filters
animal (mouth, tail)
excurrent opening
```
550
Heterochrony
evolutionary change in time of appearance or rate of development of a character relative to other characters
e.g. somatic tissues vs reproductive tissues
551
Heterochrony example
somatic tissue arrested development, reproductive tissue development = sexually mature 'juvenile'
possibly why larvacean looks similar to Ascidian tadpole
552
Heterochrony results
paedomorphosis
| peramorphosis
553
paedomorphosis
adult of a descendant is similar in appearance to the juvenile (larva) of its ancestor
554
Class Thaliacea
pelagic, colonial (at least some stages)
pharyngeal cilia for swimming and feeding
individuals resemble adults ascidians
555
Thaliacea colony
pyrosomes, up to 10+m long
hollow pelagic tubes, closed at one end, walls contain many zooids
communal tunic
bioluminescent
556
individual Thaliacea zooid
perforated pharynx, siphons, like mini ascidian
| exhaling water released into lumen of colony - expelled out colony aperture - propels colony along
557
thaliacea colony communication
no interconnected neurons but coordinated movements
| chain rxn - organism hits something - flashes- neighbour detects w/ photoreceptor - flashes - propagate message
558
Phylum Hemichordata group
Class Enteropneusta
| Also Class Pterobranchia but not for our purposes
559
Class Enteropneusta
Acorn worm (anterior looks like acorn)
live in soft sediment
secrete a lot of mucus
eucoelomate
560
Enteropneusta body
tripartite: proboscis, collar, trunk
| tricoelomic (enterocoely similar to echinoderm)
561
Enteropneust burrowing
peristaltic muscular contractions of proboscis
proboscis w/ cilia, mucus - pick up particles and carry posteriorly to move sed out of way - start burrowing motion- muscularly continue burrowing
562
Enteropneust feeding
crawl up burrow to surface, lay proboscis on surface, cilia ensnare particles, carry to mouth
back up to surface to release fecal casting
563
Acorn worm respiration
2 sets of perforations in external body wall = gill pores, perforated pharynx in dorsal region
ingested water travels out branchial pores and then external gill pores
564
Acorn worm nervous system
D and V intraepithelial nerve cords (like sea star)
intra-epithelial nerve plexus (nerve tails run out to all parts of body)
hollow dorsal nerve cord in collar
565
Enteropneust movement due to
ciliary activity and muscular contractions
566
juvenile (larva) of a descendant is similar to the adult of its ancestor
Peramorphosis
567
Acorn worm dorsal hollow nerve cord?
short region in collar
| intraepithelial nerve cord sinks down and pinches off to become a d.h.n.c.
568
Enteropneust reproduction
dioecious
larva morphologically similar to holothurian
broadcast spawn
ciliated larval stage may feed for months
569
Hemichordate echinoderm-like characters
```
larval morphology (similar to some groups, holothurians)
intraepithelial nerve system (found in sea stars and trunk region of hemichordates)
```
570
Hemichordate chordate-like characters
pharyngeal perforations
| dorsal hollow nerve cord (collar)
571
Ctenophora
```
mostly planktonic, swim but not strong enough to resist current
all marine and carnivorous
100-150spp., but large individual #'s
mm - 1.5m
often translucent
```
572
Ctenophora body
gelatinous - highly hydrated mesoglea (similar to cnidaria)
tentacles
comb rows/plates
mouth up - pharynx - stomach - anal pores
gastrovascular canals
573
Ctenophore tentacles
2, originate from pits (pentacular sheaths), can be retracted, have side branches (tentilla) loaded w/ collocytes
574
Ctenophore comb plates
8 rows of comb plates (ctenes), used for swimming, extend from oral surface down
575
ctenes
large ciliary structures known
thousands of cilia in a row = plate
move in unison, out of stroke down comb row - wave propagates down comb row
cilia connected by interciliary links
576
ctenophore cilia
up to 2mm
| largest animals that locomotive by cilia
577
ctenophore movement
effective stroke is towards aboral end
move through water column with mouth leading
beat frequency can slow and switch directions
578
Collocytes
```
release sticky adhesive
single use only
differentiate from interstitial cells
complex, used to capture prey
head covered in intercellular granules
straight filament = elongate nucleus
```
579
Ctenophore muscles
myoepithelial cells in epidermis
| bona fide muscle cells within 'mesoglea'
580
presence of stand-alone muscle cells in ctenophores
MAY suggest that ctenophores are true mesodermal animals and therefore triploblastic (no evidence)
581
ctenophore nervous system
nerve net in epidermis and mesoglea
| aboral (apical) sensory organ (rudimentary brain)
582
ctenophore aboral sensory organ
```
mostly statocyst (gravity sensor)
transparent CaCO3 dome over statolith on 4 balancers
```
583
statolith balancers (ctenophore)
bundles of hundreds of cilia
| tracks bifurcate away from dome
584
how ctenophore apical sensory organ works
turn - statolith moves - pressure on 1+ balancer = signal down comb row = more rapid beating of cilia to make that side move up and straighten out
detect direction of gravity to know which way is up
585
Pleurobrachia feeding
prey captured w/ sticky collocates on tentilla
tentacle retracts
ctenophore spins to waft tentacle over mouth
586
Ctenophore defense
possibly cnidocyte stealer
| feed on hydromedusa tentacles, place cnidocytes in ctenophore tentacles (observed in rare species)
587
Cestum spp.
Venus' Girdle
| long, thin, flat, ctenophore
588
Mnemiopsis
lobate ctenophore
invasive species, invaded black sea, no natural predator, more weight than annual world fish catch
capture prey w/ muscular oral lobes
589
Beroë
'swimming mouth', no tentacles, feeds on other ctenophores, introduced to bring down population of mnemiopsis
590
Beroë teeth
macrociliary teeth around margins of mouth, prevent prey from escaping, formed of cilia
591
Benthic ctenophores
look like flatworms
| lack comb rows in adult stage
592
ctenophore reproduction
asexual - benthic ctenophore only
sexual - simultaneous hermaphrodites
-gametes from gastrodermis
-cydippid larva (look like pleurobrachia)
593
Bryozoan main characteristics
sessile, colonial, lophophore, defense strategies, polymorphic colonies
594
example of bryozoan heterozoid
Avicularium
595
Molluscan phylogeny
Conchifera (Cephalopoda, Scaphopoda, Bivalvia, Gastropoda)
| Acquifera (Polyplacophora, Chaetodermomorpha, Neomeniomorpha)
596
largest class of Molluscs
Gastropoda
597
type of shell with mantle cavity over head
endogastric shell
| representative of torsion
598
shell perforations =
2 ctenidia (left, right)
599
largest gastropod group
Caenogastropoda (predatory, use proboscis)
600
Cone snail toxin gland homologous to
mid-esophageal gland in other gastropods
601
bivalve ctenidia modification
adapted for suspension feeding
602
shell with mantle cavity at posterior end
exogastric shell
603
Nematode secondary body compartment
pseudocoel
604
Arthropod subphyla
Chelicerata
| Mandibulata
605
Chelicerata groups
Merostomata (horseshoe crabs)
Arachnida
Pycnogonida (sea spiders)
606
Mandibulata groups
Pancrustacea
| Myriapoda (centipede, millipede)
607
Pancrustacea groups
Hexapoda
Malacostraca
Copepoda
Cirripedia
608
Malacostraca groups
Euphausiacea
Stomatopoda
Pericardia
Decapoda
609
Decapoda groups
Caridea
Astacidea
Anomura
Brachyura
610
Merostomata appendages
1st appendages = chelicera, feeding
| 2nd appendages = pedipalps, variety of fn, not very derived
611
Insect tagmata
head
thorax
abdomen
612
Holometabolous development
complete reorganization of body
613
'Whip' heterozooid
Vibraculum
