BIOL 322 Part II Flashcards
1
Q
volume of a cylinder
A
pi r^2 L
2
Q
a solid under tension, over time
A
will not continue to extend over time
3
Q
mesoglea under tension over time
A
will continue to extend over time
4
Q
cross latticed fibres stress-strain curve
A
J-shaped
5
Q
two-anchor crawling
A
alternatively push and pull against 2 anchors
6
Q
two anchors used for 2 anchor crawling
A
- penetration anchor
2. terminal anchor
7
Q
penetration anchor
A
- posterior
- contract circular muscles to push anterior end of body forward
8
Q
example organisms that use 2-anchor crawling
A
leech
caterpillar
9
Q
bivalve 2-anchor burrowing, penetration anchor
A
- adductor muscles relaxed
- shell valves open
- push against sediment
- circular muscles contract
- foot elongated, pushing deeper
10
Q
bivalve 2-anchor burrowing, terminal anchor
A
- shell valves close
- sediment loosened up
- terminal end of foot extends laterally (anchor)
- longitudinal muscle contract, pulling against anchor
- shell and body move down
11
Q
multi-anchor crawling
A
- eg. earthworm
- fat metameres push against sediment
- thin metameres push against anchor
- can be many penetration anchors at once, ‘move’ down body like a wave
- train of muscle contraction and relaxation
12
Q
terminal anchor
A
- anterior
- pull on this anchor by contracting ventral lon`gitudinal muscles to bring posterior up
13
Q
aids in gastropod movement
A
mucus
14
Q
Mucus gliding
A
- mucus is glue and lubricant depending on force
- push foot against mucus to anchor
- lift A end of foot, slide while pressing the rest of foot
- put A part of food down
- lift next segment..
15
Q
testing banana slug mucus
A
dynamic hexometer?
- 2 metal discs on a pole that rotate relative to each other w/ mucus btw discs
- constant rate of strain
- stop, strain, stop, intervals of 1s
- record stress mucus undergoes
16
Q
results of banana slug mucus test
A
- if strain is low enough mucus acts like glue
- hit yield point and it starts acting like a liquid/ lubricant
17
Q
mucus production cost, gastropod
A
7-26% of energy budget
18
Q
gastropod mucus functions
A
- chemical cues
- foraging routes
- defense
- temporary adhesion
- useful to predators
19
Q
gastropod mucus, chemical cues
A
locate conspecifics
-ex. mating
20
Q
gastropod mucus, foraging
A
adhesive trap
-ex. microalgae
21
Q
gastropod mucus defense
A
- chemical defense
- ex. stop anemone nematocyst discharge (nudibranch)
22
Q
gastropod mucus adhesion
A
epiphragm of periwinkle snail
23
Q
epiphragm
A
- temporary structure that protects against
- adhesion dessication in intertidal
- predation
- similar functions as operculum
24
Q
gastropod mucus, predators
A
a trail to their prey
25
before shedding an exoskeleton
a new exoskeleton begins secretion
26
arthropod exoskeleton number of layers
3
27
layers of arthropod exoskeleton
- epicuticle
- exocuticle
- endocuticle
28
epicuticle
lipids, waxes
| -impermeable to water
29
cuticle material
- scleratized chiton
| - crosslinked protein
30
stages of molting
- cuticle begins to separate from epithelium
- cells proliferate, animal enlarging
- inactive chitonase secreted into space btw epidermis and cuticle
- new exosk. secreted
- chitonase activated
- old endocuticle digested
- ecdysis
31
ecdysis
molting
32
how is ecdysis (final stage) facilitated
-exo/endo cuticle are fractured along planes of weakness
33
first layer of new exoskeleton secreted
epicuticle
| -VIP to protect new exosk. from chitonase
34
once new exosk. is secreted and ecdysis has occurred
- pump up fluids under new exosk. while soft
- make space to grow
- before cross linking
- release fluid once sclerotized
35
pre-formed breakage planes
- where exoskeleton will split for animal to crawl out
| - where carapace meets abdomen
36
how to get large distal appendages out of narrow basal part of appendage in ecdysis
- break down muscle myofilaments
- up to 60% of proposes muscle
- loss of proteins (actin)
- not water, not myocytes
- only chelae, not walking legs
37
myocytes
-whole muscle fibres
38
pre-moult intermoult thin:thick myofilament ratio, crustacean cheliped ecdysis
pre-moult: 6 thin: 1 thick
| inter moult: 9 thin: 1 thick
39
how do arthropods move in newly formed unscleretized skeleton
switching skeletons
- rigid skeleton
- hydrostatic skeleton
40
testing crab hydrostatic skeleton
- string around propodus to transducer - measure movement
| - pressure gauge penetrates soft exoskeleton at carpus/merus joint - measure pressure of joint fluid
41
results of crab hydrostatic skeleton experiment
- movement of joint corresponds w/ spike in hemolymph pressure
- after hardening no spike in hemolymph pressure
42
flexural stiffness of soft-hard material
soft - low
paper - low but higher
hard - high
43
tensile strength of soft -> hard materials
soft: medium
paper: highest
hard: medium
44
hydrostat container must be
-deformable but resistant to tension
45
movement during soft exosk. stage requires change to
how levers achieve flexural stiffness
46
pre-molt flexural stiffness
-high material stiffness
47
post-molt flexural stiffness
internal fluid pressure
48
hydrostatic skeleton internal fluid, arthropods intermoult
hemolymph
49
chemical signal between same species
pheromones
50
chemical signal btw different species that causes change in behaviour beneficial to producer
Allomones
51
sessile marine invert. allomones
- secondary metabolites
- protect against predators and environment
- unpallatable
- toxic
52
example of secondary metabolite forming organisms
- porifera
- cnideria
- bryozoa
- ascidiacea
53
chemical signal between different species that causes a change of behaviour beneficial to receiver
Kairomones
54
why defensive allomones important for sessile organisms
-cant limit search of pursuit phases of predator
55
allomones may provide defense against
- predators (in subjugation phase)
- space competitors
- settling larvae of other species
- pathogens
56
study of Porifera secondary metabolites
- Caribbean sponges
- novel 2º metab.
- put metabolite in tasty agar tablets
- feed to fish in lab
57
primary metabolite
formed in metabolic pathway
58
Caribbean sponges w/ novel 2º metabolite
Ectyplasia ferox
| Erylus formosus
59
Caribbean sponges novel 2º metabolite
- triterpene glycoside
- formoside
- unpalatable or toxic
60
secondary metabolite
not formed directly in metabolic pathway
61
study of Porifera secondary metabolites, stage 2
- anchored supports w/ 'clothesline' in ocean
- dangle phytogel strips w/ squid paste and metabolite
- monitor, weigh strips
62
other formoside use
-inhibit settlement of larvae
63
results of study of Porifera secondary metabolites
- in lab find pellets rejected
| - field study: eaten, but only about half as much as control
64
formoside settlement experiment
- field study
- suspend phytogel + formicide in dishes
- quantify % cover of fouling organisms on surface of gel
65
results of formoside settlement experiment
- control 40% covered
- treated less than 10% covered
- p = 0.0016
66
formoside overgrowth experiment
- tablet w/ 1 large depression in middle, 4 smaller at corners
- fix aggressive space competitive sponge in middle
- formiside in 2 corners
- suspend in ocean
- allow sponge to grow
67
results of formoside overgrowth experiment
control: 20% coverage
treated: 5%
68
minimal criteria to show allomone is adaptation
1. isolated chemical deters predator in palatable food
2. effective at native concentration
3. effective against sympatric predators
4. appropriate anatomical distribution
5. survival after attack
69
1. isolated chemical deters predator in palatable food, allomone adaptation
reduce confounding factors of food item
| ex. spicules
70
3. effective against sympatric predators, allomone adaptation
against co-occuring predators
71
4. appropriate anatomical distribution, allomone adaptation
- repel before attack is fatal
- eg. digestive glands - not appropriate
- hold chemical in superficial body structures
- eg. nudibranch cirri
72
why is survival after attack especially important, allomone adaptation
only way to pass on the genes!
73
spanish dancer nudibranch
- undulation
| - feeds on red sponge, maybe gets colour from them
74
spanish dancer allomone study
- extract and purify metabolite
- add to tasty pellet in varying concentrations
- co-occurring fish predator
- 10 control + 10 experiment food pellets offered
- offered in random order
75
results of spanish dancer allomone study
-sig. difference in treated vs control down to 0.05% concentration dry weight
76
concentration of allomone in spanish dancer body parts
- highest in egg mass
| - high in dorsal mantle, digestive gland and gonad
77
spanish dancer metabolite
dihydrohalichondromide
- secondary metabolite
- modified from halichondromide primary metabolite in sponge prey
78
why is secondary metabolite in internal organs
- difficult to separate purely
| - passing through digestive organs onto egg mass
79
de novo synthesis
made by the organism
80
Melibe de novo allomone
terpenoid synthesis from acetate building blocks
- tag radioisotopes to follow synthesis
- novel feeding strategy
- sensory cell detects predator
- release product through pore
81
saponin
- detergents
- punch holes in biological membrane
- disturb cholesterol
- if predator bites will rupture mouth membranes - irritant
82
echinodermata saponin
- toxins
- de novo synthesis, direct acquisition
- common in sea cucumber, sea star
83
sponge microbes
- up to 40% of sponge volume
| - diverse phylotype
84
spone cyanobacteria
- found right under pinacocyte (outer membrane)
| - cyano. toxin release may fn to resist predators and competitors
85
bryostatin
- found in Bugula bryozoan and nudibranch predator
- evidence that it is metabolize by bacteria
- may also have use in humans for anti-tumor treatment
86
other indirect selection of chemical defense, amphipod domicile
- cut discs of algae to make tent domocile
- choose chemically defended kelp
- put in arena with different kelps to see which it chooses
- select toxic majority of time
87
other indirect selection of chemical defense, arctic amphipod
- hold on to clione with pereiopods
| - assume clione have chemical defense
88
clione chemical defense test
- fish acceptance/ rejection tests
- separate clione and fish chunks -- clione rejected every time
- grind up clione and add to fish pellets -- clione still rejected
- amphipod w/ and w/o clione -- again, clione rejected
89
aposematic colouration
advertises toxicity
90
testing ascidian tadpole larvae aposematic colouration
- bright orange
- high E supply, good food source
- add larvae to tank w/ co-occurring predator fish
- 90% rejected
- 80% survival
- feed unpigmented larvae to same predator
- 37% rejected
- suggests predator remembers colouration and avoids
91
testing predator memory of aposematic colouration
- offer fish aposematic tadpoles until they are completely ignored = experienced fish
- inexperienced fish offer non-pigmented prey, accept
- inexperienced fish offered bad tasting fish - rejected or ignored
- experience fish given good tasting, dyed orange prey, ignored = remembered
- inexperienced f given tasty dyed fish - majority accepted
92
mimicry
edible animal resembles noxious animal
93
Hydrostat examples
- tube feet
- lophophore
- tentacles
- annelid body
94
hydrostat criteria
- fluid maintained at constant V
- deformable container
- container must resist tension
- wrapped in muscle and connective tissue
95
muscular hydrostat
- unconventional
- solid mass of muscle tissue, no fluid compartment
- cephalapod arm
- mollusc foot
96
other types of hydrostat
- any incompressible material at constant V
- eg. parenchymal cells of turbellarian
- squid tentacle
- elephant trunk
- tongue
97
skeleton features in stiff and hydrostat
- support
- transmit force by muscle shortening
- re-extend antagonistic muscles
- exploit mechanical advantage (force or displacement)
98
muscle shortening and re-extending in hydrostat example
earthworm movement
99
change in shape for cylinder of constant volume, D vs L
non-linear
- exponential
- diameter decreases rapidly with small increase in length
- then diameter asymptotes w/ further increase in L
100
mechanical advantage in hydrostat
- a small change in L makes an exponential change in D
| - displacement advantage
101
squid tentacles
- 8 arms maximize force to hold prey
| - 2 tentacles elongated to maximize displacement
102
how squid maximize displacement
- having large length
| - -> a small change in D (at large L) = a large change in L
103
squid tentacle muscles
- longitudinal: undergo large extensions, obliquely striated
| - circular muscles, transverse muscles, radial muscles: speed! - x-straited (shorter shortening)
104
wall tension
- circumferential tensile stress = longitudinal tear
| - axial tensile stress = circumferential tear
105
circumferential tensile stress =
= 2 X axial tensile stress
| = (internal pressure x radius of cylinder) / wall thickness
106
consequences of circumferential tensile stress
- highly dependent on r
- the larger the radius the greater the tension (like a heart shaped balloon)
- easier to inflate long thin structures if widened first (tentacles, tube feet)
- must limit/ control shape change
- must prevent ruptures
107
collagen
stiff, fibrous tissue
- steep stress/strain curve
- requires lots of tension to extend
108
direction of collagenous connective tissue fibres
- circumferentially? - avoid circum. tear, but needs to expand that way
- lattice work not parallel to direction of tension
109
latticework of fibers
- initially give readily
- as approach parallel, requires a lot of stress to extend further
- J-shaped S/S plot
110
role of collagenous connective tissue
1. reinforce walls of container
| 2. control and limit shape change
111
mesoglea time-dependent properties, extension vs log time
- t_o: little-no extension, behaves like solid
| - t_1: minutes-1h later, begins extension
112
stiffening with spicules
stiffening dependent on:
- spicule density
- spicule size
- spicule form (anisometric)
113
mesoglea S/S plot w/ w/o spicules
w: large slope increasing
| w/o: very small slope
114
what is mesoglea
- connective tissue
- collagen reinforced
- extracellular matrix
- highly hydrated
- random confirmation, tangled, non-branched proteoglycan polymers
115
sea cucumber tissue hardening
ossicles
116
stress/strain plot tells us
stiffness
117
anisometric
axis i > axis j
| -orient in direction against tension
118
Phases of predatory act
1. Search and detection
2. Pursuit
3. Subjugation
119
abiotic conditions to defend against
- temperature variability
- UV
- exposure
120
biotic conditions to defend against
- competition
- overgrowth
- predation
121
red queen hypothesis
RQ ordered nave to run on ground moving backwards faster and fast - must continually adapt to change
122
meaning of RQ hypothesis
predators and prey interact in a way that imposes selection in a reciprocal fashion
-force each other to continually adapt
123
search and detection phase defences
- camouflage, transparency, crypts, mimicry
- size, hiding
- peripheral vision
- activity patterns, migration
124
pursuit stage defense
- running: pattern, speed
| - pooling behaviour (grouping)
125
subjugation phase defense
armour, body size, autonomy, toxicity, secretions
126
selection in the prey is generally strongest in which phase
whichever phase their predator is weakest in
127
hypotheses of adaptation must be tested
1. phylogeny
2. effectiveness
3. consider other ideas
128
test hypotheses of adaptation, phylogeny
is trait derived or ancestral
129
test hypotheses of adaptation, convergence
- lab and field experiments
- correlation in space and time
- evidence of convergence
130
types of defensive traits
- structural
- chemical
- behavioural
- induced
131
induced defences =
phenotype plasticity
132
parts of gastropod shell
```
protoconch
whorl
spire
body whorl
aperture
outer lip
```
133
shell-crusher strategies
- apertural lip crush
- spire crush
- apertural lip peel
134
aperture lip crush
- outer lip of shell most vulnerable
| - crush in molar
135
spire crush
-put spire close to fulcrum of claw to increase force advantage
136
gastropod shell defences against crushing predators
- overall thickening of shell
- thickened apertural lip
- apertural teeth
- narrowed aperture
- reduced spire
- thickened tubercles and varices
137
helmet snail, adaptation to shell-crushers
- apertural teeth strengthen outer lip
| - very narrow aperture\
138
cone snail, adaptation to shell-crushers
- reduced spire
- thick walls
- dissolve old interior layers
139
cowries, adaptation to shell-crushers
- no spire
- aperture teeth
- very narrow aperture
140
tubercles, adaptation to shell-crushers
studs, spines
141
porcupine fish
- related to puffer
- very powerful jaws
- robust teeth
- prey = tropical gastropods
- RQ hypothesis
142
effect of tubercles on crushing attempts
1. increases effective diameter
2. reduce stress
3. focus force
143
effect of tubercles on crushing attempts, increase effective diameter
- can't get shell as close to fulcrum
| - reduce mechanical advantage of jaws
144
effect of tubercles on crushing attempts, reduce stress
-distribute force over broader are of shell
145
effect of tubercles on crushing attempts, focus force
-increased chance of damaging predator
146
critical size
size that gastropod must be to avoid predation
147
critical size of congeneric species pair (+/- spines)
-gastropods w/ strong spines have lower critical size
148
experimental manipulation of tubercles
- file off to compare same species, reduce confounding factors
- critical length smaller in spines gastropods
149
survey of gastropod family Thiadidae
- structures only found below 40º latitude
| - no structures above 40º
150
correlation between Thiadidae structured fishes and predators?
- 2/3 of crushers are found in tropics
- gastro. w/ adapted shells appear in fossil record around Triassic
- shell crushers around Jurassic
151
Lake Tanganyika
- 2nd largest FW lake
- gastropods and brachyuran crabs
- FW gasto. usually have thin shells, not here
- for any given shell length snails had thicker shell than snails not in lake T
- same w/ crab chela
152
SEM provides
- magnified images
- 3-dimensions
- shape and surface topography
- large depth of field
- non-reversed images
153
how to get 3-dimensionality with 2D image
- shading!
- light reflectance
- exploit the fact that our eyes are adapted to sun shining down on objects
154
SEM basic instrument components
- electron gun + pole piece
- lenses
- scan coil
- secondary electron detector
- monitor
155
compound light microscope basics
- light, glass
- E source focused and bent by condensor
- tranparent specimen for light to pass
- objective lense expands beam and therefore image
- magnification achieved by glass concavity
156
SEM basics
- electrons , EM lense
- energy source is e-
- focus beam w/ magnetic field
- scan coils rapidly deflect beam back and forth
- secondary e- emitted
- magnification is aspect ratio between actual and output screen
157
rapid scan rate, SEM
- low resolution
| - real time response to image adjustments
158
slow scan rate, SEM
- high resolution
| - delayed response to image adjustments
159
how to focus SEM
- intermediate scan rate
| - reduce area of scan
160
defensive behaviours
- avoidance
- escape
- retaliation
161
distinguishing features between avoidance and escape/retaliation behaviour
nature of the stimulation
| -direct vs indirect
162
avoidance behaviour, olive snail
- local species
- surface at night
- burrow during day
- enormous foot
- diel activity pattern
- protection from visual predators (birds, sea stars)
163
olive snail experiment
- aquarium w/ sediment
- seastars in separate tank w/ water flow through
- cue induces hiding
- continued cue reduces surfacing behaviour
164
Zoea larvae
- anomurans, brachyuran
- multiple zoea stages
- 1st stage no migration
- 1st stage responds to shadow reflex = sinking behaviour
- ctenophore kairomone ?
165
zoea larvae experiment
- zoea in glass tube
- different levels of irradiance reduction
- descending density increases at 50% light attenuation = shadow reflex
- add ctenophore kairomones == sig. difference in descension response at even lowest attenuation level
166
Sabellidae escape behaviour
-startle reflex
167
startle reflex criteria
1. all-or-none response
2. high threshold
3. short latency
168
startle reflexes governed by
giant axons
169
startle reflex, all-or-none
- non-graded
| - don't withdraw partially
170
startle reflex, high threshold
-need strong stimulus to elicit
| not feather duster, sabellidae
171
startle reflex, short latency
- minimal t period btw stimulus and response
| - rapid neural circuit due to giant axon
172
velocity of action potential, V =
kD^e
k = constant
D = axon diameter
e = exponent (usually around 0.5)
173
from velocity of action potential equation,
V highly dependent on diameter
| -giant axons significantly faster
174
giant axons often dedicated to
defensive behaviour
175
Aglantha digitale, giant axons
- hydromedusa
- local, open ocean
- unique fishing behaviour
- giants axons unique use -- 2 uses
176
Aglantha fishing behaviour
- slow swim
- circular muscle contractions of bell
- swim up in water column
- flip over w/ tentacles up
- descend slowly
- catch plankton w/ tentacles
177
Aglantha escape swim
-rapidly swim away when disturbed
178
Aglantha giant axons
- ring giant: interneuron, nerve ring around periphery of bell
- radial motor giants: giant motoneurons
179
interneuron
neutron between sensory and motor neurons to send messages btw the two
180
study of Aglantha giant axon
- measure action potential w/ electrodes
| - find 2 different action potential speeds on same axon
181
action potential
-depolarization by opening of ion channel, often Na
182
how does Aglantha have different action potential speeds
- 2 different types of ion channels
- fast a.p. = Na ion
- slow a.p. = Ca ion
183
Tritonia nudibranch, neurons
- seapen feeder
- dv flexion if touched by seastar
- pattern generator neurons create repetitive movement
184
lobster defenses
- escape, tail-flip
- retaliation, claws, antennae
- defense, armour
185
spiny lobster
long, spiny second pair antennae, damaging
186
slipper lobster
tank-like
thick carapace
tenaciously clinging periopods
187
lobster tail-flip
clawed lobster: giant axons mediated
| spiny, slipper: no giant axon
188
3 lobster 'types' offense vs defense experiment
- tether animals to stakes
- 5 intact of each, 5 modified
- slipper modified: tape back grasping claw
- Spiny: cut off second pr. antennae
- Clawed: remove cheliped
- record mortality after 4 and 24 h
189
results of lobster offences vs defense experiment
- manipulated had higher mortality in all species
- slipper lobster had very low mortality in all cases
- clawed had highest mortality in all cases
- retaliation not the best defense
190
induce defences, conditions for selection
- heterogenous environment
- reliable cue signaling predator risk
- conditional phenotype reduces predation risk
- costly when predator absent
191
Nucella induced defense of egg capsules
- 2 islands near Bamfield
- different thickness of egg capsule walls
- island 2 has higher density hole-drilling isopods
192
specific time in development that organism can respond to envrionmental cue
window of competence
193
Rotifer features
- paired ciliated cephalic lobes, foot w/ 2 toes and adhesive pedal gland
- jaw apparatus (mastax) lined w/ chitonous teeth (trophi)
- many have rigid body w/ reinforcing cytoskeletal elements = lorica
194
Keratella induced defense
- freshwater rotifer
- less than 1mm
- some w/ greatly elongated posterior spine
- chemical affluent from Asplanchna induces long posterior spine in Karetella
195
Asplanchna rotifer sp.
- feed on karatella
| - parthenogenic offspring - diploid egg develops in mother w/o fertilization
196
what kind of chemical does Asplanchna release to cause change in Keratella
kairomone
197
observations of predator-prey interactions between rotifers
attack: encounter - no significant difference btw long spine and short spine
capture: attack - very sig. diff., LS captured about 1/2, SS about 3/4
ingested: capture: sig. diff.
198
why asymmetrical spine elongation?
-possibly to conserve energy, if 1 does the trick why waste E on 2
199
Branchionus variabilis rotifer morphological AND behavioural polyphenism
- rotifer
- elongate spines (both) in presence of pred. cue
- facultative epibiont
- Asplanchna cue induces behaviour change -- attach to cladoceran for protection
200
Costs of induced defense, rotifers
- eggs? females amictic so no effect on egg production
| - but does reduce mictic success-- less resting eggs w/ higher [kairomone]
201
Rotifer life cycle
- amictic female (2n) can reproduce w/o fertilization over and over
- in bad conditions amictic female produces mictic (1n) -- fertilization -- resting egg (mictic fm)
202
Cladoceran inducible defense
- Daphnia spp.
- 'exuberant morphs'
- helmets, armour
- defense against gape limited predators
203
Resource allocation, Cladoceran inducible defense
- exoskeleton growth requires ca. 20% more energy for crested
- reduces reproductive output by ca. 60/400 lifetime eggs
204
Membranipora membranacea inducible defense
- bryozoan, asexual, oldes zooid at centre, colony has 4mth life-span
- nudibranch predator colour matches
- calcified sidewalls
- in presence of Doridella (nudi.) peripheral zooids respond- develop spines around walls
205
cost of Mm spine growth
reduce Mm growth rate
| reduce nudibranch feeding
206
nudibranch chemical that causes induced defense in Mm
kairomone
207
Acanthina gastropod
- gastropod predator of barnacles
- have labial tooth
- ram tooth into barnacle operculum plates
208
Acanthina induces what defense in Cthamalus
bent morphology
209
Possibilities for occurrence of bent Cthamalus morphology
1. barnacles w/ fixed bent genotype selectively recruit to substrate w/ snail mucus
2. barnacles have conditional bent phenotype induced by snail mucus
210
to test Possibilities for occurrence of bent Cthamalus morphology
- plastic plate, drill depressions for settlement
- place in field, wait for settlement, map
- put predator mucus on plate
- wait again
- re-map and compare
211
if barnacles have inducible morphology
expect the same amount of bent morphology in the recruits before and after predator presence -- no selective recruitment
212
if barnacles w/ fixed bent morphology are selectively recruited
-expect more bent recruits after mucus --recruit bent barnacles in presence of predator
213
results of testing possibilities for occurrence of bent Cthamalus morphology
3 plates show near equal proportions before and after
| = no selective recruitment
214
cost of bent morphology, Cthalamus shell mass : body length
= slightly lower slope in bent morphology, some effect but not alot
215
cost of bent morphology, Cthalamus # eggs : body length
- significant difference
- bent morphology much less eggs, particularly at low body size
- trade-off w/ fecundity
216
Nucella induced defense,
crabs feed on by peeling back apertural lip
- predator affluent induces aperture lip thickening
- Predator + prey in flow through tank to Nucella = even greater change! detect affluent of damaged conspecific
217
Littorine, periwinkle snail induced defense
- European green crap voracious invasive predator
- crab induces thicker shell
- thicker shell also appears to be occurring over time
218
induced predator phenotype, green crab
- if fed thicker walled snail -- w/i a few moults develop more powerful chelipeds
- -arms race
219
light =
particles of energy
| = photons
220
photons travel in
waves
221
visible light
400 -650nm
222
to perceive light must have
photopigments
223
most common photopigment
rhodopsin
224
what do photopigments do
- absorb photons
- open ion channels
- change cell membrane voltage (depolarize, hyper polarize) = bioelectric potential
225
quality of our visual field =
visual accuity
226
ability to distinguish details, visual
resolving power
| -how close together 2 dots can come and still be resolved as separate
227
Visual acuity depends on
1. resolution
| 2. contrast
228
Resolution
-image detail, resolving power
229
how resolution impacts visual acuity
- density of photoreceptors (high density = high detail)
| - focusing ability of lens
230
contrast, impact on visual acuity
- differential light absorbance (btw object, bckgrd)
| - differential light scattering (btw obj, backgr)
231
example of contrast
- words written in a box
- no contrast
- can't see
- no difference in light absorption and scattering of words relative to background
232
seeing transparent tissues
- we can see because of contrast
| - differential light absorption/refraction of the tissue
233
photic zone of open ocean
euphotic = 200m
234
disphotic zone
200-1000m
- sufficient light for vision but not PP
- mesopelagic
235
zone of no light
Aphotic
| bathypelagic
236
options for avoiding search/detection phase in the pelagic zone
- mirrored surfaces
- counter shading/illumination
- transparency
- all minimize contrast
237
Effectiveness of mirrored surfaces, pelagic
- if predator approaching from side
| - effective b/c background homogenous
238
counter shading/illumination
- lighter ventral surface (predator bellow)
- light emitting cells on ventral surface
- reduces silhouette/shadow
239
how to achieve counter shading
Guanine crystals
| -2 types: cuboidal, flat
240
cuboidal guanine crystals
- small, jumbled
- scatter reflected light
- matte white surface
- suitable for lightening ventral surface
241
flat guanine crystals
- large, overlapping
- reflect light uniformly
- shiny
- eg. fish scales
242
transparency
- camouflage regardless of predator angle
- multiple convergences
- highly correlated w/ pelagic lifestyle
243
examples of transparency
- hydromedusa
- larvacean
- ctenophore
- pteropod
244
why no transparency in terrestrial habitats
-refractive indices
air = 1 , SW = 1.35, cytoplasm = 1.34 - 1.55
-much easier to achieve in water
-terrestrial organisms require more robust (often opaque) structures to hold up against gravity
-more places to hide in terrestrial
-UV protection
245
how to achieve transparency
1. thinness
2. eliminate pigments
3. surface micro-bumps
4. ultrastructural specialization
246
thinness
thin tissue = less opportunity for light refraction
247
Problems with eliminating pigments
- eyes require melanin
- food - digested tissues are opaque
- sunscreens - seen by UV vision
248
Phronima sedentaria transparency
hyperiid amphipod
- fibre optic eye - smaller, simpler, less pigment
- eat tunicate and hide in its tunic
249
fibre optic eye
crystalline cone -- focus light down to reticular cells -- minimizes needed eye size
250
how to 'hide' gut contents, transparent organisms
- red gut epithelium
| - particularly protects against bioluminescent prey
251
why use red tissues
- bioluminescence typically 470nm (blue-green) -doesn't penetrate red
- also b/c red absorbed first in water column?
252
problem w/ sunscreen and transparency, experiment
- FW fish preying on daphne w/ photoreceptors
- videotape both in aquarium
- pursuit distance = when fish turns and pursues prey
- PD same max w/ and w/o UV
- w/o UV distribution shorter tails, higher max
- more shorter PD w/o UV
253
Copepod sunscreen carotenoids
- astaxanthin
- scavenges free radicals (ROS)
- when fish predator is present reduce level of pigment
- trade-off
254
surface microtuberances, transparency
- help reduce contrast
- reduces ability to see organism outline, blurs outline
- less surface area to refract light
255
Bioluminsecence
- 80% of pelagic ocean animals
- major light source in mesopelagic
- mostly blue emission (470nm)
- most NOT from bacteria
256
bioluminescence original evolutionary origin
- antioxidant hypothesis
- originally likely to scavenge for ROS
- oxidation gives off light (side effect)
257
original bioluminescent molecule
Luciferin
258
luciferin
- absorbs photons of light
- electron excitement
- electrons fall, give off E as light when oxidized
- requires light to give off light at longer wavelength
- requires luciferase or photoprotein
259
bioluminescence definition
- chemical reaction w/i organism that emits light
| - create light w/o light
260
luciferase
enzyme that catalyzes luciferin reaction
261
photoprotein
- molecule w/ binding sites for luciferin and O2
| - co-factor (usually Ca++) causes conformational change of photoprotein allowing interaction
262
functions of bioluminescence
1. communication, sexual signal
2. attraction of prey, lure
3. illumination of prey, flashlight
4. defense from predator
263
functions of bioluminescence, predator defense
- startle
- counterillumination (hiding)
- misdirection
- distractive body part (dropped off)
- burglar alarm
264
Burglar alarm hypothesis
organism 3 preys on 2, preys on 1
- 1 emits light when attacked by 2
- light attracts 3 to eat 2
265
biomineralization
-organisms produce solid from inorganic precursor
266
mineral vs biomineral
-biominerals are composites = mineral + organics
267
biomineralization in
```
Archae
Bacteria
Protoctista
Fungai
Plantai
Animalia
```
268
mineral
- solid consisting of inorganic anion + cation
- defined by chemical composition AND morphology
- crystalline or amorphous
269
Example of different crystal morphologies
CaCO3 occurs as vaterite, calcite, aragonite, or amorphous
270
organic component, biomineral
- helps control biomineralization process
- becomes incorporated into mineral component
- can influence mechanical properties
271
types of biominerals
- ca. 60 different types
- common cations: Ca, Si, Fe, Mn, Zn, Cu
- common anions: carbonate, phosphate, sulphate
272
functions of biominerals
- protection from predator, environment/ armour
- feeding (radular teeth, jaw)
- support/ stiffen skeletal
- anchorage
- storage for important ions
- sensory reception
- statocyst
- magnetite crystals in magnetotactic bacteria
- diatom frustules
273
biomimetic
synthetic methods that mimic biochemical processes
274
mechanism of biomineralization
1. space delineation
2. subdivision of space by org matrix
3. generating saturated solution
4. nucleation
5. growth and shape modulation
6. cessation
275
mechanism of biomineralization, space delineation
1. sponge spicules, space inside ring of cells
2. gorgonian spicule, space inside one cell
3. echinoderm ossicles, space inside multinucleated cell
276
Bivalve shell, space delineation
EPS - extrapallial space
- between mantle fold and shell biominerl
- where ions are deposited and diffuse
277
Bivalve shell, minerals at site
- CO3 from active transport of CO2 from environment
| - Ca++ brought in using ATP powered Ca/H antiporter within mantle fold
278
Mytilus prismatic shell layer
-organic matrix surrounding calcite crystals
279
Nacreous gastropod shell layer
-aragonite crystals
280
gastropod glycoprotein material and polymorph formed
- original: aragonite, calcite
| - Forn: vaterite
281
crack propogation, composite material
- much more energy for cracks to persist across different materials
- softer materials generally dissipate crack energy
282
plywood construction
- longitudinal axis shifted in each successive layer
- stiffens (increase flexural stiffness)
- strengthens by resisting crack propagation
- mollusc shell has same form
283
examples of biomineral functions
- statocyst
- magnetite crystals in magnetotactic bacteria
- diatom frustules
284
Energy to propogate crack
proportional to diameter at tip of crack
| -having a space in the structure (eg. holes) increases the diameter of the crack, therefore increases required energy
285
why shell dissolution (organisms own shell)?
1. enlarge aperture
2. enlarge living space
3. buffering
4. remodelling
5. mineral recycling
286
shell dissolution, enlarge aperture
- waterflow
- keyhole limpet
- scaphopod
287
shell dissolution, enlarge living space
-cone snail dissolves inner layers of overgrown shell walls
288
shell dissolution, buffering
-anaerobic respiration creates acids that must be buffered
289
shell dissolution, remodeling
- may lose or change shell at different life stages
| eg. nudibranch
290
shell dissolution, mineral recycling
dissolve and store CaCO3 to recycle into new exoskeleton
291
OA
increased atmos CO2
- 40% of ff's in atmos.
- pH of ocean 0.1 lower than pre-industrial
- pH 0.3-04 units lower by 2100
- depression of carbonate ion concentration
292
ocean carbonate reactions
CO2+H2O--H2CO3
H2CO3 --H+HCO3
HCO3- -- H + CO3 2-
H+ + CO3 2- --- HCO3 -
293
results of ocean carbonate reactions
- lower pH
- increase in [H] results in -reduction of carbonate ions (CO3 2-)
- increase in bicarbonate (HCO3 -)
- calcium carbonate dissolution
294
CaCO3 dissolution and saturation horizon
- dissolution causes saturation horizon to shoal threatening to dissolve previously deposited structures
- CCD higher form aragonite
295
amount of marine species that are molluscs
23%
296
OA ecosystem impacts
1. Food webs
2. Competitive interactions
3. Ecosystem services
4. economic importance
297
OA impact, pteropods example
- pelagic, huge swarms, large importance in food web
| - aragonite shell, begins to dissolve w/i 48 h or understaurated waters
298
mollusc embryonic shell
- initially amorphous CaCO3
- less able to isolate calcifying fluids
- strong kinetic demand for CaCO3 precipitation
- limited energy budget
299
consequence of initially forming amorphous CaCO3 shell
-less stable than calcite, aragonite
300
why are larvae less able to isolate calcifying fluids
periostracum is more leaky than adult form
301
sea urchin and OA
- sea urchin lives across variety of CO2, pH
| - larvae have calcareous spicules supporting larval arms-- fundamental to functions
302
Adaptive capacity to respond to OA, study
- collect sea urchin adults
- fertilize eggs, rear large under normal and elevated CO2
- measure features
- larval development and morphology showed little response
- frequency of allele transcripts (skeleton building genes) substantially different
- natural selection in low pH condition
- genetic variation could be reservoir of resilience
303
for a population to respond to change
1. Genetic variation w/i population
| 2. Population robust w high reproductive capacity
304
groups of broadcast spawners
```
almost all:
- echinoderms
-cnidarians
-bivalves
some mollusc
```
305
Problem w/ external fertilization
- high risk of wasted gametes
| - only a few hours in water until non-viable
306
test magnitude of external fertilization problem
- inject sea urchin w/ 0.5 M KCl to make spawn
- have eggs waiting at different distances away
- determine amount fertilized, easy to count, fertilization envelope
307
test magnitude of external fertilization problem, results
20% or less fertilization at distance greater than 20cm
308
test magnitude of external fertilization problem, implication
two urchins must be spawning at near exact same time and location to be successful
309
fertilization success may be increased if
- cluster of organisms spawning
| - higher current speed (greater than 0.2 m/s)
310
allee effect
-population density effect on rate of population increase (#offspring, individual)
311
strategy to minimize gamete waste
1. reproductive aggregations
2. synchronized release of gametes
3. sperm attractants
312
synchronized release of gametes
- key to respond to environmental cue
| - eg. corals, hydrozoans
313
Spirocodon hydromedusae spawning cue
light
- sperm develop beneath epidermal epithelium
- loss of microvilli = pore formation -- allows sperm release
- gaps appear in response to onset of darkness and heal shut w/i 40 min
- darkness must remain for 30+ minutes
314
GBR spawning
- mass spawning event
- all release gametes at same time in 'balls', packets of eggs and sperm
- 5-8 days after new moon in Oct.
315
Spawning cue for GBR
1. increased SW T, photoperiod
2. Lunar cue
3. Light-ff cue (only after sunset)
316
why October?, GBR
wind speed lowest in Oct.
- influences currents
- strong wind dissipate gametes too much
317
Caballes spawning cue
- crown of thorns starfish
- polyp predator
- various cues in lab to try to induce: T increase
- males have lower threshold to release than fm in most scenarios
318
sperm attractants
- spawned eggs release chemical signals to modify sperm movement
- species specificity
319
sperm attractant molecules
Ascidians: suffocated steroid
Sea urchin: peptides
Abalone: tryptophan
320
Abolone sperm attractant experiment
-tryptophanase shows sperm attractant improves fertilization success
321
acrosome reaction
- sperm have acrosomal membrane and and enzymes
| - after contacting egg jelly, membrane breaks down, acrosomal enzymes digest jelly coat so coat sperm/egg can fuse
322
Bindin
- gamete recognition protein of sea urchin
- exposed on acrosomal process acrosome reaction
- bindin receptors on vitelline envelope of egg
- facilitate conspecific gamete binding
323
simultaneous fusion of 2+ sperm
polyspermy
324
consequence of polyspermy
-fatal for egg
325
blocking polyspermy
fast- membrane depolarization upon fusing, temporary
| slow: cross-linking of vitelline envelope
326
male density and reproductive failure in spawning organisms
low density = low sperm concentration
| high density = polyspermy
327
different alleles of bindin
- LOW sperm density = fertilization enhancement
| - HIGH sperm density = minimizes polyspermy
328
Red sea urchin bindin alleles
LD - greater success at low m density
| HD - greater success at h.d.
329
change in concentration of Red sea urchin bindin alleles over time
- animals 200 ya had higher LD -- lower population density
- animals now have higher HD frequency -- higher population density
- increased risk of polyspermy
330
Aplysia fertilization
California sea hare
- simultaneous hermaphrodites
- copulate (internal fert.)
- breeding seasons (spring-summer)
- reproductive aggregations (12-15 individuals)
- egg laying (packed in jelly string, initially sticky)
- complex life history
331
Aplysia life cycle
- eggs w/i capsule embedded in string of jelly
- veliger: to 34 d, planktotrophy
- metamorphosis 34-37 doh
- juvenile 40-60 doh
- adult has siphon, parapodium, tentacles
- adult lays egg mass
332
hermaphroditic challenges
must:
- keep gametes separate
- prevent self-fertilization
- store self and received sperm
- have fertilization chamber
- encapsulate eggs
333
hormonal control of egg laying
- initiates egg laying behaviour, back and forth waving of head to to attach egg mucus to substrate
- Aplysia abdominal ganglion (visceral)
334
abdominal ganglion
- surrounded by connective tissue sheath
| - contains bag cells
335
bag cells
- neurosecretory cells
- neurons w/ axons
- secrete egg laying hormone (ELH)
- self-activitating
336
ELH
- small peptide (36 a.a.'s)
- released from vesicles during bursts of bag cell depolarization
- autocrine and endocrine activity
- initiates ovulation
337
ELH paralogs
Aplysia genome has 5 paralogs
- duplication and divergence
- 1 undergoes tc, translation, processing in bag cells - generate ELH
- 2. tc, tl in albumen gland = attraction
338
attractin
pheromone
peptide
58aa
339
other Aplysia peptide pheromones
enticin
temptin
seductin
340
contact pheromones
physical contact w/ recently laid egg mass intiates release of ELH
341
Carcinus reproduction
- European green crab
- copulation window - post- female ecdysis
- guard mate
- penis from base of last walking leg
- pleopods 2 push sperm along groove into female
- hold brooded eggs onto abdomen w/ pleopods
342
Carcinus uridine disphosphate
UDP
- in fm urine
- waste product of chitin biosynthesis
- i.e. signal of ecdysis
343
consequence of UDP production
- activates male mating behaviour
- fm sex pheromone
- males show seasonal sensitivity/response to UDP (highest in mid season)
344
basic life history patterns
1. planktotrophic larvae
2. lecithotrophic larvae
3. Aplanktonic (direct development)
345
planktotrophic vs lecithotrophic fecundity
plankt: high
lecith: low
aplanktonic: very low
346
Brisaster life history
- heart urchin
| - facultative planktotroph
347
Gunnar Thorson
- Danish marine biologist
- pioneer in larval ecology
- influential publications
348
Thorson's law
- species producing feeding larvae rare at higher latitudes and deep depths
- -trend exists but many exceptions
349
optimal life history theory
Vance 1973
- important variables affecting recruitment of juveniles:
1. fecundity
2. developmental time
3. mortality risk
- all depend on egg size
350
optimal life history theory, fecundity
-negative linear rltship w/ egg size and fecundity
351
optimal life history theory, development time
negative linear
| egg size vs development time
352
optimal life history theory, mortality
positive linear
| development t, mortality risk
353
Vance prediction for optimal egg diameter
U-shaped
| -smallest and largest have highest recruits
354
problems with Vance theory
1. empirical data
| 2. phylogenetic reconstructions
355
protonephridium
1. terminal cell = ultrafiltration
| 2. duct cells = selective absorption
356
Neptunea egg capsule
1 viable embryo
| many nurse eggs
357
Liracbuccinum egg capsule
also have nurse eggs but variation in viable embryos and # nurse eggs
- 1 v.e., 130-170 n.e.
- 3-12 embryos, 10-40 n.e.
358
Liracbuccinum hatching size vs hatchlings per capsule
- negative linear
| - less hatchlings = greater hatching size
359
parental provisions of eggs
yolk
albumen
nurse eggs
360
value of encapsulating egg material, Conus
-length of t w/i egg capsule directly correlated w/ thickness and puncture resistance of egg capsule
361
larval defensive strategies
- spines
| - crown-of-thorns seastar: large pink larvae w/ saponins
362
majority of inverts life history
planktonic
| back to paleozoic
363
why have pelagic larval stage`
- ancestry
- dispersal
- resource availability
- predation avoidance
364
benefits of dispersal
- resources
- oxygen
- reduce competition
- mating -- heterogeneity
365
larval duration adapted for dispersal
very short
366
test abundance of predators in pelagic relative to benthos
- float brachyuran larvae in water on line weighted down
- one line at bottom, one at 3m
- glue larvae onto line
- pull up after 3hrs
- tally number eaten
367
results of predator abundance test
- more benthic larvae lost
| - more larvae lost at night
368
expected consequences of dispersal
1. extensive gene flow btw distant populations
2. low speciation rates, minimal local adaptation
3. low extinction rate
369
why does dispersal cause low extinction rate
- spreads risk
| - survive local catastrophe
370
evidence for expected consequences of dispersal, gene flow
low genetic differentiation among populations
371
evidence for expected consequences of dispersal, minimal local adaptation
extinction, speciations in fossil record
372
evidence for expected consequences of dispersal, low extinction rate
spread of invading species
373
test of genetic differentiation, nudibranchs
- 2 species, similar in many ways
- rocky shores of Great Britain
- feed on bryozoans
- annual life cycle
- spawn during winter
- 1 has longterm planktotrophic larvae (3mth), other 1-2 days
- map distribution
374
test of genetic differentiation, nudibranchs, long-term planktotrophic larvae
- gene w/ 3 alleles
- alleles expressed in pretty similar frequencies over large area
- lots of genetic exchange
- long time, lots of time for exchange
375
test of genetic differentiation, nudibranchs, short-term planktotrophic larvae
gene w/ 2 alleles
much different allele frequencies around isles, even populations close together
-high heterogeneity
-consistent w/ short-lived larvae
376
gastropod shell, embryo, larvae, etc.
transitions in shell whorls mark stages of development
377
Thorson's shell apex rule for gastropods
protoconch retained at apex of shell
| -size and shape of protoconch indicates planktotrophy or lecithotrophy
378
duration of fossil gastropod species, planktonic vs non-planktonic
planktonic species appear to have persisted significantly longer, 12-4my
-non-planktonic max 6-8, majority 1-2my
379
neogastropod pelagic speciation
35-65 MYa
- Atl coast
- trend towards increased non-pelagic species
- speciation?
380
Varnish clam
- native to Korea, Japan
- introduced to Vancouver harbour 1980s
- spread to SOG and Washington by 1998
381
evidence of unexpected consequences of dispersal
1. test of species selection
2. genetic structure
3. paradox of rockall
382
Phylogenetic test of species selection
- must know phylogeny to consider something speciation
- if 'burst' of speciation after a trait evolved then probably trait selected for
- if trait is on different tree branches then not selected for, not speciaition
383
test speciation in cone snails
- 70 species
- aplanktonic secondarily adapted for found on different branches
- no evidence of selection
384
unexpected consequences of dispersal, genetic structure
- unexpected genetic heterogeneity
| - more genetic variation along coastline than expected
385
Paradox of Rockall
- NAtl, 400km W of land
- 30My isolation
- 110ft diameter, 63ft high
- lots of inverts live there
- must have dispersal stage to get so far..
- but all aplanktonic..
- only self-recruits would be likely to keep it populated
386
Conus, Cape Verdes Archipelago
- 600km off W Africa
- 50 endemic species
- aplanktonic
- 2 clades
- 2 founder species, egg mass rafted to islands
387
local recruitment
- larval retention
- self recruitment
- may have been founder of wide dispersal but return phase was lost
- if parents successful in habitat then probably good
388
mechanism to control larval dispersal and recruitment
-environmental cues
389
flood tide transport
- Ebb tide: low S, Megalopae remain on bottom
- Flood tide: M ascend into water column as S rises
- turbulence promotes continued swimming
- end of flood tide, M descend as salinity drops
- brought back to parental habitat
- take advantage of prevailing currents
390
settlement
- behavioural process
- cessation of swimming
- adherence to substrate
- REVERSIBLE
391
Metamorphosis
- developmental process
- loss of larval characters
- emergence of functionalization of juvenile characters
- NONREVERSIBLE
392
metamorphic competence
- stage of life
| - maturation great enough for metamorphosis
393
delay of metamorphosis
- competence and induction
| - possiblity variable per species
394
consequences of delay of metamorphosis, negative, abolone
Abalone
- lecithotrophic larvae
- 11 days
- delay in absence of inducer
- reduced post-larval survival
395
consequences of delay of metamorphosis, no effect, Phestilla nudibranch
- facultative planktotrophy
- delay in absence of metamorphic inducer
- no effect found on post-metamorphic lifespan or fecundity
396
consequences of delay of metamorphosis, positive effect, moon snail
- continue to grow after reaching competence
| - if meta. delayed, get larger, release from predators, may increase survival
397
Metamorphogenesis
1. loss of cells/tissues
2. De novo differentiation of cells/tissues (set-aside cells)
3. remodelling of larval cells/tissues
398
why is considering metamorphogenesis important
- sometimes metamorphosis is a minimal change of tissues - ex. slipper limpet only loses velar lobes
- sometimes its a huge change! ex. sea urchin!
399
sea urchin metamorphogenesis
- catastrophic metamorphosis
- juvenile rudiment small mass of tissue inside of larvae
- complete change of form must be accompanied by changes in internal cells/tissues
400
induction of settlement and metamorphosis
1 associative
2. gregarious
3. avoidance
- all chemical cues
401
Associative settlement and metamorphosis cue
- prey
- habitat quality indicator
- water flow indicator
402
Abalone induction cue examples
- chemical from red coralline algae
- phycobiliprotein
- indicator of good water flow
403
environmental induction cue come from conspecific
- sexual reproduction
- good habitat indicator
- protection of new recruits
404
Associative settlement and metamorphosis cue
environmental induction cue come from an organism of different species
405
gregarious settlement and metamorphosis cue from
conspecifics
406
gregarious tube-dwelling polychaete
- Phragmatopoma
| - cement holding tubes together induces metamorphosis
407
sand dollar gregarious settlement
- adult chemical component induces S, M
- adults exclude tanned
- tenaid predator of larvae
- S, M w/ adults offers protection
408
Avoidance settlement and metamorphosis
- environmental cue
- inhibits metamorphosis
- superior competitor
- predators
409
thickness around boundary layer as Re # increases
becomes thinner
410
mechanisms to capture suspended particles
```
filtering
scan and trap
direct interception
adhesion
ciliary mechanisms
```
411
critically important for oyster reef success
height
412
primary source of DOM in ocean
exudate from phytoplankton
413
epidermal epithelial cells of marine inverts have intrinsic membrane proteins in the apical cell membrane that enable import of dissolved organic molecules against concentration gradient
sodium-dependent co-transporter
414
endosymbiont acquisition of microbial symbiont from parent
vertical transmission
415
enzyme in hosts of photosynthetic endosymbionts to prevent ROS damage
superoxide dismutase
416
excess photosynthate released by corals as
mucus
417
Solemya reidi bivalve have ctenidia populated by prokaryotic endosymbionts that utilize
hydrogen sulfide as energy source
418
skeletons perform functions by accommodating forces, they may
1. resist force
2. transmit force
3. store energy of force
419
mechano-enzyme directly responsible for muscle cell shortening
myosin
420
obliquely-striated muscles have greater __ than cross-striated
working length
421
internal projection of arthropod exoskeleton analogous to tendons
apodemes
422
describe S/S plot of highly resilient material
- S/S plots during loading and unloading would be exactly the same
- length of material before and after would be same (extension)
423
internal fertilization accomplished either by
- transfer of spermatophores
| - direct introduction via organ (penis)
