Exam 2 Flashcards
(68 cards)
1
Q
trPlatyhelminthes
A
- no known synapomorphies
- anterior brain connected to nerve cords (usually 2)
- no anus
- flat = high surface area to volume ratio
- waste exits by diffusion, helped by
flame cells - simultaneous hermaphrodites
2
Q
special characteristics of Platyhelminthes
A
- 34,000 species
- respiratory & circulatory system
- 80% parasitic
- triploblastic
- acoelomate
- bilaterally symmetrical
3
Q
Platyhelminthesis
A
flatworm
4
Q
tripoblastic
A
3 embryonic cell layers
5
Q
acoelomate
A
lacking coelom
6
Q
classes of Phylum Platyhelminthes
A
- class turbellaria
- class castoda
- class monogenea
- class trematoda
7
Q
class Castoda
A
- 6,000 species
- found in vertebrates
- syncytial tegnment, heavily folded
- no mouth or digestive tract: diffusion
- scolex
8
Q
scolex
A
anterior structure with hooks/suckers to attach
9
Q
life cycle of Castoda
A
- adult (in intestine of host)
- eggs leave with feces
- eggs enter intermediate host
- eggs hatch into oncosphere larvae
- oncosphere lyses (dissolve) intestine of
intermediate host, form cysts - intermediate host consumed by
definitive host, matures in intestine
10
Q
class Monogenea
A
- 8,000 species of fish ectoparasites
- no intermediate host
11
Q
life cycle of Monogenea
A
- adult on fish
- make eggs
- oncomiracidium larvae
- attach to fish
12
Q
ectoparasites
A
attach to outside of fish
13
Q
haptors of Monogenea
A
POSTERIOR attachment organ that has suckers and hooks for attachment
14
Q
prohaptors of Monogenea
A
ANTERIOR attachment organ that has suckers and hooks
15
Q
class Trematoda
A
- 8000 species
- all parasites, all vertebrate
definitive hosts - Ex chinese liner fluke
16
Q
life cycle of Trematoda
A
- adult in definitive host —> eggs
- eggs released into environment, hatch
into free living, gutless miracidium
larvae - miracidium enters 1st intermediate host
- miracidium -> spirocyst -> redia larvae
-> cercaria - cercaria exits
- cercaria enters 2nd intermediate host
- becomes encysted metacercaria,
develops further - 2nd intermediate host eaten by
definitive host, migrate to appropriate
place and mature
17
Q
Gnathiferans
A
clade of small spiralians characterized by jaws
18
Q
Phylum’s within Gnathiferans
A
- phylum micrognathozoa
- phylum gnathostomulida
- phylum rotifera
- phylum acanthocephala
19
Q
Phylum Micrognathozoa
A
- 1 freshwater species from cold spring
in greenland - make resting eggs to survive winter
- about 1/10 mm, 15 part jaws with
supporting muscles - forehead cilia move food to jaws
- reproduce by parthenogenesis
- protandrous? male first then female
later
20
Q
Phylum Gnathostomulida
A
- 100 marine species
- tiny worms that live in interstitial spaces
(b/t sand) - can live in anoxic habitats
- no respiratory/circulatory system
- simultaneous hermaphroditic
- eggs fertilize internally, released, no
larvae
21
Q
anoxic
A
without oxygen
22
Q
Phylum Rotifera
A
- > 2000 species, freshwater
- corona: ciliated anterior bring in food
- muscular pharynx with jaws
- toes with adhesive glands
- lots of muscle
- lack resp. and circ. system
- free living omnivores
- move with corona also looping
- brain
- antennae as mechano and
chemoreceptors - simple photoreceptors
- short lived eutely
23
Q
eutely
A
constant number of cells
24
Q
Phylum Nemertea
A
-1300 marine
- up to 20 cm, rarely to 30 cm
- circulatory system: no heart, no valves
- pigmented photoreceptors: up to 80
25
Phylum Mollusca
- >100,000
- extremely flexible body plan
- mantle cavity: exit for excretory,
reproductive system, holds ctenidia,
involved in feeding, gills: use
countercurrent exchange to maximize
oxygen uptake
- blood circulatory system: close system
in cephalopods, open in others, most
have heart (s), hemoglobin or
hemocyanin
- metanephridia
- complete digestive system
- reproduce sexually
26
defining characteristics for Phylum Mollusca
- dorsal mantle secretes calcareous shell
- radula in esophagus (helps to eat)
- ventral foot
27
classes of Mollusca
- class polyplacophora
- class gastropoda
- class bivalvia
- class cephalopoda
28
Polyplacophora
chitons
29
Class Polyplacophora
- 7 or 8 dorsal shell plates
- dorsal/lateral mantle skirt = girdle
- girdle allows for suction
- up to 80 ventral ctenida on either side
- ventral foot moves with predal waves
- live close to shore in intertidal shore
- sensory structures and nervous system
reduced
- feed by scraping algae from rocks
30
Gastropoda
snails and slugs
31
Class Gastropoda
- largest class > 60,000
- freshwater, marine, terrestrial
- shell anatomy: most lean to left
32
defining characteristics for class Gastropoda
- operculum = proteinaceous foot shield
- torsion = 180 degree twisting of head
and foot
- visceral mass protected by single shell
- muscular foot moves by pedal waves
33
Groups of Gastropoda (6)
- prosobranchs
- pulmonates
- opisthobranchs
- nadibranchs
- pteropods
- bubble snail
34
Prosobranchs
- marine, diverse feeding strategies
- carnivorous species are venomous,
inject with hollow radula tooth
- siphon morphology: varies by ecology
- carnivores have larger siphons to
detect prey
- herbivores have smaller siphons b/c
they don't detect prey
35
Pulmonates
- slugs and snails, terrestrial or
freshwater
- mantle cavity highly modified: highly
vascularized (lack ctenidia)
- few have operculum
- herbivores
36
Opisthobranchs
- marine, lack shell, operculum, gills,
mantle cavity, limited torsion
- no shell: alternative defenses
- cerata: hold nematocysts
- chemical defenses
37
Nadibranchs
- soft bodies
- marine
- shed shell after larvae stage
38
Bubble snails
- small shells
- don't cover body
- burrow through sand with head
39
class Bivalvia
- 9200
- anatomy: skulls open with springy
ligament
- typically sedentary lifestyle
- lack cephalization
- no rodula
- all aquatic
- suspension-feeders
40
defining characteristics for class Bivalvia
- hinged, 2-valves
- laterally flattened
41
groups of Bivalvia
- protobranchia
- lamellibranchs
42
Protobranchia
- most primitive bivalves
- small, gastropod like gills mainly for
respiration
- feed by palp proboscides
- marine, soft sediments
- gills: water passes through incurrent
chamber then excurerent chamber
- gills attached by immotile cilia
- particles sorted: eat organics, expel
pseudofeces
43
Lamellibranchs
- marine, freshwater bivalves
- important for food, ecology,
environmental monitoring
- gills modified to collect food
- byssus gland: secrete own adhesive
- gill modification: larger, ciliated food
grooves, pseudofeces can be helpful
source of nutrients
44
Lamellibranchs reproduction
- external fertilization
- trochophore larva, then veliger
- draw in sperm with incurrent siphon,
internal fertilization, glochidia larvae
- glochidia larvae attach parasitically to
fish gills
45
Zebra muscle (lamellibranch example)
- black sea native
- widespread in E. US
- grow in dense mats
46
ecological effects of zebra muscle
- filter
- increase water clarity
- increase good algae
- compete with zooplankton
- change nutrient dynamics
- kill birds
47
Class Cephalopoda
- quick predators
- marine
- < 2 cm to 15 m
- radule & ctenidia
- highly developed head
- highly developed sensory structures
- muscular hydrostat appendages
- dense muscle fibers with central nerve
fiber & vasculature
- muscle tissue is liquid
48
defining characteristics of class Cephalopoda
- shell divided by septa
- chambers connected by siphuncle
- closed circulatory system
- modified foot --> arms, siphon
- ganglia fused to form large brain
49
ctenidia
internal gills
50
Cephalopoda reproduction
- hectocotylus: modified male arm
transfers spermatophores to female
51
Cephalopoda shell
- few external shell
- spiral, linked by siphuncle
52
siphuncle
- calcified tube
- regulates water/air
53
phylum Acanthocephala
- 1200 vertebrate gut parasite, freshwater fishes
- few cm, body = gonad
- extendable spined proboscis attach to host
- males have cement glands
- alter behavior of hosts
- complex life cycle
54
class Turbellaria
- 4500
- free-living, marine
- < 1 cm
- eyes: simple pigmented cups
- variety of special sensorys: pressure, chemical
- benthic
- branching gut, loop by duo glands
55
class Turbellaria reproduction
- male and female parts
- sperm transfer is reciprocal
- penis fencing
56
benthic
live on bottom, move by cilia, pedal waves/looping
57
Cephalopoda movement
- jet propulsion
- arms
- fins
58
Cephalopoda circulatory system
- systemic heart, branchial heart for each gill
- high levels of hemocyanin, very efficient
59
evolutionary theme
- internal shells: very flexible, doesn't affect movement
- octipi: complete lack shell
- paper nautilus: fake shell, secrete shell when have eggs to protect, very fragile, males stay to help with children
60
lack of shell
- lack of protection
- iridocytes: iridescence
- stack cells together to create color shifts
- changes color quickly
61
inking
- melanin
- neurotransmitters
- mucous
62
neurotrans
warns others of same kind there is danger in area
63
mucous
keeps cloud thick and long lasting to let them propel away
64
photophores (cephalopoda)
- light cells/organs
- bioluminescence: startles predator
65
cephalization
- ability to form memories
- learn
- distinguish objects based on shape and texture
- can't distinguish objects by weight
66
eye types (2)
- nautius: simple
- other: sharp images
67
vertebrate eye
came from outfolding of brain tussues
68
cephalopod eye
infolding of ectoderm
