Summary: Animals of the Intertidal Zone Flashcards
The phylum Echinodermata means ___ ___
spiny skin
Echinodermata have ___ symmetry
pentaradiate (5-fold)
Echinodermata have a water vascular system (WVS) which is a hydraulic _____. How do they use this?
skeleton!
Use water-filled tubes to walk, feed, and for defense
Echinodermata have an __skeleton made up of __ ___.
endoskeleton (internal- skin covers the spines)
calcium carbonate
Sea urchins and sand dollars have ____, covered by skin because they have an endoskeleton
Sea stars and cucumbers have ___ embedded in their body wall (endoskeleton)
spines
ossicles
What are ossicles and which intertidal animal has them?
small calcareous elements embedded in the dermis of the body wall of echinoderms. They form part of the endoskeleton and provide rigidity.
sea stars
What is mutable collagenous tissue? What phylum of animals has it?
MCT is collagen that can stiffen or soften by nervous input; found in echinoderms (eg sea stars)
What does mutable collagenous tissue do?
In echinoderms, it is used to lock spines in place, lock skeleton for leverage, or to autonomize arms or spines
What are the 5 classes of echinoderms?
- sea stars
- sea cucumbers
- sea urchins
- brittle stars
- crinoids
how do sea stars feed?
They feed by using water vascular system (WVS) with mutable collagenous tissue (MCT) to lock their skeleton
- then pull valves apart to insert their cardiac stomach and digest the animal extracellularly
How do sea cucumbers feed?
Deposit or suspension feed with modified tube feet at mouth
How do sea urchins feed?
They graze algae with 5 teeth in their Aristotle’s lantern
What is the Aristotle’s lantern found in sea urchins?
A structure of 5 teeth held and moved by muscles
What are the 3 characteristics found in all classes of echinoderms?
- pentaradiate symmetry (5)
- Hydrostatic skeleton (water vascular system) “tube feet”
- calcium carbonate skeleton (plate/ ossicles)
How do brittle stars feed?
Deposit or suspension feed with tiny tube feet on their arms
How do crinoids feed?
suspension feed using modified tube feet to catch particles from water
The phylum Arthropoda means “___ ___”
jointed legs
Need to know 2 groups of arthropods:
1:
2:
- Decapoda (crabs): 10 (walking) legs
- Cirripedia (barnacles): “settle on head” feet become feeding appendages
Decapods have an exoskeleton made of ____ that is hardened (sometimes hardened with ___)
- They ___ their skeleton to grow: produce the hormone ___ to do this
chitin
calcium
molt
ecdysone
What are the 2 body regions of crabs (decapods)?
- thorax (head/ stomach)
- abdomen (tail tucked under body)
What are some things that crabs eat?
snails, other crabs, deposit feed using setae on claws, filter feed using setae on antennae
Crabs can filter feed using the ___ on their ____
They can also deposit feed using the ____ on their ___
filter: setae on antennae
deposit: setae on claws
Crab claws and legs have many sensory ___ that detect __ and ___ in the water
setae
chemicals and vibrations
How do barnacles (Cirripedia) feed?
they have cirri- arthropod feed that have setae and rake the water to capture particles
“settle on head”
The body of barnacles is usually ___, except in goose neck barnacles which have a ___ ___
calcified
muscular stalk
the calcified body of barnacles resists ___ and ____
Therefore barnacles can live at highest high tidelines
desiccation and predation
Which animal can live at the highest high tidelines?
barnacles
Phylum Mollusca includes classes ___, ____, ____ and ____
cephalopods, gastropods, bivalves, chitins
Gastropods are a class of ____, and their name means “___-___”
Mollusca
stomach-foot
___ are a shelled mollusc with a __/__ region and a __/___ region
snails
head/ foot
stomach/ shell
gastropods are characterized by a “creeping ___”, and their shell is secreted by the ____
creeping foot
mantle
t/f
the mantle is a basic characteristic for all molluscs
true
How do gastropods feed? What do they eat?
List 2 different types
Some graze on algae using a radula (a ribbon of teeth that is pushed out of the buccal cavity (mouth) and rasps the food
Others (called ‘drills) drill into the shells of other snails and bivalves and eat them
____ are gastropod molluscs with 8 plates that make up a protective shell.
They typically lie flat on a rock and graze ___, but some are ____
chitons
algae
carnivorous
_____ molluscs have a shell that’s formed into 2 sides that close together at a hinge (using strong ___)
bivalve
muscles
How do bivalve molluscs feed?
inside the valves are gills- they use ciliary mucus filter feeding
In bivalve molluscs, the shell is secreted by the ___, which forms 2 siphons. What do these siphons allow for?
mantle
2 siphons to allow water into the space between the valves
The main characteristic of the phylum cnidaria is their ability to ___ (using the ___)
sting
cnidocyst
Anthozoans are commonly known as ___ and are part of phylum ____
anemones
cnidaria
T/F
Anthozoans (anemones) have no medusa stage
true
Anthozoans (anemones) are
- soft or hard bodied
- sessile or mobile
- ___ shaped
- in the nemertea/ cnidaria phylum
soft
sessile
sac-shaped
cnidaria
anemones have:
- tentacles with ____
- a ____ cavity
- ____ to wipe stinging cells onto neighbors to fight
cnidocytes
gastrovascular
acrorhagi
Explain how anemones use their tentacles to sting
The tentacles have stinging cells called cnidocytes that contain stinging organelles called cnidocysts
- Anemones can have different cnidocysts for diff _____ and also different ____ ____
- some cnidocysts ___ their prey while some are ____ and hold onto shell bits to protect the anemone from_____
species
body regions
pierce
sticky
desiccation
Cnidocyst vs cnidocyte?
Cnidocytes are the stinging cells attached to tentacles, while cnidocysts are the stinging organelles on the cnydocyte
t/f
sea anemones cannot swim away from predators
false, some of them can! Some can’t, so they just sting
What are acrorhagi?
A region of cnidocysts on anemone tentacles- the anemones use acrorhagi to wipe stinging cells onto neighbors to fight
The phylum Nemertea means ___ because they’re very accurate ___
unerring (ie always right/ accurate)
predators
The Nemertea phylum consists of ___ worms which have special ____ allowing them to stretch very ___
ribbon
muscles
long
Ribbon worms have a muscular mouth cavity called a ____. How do they eat?
Rhyncocoel
The phyncocoel shoots out a dart (stylet) to harpoon prey
What do Nemerteas eat?
Nemerteas (ie ribbon worms) eat other worms and small crustaceans
What is a rhyncocoel?
a muscular mouth cavity that ribbon worms have; they use it to shoot out a dart and harpoon their prey
The phylum Platyhelminthes consists of ____
flatworms
platy= flat
helminthes= worm
how big are flatworms?
small!
<1cm to 5cm
very very flat
t/f
platyhelminthes do not have a body cavity
true!
How do flatworms feed?
They don’t have a body cavity, so they feed with a pharynx that is ciliated and can crawl into prey
What do flatworms eat?
barnacles, tunicates, etc
(crawl inside them to ingest)
The phylum “annelida” means ___ worms
segmented
ie rings (they have segments that look like rings)
Polychaetes are segmented worms with many ____
setae
poly=many
chaetes= setae
Annelids have muscular ____ for biting/ grazing and specialized appendages for ___ or ___
jaws
walking or respiration
How do some annelids feed?
Some secrete tubes and filter feed with tentacles
Do hydrothermal vent worms filter feed in the same way that some annelids do?
No!
Vent worms do not filter feed, they have symbionts for chemosynthesis
List 3 other encrusting animals under rocks
- bryozoa
- sponges
- ascidians
Bryozoa:
- are a phylum of “__” animals
- have a feeding organ called a ______ which is a horseshoe-shaped structure with ____ that creates a filter feeding current
moss
lophophore
cilia
