Mollusks and Annelids Flashcards
(33 cards)
What animals are in Phylum Molusca?
snails, slugs, clams, scallops, oysters, squid, and octopuses
Phylogenetically, mollusks share a common ancestor with __________, and both exhibit ________ ________.
Also both phyla include representatives with a __________-_________ larval stage called a ____________.
annelids, spiral cleavage
free-swimming, trochophore
What is the basic body plan of a Chitons (Mollusk)?
- muscular foot
- gills
What is the basic body plan of a Gastropods-snail (mollusk)?
- snails don’t have gills
- shell, skin is highly vascularized like a lung
What is the basic body plan of a Cephalopods (mollusk)?
- radula
- 8 legs, 2 tenticls for moving foot
What is a polyplacophora: chitons?
inter-tidal marine organisms that rasp algae from rocks
Class Gastropoda includes the animals…?
snails, slugs, nudibranchs
What is Torsion in Snail Shells?
- side view of the snail, poops out near its head
- viscera in snails is rotated 180 degrees
What is coiling in Snail Shells doing for it?
-gives the animal a better sense of gravity is stronger with it coiled.
what are the characteristics of Class Bivalvia?
- most are sedentary filter feeders that depend on ciliary action of gills to bring in food.
- no radula and little cephalization
- movement via the muscular foot
What are the characteristics of Class Cephalopoda?
- active marine predators with closed circulatory systems(the others don’t have this!)
- All the wiring is behind the eye, retina first and is more highly evolved that our eye.
- NO larval stages
- A siphon is used for jet propulsion
What is the most ancient (chambered mollusk)?
Nautilus
What has a very sophisticated brain? and what kind of shell does it have?/
Cuttlefish
intermediate shell
What has a slightly smaller shell than a cuttlefish, and what specialization does it have?
Squid
helps in expelling water
What has no shell, and is very smart learning capacity to open a crab jar? What else an its body do?
Octopus
Change color
What did the true coelom open the door for?
complexity of design-blood vessels and organ protection
What does segmentation allow the body to be able to do?
- septa between segments allow for an improved hydrostatic skeleton.
- circular and longitudinal muscles (longitudinal are the length of the body and circular can then scrunch up)
- opportunity for specialization(head region, and other sections of body)
What kind of circulatory system does an Annelida have?
Closed circulatory system
How does gas exchange through the an Annelida?
through the bodies surface
Class Polychaeta are what type of water livers?
Marine
Class Polychaeta have what kind of head and organs?
differentiated head
specialized sense organs
Class Polychaeta have chaetae=…?
setae- in budles on parapodia
Is a Polychaeta monoecious or dioecious?
The early larvae is a _______?
dioecious
trochophore
In Class Clitellata is Cephalization pronounced?
No
