Midterm 2 Flashcards
(29 cards)
1
Q
Mollusc key characteristics
A
- Visceral Mass
* Head- foot
2
Q
The Head
A
- Feeding
- Sense organs
- Brain, eyespots-to-eyes, tentacles
3
Q
The Radula
A
- Part of the Head-Foot
- Chitinous ribbon of teeth
- NOT in any Bivalve
- Odontophore cartilage holds teeth
- Muscles move it in and out
- Muscles to move odontophore and muscles to move radula
4
Q
The Foot
A
Locomotion, attachment
Ventral
5
Q
- Visceral Mass
A
- Internal organs
- Digestive, excretory, reproductive and respiratory
contains mantle and mantel cavity
- Digestive, excretory, reproductive and respiratory
6
Q
Mantle
A
- the “skin”
* Can have muscles, or chemoreceptors, etc
* Makes the shell
7
Q
- Mantle Cavity
A
open to “world”
* Excretion (metabolic and digestive), respiration, reproduction
8
Q
- Periostracum
A
- Outer organic layer (resistant protein conchiolin)
9
Q
- Prismatic layer
A
- Calcium carbonate stacks
10
Q
- Nacre
A
- Continuously thickens
- Calcium carbonate + protein sheets
Pearls
- Calcium carbonate + protein sheets
11
Q
Mantel layers
A
Nacre
Prismatic layer
Periostracum
12
Q
Reproductive System of Molluscs
A
- Never asexual
- Diocieous or monoecious
- Trochophore larvae in most
- Veliger larvae common
- Aquatic Bivalves and Gastropods
- Some have direct development (no larvae)
13
Q
The Aplacophorans
A
- Contains classes Caudofoveata and Solenogastres
- Wormlike and shell-less
- Calcareous scales/spicules
- Marine detrital/microorganism consumers – burrowers!
14
Q
Class Monoplacophora
A
- Means one plate
- Thought to be extinct until 1952!
- Round shell, large foot
- Serial repetition of body parts
- Gills, nerves, gonads, nephridia…
15
Q
Class Polyplacophora
A
- Means many plates” – the chitons
- 8 moveable plates
- Mantle girdle around outside
- Intertidal rocky areas
- Serial repetition seen
16
Q
Class Scaphopoda
A
- Tusk shells/tooth shells
- Sedentary
- Tubular shell (open at both ends)
- Tentacular foot for burrowing and food capture
- A lot of diffusion in mantle cavity
- No heart, no gills..
17
Q
Class Gastropoda
A
- Means stomach foot
- Most taxonomic rich (diverse) class – 60,000+
- Snails, periwinkles, limpets, sea slugs, slugs
- Marine, freshwater, terrestrial
- Coiled shell, domed shell, no shell
- 3 Main groups of Gastropods
18
Q
- Prosobranchia
A
- Most marine snails (periwinkles, limpets, conchs…)
Gastropods
19
Q
- Opisthobranchia
A
Gastropods
* (mostly) marine shell-less forms (nudibranchs, sea slugs...) * cerrata
20
Q
- Pulmonata
A
Gastropods
* Most land and freshwater snails and slugs (mantle cavity into lung)
21
Q
Torsion
A
180 degree rotation of the mantle/mantle cavity, internal
22
Q
Coiling
A
whorling of the shell
23
Q
- Feeding Gastropods
A
all feed with some adaptation of the radula
24
Q
Gastropods reproduction
A
- Simultaneous hermaphrodites * Eversible penises and simultaneous sperm transfer
- Love Darts and Slug Orgies
25
Class Bivalvia
* Laterally compressed shells
* Hinged dorsally; gape open ventrally
* Means two valve
* No head, no radula
* Bivalve locomotion
* Foot to burrow (clams)
* Adductor muscles to swim (scallops)
* Some sessile
* Byssal threads (mussels)
* Cemented (oysters)
26
Class Cephalopoda
```
* Means head-foot
predators
* Exclusively marine
* Most have 1 pair of gills
8 arms (2 tentacles for squid and cuttlefish)
* Closed circulatory system
* Incredible nervous system
```
27
Chromatophores
Cephalopoda. Camouflage cells 4 types
28
Cephalopoda Reproduction
* Dioecious
* With some amazing mating rituals!
* Copulation
* Direct development (no larvae)
* All but a couple species die
29
Conchiolin
found in outermost layer of mantel shell (Prperiostracum)
