1. Bivalves and Cephalopods

2. one thousand species live in fresh water Zebra Mussel
About
one thousand
species live in
fresh water
Zebra Mussel
Zebras on native clams
(Unionidae)

3. Best understood in the context of their
Best understood in the context of their largely sedentary adult life style

4. umbo ctenidium Foot Adductor muscle Right valve Labial palps mouth
Excurrent
Incurrent
siphons
mouth
Foot
Mantle edge

5. distinguished by their Ctenidia
Two principal types,
distinguished by their Ctenidia
and mode of feeding
Class Bivalvia
Protobranchia
Llamellibranchia
Filibranchia
Eullamellibranchia

6. Ctenidia of Bivalves are modified for feeding
except in one group: the Protobranchs

7. In most bivalves ctenidia are sheet-like
with high S.A., and are used for feeding

8. Captured particles are moved to a ciliated ventral groove and then as a mucus strand to the mouth.

9. Summary of Water Flow and Feeding
The sheetlike, arrangement of ctenidia in most bivalves is known as the Llamellibranch condition

10. There are two basic type of
Llamellibranch ctenidia in bivalves
Filibranch
(in mussels)
Eullamellibranch
(most clams)

11. Living Cephalopods Squid Nautilus
Cuttlefish
Octopods
--The class as a whole is adapted for swimming, suspended in the water by buoyancy mechanisms.
-- all are carnivores, occupying the same niche as fishes

12. Architeuthys Mesonycheteuthis Colossal squid Dosidicus
Giant squid up to
20 m long
Mesonycheteuthis
Colossal squid
up to 14 m major prey
item of sperm whales
Dosidicus
Humboldt squid, smaller
but numerous (2 m) and comes to surface to
feed

13. Ammonites
Largest is 3 m in
diameter

14. Sub Class Nautiloidea
5-6 species remain from
diversity in geologic past
Live in the last chamber of
a multi-chambered shell
Move by forcing water through a siphon.

15. Sub Class Nautiloidea
How does a Nautilus adjust and maintain
its buoyancy in water?

16. Cuttles, Squids and Octopuses
tendency is reduction of shell.
compensated for by selective ionic control; accumulate ammonium
other adaptations to shell loss and life style

17. cuttle
chameleons of the sea
most specialized, agile and cryptic
octopus

18. Specifically, compensation takes the following forms:
Stealth and other defenses
Acute sensory structures
Speed
Cunning

19. A. Stealth and other defenses
Ink Sack : ink with melanin and mucus
also dopamine, L-DOPA, tyrosinase
L-Dopa is a precursor to catecholamines including dopamine which are involved in neurotransmitter function
Tyrosinase is an oxidizing enzyme
Pseudomorphs

20. A. Stealth and other defenses
Chromatophores: each cell contains a different pigment
which may be red, orange, brown, black, yellow or blue

21. Cephalopod Chromatophore
The pigments in chromatophores can be black, brown, red, orange or yellow.
They are not responsible for producing the blue and green colors seen in some species. Those are produced by iridiophores which are reflective cells.
Cephalopods have several organs that allow them to hear high frequency sounds
Black, brown, orange or yellow colors
Also iridiophore reflective cells
Most cephalopods are completely colorblind
neurophilosophy.files.wordpress.com

22. B. Acute sensory structures
-- Vision
-- Lateral line analogs

23. C. Speed Rival fish in ability to swim, attaining
burst speeds of 5-10 m second sustained
for short distances at speeds of up to 40 km hr.
Burst speed is achieved by jet propulsion
More gradual swimming is fin undulation

24. complex nerve control of locomotion
C. Speed :
complex nerve control of locomotion
Assures synchronized contraction of mantle muscles

25. C. Speed : circulatory system
Hearts
Requires a
closed,
elaborate
circulatory
system

26. D. Cunning -- Relative to body size, the brain is larger than that of
most fish

27. Experiments with Octopus vulgaris show their ability to learn.
They learn to choose colors not associated with shock.
Observers choose properly colored objects after watching demonstrators