The document provides information on the anatomy and physiology of giant clams and fish. It begins with an introduction to clams, noting that they first appeared 510 million years ago and can range in size from microscopic to giant clams weighing 200kg. It then discusses the key characteristics of clams, including their two calcareous shells, ability to filter feed, and use of siphons. For fish, it outlines their three main classes - Agnatha, Chondrichthyes, and Osteichthyes - and provides details on the external anatomy, senses, fins, skin, scales, coloration, muscles, body shapes, and adaptations of different fish types.

1. ANATOMY
&
PHYSIOLOGY
GIANT CLAM
&
FISH

2. INTRODUCTION:
• CLAM is an informal term refers to any molluscan within class Bivalvia
• 1st appeared in cambrian age rocks 510 million years ago.
• They presently live in both freshwater and marine habitats, and range
in adult size from nearly microscopic to the giant clam, which can
weigh 200kg (440 lb). Some have life cycles of only one year, while at
least one has been discovered that may be over 500 years old.
• All clams have two calcareous shells or valves joined near a hinge
structure with a flexible ligament, and all are filter feeders.

3. Bivalvia
Sub class: Paleo
heterodonta
cryptodonata heterodonata Nuculoidea
Sub class:
pteriomorphia

5. What is the difference between mussels,
oyster, scallops and clams?
• A clam is any of various bivalve mollusks, especially certain edible species.
• An oyster is any of several edible, marine, bivalves mollusks of the family
Ostreidae, having an irregularly shaped shell, occurring on the bottom of or
adhering to rocks or other objects in shallow water.
• Mussels are any bivalves mollusk, especially an edible marine bivalve of the
family Mytilidae and freshwater Mussels of the family Unionidae.
• And scallops are any of the bibalves mollusks of the genus Argopecten
(Pecten) and related genera that swim by rapidly clapping the fluted shell
valves together.
• Clams and scallops can move about in their environment, while mussels
and oyster are rooted into wherever they attach their shells.

6. General Charecteristics
• Clams have symmetrical shells (bivalve)
• They can filters their food.
• Clams can control their outer shells and shut them in response to
stimuli, via a elastic ligament and two large muscles.
• Clams have siphons that forces water out and allows them to take in
micro organisms.

8. Distribution and habitat
• Marine clams are abundant in the low and mid intertidal zone in
temperate seas globally. Other species of marine mussel live in
tropical intertidal areas, but nit in the same huge numbers as in
temperate zones.
• Certain species of marine clams prefer salt marshes or quiet bays,
while others thrive in pounding surf, completely covering wave
washed rocks.

9. Feeding habit
• CLAMS are filter feeders; they feed
on plankton and other microscopic
sea creatures which are free
floating in sea water. A mussels
draw water in through its incurrent
siphon. The water is then brought
into the branchial champers by the
actions of the cilia located on the
gills for ciliary – mucus feeding. The
wastewater exits through the
excurrent siphon. The labial palps
finally funnel the food into the
mouth where digestion begins.

10. LIFE CYCLE

13. Craft and gear • Dredges are large, metal – framed
baskets that are dredged across the
seafloor to collect shellfish like
oysters, clams and scallops. In
order to lift the catch into the
basket, metal teeth dig into the
seafloor, which can significantly
impact seafloor habitat and
bottom – dwelling seafloor habitat
and bottom – dwelling species.
• Dredgging also results in high levels
of bycatch. By restricting dredging
areas, bycatch and damage to
seafloor life can be reduced.

15. Conclusion:
• There are over 150 edible species.
• There are over 15,000 species of clams.
• Small freshwater clams fertilize eggs in a pouch and bear their young
until its shells develops.
• The giant clam can weigh more than 400lb and live for over 150 years
• It takes 3 – 4 years for a clam to mature to market size.
• Some clams can produce pearls. One in 5,000 clams forms a pearl.
• A clam can live until about 35 years if not eaten.

17. Classification
•Kingdom- Animalia
•Phylum- Chordata
•Sub Phylum- Vertebrata
•Classes- Agnatha, Chondrichthyes,
Osteichthyes

18. Introduction:
• Fish are largest, most
common and most
diverse vertebrate group
in the world.
•Transition of fish out of
the water and the
invasion of land by
amphibians = Evolution

19. Agnatha – Jawless Vertebrate
(fish)
Jawless fish: Lampreys, Hagfish
Most species are prehistoric or extinct
60 Modern species divided into two classes;
Class Myxini – the hagfish
Class Cephaloaspidomorphi – the lampreys

20. Types of Agnathans
•Hagfish- Ocean scavengers,
not much is known about
them.
•Lamprey- fresh and salt
water, they are parasitic and
prey on other fish.
* Both have cartilagenous
skeletons and sucker-like
mouths.

21. Class Agnatha
Jawless fishes
Ex. Hagfish, lampreys
No paired fins
Gill holes, no slits or operculum
Large sucking mouth with teeth
Scavengers
As a defense mechanism, secrete slime then tie itself in knots to
escape predators
Also tie in knots for pulling food off carcasses, and cleaning slime from
body

23. Gnathostomata – Jawed
Vertebrates
Comprises roughly of 60, 000 sp
99% of all living vertebrates
*Class – Chondrichythyes - Cartilagenous Fish:
Shark, Ray.
Class – Osteichthyes – bony fish, which has two
subclasses;
Sarcopterygii – lobe finned fish
Actinopterygii – ray finned fish

24. Chondrichthyes
• Sharks are adapted for a predatory
lifestyle.
• Cartilage skeletons, stiff pectoral fins
(speed).
• No operculum, must keep moving to
breathe.
• Have live births.
• Special scales feel like sandpaper.
• Manta, and Sting Rays- live in shallow
water, have mouths located on the
underside, are fairly docile, wide flat

25. Types of Chondrichthyes
• Sharks and Rays- have no
operculum and must keep
moving to breathe.
• Have different kinds of
scales that feel and look
more like sandpaper.
• Have skeletons made of
cartilage not bones.

28. Osteichthyes
Bony Fish: Salmon,
Carp, Tuna
Over 20,000 different
species

29. Types of Osteichthyes
Ray Finned:
• Most fish are this type
• Fins are supported by bony
structures called Rays.
• Teleosts are the most advanced form
of ray finned fish (symmetrical tails
and mobile fins).
Lobe Finned:
• Fins are long, fleshy, muscular,
supported by central core of bones.
• Thought to be ancestors of
amphibians.
• Examples are: Coelacanth, Lungfish

34. EXTRENAL ANATOMY
• Nares: Used for smelling only not breathing

35. EXTRENAL ANATOMY
• MOUTH – consumes food

36. Fish-mouth types (some)
• Large mouth with teeth (e.g. barracuda)
• Long snout/small mouth (e.g. butterfly fish)
• Protrusible mouth (e.g. slipmouth)
• Large mouth (e.g. herrings)
• Beak-like mouth (e.g. parrotfish)

37. Barbels
• Sensory organ to help track
down prey or food.

38. EXTRENAL ANATOMY
• OPPERCULUM: Bony flap that protects the gills from harm, allow
water to pass over the gills

39. FISH SENSES
• Eyesight:
• Two directions, one eye focusing on an object
• independent of the other (human’s eyes can only focus on one
object at a time)
• Hearing:
• No external ear openings, sound travels faster in water than in air.
Fish have internal ears with pairs of inner ear bones
• called otoliths. Which allows fish to sense sounds in the water.
• Otoliths can be used to determine fish age and the heal the Smell:
• Locate food and to aid in migrating

40. • Taste:
• Some fish have taste buds located on the outside of
the fish’s head and fins in small pores
• Lateral Line: Alongside a fish’s body from the
operculum to the tail,
• senses vibrations or movements in the water. Fish can
locate predators and find prey

41. Vent:
Waste and extra
water discharge,
outlet for eggs or
milt (sperm)
during spawning

42. Fins
Types of fins:
Paired fins: pectoral and pelvic
Median fins: dorsal, caudal, anal, & adipose

43. Fins
Main functions:
Swimming – increase surface area w/o increasing mass
Stabilizers – yaw, stability-dorsal and anal fins
- brake, pitch, roll, reverse -pectoral/pelvic
thrust with caudal fin
Modifications in fins:
Defense – spines, enlarge fish
Locomotion – modified for crawling, flying, gliding
Hunting – lures, sensory organs
Respiratory organ – lungfish, supply oxygen to eggs

44. Fins
Soft rays vs. Spines
Soft rays:
Usually soft and not pointed
Segmented
Usually branched
Bilateral, w/left and right halves
Spines:
Usually hard and pointed
Unsegmented
Unbranched
Solid

45. EXTRENAL ANATOMY
• Pectoral Fin:
• Changes in side-to-side direction and speed, a
brake to decrease speed
• Pelvic Fin: Stabilizes the fish while swimming and
allows for up-and-down movement

46. EXTRENAL ANATOMY
• Anal Fin:
• Stabilizes the fish while swimming
• Caudal Fin:
• Moves, propels or pushes the fish through the
water
• Dorsal Fin:
• Helps maintain balance while swimming

47. Fish Morphology
Skin
Color
Bioluminescence
Swimming Locomotion
Fins
Muscles

48. Skin
Organ of the body
Consists of connective tissue
Muscles pull against skin tissue & skeleton
Key component of the muscle-tendon-tail fin system
Layers
Epidermis
Typically 250 m thick  10-30 cell layers
Range 20 m – 3 mm
Dermis

49. Fish Skin
Function:
Hold fish together
Serves as barrier against abrasive agents
Osmoregulation (what does this mean?)
Permeable  respiratory function
Biomechanical properties in sharks

50. Fish Skin
Mucous formed in epidermis cells
Protect against infection
Constantly shed to remove bacteria and fungus
Ex. Clingfish lack scales, protect their bodies by a thick
layer of mucous
Bone is also skin derivative
scales, most important
Derivatives:

51. Fish ScalesFirst appear as dermal bone
Found in fossil of Cambrian period (570 mya)
Layered bone, solid armor-constrained movement
Evolved smaller and reduced into scales
5 types of scales (examples with images to follow)
Placoid
Cosmoid
Ganoid
Cycloid
Ctenoid

52. Fish Scales: Placoid
Found in elasmobranchs (sharks &
rays)
“teeth like”, same composition
As fish grows, do not increase in size,
instead new scales are added

53. Fish Scales: Cosmoid
In the Sarcopterygii (fish with fleshy lobe
fins), primitive fish
Less evolved than Elasmobranchs and
Actinopterygii (fish with rayed fins)
Scales found in fossil record but not in any
living fish,
Except in simplified version of
coelocanth and lungfish

54. Fish Scales: Ganoid
In primitive Actinopterygii
Found in reedfish, polypterus,
gar, bowfin, and sturgeons
Were thick heavy scales when
first appeared
Rhomboid-shaped
Developed into teleost scales

55. Fish Scales: Teleost scales
Ctenoid scales
Cycloid scales
Two types:
Ctenoid-higher fish
Cycloid-soft-rayed, anchovies, sardine
Mineralized surface layer & inner collagenous layer
Scales surrounded by dermis, in dermal pockets
Grow from top, bottom, and insides; overlap lower part
Scales grow with fish
Characterized by concentric ridges (growth increments)

56. Coloration

57. Coloration
Fish display a multitude of patterns involving
2 or more colors,
in many tints and shades,
arranged in spots, stripes, patches, and blotches
3 Types of coloration predominant in oceans
Silver – pelagic, upper zone
Red – deeper zone (~ 500 m)
Black or violet – deep sea
Countershaded near shore and colorful in coral reefs

58. Coloration
Chromatophores
Colored cells from which light is reflected off
Located in the skin (dermis), eyes
Various colors/hues-combination of different chromatophores
Functional Roles of Colors in Fishes-examples of each to follow
Social Roles
Advertisement
Mimicry
Hiding
Protection from sun (especially larvae)

59. Coloration: Social roles
Cleaner Fish:
distinctive markings
recognized by larger fish

60. Coloration:
Advertisement:
Bright, bold and showy males indicate:
Reproductive availability, either permanently or seasonally, e.g.
cichlids, wrasses, minnows, sunfish
Unpalatable or venomous, e.g. lionfishes
Mimicry – Disguise:
Disguises: look like something in habitat, e.g. leaffish, sargasso fish
Mimicry: mimic distasteful species

61. Coloration: Concealment
General color resemblance – resemble background
Variable color resemblance – change with background,
e.g. flatfish
Obliterative shading – countershading, dark above,
light below (invisible fish)
Disruptive coloration – disruptive contours that
breakup outline; bold stripes, bars, false eye spots
Coincident disruptive coloration – joining together of
unrelated parts of the body to reduce recognition; e.g.
sea dragon

62. Bioluminescence
Most luminous fish found 300-1000 m depths, few shallow
3 Types of light producing methods:
Self-luminous (on/off)
Symbiotic bacteria nurtured in special glands
Acquire from other bioluminescent organisms- diet contains light-emitting
compounds
Function:
Concealment by counter-illumination - ventral placement matches background from
above, against attack from below
Dorsal photophores safeguard against predators from above
Advertisement for courting, maintaining territory, to startle and confuse predators, and
feeding

63. LATERAL LINE -

64. Fish Muscles
Muscles provide power for swimming
Myomers=bands of muscle, run along sides of body, attached to backbone
Constitute up to 80% of the fish itself
Much hardly used except during emergencies
Don’t have to contend with same effect of gravity
Fish muscle arrangement not suitable on land
Cow: 30% muscle/wt
Tuna: 60% muscle/wt
Contraction causes oscillation of body and tail
Body bends as one side contracts b/c of an incompressible
notochord or vertebral column
Caused by bands of muscle = myomeres

65. Fish Muscles
Major fibers (see handout):
Red, pink, and white
Pink intermediate between red and white
Muscle types do not intermingle
Different motor systems used for different
swimming conditions
Red – cruising
White – short duration, burst swimming
Pink – sustained swimming, used after red
and before white

66. Fish-Body shapes
• Fusiform-spindle shaped, e.g. tuna
• Compressiform-laterally compressed,
angelfish, butterfly fish
• Anguilliform-eel-like
• Filiform-even smaller anguilliform,
e.g. snipe eel

67. Body shapes
• Depressiform-flatfish, rays,
flounder
• Taeniform-gunnel
• Sagittiform-e.g. pike
• Globiform-e.g. lumpsucker

68. Fish Adaptations
• Lateral Line System- used to detect vibrations, orient
the fish in water, it is a line of cells running down the side
of the fish.
• Operculum- gill cover, movement of operculum allows
more water to be drawn in.
• Swim Bladder- a gas filled sac that helps the fish
maintain buoyancy. Sharks don’t have a swim bladder!
• Fins- Dorsal, Caudal, Pectoral, Pelvic, Anal.

69. Adaptations
Air Bladder Operculum Lateral
Gills Line
Fins