FISH FACTSFISH FACTS

PHYLUM CHORDATAPHYLUM CHORDATA

Dorsal Notochord-Dorsal Notochord-long rod that supports the long rod that supports the body-becomes the vertebrae in most.body-becomes the vertebrae in most.

Dorsal Nerve cord-Dorsal Nerve cord-becomes the central becomes the central nervous system.nervous system.

Pharyngeal gill slits-Pharyngeal gill slits-openings in the throat for openings in the throat for feeding & breathing-becomes the Pharynx in feeding & breathing-becomes the Pharynx in humans.humans.

TailTail-forms in embryos and extends past the -forms in embryos and extends past the anus.anus.

Traits Shared by ALL Chordates

CLASSES OF CHORDATESCLASSES OF CHORDATES

PHYLUM CHORDATA

PISCES AMPHIBIA REPTILIA AVES MAMMALIA

The group we care about most in Marine Biology

CLASS PISCESCLASS PISCES

BECAUSE THEREARE 20,000 SPECIES

THERE ARE 3SUBCLASSES

SUBCLASS AGNATHA

(JAWLESS FISH)

CHONDRICHTHYES(CARTILAGE)

OSTEICHTHYES(BONY FISH)

SUBCLASS SUBCLASS

SUBCLASS AGNATHASUBCLASS AGNATHA

Jawless fish, that are Jawless fish, that are the only vertebrate the only vertebrate parasites.parasites.

HagfishHagfish live in salt live in salt waterwater

LampreysLampreys live in fresh live in fresh waterwater

Have a sucker-like Have a sucker-like oral disk, with teeth oral disk, with teeth that rasp the flesh & that rasp the flesh & suck out juices from suck out juices from tissue.tissue.

CARTILAGINOUS FISHCARTILAGINOUS FISH 850 Species of 850 Species of

Sharks, Rays, & Sharks, Rays, & SkatesSkates

Skeleton is made of Skeleton is made of cartilage. cartilage.

External Gill slits.External Gill slits. Store oils & constant Store oils & constant

motion to stay afloat.motion to stay afloat. Scales are small bony Scales are small bony

plates (at one time plates (at one time used as sandpaper).used as sandpaper).

RAYS & SKATESRAYS & SKATES

Flattened body for a Flattened body for a bottom-dwelling nichebottom-dwelling niche

Spiracles & eyes on Spiracles & eyes on the dorsal side.the dorsal side.

Mouth, nostrils & gill Mouth, nostrils & gill slits on ventral side.slits on ventral side.

Stingrays have a Stingrays have a hollow barb.hollow barb.

Manta ray grows to Manta ray grows to 18’.18’.

SHARKSSHARKS Close to 300 species.Close to 300 species. Largest fish in the Largest fish in the

world-Whale Shark.world-Whale Shark. Can smell bloodCan smell blood Lateral line detect Lateral line detect

vibrations in the vibrations in the waterwater

Ampullae of Ampullae of LorenziniLorenzini

Sense changes in Sense changes in electrical field.electrical field.We aren’t here to hunt humans, we are

misunderstood!!!

Shark Food FactsShark Food Facts

Many rows of teethMany rows of teeth Usually tear off pieces of food and Usually tear off pieces of food and

swallow it wholeswallow it whole Strange things sharks have had in Strange things sharks have had in

their digestive system:their digestive system: Legs of lamb, horseflesh, part of a ham, front half of a Legs of lamb, horseflesh, part of a ham, front half of a

bulldog, rear half of a pig, coal, 34 leather jackets, bulldog, rear half of a pig, coal, 34 leather jackets, parts of a reindeer, telephone books, pots and pans, parts of a reindeer, telephone books, pots and pans, bottle of madeira wine, a keg of nails, kerosene bottle of madeira wine, a keg of nails, kerosene lanternlantern

CLASS OSTEICHTHYESCLASS OSTEICHTHYES(BONY FISH)(BONY FISH)

96% of all fish belong to this 96% of all fish belong to this group.group.

Bony skeletons, gill operculums.Bony skeletons, gill operculums. Rigid bodies, flexible fins.Rigid bodies, flexible fins. Swim bladders for buoyancy.Swim bladders for buoyancy. Chromatophores for color.Chromatophores for color.

SKIN & SCALESSKIN & SCALES

The skin of bony The skin of bony fish has fish has chromatophoreschromatophores

Light, flexible Light, flexible scales scales for for protection.protection.

Produce Produce mucusmucus to to reduce friction in reduce friction in water & protect water & protect against predators.against predators.

FINS & LOCOMOTIONFINS & LOCOMOTION Due to the rigid Due to the rigid

nature of their nature of their body, bony fish body, bony fish “flex” their fins for “flex” their fins for propulsion.propulsion.

Paired fins are for Paired fins are for fine movements.fine movements.

Dorsal & Ventral are Dorsal & Ventral are used to stabilize.used to stabilize.

Caudal is for speed.Caudal is for speed.

SWIM BLADDER & GILLSSWIM BLADDER & GILLS

Swim/air bladderSwim/air bladder-gas filled sac that can -gas filled sac that can be used for buoyancy, sound & be used for buoyancy, sound & protection.protection.

Gills extract Oxygen efficiently from Gills extract Oxygen efficiently from water.water.

Blood flow in the filaments is opposite Blood flow in the filaments is opposite the flow of water resulting in the the flow of water resulting in the greatest amount of gas exchange!greatest amount of gas exchange!

LATERAL LINELATERAL LINE Lateral line is a series of Lateral line is a series of

pits on the side of a fish pits on the side of a fish that lead directly to spinal that lead directly to spinal cord.cord.

It can sense the slightest It can sense the slightest movements in the water. movements in the water. (vibrations)(vibrations)

SchoolingSchooling: fish use this : fish use this sense to school..(about sense to school..(about 80% of all species school 80% of all species school at some point in their life)at some point in their life)

Schooling helps with Schooling helps with mating +Protection.mating +Protection.

REPRODUCTIONREPRODUCTION OviparousOviparous-both -both

sexes spawn & eggs sexes spawn & eggs are fertilized are fertilized externally.externally.

Ovoviviparous-Ovoviviparous-some some incubate the eggs, incubate the eggs, internal fert., no internal fert., no nourishment, some nourishment, some species actually bear species actually bear their young living!their young living!

ViviparousViviparous-internal, -internal, nourishment, all nourishment, all species bear their species bear their young living.young living.

MigrationsMigrations

CatadromousCatadromous- - Breed in the Breed in the oceans but live in oceans but live in freshwaterfreshwater

Eels migrate to the Eels migrate to the Sargasso Sea, they Sargasso Sea, they spawn at depths of spawn at depths of 300 meters and 300 meters and die when donedie when done

AnadromousAnadromous- - Breed in Breed in freshwater but freshwater but live in saltlive in salt

Atlantic Salmon Atlantic Salmon makes multiple makes multiple trips in its lifetimetrips in its lifetime

Pacific Salmon Pacific Salmon only onceonly once