The Bony FishThe Bony Fish

Class Osteichtyes

Characteristics of the bony fishCharacteristics of the bony fish

Skeleton of bone“Ray-finned”

– Slender bony spines supporting fins– Present in most bony fish

“Lobe-finned”– Fleshy fins supported by bones– Only 7 known species (lungfish, coelacanth)

Can be fresh water, salt water, or bothMost have scales

COLORATIONCOLORATION

Chromatophore – pigment controlling organelle in fish– Gives fish their coloration

Mimicry Camouflage Disruptive coloration

Coloration PatternsColoration Patterns

RESPIRATIONRESPIRATION

Exchange gas using gills located on either side of the pharynx

Gills – feathery, threadlike structures called filaments. Each filament contains capillaries that proved a large surface area for gas exchange.

Oxygen-rich water is moved through the mouth and over the gills

Operculum – bony protective plate covering gills

CIRCULATIONCIRCULATION

Closed circulatory systemSingle loop system

– heart gills body heart2-lobed heart

– Atrium Receives deoxygenated blood from the body and

pumps it to the ventricle

– Ventricle Pumps deoxygenated blood to the gills and

throughout the body.

FISH HEARTFISH HEART

EXCRETIONEXCRETION

Waste is emitted in the form of ammonia– Gills– Kidneys

Filter waste from the blood Control the amount of water in the fish Freshwater fish have dilute urine Marine fish concentrate urine to reduce water loss

(through osmosis)

RESPONSERESPONSE

Well developed nervous system– Organized around the brain

Cerebrum – voluntary activities Olfactory Lobe – interprets odor Cerebellum – coordinates body movement Medulla Oblongata – controls internal organs

Well developed eyes Lateral line

– Fluid-filled line on side of body that senses pressure changes in the surroundings

MOVEMENTMOVEMENT

S-shaped movement caused by alternating muscle contractions along the spine

Paired fins for movement– Pectoral fins– Pelvic fins– Dorsal fins– Caudal fins

FISH FINSFISH FINS

REPRODUCTIONREPRODUCTION

Eggs may be fertilized externally (oviparous) or internally (ovoviviparous)

Oviparous – eggs fertilized externally, developing embryo obtains nutrients from a yolk

Ovoviviparous – eggs fertilized internally, developing embryo obtains nutrients from a yolk. Young are “born alive”

Viviparous - internal fertilization and the young obtain nutrients from the mother. Young are “born alive”.