Download The Bony Fish

The Bony Fish
Class Osteichtyes
Characteristics 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 both
 Most have scales
COLORATION

Chromatophore – pigment controlling
organelle in fish
– Gives fish their coloration
 Mimicry
 Camouflage
 Disruptive coloration
Coloration Patterns
RESPIRATION

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
CIRCULATION

Closed circulatory system
 Single loop system
– heart  gills body heart

2-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 HEART
EXCRETION

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)
RESPONSE

Well developed nervous system
– Organized around the brain
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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
MOVEMENT

S-shaped movement caused by alternating
muscle contractions along the spine
 Paired fins for movement
– Pectoral fins
– Pelvic fins
– Dorsal fins
– Caudal fins
FISH FINS
REPRODUCTION

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”.