Bony Fish

Kingdom: Animalia

Phylum: Chordata

Subphylum: Vertebrata

Class: Osteichthyes

Class Osteichthyes

“Bony Fish” Skeleton made of

bone Thin, flexible scales

Class Osteichthyes

Operculum – a gill cover that protects the gills

Swim Bladder – a gas-filled sac above the stomach allows for adjustments in buoyancy

Fins

Fins

Upper and lower lobes of Caudal Fin almost always the same size

Fin rays – rigid spines that support a thin membrane

Mouth & Jaws

Mouth of most bony fish is terminal or anterior end

Overall jaw movement is more than that of sharks with teeth that are fused to jaw

Feeding

Most bony fish are carnivores

Well developed teeth used for capture and holding

Roof of mouth, gill rakers, and pharynx may have teeth to help hold

Feeding

Grazers – fish that feed primarily on seaweeds and other plants

Some develop beaks to help scrape off algae or pieces of coral

Feeding

Filter feeders filter plankton through their gills

Tend to be smaller, schooling fish such as herrings, anchovies, and sardines

Internal Anatomy

Digestive System

Digestive System: stomach, intestine, pancreas, liver, pyloric caecae

Pyloric caecae – slender tubes that secrete digestive enzymes

Plant eaters = long intestine, Meat eaters = short intestines

Circulatory System

Two chambered heart Gas exchange occurs in the gills

Gill Irrigation Gills share a common

gill chamber Mouth opens,

operculum closes, and pharynx expands to allow in water and the opposite is true

Fast swimmers just open their mouths

Nervous System

Brain & spinal cord Olfactory sacs or bulbs located on either side of

the head and connected to nostrils (smell) Taste buds located in mouths or barbels

Vision

Better eyes than chondrichthyes

Fish eyes focus by moving closer or farther away from subject

Many have color vision

Hearing

Presence of inner ears Chambers similar to the

lateral line Located on either side of

the head just behind the brain

Can resonate/amplify sound through swim bladder

Lateral Line Detects vibrations in

water Small canals filled

with sensory cells

Behaviors

Territories – home areas that fish defend against intruders

Most common in crowded environments

Some defend as groups

Behaviors Schools – well defined

groups of fishes Well coordinated with no

leaders Used a protection by

confusion Increase swimming

efficiency Advantageous in feeding No single reason and

vary species to species

Behavior Migration – regular

mass movements from one place to another

Anadromous fish – live mostly at sea and migrate to freshwater to breed (salmon)

Catadromous fish – breed a sea and live in rivers (eels)

Subclass Dipnoi

“Lungfish” Jaw fused to brain

case Caudal, dorsal, and

anal fin connected Pectoral fins long and

tubular Air breathing organ

attached to esophogus

Subclass Crossopterygii

“Coelacanths” Cosmoid scale Two dorsal fins and

fleshy paired fins with skeletal elements

Thought to be extinct till found

Sometimes grouped with lungfish in Subclass Sarcopterygii

Subclass Actinopterygii

Ray-finned fishes Most familiar fish Have fin rays, swim

bladders, and a symmetrically lobed caudal fin

Cartilaginous Fish

Lungfish

Ray-Finned Fish

Lobed-Finned Fish

Jawed Vertebrates

Birds, lizards, turtles, dinosaurs, mammals

Subclass Actinopterygii

Superorder Teleostei

Bass

Goldfish

Guppies

Seahorses

Sturgeons

Tuna

Etc.

Superorder Holostean

Garpikes

Bowfins

Superorder Chondrostei

Freshwater Sturgeon

Bichirs

Paddlefish

Reedfish

Superorder Holostean

Fin arrangements make for more efficient swimmers

Superorder Chondrostei

Lack bone Sometimes classified

with sharks Though more in

common with the telosts

Superorder Telostei

Most prolific class 96% of all fish 12 suborders Symmetrical caudal

fin Spines on fins

Osteoglossmorpha

Order Osteoglossiformes

Order Hiodontiformes

Elopomorpha

Order Elopiformes Order Albuliformes Order Notacanthiformes Order Anguilliformes Order

Saccopharyngiformes

Clupeomorpha

Order Clupeiformes

Ostariophysi

OrderGonorynchiformes Order Cypriniformes Order Characiformes Order Gymnotiformes Order Silurioformes

Protacanthopterygii

Order Salmoniformes Order Escociformes Order Osmeriformes

Stenopterygii

Order Ateleopodiformes

Order Stomiiformes

Cyclosquamata

Order Aulopiformes

Scopelomorpha

Order Myctophiformes

Lampridiomorpha

Order Lampriformes

Polymyxiomorpha

Order Polymixiiformes

Paracanthopterygii

Order Percopsiformes Order Batrachoidiformes Order Lophiiformes Order Gadiformes Order Ophidiiformes

Acanthopterygii

Order Mugiliformes Order Atheriniformes Order Beloniformes Order Cetomimiformes Order Cyprinodontiformes Order Stephanoberyciformes Order Bericiformes Order Zeiformes

Acanthopterygii

Order Gobiescociformes Order Gasterosteiformes Order Syngnathiformes Order Synbranchiformes Order Tetraodontiformes Order Pleuronectiformes Order Scorpaeniformes Order Perciformes

- 46% of fish