Chapter 4 Bones, Scales, Skin, etc.

Two main groups

Cartilaginous fishes (Chondrichthyes)

Bony fish (Osteichthyes)

Two types of bones in teleosts

cellular (composed of osteocytes)

acellular (no osteocytes)

Osteocytes

bone cells that repair damage and respond to loading

Two teleost skeletal systems

Axial Skeleton (blue area)

Appendicular Skeleton (orange area)

Axial Skeleton

Skull

Vertebral column

Ribs

Appendicular Skeleton

Fins

Girdles supporting paired fins

Parts of the Axial Skeletal System

orbit

eye orbit bone

maxilla

premaxilla

dentary

preopercle

interopercle

opercle

subopercle

dorsal ribs

ventral ribs

vertebral column

vertebral superior process

vertebral inferior process

Parts of the Appendicular Skeletal System

dorsal fin pterygiphores

dorsal fin spines

dorsal fin rays

caudal plate

caudal fin

anal fin pterygiophores

anal fin rays

pectoral fin rays

scapula

pelvic fin

pelvic fin rays

Parts of a Cartilaginous skeleton

palatoquadrate

chondrocranium

basals

radials

ceratotrichia

vetebral column

2nd dorsal fin

caudal fin ceratotrichia

meckel’s cartilage

branchial arches

pectoral fin pterygiophores

ceratotrichia

pelvic fin

anal fin basal

Chondrichthyes fish fin properties

heterocercal tail

ceratotrichia

no hypurals

Teleost fish fin properties

homocercal tail

lepidotrichia

hypurals form the “caudal plate” (support lepidotrichia)

Chondrichthyiian types of feeding

Suction feeding (squalliformes)

bite feeding (lamnidae)

crushing, benthic invertebrates (chimeras)

benthic, suction feeding

mostly invertebrates

Types of scales

placoid (Chondrichthyes)

ganoine (non-teleost bony fishes)

cycloid (teleost fishes)

ctenoid (teleost fishes)

cosmoid (lungfish)

scutes (sturgeon)

lepidotrichia

bony rays that support the fins of boney fish

Allow for fine motor control during locomotion