Osteichthyes Flashcards
Characteristic of bony fish
Bone in their skeleton Swimbladder or lung Tre scales Homocercal tail Mouth terminal
Osteichthyes are divided in two subclasses
Lobe finned fish
Ray finned fish
Characteristics of sarcopterygians
Have lungs for gas exchange
Enae on teeth
Lobe finned
Actinopterygains
Ray finned fish(fins lack muscular lobe)
Fins function —-
Movements,camouflage,streamlining
Outer covering of bony fish
- Mucus:reduces friction and prevents infection.
- scales :can tell age of fish ,like roof shingles
Type of outer cover
Ganoid Placoid Ctenoid Cycloid Myomer
Characteristics of labeo (Rohu)
Scales are cycloid and head devoid of scale.
Lips are lobate.
Jaws devoid of teeth ,3rows
What does the digestive system do ?
changes food into materials that nourish the body cells
eliminates materials that are not used
Organs of the Digestive System
jawed mouth with a tongue and teeth
fish cannot move its tongue
fish have their teeth rooted in the jaws
Pharynx
a short tube behind the mouth Esophagus
a tubelike organ - expands easily, which allows the fish to swallow
its food whole
Stomach
Liver - Bile-producing digestive gland • Gall Bladder - Small sac containing the bl • Pyloric cecum - cul-de-sac related to the intestine - where a part of digestion mainly occurs, as well as fermentation • Intestines Anus
Pyloric caeca
Present in bony fish
Work as accessory food reservoirs.
enhance the absorptive area.
How does digestion work in fish?
Fish use their teeth to seize prey or to tear off pieces of their victim’s flesh. Most fish also have teeth in the pharynx, which they use to crush or grind food.
Grazer
Fish that feed primarily on seaweeda and other plant
Mode of nutrition in bony fish
Suspension feeders مغذيات التعلق
Scavengers
Detritivores
Parasitesالطفيليات
Difference between scavengers & detritivores
scavengers: make place clean eat tiny animal
detritivores: make place clean but can’t eat tiny animal
