Ferran Pueyo 9B

 Taxonomic group of fish with bony skeletons instead of cartiligious Chordata i)Pisces 1) Chondricthyes/agnatha 2) Osteicthyes  Over 29,000 species ( most of fishes)  Divided into two large groups which are the ray-finned fish (majority) and the lobe-finned fish  Oldest known fossil 420 million years  Unique tooth pattern between the rows of teeth, found in fossils  Name comes from the latin word osteo which means bone Introduction Introduction to Osteicthyes

 Osteicthyes means osseus or bony fish, Chondricthyes means cartilagenous  Difference in scales and covering of body  Chondricthyes has no air bladder or lungs  Difference in gill number

Skeleton  Cranial bones  Rooted teeth  Eyeball held by four small bones (some fish have lost or changed this characteristic)  Braincase divided into anterior and posterior sections  Do not have fin spines instead have bone fin rays (lepidotrichia)  Specific characteristic that allows them to breath without swimming (operculum)  Fin limbs, related to tretapods

 Endochondral bone  Known as replacement bone  Bone ossified internally  Cartilage inside the bone is calcified and replaced with osteoplasts  Final result, bone now surrounds other bone  Very special because bone starts as cartilage but then calcifies  Liightweight, flexible interior, surrounded by denser bone

 Breathe through gills located on either side of the pharynx  Threadlike structures called filaments  Capillary network which creates space for exchanging oxygen and carbon dioxide  Exhale through a single opening, the gill slits, protected by a gill cover ( to keep out water from entering the lungs)

 Two muscular chambers that pump the blood, atrium and ventricle.  Atrium pumps blood into the ventricle  Bulbus arteriosus  Blood is pumped into capillary network, where the exchange of gas takes place (from aorta)  Gathers in a thin-walled sac, sinus venosus  Returns to the atrium

 Highly developed sense organs, vital for fish  Color vision, at least better than humans  Chemoreceptors that are responsible for superior senses of taste and smell  Catfish, have organs that detect weak electric currents (example)  Fish eyes are similar to those of terrestrial vertebrates like mammals, but have a more spherical lens  Fish have pain and fear responses  Nervous system poorly developed

 Esophagus is short and flexible, large amounts can be swallowed (layered with muscle)  Stomach muscular tube in a ‘u’ or ‘v’ shape. Gastric glands, break down food  The pyloric caeca is an adaptation for increasing the gut area; they digest food.  Pancreas  Food absorption takes place in the intestine.  Plant-eating bony fishes generally have long intestines. Carnivorous bony fishes have shorter intestines

 Birth ; hatched from eggs (incubation)  Reproduction ; 1. SEXUAL MATURITY 2.REPRODUCTIVE BEHAVIOR 3. PARENTAL CARE  Death; Life expectancy varies greatly, usually cold-water live longer than warm.  Oldest known osteicthyes is the orange roughy that can live up to 100 years

 Impossible to generalize  May be carnovour, omnivour or herbivore  Common diet: annelid worms marine snails mussels clams squids insects birds amphibians, small mammals and other fishes.

 Sturgeons  Gars  Eels  Carp  Herrings  Anchovies  Catfish  Goldfishes  Piranhas  Seahorses  Bass  Cichlids  Pickerel  Salmon  Trout  Oarfish