Taxonomy Of Fishes.pptx

Taxonomy of fish

1. Taxonomy Of Fishes

2. Taxonomy Science of biological nomenclature The first part: genus The second part: species Ex: Oreochromis niloticus Oreochromis niloticus

3. Tools of taxonomy 1- Morphometric : measurements relative to length 2- Meristic : counts 3- Anatomical traits: shape, presence/absence 4-Color patterns 5-karyotypes : chromosome counts, shape , banding patterns 6- Biochemical methods 7-Physiological differences: ( e.g., temperature preferences) 8- Behavior 9- Diet

4. niloticus Oreochromis Cichlidae Cichliformes Actinopterygii Chordata Animalia sub phylum vertebrate Example

5. Fishes Osteichthyes  (bony fish) Chondrichthyes   ( cartilaginous fish) Agnatha  (jawless fish) Gnathostomata

6. Agnatha  (jawless fish) Agnathan are jawless fish and lack paired fins. They also lack the internal skeleton system. They have a circular tooth mouth ( cyclostomic ) by which they bore the body of their victim and suck their blood. Gill pouches are present. Stomach is absent in the digestive system T hey lack scales and fins These are classified in to two major types:    Lampreys and Hagfish

7. Chondrichthyes   ( cartilaginous fish) Cartilaginous fish  include sharks, rays, and ratfish E ndoskeleton composed of cartilage, these fish have a complete backbone. They also have a relatively large brain. They are generally predators Cartilaginous fish lack a swim bladder. Instead, they stay afloat by using a pair of muscular fins. cartilaginous fish have jaws . Jaws allow them to bite food and break it into smaller pieces

8. Osteichthyes  (bony fish) Skins are protected by protective scales. Some fishes of this category have actual lungs to breathe and also have sharp eyesight. These bony fishes have a special gas filled chamber called airbladder housed under the skeleton to allow them to remain buoyant. Another adaptation is operculum, a bone on the sides of the fish to protect the chambers that house the gills. Bony fish fertilizes either internally or externally. Two types of eggs are laid by the bony fish (float and sink eggs). Bony fish are again classified into ray finned and lobe finned fish.

9. Ray finned fish have thin fins consist of webs of skin over flexible bony rays, or spines. The fins lack muscle, so their movements are controlled by muscles in the body wall . Example: goldfish, tuna, salmon, perch, and cod Lobe finned fish have fins contain a stump-like appendage of bone and muscle. There are two groups of lobe-finned fish still alive today: coelacanths and lungfish . 1- Coelacanths 2- Lungfish  have a lung-like organ for breathing air. The organ is an adaptation of the swim bladder. It allows them to survive for long periods out of water.

10. 2. According to the media "water in which they live in A)Fresh water fish : 0 - 7 Ex: Tilapia- Catfish B) Brackish water fish : 7 - 14 Ex: Guppy fish - killifish C) Marine water : 14 - 42 Ex: Eels – tuna - salmon D) Metahaline fish: high salinity of water E) Euryhaline fish: resist wide range of salinity Ex: Mullet

11. 3. according to the position in water" fish site": a) Pelagic fish : which lives near water surface where more dissolved oxygen & phytoplankton Ex: Mackerel b) Demersal fish : which lives near water bottom Ex: Ray - flatfish

12. 4.according to the migratory behavior: A)Non migratory fish ex: carp b) Migratory fish : divided into : 1- Vertical migration: migrates from the surface to the bottom & vice versa for feeding. 2- Horizontal migration: • Anadromous fishes which migrate from sea to fresh water fish for spawning Ex : Atlantic salmon – Sturgeon • Catadrmous fishes which migrate from fresh water & rivers to sea water for spawning Ex: Eels

13. 5.according to the reproductive behavior : a) Non-mouth breeders "guarders" substrate brooders. Both male and female guards the eggs & protect it till hatching Ex: Tilapia zilli b) Maternal mouth breeders: after fertilization, females protect and incubate their eggs & frys in their mouth for a limited time . Ex : Nile Tilapia c ) Paternal mouth breeders: both males and females protect & incubate eggs & fry in their mouth for a limited time. Ex: xenotilapia

14. 6.acorrding to buoyancy ( presesnce of swim bladder): a) Fishes with swim bladder &divided into : 1- Physostome fishes" opened gas bladder”, Swim bladder is attached to the esophagus by pneumatic duct Ex: carp - salmon. 2- Physoclist fishes "closed gas bladder“, Swim bladder is attached to the circulation Ex : perch-tilapia 3- Fat invested and fat filled gas bladder b) Fishes without swim bladder : Ex : shark – rays.

15. 7. according to feeding behavior: a) Herbivorus : consume plants and macroalgea Ex : carp b) Dentritivorus : consume non- living organic matter Ex : mullet c) Carnivorus : consume large invertebrates & other fishes Ex : shark d) Omnivorus : consume mixed diets Ex : tilapia

16. 8. Other classifications according to : 1- presesnce or absence of lateral line 2- presence or absence of scales 3-Presesnce or absence of barbels