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
 They 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
 Endoskeleton 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