السيكشن الثالث درسنا فيه ستة أسماك وهي:-
1- Clarias gariepinus2- Malapterurus electricus3- Synodontis schall4- Lates niloticus5- Oreochromis niloticus6- Mugil cephalusفبسم الله نبدأ:-
أولا:
Clarias gariepinusوتصنيفها كالآتي:Class: OsteichthyesFamily: Clariidaee.g: Clarias gariepinusThis kind of fishes is characterized with:-
1- Granulated head shield
2- one part dorsal fin
3- Presence of 4 pairs of barbels
وهذه صورة لقرموط عملاق
ثانيا:
Malapterurus electricusوتصنيفها كالآتي:Class: OsteichthyesFamily: Malapteruridaee.g: Malapterurus electricusThis kind of fishes is characterized with:-
1- short shifted adipose posteriorly
2- Presence of dark patched
وقد تستبدل هذه البقع الداكنة اللون بخط او اكثر في مؤخرة الجسم مثل هذه الصورة
ثالثا:
Synodontus schallوتصنيفها كالآتي:Class: OsteichthyesFamily: Mochokidaee.g: Synodontus schallThis kind of fishes is characterized with:-
1- Rough head shield
2- Presence of large adipose
3- Presence of Strong serrated spine in the dorsal portion
4- Presence of humeral process -spine in the pectoral portion-which is very characterized
رابعا:
Lates niloticusوتصنيفها كالآتي:Class: OsteichthyesFamily: Centropomidaee.g: Lates niloticusThis kind of fishes is characterized with:-
1- Presence of pre-opirculum
2- Presence of bridle like in the articulation of the upper & lower jaws
3- Presence of 7to8 spines in the dorsal fin
وهذه الصورة تبين اللجام الذي تكلمنا عليه
خامسا:
Oreochromis niloticus,jصنيفها كالآتي:Class: OsteichthyesFamily: Cichlidaee.g: Oreochromis niloticusThis kind of fishes is characterized with:-
1- The dorsal fin composed of 15 to 18 spine & soft fin rays
2- Presence of 3 Spines in the anal fin
3- Presence of thoracic pelvic fin
*Thoracic pelvic fin means that pelvic fin is shifted anteriorly to the thoracic portion
4- Projected lower jaw
سادسا:-
Mugil cephalusوتصنيفها كالآتي:Class: OsteichthyesFamily:Mugilidaee.g: Mugil caphalusThis kind of fishes is characterized with:-
1- Inferior mouth
2- The out line of the body is straight dorsally & curved venterally