Taxonomy of Finfish (1+2)

Procedure

Based on the exercise ----- separate the group of or using the following character separate the order.

Elopiformes :

* Body slender and compressed.

* Pelvic fin abdominal

* Caudal fin deeply forked with seven hypurals.

* Branchiostegal rays 23- 35.

* Upper jaw extending beyond eye.

Gonorynchiformes

* Parital small

* Suprabranchial organ present.

* Mouth small and jaw toothless

Gadiformes

* Pelvic fin inserted below or in from of the pectoral fin.

* No true spines in the fins.

* Dorsal and anal fins long.

* Branchiostegal rays 6-8

* Swim bladder without pneumatic duct.

* Trunk short, moderately compressed

Mugiliformes

* Don’t have any articulation between the pelvic girdle and the cleithra.

* Two well separated dorsal fin.

* Lateral line absent.

* Ctenoid scale present.

* Mouth moderate in size.

Familiarize the following families using the characters coming under the listed orders.

Megalopidae

* Body moderately deep, compressed

* Eye large. Mouth large,

* lower jaw projects beyond snout;

* a bony gular plate present between arms of lower jaw;

* last dorsal-fin ray filamentous;

* scales large, 30 to 40 in lateral line.

* Branchiostegal rays numerous, 26 or 27.

* Insertion of the pelvic fin is beneath or posterior to origin of dorsal fin.

Elopidae

* Body elongate and fusiform

* Mouth much larger, maxilla reaching back behind eye; mouth terminal or superior,

* Jaws approximately equal;

* A bony gular plate between arms of lower jaw.

* Branchiostegal rays numerous, approximately 20 to 25.

* Scales very small, approximately 100 in lateral line

Chanidae

* Body elongate, smooth, and streamlined.

* Eye covered by adipose tissue.

* Mouth small, terminal, without teeth.

* Lower jaw with small tubercle at tip, fitting into a notch in upper jaw.

* No bony gular plate between arms of lower jaw. Branchiostegal rays only 4. 5

* Gill rakers fine and numerous.

* Pharyngeal sacs present.

* Fins without spines; dorsal fin with 13 to 17 rays, about midpoint of body; anal fin short, with 9 to 11 rays, close to caudal fin;

* caudal fin deeply forked, with scale flaps at base in adults;

* pectoral and pelvic fins with axillary scales.

* No scutes along belly.

* Scales small and smooth, 75 to 91 on lateral line.

Bregmacerotidae

* Body elongate, head relatively short.

* Two dorsal fins, the first a single long ray on top of rear part of head , the second with a long base, middle rays much shorter;

* A single long-based anal fin with middle rays much shorter;

* Pelvic fins inserted under rear part of head, with long, thick rays that extend far beyond beginning of anal fin .

Mugilidae:

* Head often broad and flattened dorsally (except Aldrichetta and Cestraeus ).

* Eyes often partly covered by adipose “eye fold” tissue.

* Mouth small or moderate in size, terminal or inferior ;

* Teeth relatively small, hidden or absent.

* Two short dorsal fins, well separated; first with iv slender spines ;

* Caudal fin emarginate or forked;

* Pectoral fins inserted high on body ;

* Dorsal ray of pectoral fins developed as a short spur or ‘spine’ (not a true spine);

* Pelvic fins, inserted about equidistant between origins of pectoral fins and first dorsal fin .

* Lateral line absent .

* Large, modified scales may be present above pectoral and pelvic fins (axillary scales) and below first dorsal fin .

* Specialized “pharyngobranchial organ” comprising large, denticulate “pharyngeal pad” and pharyngeal “sulcus” on each side of pharyngobranchial chamber

Based on the figures given identify some of the similar species available in your region.