Taxonomy of Finfish (1+2)

Procedure

 

Based on the exercise 5. separate the group of Perciformes.

Stromateoidei character:

* Shapes variable;

* snout blunt and thick;

* toothed saccular outgrowths (pharyngeal sacs) present in the gullet immediately behind the last gill arch;

* teeth small, usually in single serial

Scombroidei character

* Finlets frequently present at posterior ends of dorsal

* and anal fins; 1 to 3 keels on either side of caudal peduncle (except in most species of Gempylidae)

* Scombridae: also with moderately large mouth and 2 dorsal fins, but easily distinguished by presence of distinct finlets behind second dorsal fin and anal fin.

Gobioidei

* Usually small fishes with pelvic fins either very close together, or united into a single cup-like structure.

Based on the given character identify the following families using standard identification book or manual. Identify some of the species belong to these families.

Scombridae:

* Snout pointed. Adipose eyelid sometimes present (Scomber)

* mouth moderately large; teeth in jaws strong

* Two dorsal fins, the first usually short and separated from second dorsal fin;

* finlets present behind dorsal and anal fins ; caudal fin deeply forked ,

* At least 2 small keels on each side of caudal peduncle, a larger keel in between in many species .

Stromateidae:

* Caudal peduncle short, deep, very compressed; without keels or scutes near caudal-fin base

* deep bodied, compressed stromateoid fishes

* that lack pelvic fins as adults; a single dorsal fin that is falcate

* Branchiostegal rays 5 or 6 to triangular rising to greatest height on anterior half.

* I to X flat, blade-like spines preceding dorsal fin .

* Lateral line on upper side ,

* Small mouth maxillae immobile

Gobidae:

* Highly diverse small sized fishes.

* Smallest fish Pandaka belongs to this family.

* Head short and broad usually scaly;

* Head with a series of sensory canals and pores, and cutaneous papillae .

* Snout blunt

* Gill membranes broadly joined to isthmus.

* Two separate dorsal fins , the first with V to X flexible spines, the second with I flexible spine and 5 to 37 soft rays;

* innermost pelvic-fin rays usually joined by membrane, forming a disk

*  Lateral line absent on body.

* Caudal fin broad and rounded, with 16 or 17 segmented rays.

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