Taxonomy of Finfish (1+2)

Procedure

Based on the exercise ----- separate the group of Clupeiformes using the character

Spines absent in the fin. a single dorsal fin located above middle of body;

pelvic fins in abdominal position;

lateral line absent; color silvery.

Try to identify the key character used to identify the following fishes.

Chirocentrus dorab

Chirocentrus nudus.

Coilia dusslimieri Valenciennes, 1848

Stolephorus indicus (van Hasselt, 1823)

Stolephorus waitei Jordan & Seale

Thryssa malabarica (Bloch, 1795)

Thryssa mystax (Schneider, 1801)

Chirocentridae:

Very elongate, highly compressed fishes but without scutes along belly.

Large canine teeth in both jaws. pelvic fins about equidistant between pectoral base and anal origin

no scutes along abdomen

Based on the key available identify various genera reported in your area.

Dorsal fin located in the posterior part.

Identify the following fishes using the key characters.

Note the following key character used to identify these group of fishes.

Pectoral fin length in comparison with head length.

Coloration of dorsal and anal fin.

Use the following key to separate the group of Engraulidae:

Small silvery fishes.

Body mostly fusiform

Scutes usually present along the belly

Snout usually pig-like and projecting, lower jaw characteristically "underslung"; hind tip of upper jaw (maxilla) extending far backward

Body tapering to a point in the grenadier anchovies Coilia

Caudal fin normally forked, but small and rounded in the grenadier anchovies (Coilia)

Based on the key available identify various genera reported in your area.

Note the following key character used to identify these group of fishes.

o Observe the snout position and tapering.

o Belly scutes, position and number

o Position of pelvic fin

o Maxillary tip length and shape

o Pectoral fin filament

o isthmus

Engraulis

No scutes before or behind pelvic fin base (except a single pelvic scute); maxilla tip blunt; anal fin origin well behind last dorsal fin ray

Stolephorus:

Scutes needle-like, present only before pelvic fin base; anal fin short, less than 25 fin rays; small,

slender fishes (usually 4 to 8 cm) with a silvery band on flanks. dorsal-fin origin usually just

posterior to body midpoint;; Isthmus muscle reaching to and beyond gill membrane

Thryssa:

Maxilla extended. Scutes present before and behind pelvic fin base, forming a keel; anal fin longer, with more than 25 fin rays; larger, more compressed fishes (usually 10 to 14 cm), with a dark humeral area behind gill opening. Upper pectoral-fin ray not extended as a filament .

Coilia :

Body tapering to a point, caudal fin small, not forked; 6 or 7 upper pectoral rays filamentous; anal fin very long and joined to caudal fin

Pristigastridae:

Mouth terminal, lower jaw projecting, strongly oblique. scutes present along the belly, anal fin long.

Eyelids with broad vertical opening in middle.

Based on swim bladder character the species are separated.

Ilisha characters

Hypo maxilla present. Anal fin rays 30-92 scales in lateral series about 35-55 vertebrate about 40-55.

kempeni characters

The swim bladder tube is branched. 20-24 gill rakers on lower limb of 1^st arch. 27-29 pre pelvic scutes present. The striae not continuous in the scales.