(Plate II, Fig. 2; Tables 1–3)

Equula leuciscus Günther, 1860. Cat. Brit. Mus., 2: 503.

Material examined. 10 specimens (5 females, 4 males, I in determinant) of 77–134 mm (Cochin, Neendakara).

Description. D.VIII, 16; P. ii, 13–14, iii; V. I, 5; A. III, 14; C. 15; Ll. 61–64.

As percent of standard length: Total length 128.77–135.09 (131.37); fork length 113.04– 116.28 (114.40); predorsal 36.23–38.46 (37.37); preanal 49.12–55.77 (50.92); dorsal base 54.10–58.14 (55.88); anal base 38.46–44.26 (42.24); head 26.25–28.85 (27.87); dorsal height 21.05–27.54 (24.72); anal height 15.79–20.51 (17.52); pectoral 15.94–17.91 (16.71); depth 36.07–41.86 (39.06).

As percent of head length: Snout 28.57–33.33 (30.41); eye 29.17–37.50 (32.58); head height 76.19–85.71 (79.78).

Body compressed and elongate. Dorsal profile somewhat more convex than the ventral. Upper profile of head rises back with a little concavity. Snout pointed. Mouth small pointing downwards when protracted. Cleft of mouth opposite middle to lower third of eye. Mandibular profile slightly concave. Two spines on the supraorbital edge of the eye. Villiform teeth present in each jaw. Lateral line extends beyond soft dorsal and anal fins, up to the base of the caudal fin. Second dorsal spine elongated and filiform, upper half of which is flexible. The second dorsal spine when flexed backwards extends up to the second to the fourth dorsal ray (only 3 specimens examined for this character, since in all the others the second dorsal spine was broken), i.e. well in front of the middle of the soft dorsal. The third dorsal spine is only about half the length of the preceding. The anal fin commences vertically below the eighth dorsal spine. Ventral fins reaching only to about two-thirds of the distance to the anal fin origin. Caudal forked. Dorsolateral lobes of light organs hypertrophied, extend posteriorly into gas bladder.

Color. Body silvery, back and sides marked with a number of irregular semicircular and undulated, dark, gray– brown spots and vermiculations. Yellow spots below lateral line on large specimens, fading almost completely on preservation in formalin. Pectoral axil, black with minute dots. Membrane between dorsal fin spines soft yellow at mid height, edge of soft part of dorsal fin also yellow. Posterior part of caudal fin also yellowish.

Distribution. Distributed off Cochin, Quilon, Palk Bay, Gulf of Mannar and Madras.