Lates lakdiva, Pethiyagoda, Rohan & Gill, Anthony C., 2012

Pethiyagoda, Rohan & Gill, Anthony C., 2012, Description of two new species of sea bass (Teleostei: Latidae: Lates) from Myanmar and Sri Lanka, Zootaxa 3314, pp. 1-16 : 4-6

Lates lakdiva , new species

( Fig. 2 )

Material examined: holotype, AMS I.37516-001, 220 mm SL, St John’s Fish Market, Colombo, Sri Lanka, 1994; paratypes, AMS I. 37516-001, 2, 239 mm SL and 256 mm SL, same data as holotype.

Diagnosis. Lates lakdiva is distinguished from L. calcarifer by its lesser body depth (26.6‒27.6% SL, vs. 28.9‒34.6% SL); possessing 5 (vs. 6) rows of scales between the base of the third dorsal-fin spine and lateral line; 31‒34 (vs. 16‒26) serrae on the posterior edge of the preoperculum; and having the third dorsal-fin spine 3.0‒3.5 (vs. 2.1‒2.8) times the length of the second. It differs from L. japonicus by having the third anal-fin spine longer (vs. shorter) than the second; and possessing 5 (vs. 7) rows of scales between the base of the third dorsal-fin spine and the lateral line, a lesser body depth (26.6‒27.6% SL, vs. 30.3‒33.7% SL), and 47‒52 (vs. 58‒63) lateral-line scales. Lates lakdiva differs from L. uwisara by having a greater eye diameter (5.5‒5.6% SL, vs. 4.4‒4.7% SL), a lesser body depth (26.6‒27.6% SL, vs. 28.4‒34.5% SL), a shorter dorsal-fin base (41.1‒43.2% SL, vs. 43.3‒45.0% SL), and by possessing 5 (vs. 7) rows of scales between the base of the third dorsal-fin spine and lateral line.

Description. See Table 1 for proportional measurements. Body compressed (body width 43.6‒45.7% body depth), its depth 2.9‒3.8 times in SL, deepest at dorsal-fin origin. Dorsal profile concave in interorbital region, rising steeply (convex) thereafter to dorsal-fin origin. Head moderately acute, its length 2.8 times in SL. Eye oval, height less than width, eye diameter 6.4‒6.6 times in head length. Snout 5.3‒5.4 times in head length. Interorbital space 90.6‒95.2% eye diameter. Mouth oblique, lower jaw projecting beyond upper one when closed. Maxilla deep, its depth 82.1‒92.7% eye diameter, extending posterior to level of eye. Villiform teeth present on jaws, palatines, pterygoids and vomer. Tongue smooth. Three sharp, strong spines on inferior margin of preoperculum, the first antrorse; a retrorse spine at angle of preoperculum, the posterior margin of which bears 31‒34 serrae. A sharp spine at angle of operculum. Seven branchiostegal rays. Inferior margin of infraorbitals 1 and 2 finely serrated. Nares level with middle of eye, separated from eye by distance less than diameter of posterior naris. Gill rakers 3+1+8, densely denticulated on proximal side. Cleithrum and supracleithrum each with 4 or 5 serrae.

First dorsal fin commencing slightly behind pelvic-fin, with 7 spines, third spine longest (III>IV>V>VI>II>VII>I). Base of first dorsal fin subequal to (97.5‒110%) that of second dorsal fin. Second dorsal with 1 spine and 10 or 11 rays. Anal fin commencing beneath base of second-dorsal fin ray 4, with 3 spines, third one longest (III>II>I) and 7 or 8 rays. Pectoral fin with 14 rays, 76.7‒81.1% length of pelvic fin, which has 1 spine and 5 rays. Pelvic-fin spine slightly shorter than dorsal spine IV, longer than dorsal spine V. Distal profiles of pectoral, pelvic, anal and second-dorsal fins rounded. Caudal fin rounded, with 7+9+8+7 rays. Caudal peduncle depth 66.1‒69.1% its length.

Scales ctenoid; body and head scaled, except for snout, throat, preorbital and interorbital regions. Dorsal and anal fins reposed in a scaly sheath. Second-dorsal, caudal, anal and lateral area of pelvic fin densely covered with minute scales. Lateral line with 47‒52 posteriorly notched scales on body, commencing immediately posterior to supracleithrum, extending almost to tip of caudal fin; two rows of pored scales on caudal fin, one above and one below median lateral line. Five scales in transverse line between base of third dorsal-fin spine and lateral line; 9 or 10 in transverse line between anus and lateral line; 22 circumpeduncular scales.

Coloration. In 70% alcohol ( Fig. 2 ), head and body olive brown, darker above lateral line and on dorsal region of head, lighter below, ventrally creamy yellow. Fins dark olive, interradial membrane of dorsal fin white, darkolive towards distal margin. Second dorsal fin, caudal and anal fins dark olive brown, pectoral and pelvic fins somewhat lighter, pelvic-fin spine almost white.

Etymology. The specific epithet Lakdiva is Sinhala for the island of Sri Lanka, here used as a substantive in apposition. We propose Sri Lankan Sea Bass as the common name for this species, which is also known by the local names ‘modha’ (Sinhala) and ‘koduwa’ (Tamil).

Conservation. The growth of the fisheries industry in Sri Lanka has seen the introduction of large numbers of juvenile Lates of unknown provenance into the island’s estuaries during the recent past ( RP, pers. obs.). The effects of these introductions on the population of L. lakdiva , are unknown and warrant future investigation.

Figures

FIGURE 2. Lates lakdiva, holotype, AMS I. 37516 - 001, 220 mm SL.

Tables

TABLE 1. Measurements as a percentage of standard length of holotype and 2 paratypes of Lates lakdiva (220 ‒ 256 mm SL); holotype and 3 paratypes of L. uwisara (332 ‒ 363 mm SL); 27 specimens of L. calcarifer (97.6 ‒ 315 mm SL); and 11 specimens of L. japonicus (134 ‒ 263 mm SL). Non-overlapping ranges between species are italicized. Specimen details are given in species accounts of L. lakdiva and L. uwisara, and Comparative Material.

	L. lakdiva	L. uwisara	L. calcarifer	L. japonicus
	min max	min max	min max	min max
Total length	121 121	121 124	120 128	119 123
Snout to base of last dorsal-fin ray	82.4 83.2	82.6 85.2	82.0 88.4	82.0 85.8
Snout to base of last anal-fin ray	84.8 85.4	83.3 86.4	82.3 88.1	82.5 88.9
Preanal length	73.9 74.8	72.9 75.6	69.9 76.1	67.5 72.3
Prepelvic length	34.6 36.3	34.6 36.5	34.4 43.9	33.1 38.3
Prepectoral length	32.9 34.8	31.3 33.7	31.4 38.7	30.2 34.3
Predorsal length	44.8 45.0	44.7 47.2	42.0 47.4	42.3 45.7
Length of dorsal-fin base	41.1 42.0	43.9 45.0	41.3 46.3	42.8 45.5
Length of 1st dorsal-fin base	19.4 19.4	21.1 23.0	19.6 25.7	22.3 26.6
Length of 2nd dorsal-fin base	18.3 19.2	21.0 21.8	17.8 21.5	18.5 21.0
Dorsal-fin origin to caudal-fin base	60.2 60.2	59.3 62.3	58.6 65.0	60.9 65.2
Post-dorsal distance	18.7 18.7	16.0 19.4	14.3 19.5	17.9 20.2
Body depth	26.6 27.6	28.4 32.0	28.9 34.6	30.5 33.7