Lentipes argenteus, Keith & Hadiaty & Hubert & Busson & Lord, 2014

Keith, Philippe, Hadiaty, Renny K., Hubert, Nicolas, Busson, Frédéric & Lord, Clara, 2014, Three new species of Lentipes from Indonesia (Gobiidae), Cybium 38 (2), pp. 133-146 : 139-143

Lentipes argenteus , n. sp. Keith, Hadiaty & Lord

( Figs 4-6 , Tabs V-VII)

Comparative material

The new species is compared with Lentipes species having no enlarged lobes associated with the urogenital papillae or elongate finger like projections in males, having an urogenital papilla in both sexes that is retractable into a sheath-like groove, and having 15-17 pectoral rays. These species are Lentipes dimetrodon Watson & Allen, 1999 , Lentipes watsoni Allen, 1997 and Lentipes ikeae n. sp., this paper.

Lentipes dimetrodon . - MZB 8001 (holotype), male (21.6 mm SL); Indonesia, Papua, Omamerwai Creek , 9 Aug. 1995; G.R. Allen. MZB 8002 (paratype), male (19 mm SL), same data as holotype . WAM P.31059-003 (paratypes), 2 males (21.0- 23.3 mm SL) and 1 male, 1 female (19.0- 23.5 mm) same data as holotype .

NB: WAM P.31059-003 is the correct catalog number of WAM paratypes of L. dimetrodon and not WAM P.31059- 002 as cited by mistake in the original description [S. Morrison ( WAM), pers. com.] .

Lentipes watsoni . - WAM P.31221-001 (holotype), male, 47.4 mm SL, Papua New Guinea: Gulf Province, Sapoi River ; 12-19 Nov. 1996; G.R. Allen. WAM P.31221-002 (paratypes), 3 males, 3 females (44.7-64.4 mm SL), same data as holotype .

Lentipes ikeae n. sp. this paper.

Material examined

Eleven specimens from Sumatra, totalling 8 males, 3 females; size range 26-38 mm SL [33-46 mm, total length (TL)], largest male 34 mm SL, largest female 38 mm SL.

Holotype. - MZB 21475, male (29.7 mm SL), Clearwater Hillstreams in Padang , West Sumatra, Jun. 2013, M. Negrini don.

Paratypes. - MZB 21476, 2 males (25.8-27.8 mm SL) and 1 female (38.4 mm SL), same data as holotype . MNHN 2013-0651, 5 males (26.7-34.0 mm SL) and 2 females (33.6- 37.8 mm SL), same data as holotype .

Diagnosis

The new species has 16-17 pectoral rays, 4-8 scales in transverse backwards series, 35-49 lateral scales and a first dorsal fin with 5-6 flexible spines. The urogenital papilla is retractable into a sheath-like groove and is without lobes or other expanded tissue. The female is characterised by 30-34 tricuspid teeth in the upper jaw. The male has a specific body colour, generally entirely greyish to silver with a slightly reddish upper lip.

Description

The number of pectoral rays in Lentipes species are given in table I, the number of upper jaw teeth in table V, meristic counts in table VI, and morphometrics expressed to the nearest whole percent of standard length in table VII. Below, the holotype counts are given first, followed in brackets if different, by paratype counts.

First dorsal fin (D1) with 5-6 flexible spines, second dorsal fin (D2) with one flexible spine and 9-10 segmented rays (D1 V-VI; D2 I,9-10). Anal fin with one flexible spine and 9-10 segmented rays (A I,9-10) and directly opposite to second dorsal fin. Base of first dorsal fin not reaching base of second dorsal fin origin in both sexes; the distance between D1 & D2 is about half (or more) the eye diameter in male. Spines of D1 not filamentous in both sexes; 4 th and 5 th longer. Pelvic fins constitute a strong adhesive disc adherent to abdomen between all five rays. Pectoral fin with 16-17 rays, ventralmost 1 st or 2 nd rays simple; posterior margin slightly straight. Caudal fin (C) with 13 branched rays.

Lateral scales (LS) 36(35-49). They are lightly embedded and mainly cycloid in female. Generally not limited to caudal peduncle, many extend anteriorly along midline between second dorsal and anal fins; some ctenoid scales are on the anteriormost part of the flanks. Males have mainly ctenoid scales, developed with prominent spines on anterior body region, and few cycloid scales on caudal peduncle. Scales in transverse backwards (TRB) series 6(4-8) and in transverse forward series (TRF) 3(1-8). Zigzag scales (ZZ) 11(8-11). Head, breast, nape and belly without scales. Upper jaw teeth distinctly tricuspid anteriorly, males 17(17-22), females 30-34. Premaxilla in males with 2(2-5) recurved canines posterior to tricuspid teeth; females without teeth posterior to tricuspid teeth. Teeth in lower jaw recurved and canine in males 5(2- 6), no teeth in females. Cephalic sensory pore system A, B, C, D, F, H, K, L, N and O. One male with M, N and O; pore D missing in one male, but when present singular with all others paired ( Fig. 5 ); oculoscapular canal divided into anterior and posterior canal between pores H and K. Some cutaneous sensory papillae present on head and body.

Sexual dimorphism well developed. Ctenoid scales on anterior body region ossified in males, each with generally three prominent spines; scales on posterior part of body with fewer, but larger ctenii than those of females. Urogenital papilla in males slender and pointed distally without associated lobes or expanded tissue ( Fig. 6A ), urogenital papilla retractable into a sheath-like groove; female urogenital papilla rectangular in appearance ( Fig. 6B ) and also retractable into a sheath-like groove. Second dorsal, anal and caudal fin lengths, jaw length and caudal peduncle depth greater in males.

Colour in preservation

Male. - Background of body greyish. Background of head greyish. Head ventrally greyish. Lateral midline with a marked black subcutaneous band. All scales on flanks and caudal peduncle with black margins. Top of head blackish. Nape greyish. Caudal peduncle pinkish to reddish. Caudal fin rays greyish. Dorsal and anal fins blackish. Pelvic disk without pigment. Pectoral rays greyish. Pectoral fin base greyish.

Female. - Mostly greyish. Head and body greyish to whitish. More or less lateral midline with a black subcutaneous band. Caudal fin rays greyish. Dorsal rays and spines whitish, membrane and rays distally without pigment. Caudal fin rays whitish, membrane and distal margin without pigment. Anal fin without pigmentation at base of rays and spine. Pelvic disc not pigmented. Pectoral rays and membrane greyish. Pectoral base greyish.

Colour in life ( Fig. 4 )

Male. - Background of body greyish to silver. Background of head greyish to silver. Dorsal margin of head greyish to silver, upper lip slightly reddish. Head ventrally greyish to silver; opercula and pectoral fin base pinkish. Lateral midline greyish to silver. All ctenoid scales on flanks and caudal peduncle with black margins. Belly white to silver. Caudal peduncle greyish or slightly reddish. Dorsal fins greyish, with tiny black spots on the membrane. Sometimes a slightly black and blue spot on the anterior part of the second dorsal fin. Caudal and pectoral fins translucent. Anal fin greyish.

Female. - Greyish to silver with markings appearing similar to that in preservation.

Distribution

Currently known from Padang, West Sumatra Province ( Indonesia).

Ecology

Lentipes argenteus was collected in a swift, clear high gradient stream with a rocky and boulder-strewn bottom. It is presumed to be amphidromous as the other members of the subfamily ( Keith and Lord, 2011b).

Comparison

Lentipes argenteus differs from L. kaaea , L. rubrofasciatus , L. solomonensis and L. whittenorum in not having enlarged lobes associated with the urogenital papilla in males. It differs from L. adelphizonus in not having elongate finger like projections anterior to the urogenital papillae in males. It differs from L. armatus , L. venustus , L. multiradiatus in having 16-17 pectoral fin rays vs. 17-20 and a second dorsal fin mainly I,9 vs. I,10.

Lentipes argenteus differs from L. dimetrodon in having more scales in lateral series (36-49 vs. 14-20), a shorter anal fin length (28-35 vs. 34-39% SL), generally the 4 th and the 5 th spines of D2 longer vs. the 5 th and 6 th spines of D2 longer, and the coloration in males. Furthermore, it differs from L. watsoni in having fewer teeth in upper jaw in females (30-34 vs. more than 39), fewer scales in transverse backwards (TRB) series (4-8 vs. 11-13), in transverse forward series (TRF) (1-8 vs. 8-10), and live coloration in males. It differs from L. ikeae n. sp. (this paper) in having more scales in lateral series (35-49 vs. 23-35), a greater distance between the bases of D1 and D 2 in males [about half (or more) the eye diameter vs. nearly touching]; a lower peduncle depth in both males and females (7-9 vs. 10-12 / 7 vs. 9-11% SL, respectively), a smaller predorsal length (30-37 vs. 35-42), a longer caudal peduncle length in males (17-21 vs. 13-17), and the coloration in males.

Etymology

The new species is named argenteus with reference to the distinctive colour pattern of males.

Figures

Figure 4. - Lentipes argenteus. A: Male; B: Female. (Pictures by P. Keith)

Figure 5. - Diagrammatic illustration of head in Lentipes argenteus (male) showing head pores and sensory papillae. A: Dorsal view; B: Lateral view.

Figure 6. - Diagrammatic illustration of urogenital papilla in Lentipes argenteus. A: Male; B: Female. 1: anus; 2: urogenital papilla; 3: anal fin.