Sicyopus rubicundus, Keith & Hadiaty & Busson & Hubert, 2014

Keith, Philippe, Hadiaty, Renny K., Busson, Frédéric & Hubert, Nicolas, 2014, A new species of Sicyopus (Gobiidae) from Java and Bali, Cybium 38 (3), pp. 173-178 : 174-178

Sicyopus rubicundus n. sp.

( Figs 1-2 , Tabs I-IV)

Comparative material

The new species is compared with two Sicyopus species having a first dorsal fin with generally five spines, a second dorsal fin with one spine and nine segmented rays and an anal fin with one spine and nine segmented rays. These species are Sicyopus jonklaasi (Axelrod, 1972) and Sicyopus discordipinnis Watson, 1995 .

Sicyopus jonklaasi . – SMF 20401, 1 female, 31.1 mm SL, paratype; mountain stream in southwestern Sri Lanka , Dec. 1985, Aquarium Dietzenback. SMF 20403, 2 males, 31-35 mm SL, paratypes; mountain stream in southwestern Sri Lanka , Dec. 1985, Aquarium Dietzenback. SMF 20404, 1 female, 32.7 mm SL, paratype; mountain stream in southwestern Sri Lanka , Dec. 1985, Aquarium Dietzenback. SMF 20405, 3 males, 32.7-37.2 mm SL; mountain stream in southwestern Sri Lanka , Dec. 1985, Aquarium Dietzenback. SMF 20411, 2 males, 30.6-32.7 mm SL, paratypes, mountain stream in southwestern Sri Lanka , Dec. 1985, Aquarium Dietzenback. SMF 20413, 2 males, 33-34.3 mm SL; Elpitiya area , Atweltota, SW Sri Lanka .

Sicyopus discordipinnis . – MNHN 2011-0047, 4 males, 31.7-34.4 mm SL; Bichain River , Papua, 19 Oct. 2010 , Keith et al. coll. WAM P.27834-004, holotype, male, 25.4 mm SL; Letak Creek , 25 km southeast of Wewak, New Guinea, Papua New Guinea, 17 Oct. 1982, G.R. Allen & D. Coates coll. WAM P.32372-006, 3 males and 4 females, Papua New Guinea, Apatabuia River , above village; 30 Jan. 2003, G. Allen & T. Stevenson coll. WAM P.27834-005, paratypes, 2 females, 26.0- 27.6 mm SL; same data as holotype. WAM P.28167-001, 2 males and 4 females, 29.3-34.3 mm SL; about 18 km southwest of Arawa on Panguna Road , Bougainville, Papua New Guinea, 4 Oct. 1983, G.R. Allen & R. Steene coll. NMBA 5075, male, 24.4 mm SL; Namamosa , New Hanover, Bismarck Archipelago, Papua New Guinea, Nov. 1931, A. Bühler coll.

Material examined

Twelve specimens from Java and Bali, totalling 7 males and 5 females; size range 39-50 mm SL (45-58.5 mm, total length), largest male 47 mm SL, largest female 50 mm SL.

Holotype. – MZB 22123, male, 47 mm SL, Indonesia, Java, Banten, Kab Pandeglang, Cisiih , 8 Dec. 2013, Hubert et al. coll.; BIF 1485.

Paratypes. – MZB 22124, 2 males, 41-44 mm SL and 1 female, 45 mm SL, same data as holotype; BIF 1486, 1488, 1492. MZB 22125, 2 females, 42-44 mm SL, Indonesia, Java, Kab Sukabumi, Cisukawayana, 12 Dec. 2013, Hubert et al. coll.; BIF 1748, 1749. MNHN 2014-0133, 1 male, 39 mm SL, and 2 females, 47.5-50 mm SL, same data as holotype; BIF 1487, 1489, 1490. MNHN 2014-0139, 2 males, 39-43 mm SL, Indonesia, Java, Kab Sukabumi , Cisukawayana , 12 Dec. 2013, Hubert et al. coll.; BIF 1737, 1738. MNHN 2014-0140, 1 male, 41 mm SL, Indonesia, Bali, Kab Buleleng , waterfall Aling Aling , 261 m asl, 21 Apr. 2014; BIF 2708 .

Diagnosis

The new species has a first dorsal fin with five spines in both sexes, a second dorsal fin with one spine and nine segmented rays and an anal fin with one spine and nine segmented rays. The base of the first dorsal fin does not reach the base of the second dorsal fin origin in both sexes. The new species is also distinguished from congeners by 15 pectoral fin rays, more scales in zigzag series (10-12 vs. 7-9), a greater caudal peduncle depth (10-12 vs. 8-10%SL) and greater fins length.

Description

Scale counts in Sicyopus rubicundus n. sp. and related species are given in table I, number of upper jaw teeth in table II, morphometrics in table III and fin lengths in table IV. Below, the holotype counts are given first, followed, in brackets if different, by paratype counts.

First dorsal fin (D1) with five spines in both sexes, second dorsal fin (D2) with one spine and nine segmented rays (D V-I,9). Spines not filamentous in males and females, spines 3-4 longest. Base of first dorsal fin not reaching base of second dorsal fin origin in both sexes; distance between insertion of D1 and origin of D2 is about twice eye diameter. Anal fin with one flexible spine and 9-10 segmented rays (A I,9-10) and directly opposite second dorsal fin. Pectoral fin rays 15. Caudal fin with 13-15 branched rays with posterior margin slightly rounded. Pelvic disc with 1 spine and 5 branched rays.

Scales in lateral series 40 (35-41); scales may extend midlaterally anterior to the origin of first dorsal fin in male and female, and posteriorly to the hypural base. Scales usually ctenoid from hypural base to origin of the first dorsal fin. A few cycloid scales along dorsal and anal fin base. Scales along dorsum usually extending anteriorly along medial base of first dorsal fin. Ctenoid scales on anterior body region strongly ossified, each with 3-5 prominent cteni; ctenoid scales on posterior part of body with more and larger cteni (12-15). Scales in zigzag series 10 (10-12), transverse back series 15 (10-16), transverse forward series 11 (9-13). Predorsal midline naked. Head, breast, pectoral base and belly naked in most specimens. Lips smooth without cleft. The tongue is free from the floor of the mouth. Upper jaw teeth in one row, mostly conical in females with fewer canines and more teeth (12-16) than in males 8(6-9), mostly caniniform (Tab. II). Lower jaw teeth conical in females (range 3-11) and males 4(3-6).

Cephalic sensory pore system A, B, C, D, F, H, K, L, N and O; D single, with all others paired, oculoscapular canal separated into anterior and posterior canals between pores H and K ( Fig. 1 ).

Urogenital papilla in male long and thin with pointed to rounded tip. Urogenital papilla in female rounded. Jaw, dorsal, caudal and anal fins slightly longer in males.

Colour in preservative

Male. – Background of head and body greyish. Snout dusky. Head ventrally greyish. Lateral midline not wellmarked. All scales on flanks and caudal peduncle with black margins. Nape greyish. Caudal fin rays greyish. Dorsal and anal fins greyish to blackish, with a lighter basal part. Pelvic disk, pectoral rays and pectoral fin base greyish.

Female. – Mostly yellowish to whitish. Head and body greyish to whitish, snout dusky. Lateral midline with a diffuse greyish subcutaneous stripe. Inferior part of body yellowish. Above midline body greyish. All scales on flanks and caudal peduncle with black margins. Dorsal rays and spines blackish. Caudal fin rays greyish as is the membrane and distal margin. Anal fin whitish to greyish. Pelvic disc not pigmented. Pectoral rays and membrane greyish to whitish.

Colour in life ( Fig. 2 )

Male. Background of body greyish. Lateral parts of head, lips and snout reddish. Dorsal margin of head greyish. Ventral half of head, opercle and pectoral base reddish. Two indistinct dusky stripes along the upper part of the body. Orange-red colour on the body from about the anal fin origin to the caudal fin. All scales on flanks and caudal peduncle with black margins. Second dorsal and anal fins with a blue-edged black line and an orange base; or translucent. Caudal fin with red centre and two blue-edged black lines, one on upper part and one on lower part; or translucent. First dorsal fin and pectoral fins translucent.

Female. Colour less variable in females than males. Greyish to brownish with dusky markings appearing similar to that in preservation. Upper lip slightly reddish.

Distribution

Currently known from freshwater streams in Java and Bali, Indonesia .

Ecology

Sicyopus rubicundus was collected in small, rapid and boulder-strewn mountain streams with rocky bottoms at altitudes ranging between 100 and 500 m asl. It is assumed to be amphidromous as the other members of the subfamily ( Keith, 2003; Keith and Lord 2011b).

Comparison

Sicyopus rubicundus differs from S. jonklaasi in having conical and caniniform teeth in female versus tricuspid and caniniform teeth, 15 pectoral fin rays versus 16-17, more scales in zigzag series (10-12 versus 6-9), and a first dorsal fin with five spines in both sexes versus generally five to six spines in females and five in males. It differs from S. discordipinnis in having more scales in zigzag series (10-12 versus 8-9), a greater caudal peduncle depth (10-12 versus 9-10% SL), a longer second dorsal fin in female (28-32 versus 25-28% LS), a first dorsal fin with five spines in both sexes versus generally five to six spines in males and five in females.

Etymology

The new species is named rubicundus for ruddy, rubicund, referring to the bright red throat and belly.

Acknowledgements. – We wish to thank Jean-Paul Toutain and Domenico Caruso for their support. We also thank Sopian Sauri, Daisy Wowor, Aditya Hutama, Ujang Nurhaman and Sumanta, Goris and Ketut for their help during field sampling in Java and Bali. Part of the present study was funded by the MNHN (UMR 7208 BOREA) , the Institut de Recherche pour le Développement (UMR ISEM) , Research Center for Biology-the Indonesian Institute of Sciences ( LIPI) , the French Ichthyological Society ( SFI) and the Fondation de France. This study was approved by the Indonesian Ministry of Research and field sampling was conducted according to the research permits 440/SIP/FRP/SM/ XI/2013 for Philippe Keith and Frédéric Busson, and the research permit 68/EXT/SIP/FRP/ SM/ VIII/2013 for Nicolas Hubert. We wish to thank RISTEK & Research Center for Biology-LIPI for the research permits and supporting letter. Finally, we thank for the loan of specimens: S. Morrison ( WAM) ; F. Krupp, S. Dorow ( SMF) ; P. Pruvost, R. Causse, Z. Gabsi, C. Ferrara, and for X-rays, M. Hautecoeur ( MNHN) . The number ISEM 2014-138 is associated to this publication .

Figures

Figure 1. - Diagrammatic illustration of the head in Sicyopus rubicundus showing head pores and sensory papillae. A: Dorsal view; B: Lateral view. Scale bar = 5 mm.

Figure 2. - Sicyopus rubicundus. A: Male, Bali, Photo P. Keith; B: Above: male, holotype MZB 22123 (BIF 1485); below: female, paratype MNHN 2014-0133 (BIF 1489), Photo N. Hubert.