Lentipes kolobangara, Keith & Lord & Boseto & Ebner, 2016

Keith, Philippe, Lord, Clara, Boseto, David & Ebner, Brendan C., 2016, A new species of Lentipes (Gobiidae) from the Solomon Islands, Cybium 40 (2), pp. 139-146 : 140-146

Lentipes kolobangara n. sp.

( Figs 1-3 , Tabs I-IV)

Material examined

Eleven specimens from Solomon Islands (6 males, 5 females); size range 22.7-33.3 mm SL (26.7-39.2 mm, total length, TL), largest male 24.8 mm SL, largest female 33.3 mm SL.

Holotype. – MNHN 2015-473, male (24.8 mm SL), Kolobongara Island , Solomon Islands, Poitete River; 14 Nov. 2015, Keith, Lord, Boseto, Marquet et al. coll.

Paratypes. – MNHN 2015-474, 5 males (22.7-23.8 mm SL) and 2 females (26.4-30.3 mm SL), same data as holotype. MNHN 2015-475, 3 females (28.2-33.3 mm SL), Kolobongara Island , Solomon Islands, Poitete River ; 15 Nov. 2015, Keith, Lord, Boseto, Marquet et al. coll.

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 a urogenital papilla in male that is retractable into a sheath-like groove, and having 17 or more pectoral rays. These species are Lentipes armatus Sakai & Nakamura, 1979 , Lentipes mekonggaensis Keith & Hadiaty, 2014 , Lentipes multiradiatus Allen, 2001 and Lentipes venustus Allen, 2004 .

Lentipes armatus Sakai & Nakamura, 1979 . – 21 specimens from Ishigaki City, Ishigaki Island , Okinawa Prefecture, Ryukyu Islands, Japan. BLIH 1983379, male (34.2 mm SL); Ara River; 10 Jul. 1983. BLIH 1989134, male (39.0 mm SL), BLIH 1989142, female (37.4 mm SL); Ara River ; 26 Aug. 1989 . BLIH 1989795, 1 male, 1 female (34.0- 36.6 mm SL); Ara River ; 17 Oct. 1989 . BLIH 1991375, female (42.9 mm SL), BLIH 1991686, 2 females (41.4- 46.9 mm SL); Ara River ; 2 Jul. 1991 . NSMT P.29315, paratype, male (34.9 mm SL); Arakawa River ; 3 Sep. 1974 . URM P3842, 5 males, 5 females (33.1-45.2 mm SL); Miyara River ; 29 May 1982 . URM P4533, female (41.9 mm SL); Ara River ; 4 Sep. 1982 . URM P4872, male (37.9 mm SL); Miyara River ; 16 Sep. 1982 .

Lentipes mekonggaensis Keith & Hadiaty, 2014 . – MZB 21473 (holotype), male (34.4 mm SL), Indonesia, Sulawesi Tenggara province, Kolaka Utara regency, Wawo district, Tinukari village , Sungai Tepasa , (‘sungai’ is river in Bahasa Indonesia); 30 Jun. 2011, Hadiaty, Wowor & Sopian coll. MZB 21474 (paratypes), 2 males (29.3-30.9 mm SL) and 3 females (43.4-46.3 mm SL), same data as holotype. MNHN 2013-0653 (paratypes), 2 males (29.3- 32.0 mm SL), same data as holotype . MNHN 2013-0652 (paratypes), 3 females (37.6-39.0 mm SL), same data as holotype .

Lentipes multiradiatus Allen, 2001 . – WAM 32370.003, 1 male, 3 females (30.0-37.0 mm SL); Papua New Guinea, Awaetowa River , D’Entrecasteaux Islands, Fergusson Island, 09°30.907’S 150°52.04’E, 27 Jan. 2003; Allen & Stevenson coll. WAM 32374.002, 5 males, 1 female (25.7-37.5 mm SL); Papua New Guinea, Dibuwa River D’Entrecasteaux Islands , Normanby Island, Yeluyelua Village 10°02.77’S 151°14.883’E, 30 Jan. 2003; Allen coll.

Lentipes venustus Allen, 2004 . – WAM 32372.001 (paratypes) 1 male, 1 female (24.0- 28.8 mm SL); Papua New Guinea, Apatabuia River , D’Entrecasteaux Islands, Normanby Island Bunama Village, 10°07.067’S 150°09.12’E, 30 Jan. 2003; Allen & Stevenson coll. MNHN, uncatalogued, 4 males, 3 females, Papua, crique Bichain 19 Oct. 2010; Keith et al. coll.

Other comparative specimens are those cited in Lynch et al. (2013) and Keith et al. (2014).

Diagnosis

The new species has 17-18 pectoral rays, a second dorsal fin I10, an anal fin I9-10, and few scales in zigzag (7-9), transverse forward (1-6) and transverse back series (4-8). The urogenital papilla is retractable into a sheath-like groove in male and is without lobes or other expanded tissue. The male is characterised by few tricuspid teeth in the upper jaw (8-15) and 2-5 recurved canines posterior to tricuspid teeth, ctenoid scales on anterior body region strongly ossified, and the base of the first dorsal fin not reaching the base of the second dorsal fin origin. The male has also a specific body colour with a red slim mustache on the snout reaching the eye and the base of the pectoral fins and the first third of their membrane are red.

Description

The number of pectoral rays in species of Lentipes are given in table I, the number of upper jaw teeth in table II, meristic counts in table III, and morphometrics expressed to the nearest whole percent of standard length in table IV.

Below, the holotype counts are given first, followed in brackets, if different, by paratype counts.

First dorsal fin (D1) with six flexible spines, second dorsal fin (D2) with one flexible spine and ten segmented rays.

Lentipes of species studied in teeth jaw upper of

Number

-

.

II

Table (D VI-I,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 and D2 is nearly equal to the eye diameter in male; spines not filamentous in both sexes. Pelvic fins constitute a strong adhesive disc adherent to abdomen between all five rays. Pectoral fin with 17-18 rays, ventralmost 1 st or 2 nd ray simple; posterior margin slightly rounded. Caudal fin (C) with 13 branched rays.

Sexual dimorphism well developed. Differences are noted in scale number and arrangement between sexes. Female generally with more scales lightly embedded and mainly cycloid; scales may extend anteriorly along the anteriormost part of the flanks; lateral scales (LS) (28-32); scales in transverse backwards (TRB) series (6-8) and in transverse forward series (TRF) (4-6); zigzag scales (ZZ) (7-9). Males have mainly ctenoid scales, strongly ossified with prominent spines (5-7) on anterior body region from pectoral base to D1, and few cycloid scales on the flanks and the caudal peduncle; lateral scales (LS) 28(23-30); scales in transverse backwards (TRB) series 6(4-6) and in transverse forward series (TRF) 4(1-4); zigzag scales (ZZ) 8(7-8). Head, breast, nape and belly without scales in both sexes. Upper lip with a small median cleft. Upper jaw teeth distinctly tricuspid anteriorly, males 8(8- 15), females (21-26). Premaxilla in males with 5(2-5) recurved canines posterior to tricuspid teeth; females without teeth posterior to tricuspid teeth. Teeth in lower jaw recurved and canine in males 6(3-6); no teeth in females. Cephalic sensory pore system A, B, C, D, F, H, K, L, N and O; pore D singular with all others paired ( Fig. 2 ); oculoscapular canal divided into anterior and posterior canals between pores H and K. Cutaneous sensory papillae present on head.

Urogenital papilla in males slender and pointed distally

without associated lobes

or

expanded tissue (Fig

. 3

A), urogenital

papilla

retractable

into

a

sheathlike groove; female urogenital papilla rectangular in appearance ( Fig. 3B ) and not retractable into a sheath-like groove.

Colour in preservation

Males. – Body greyish; slightly dusky and with three vertical black stripes between second dorsal and anal fins. First dorsal fin appears greyish. Second dorsal fin with a black spot medially; membrane between spine and ray 1 mostly without pigment. The area between the second dorsal and the anal fin is reddish. Caudal fin with greyish rays; membrane mostly without pigment. Anal fin base clear. Pelvic disc dusky whitish. First third of pectoral fin and pectoral fin base slightly reddish to dusky.

Females. – Mostly grey. Head dusky on upper part; body darkest midlaterally on caudal peduncle; sometimes a yellow band along lateral midline. Opercle with a blackish patch. A yellow patch is present at the base of the pectoral fins as at the first fourth of these fins and as at the base of the caudal fin. Dorsal rays and spines greyish; membrane without pigment. Caudal fin rays dusky; membrane without pigment. Pelvic disc not pigmented but the anterior part of the frenum is yellowish.

Colour in life ( Fig. 1 )

Males ( Fig. 1A, B ). – Background of body greyish on the flanks, brownish on the dorsum. The trunk has generally three blackish vertical bars. The base of the second dorsal fin is red; the upper part is white with a small black dot on the anterior region. A red area is present on the flanks, just below the second dorsal fin and reaching the anal fin. The snout has a red slim mustache reaching the eye. The base of the pectoral fins and the first third of their membrane are red. The pectoral fin rays are goldish. The base of the anal fin is white and the remainder is blue.

Females ( Fig. 1C ). – Greyish to brownish with yellowish markings appearing similar to that in preservation.

Distribution

Currently known only from the Solomon Islands of Choiseul , Kolobangara, Ranongga and Makira.

Ecology

Lentipes kolobangara was collected in swift, clear, high-gradient streams with a rocky and boulder-strewn bottom between 50 and more than 600 m above sea level. It is presumed to be amphidromous as is the majority of the subfamily ( Keith, 2003; McDowall, 2007).

Comparison Lentipes kolobangara differs from L. armatus , L.

venustus and L. multiradiatus in having, in males, the base of the first dorsal fin not reaching the base of the second dorsal fin origin vs. reaching the base of the second dorsal fin origin and a specific body colour in male with a red slim mustache on the snout reaching the eye and the base of the pectoral fins and the first third of their membrane are red. Furthermore, it differs also from L. armatus in having fewer tricuspid teeth in the upper jaw in males (8-15 vs. 18-27) and female (21-26 vs. 28-34), fewer scales in zigzag series (7-9 vs. 9-13) and transverse back series (4-8 vs. 11-16); from L. multiradiatus in having fewer scales in zigzag series (7-9 vs. 9-12), transverse back series (4-8 vs. 12-15) and transverse forward series (1-6 vs. 7-10); from L. venustus in having fewer scales in zigzag series (7-9 vs. 8-11), smaller head length in males (20-23 vs. 24-27%LS) and females (20 vs. 22-23%LS) and smaller jaw length in males and females (8-10 vs. 12-14%LS). Finally, it differs from L. mekonggaensis in having fewer pectoral rays (17-18 vs. 19-20), fewer scales in zigzag series (7-9 vs. 9-12), transverse back series (4-8 vs. 11-13) and transverse forward series (1-6 vs. 7-12).

Etymology

The name of the species is dedicated to Kolobangara Island, where most of the specimens were caught. Kolobangara also means, in Kolobangara Island dialect, ‘water king’ which is suited for this colourful species.

Remarks

Streams of the Solomon Islands are particularly rich in Lentipes species, as four species are known from this area including: L. solomonensis and L. kaaea , both with enlarged lobes associated with the urogenital papillae in male, and L. multiradiatus and Lentipes kolobangara ( Keith et al., 2015; this paper), both having a urogenital papilla in male that is retractable into a sheath-like groove and without enlarged lobes. Jenkins et al. (2008) provided a picture of this last species but named it L. kaaea , despite the difference in urogenital papillae.

Acknowledgments. – The study was made possible by a grant given to the French Ichthyological Society in the context of the ‘Critical Ecosystem Partnership Fund (CEPF)’ (Melanesia hotspot). The Critical Ecosystem Partnership Fund is a joint initiative of l’Agence Française de Développement, Conservation International, the Global Environment Facility, the Government of Japan, the MacArthur Foundation and the World Bank. A fundamental goal is to ensure civil society is engaged in biodiversity conservation. We would like to acknowledge the customary landowners, villages and tribes of Hunda-Kena, Jack Harbour, Poitete, Lodumoe and Vanga who welcomed us on Kolobangara Island and for allowing the expedition team to enter their customary lands. We would also like to thank KIBCA and ESSI for the meetings in the villages prior to the expeditions and for the organisation of the trip. Thanks to Rex Loka, Piokera Holland and Gérard Marquet, our very efficient partners on the Kolobangara field work. Thanks also to the MNHN and the BOREA team. We would like to acknowledge the customary landowners and tribes of Mount Maetambe to Kolobangara River Watershed in Choiseul for allowing the expedition team to enter their customary lands; the Lauru Land Conference of Tribal Community, Choiseul and Western Provinces, and the Solomon Islands’ Government for the support and facilitation of the legal process that have allowed the expedition team to conduct the scientific research, and of course ESSI which organised the trips very efficiently. Finally, we thank for the loan of specimens: S. Morrison and G.R. Allen (WAM), R. Hadiaty (MZB), P. Pruvost, R. Causse, Z. Gabsi, C. Ferrara, M. Hautecoeur (MNHN).

Figures

Figure 1. - Lentipes kolobangara. A: Male; B: Male; C: Female.A, C: photos C. Lord; B: photo P. Keith.

Figure 2. - Diagrammatic illustration of head in Lentipes kolobangara (male) showing head pores and sensory papillae. A: Dorsal view; B: Lateral view.

Figure 3. - Diagrammatic illustration of urogenital papilla in Lentipes kolobangara. A: Male; B: Female. 1: anus; 2: urogenital papilla; 3: anal fin; 4: groove.