Eleotris (Giuris) vanicolensis Sauvage, 1880

Keith, Philippe, Mennesson, Marion I., Sauri, Sopian, Busson, Frédéric, Delrieu-Trottin, Erwan, Limmon, Gino, Nurjirana, Dahruddin, Hadi & Hubert, Nicolas, 2020, Giuris (Teleostei: Eleotridae) from Indonesia, with description of a new species, Cybium 44 (4), pp. 317-329 : 321-324

Eleotris (Giuris) vanicolensis Sauvage, 1880

NB. – Kottelat (2013) considered that the rejection of E. margaritacea by Akihito and Meguro (1974) was not possible; he thus considered that it is the oldest available and valid name for the present species.

Material examined

Holotype. – MNHN A-1575, Vanikoro Island , Santa Cruz Islands, southwestern Pacific.

Others. – Eleotris aporos Bleeker, 1854 : Syntypes: (4) RMNH 5178 (2 of 6). Sindangole; Halmahera (not Ternate), Moluccas, Indonesia. – Eleotris hoedtii Bleeker, 1854 . Holotype: RMNH 5180 (largest of 17). Ambon Island, Moluccas, Indonesia. – Ophiocara aporos guentheri, Koumans, 1937 . Holotype: RMNH 11422. Palau Islands, western Pacific. – Eleotris (Giuris) vanicolensis Sauvage, 1880 . Holotype: MNHN A-1675. Vanikoro Island, Santa Cruz Islands, southwestern Pacific.

MZB.25326, Moluccas, Ambon, Waai Tasoi River , 26 Mar. 2016, Hubert et al. coll.; BIF 5235, BIF 5237, BIF 5238, BIF 5240, BIF 5241 . – MZB.25327, Moluccas, Halmahera , Saluta, Sungai Kam, 25 Mar. 2017, Hubert et al. coll.; BIF 6869 . – MNHN 2019-0239 (tag 17729), Water Lily Hole , Nut, West New Britain, Papua New Guinea, 23 Oct. 2018, Keith et al. coll . – MNHN 2015-0358 (4 spms), Pisuku , Choiseul Island, Solomon, 10 Oct. 2014, Keith et al. coll . – MNHN 2015-0359 (2 spms), Lokasereke , Choiseul Island, Solomon, 13 Oct. 2014, Keith et al. coll . MNHN 2016-0224 , Kolobangara Island , Solomon, 11 Nov. 2015, Keith et al. coll . – MNHN 2016-0229 , Kolobangara Island , Solomon, 9 Nov. 2015, Keith et al. coll . MNHN 2019-0249 (tags 17687 & 17688), Ore , West New Britain, Papua New Guinea, 25 Oct. 2018, Keith et al. coll .

Description

The scale and ray counts are given in table II and morphomeristic data in table III.

The body is more ovoid than elongated. The body depth at anus is 20-24 (% SL), at first dorsal fin 20-25 (% SL), and the caudal peduncle depth is 13-16 (% SL). Predorsal length 43-49 (% SL) and preanal length 59-66 (% SL). Size: up to 18 cm SL.

The head (30-35% SL) is depressed, the snout is convex. The anterior nostrils are short, not reaching upper margin of upper lip. The mouth and the jaw length (10-11% SL) are small. Inwardly curved teeth set on both jaws and larger on outer row. Posterior end of maxillary extending to nearly below anterior margin of eye. Lips with internal short and sometimes bifid papillae. Generally no external papillae on mentum, snout, inferior lip and between nostrils. Eye diameter 6-8 (% SL) and interorbital length 12-14 (% SL).

Dorsal fins VI-I,8 without filamentous rays. The first dorsal fin is with second, third and fourth rays longer. Anal fin I,9 directly opposite to the second dorsal fin. The caudal fin is with 13-14 branched rays and its posterior margin is rounded. Pelvic fins separate, I,5. Pectoral fins 14-15, with the posterior margin rounded. Lateral scales 28-31, with ctenoid scales on flanks and caudal peduncle. Cycloid scales from snout to top of head and anterior part of D1, on operculum, on base of pectoral fins and on belly extending to anus. Scales on top of head and back bigger than those on belly. Scales in transverse back series 9-10, in transverse forward 13-14, in predorsal 15-17 and in zigzag 9-10. 8-11 scales around the eye (ENO). 25 vertebrae.

Absence of oculoscapular canal and supratemporals and presence of a short preopercular canal with pores N’ and O’.

Cephalic sensory papillae system developed as described by Akihito et al. (1988).

Males with a rounded/triangular urogenital papilla with distal tip rounded. Females have a bulbous urogenital papilla with fimbriate projections around distal opening.

Colour in preservation

For the most common pattern, male and female similar. Background of body brownish to beige on the back and on the flanks. Lateral part of head brownish with 3 stripes radiating from the eye to the cheeks and operculum, the upper one continuing on the pectoral base. The belly is whitish to greyish. Nine to eleven large alternating dark patches along the flanks from pectoral base to hypural base. Base of caudal fin with 3 brown spots. The first dorsal fin is greyish. The second dorsal fin is greyish with a white stripe at the distal tip. Pectoral, pelvic, anal and caudal fins greyish.

Colour in life

Males. – ( Fig. 2 ) More colourful than females. General pattern variable and three main were observed: (1) The most

.

common male pattern found ( Fig. 2A ) corresponds to males with background of body brownish to beige on the back to bright yellow or beige on the flanks. Top of head light brown, with sometimes several reddish dots, lateral part light brown with 3 red stripes radiating from the eye to the cheeks and operculum, the two upper ones continuing on the pectoral base. The belly is whitish to greyish. Nine to fourteen large alternating reddish to bluish rounded patches along the flanks from pectoral base to hypural base. These patches are underlined by a more or less discontinuous red line. Base of caudal fin with 3 red spots. The first dorsal fin is translucent with about 4 dark spots at the base. The second dorsal fin is slightly greyish with dark spots at the base and a white stripe at the distal tip. Pectoral fins hyaline. Pelvic fins translucent with a bright yellow stripe at the base and a white stripe at the distal part. Anal fin translucent in its distal half and with a large yellow band in its inner half. Caudal fin hyaline. (2) The second type of male pattern found ( Fig. 2B ) corresponds to males with background of body entirely reddish and covered with numerous silver spots including at the base of the two dorsal, the anal and the caudal fins. Three red stripes and three spotted blue rows radiating from the eye to the cheeks and operculum, the upper red one continuing on the pectoral base. The belly is whitish to yellowish. The two dorsal fins have a central bright yellow stripe. Second dorsal fin with a white stripe in its distal part. The anal fin is reddish. The caudal fin has a bright red basal part, has a yellow tinge in the dorsal and ventral parts of the caudal peduncle as well as on the rest of the fin. (3) The rarest pattern male ( Fig. 2C ) corresponds to males with background of body entirely dark brown and with sinuous longitudinal line of small sliver to bluish spots. Two spotted blue rows radiating from the eye to the cheeks and operculum, the upper one continuing on the pectoral base and along midline. The belly is whitish to greyish. The anal and dorsal fins are red-brown at the base, with silver spots and surmounted by an orange band. The caudal fin is red-brown and orange spotted with a red basal part. Females. – ( Fig. 2D ) Background of body brownish to greyish on the back. Top of head brownish, lateral part yellowish with 3 slight red stripes radiating from the eye to the cheeks and operculum, the upper one continuing on the pectoral base. Nine to eleven small alternating reddish to bluish rounded patches along the flanks from pectoral base to hypural base. Belly whitish as lower part of flanks. The first dorsal fin is translucent. The second dorsal fin is slightly greyish with a thin white stripe at the distal tip. Pectoral fins hyaline. Pelvic fins hyaline. The anal fin hyaline with a light yellow base. Caudal fin hyaline.

Ecology

Giuris margaritaceus occurs in estuaries, lower parts of coastal streams and ponds, usually in riverbank vegetation and in shelters over rocky or gravel bottoms. It is mostly carnivorous and feeds on small crustaceans, insects and fish. It is thought to be amphidromous as some other species of the family ( Keith et al., 2010). In Indonesia, it is sometimes found in sympatry with Giuris viator n. sp. (present paper) or Giuris tolsoni .

Distribution

Giuris margaritacea is known from Indonesia ( Ambon, Ceram, Halmahera, Sulawesi), Philippines, Palau, Salomon, Gaua ( Vanuatu), and Papua New Guinea.

Comparison

Giuris margaritaceus differs from the other species sequenced and present in the area by displaying distinct mitochondrial lineages from its closest relatives and high K80+I genetic distances to its relatives at COI gene (0.0556 to its closest relative G. tolsoni ). Moreover, it differs from Giuris tolsoni in having more scales around the eye (8-11 vs. 6-9), a greater interorbital length (12-14 vs. 9-12), 14 or 15 pectorals rays vs. always 14 and by the different male colourful patterns. It differs from Giuris viator n. sp. (present paper) in having 14 or 15 pectorals rays vs. always 14, fewer scales in backward series (9-10 vs. 10-12) and by the different male colourful patterns.

Figures

Figure 2. – A: Giuris margaritaceus, in MZB.25326, male; Moluccas, Ambon; BIF 5237; SL 120 mm (Photo N. Hubert). B: G. margaritaceus, in MZB.25326, male; Moluccas, Ambon; BIF 5235; SL 136 mm (Photo N. Hubert). C: G. margaritaceus, MNHN 2020- 0135, male; New Britain, Papua New Guinea (Photo P. Keith). D: G. margaritaceus, in MZB.25326, female; Moluccas, Ambon; BIF 5238; SL 114 mm (Photo N. Hubert).