Giuris viator, Keith & Mennesson & Sauri & Busson & Delrieu-Trottin & Limmon & Nurjirana & Dahruddin & Hubert, 2020

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 : 325-327

Giuris viator n. sp. Keith, Mennesson, Lord, Hubert

( Figs 1-4 ; Tabs II-III)

Material examined

Eleven specimens, totalling 6 males and 5 females; size range 37.3-122 mm SL, largest male 122 mm SL, largest female 79.5 mm SL.

Holotype. – MNHN 2019-0238 , male (122 mm SL), Fausse Yaté, 29 Nov. 2018, New Caledonia, Charpin coll.; tag 6844.

Paratypes. – MNHN 2007-0093 , female (64.5 mm SL), Peavot, Santo , Vanuatu, 22 Nov. 2006, Keith, Lord, Kalfatak, Gerbeaux et al. coll.; tag 12678 . – MNHN 2007-0107 , male (35.5 mm SL), Santo , Vanuatu, 8 Nov. 2006, Keith, Lord, Kalfatak, Gerbeaux et al. coll . – MNHN 2019-0237 , male (72.3 mm SL), Kolobangara, Solomon, 18 Nov. 2015, Keith, Lord, Boseto, Marquet et al. coll.; tag 06932. – M NHN 2019-0247, female (128.6 mm SL), Kû Bwéné , New Caledonia, 8 Jul. 2019, Charpin coll.; tag 12599 . – MZB.25333, male (90 mm SL), Moluccas, Ceram, Ceram Barat, Wai Sia , 1 Apr. 2016, Hubert et al. coll.; BIF 5419 . – MZB.25334, female (69 mm SL), Moluccas, Ceram, Ceram Barat, Wai Sia , 28 Mar. 2016, Hubert et al. coll.; BIF 5302 . – MZB.25335, female (49.5 mm SL), Java, Banten, Kab Pandeglang, Cikareo , 9 Dec. 2013, Hubert et al.; coll. BIF 1555 . – MZB.25336, male (37.3 mm SL), Java, East Java, Kab Lumajang, Mujur , 13 Apr. 2014, Hubert et al. coll.; BIF 2148 . – MZB.25337, 1 male and 1 female (50-79.5 mm SL), Moluccas, Halmahera, Bibisingo, Kali Aru , 24 Mar. 2017, Hubert et al.; coll.; BIF 6882 & BIF 6864 .

Diagnosis

The new species has 14 pectorals rays, a medium body depth at anus (21-24% SL), and 10-13 scales around the eye.

Description

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

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

The body is more ovoid than elongated. The body depth at anus is 24 (21-24% SL), at first dorsal fin 23 (20-24% SL), and the caudal peduncle depth is 15 (14-15% SL). Predorsal length 44 (42-47% SL) and preanal length 64 (59-66% SL).

The head 33 (31-35% SL) is depressed, the snout is convex. The anterior nostrils are short, not reaching upper margin of upper lip. Mouth and jaw length 11 (10-12% SL) small. Inwardly curved teeth set on both jaws and larger on outer row. Posterior end of maxillary extending to below around anterior margin of eye. Lips with numerous internal short and fine papillae. Several specimens with numerous external papillae on mentum, snout, inferior lip and between nostrils. Eye diameter 6 (6-8% SL) and interorbital length 13 (10-14% SL).

Dorsal fins VI-I,8 with no 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 14 (13-14) branched rays and its posterior margin is rounded. Pelvic fins separate, I,5. Pectoral fins 14, with the posterior margin rounded. Lateral Scales 30 (28-32), 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 10 (10-12), in transverse forward 14 (14-15), in predorsal 16 (14-16) and in zigzag 9 (9-10). Scales around the eye 11 (10-13). 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

Males. – Background of body brown on the back to greyish on the flanks. Top of head brownish, lateral parts lighter with 3 brown stripes (more or less thick) radiating from the eye to the cheeks and operculum. Eight to ten large alternating brownish rounded patches along the flanks from pectoral base to hypural base. Base of caudal fin with 3-4 brown spots. The first dorsal fin is greyish with black zebra stripes in the medium part. The second dorsal fin is slightly greyish. Pectoral and pelvic fins are light brown. Anal fin greyish. Caudal fin greyish.

Females. – Background of body brownish on the back. Top of head brownish, lateral parts beige with 3 light brown stripes radiating from the eye to the cheeks and operculum. Eight to ten small alternating brownish rounded patches along the flanks from pectoral base to hypural base. Belly whitish as are the lower parts of the flanks. Base of caudal fin with one large brown spot. The first dorsal fin is greyish. The second dorsal fin is slightly greyish with a thin white stripe at the distal tip. Pectoral and caudal fins greyish. Pelvic and anal fins greyish with a white distal margin.

Colour in life

Males ( Fig. 4A, B ). – More colourful than females. The general colour pattern is variable depending on the maturity of the individual. Two main patterns: (1) with background of body brown on the back to bright red and yellow on the flanks. Belly yellow. Top of head brown and slightly spotted, lateral part yellow with 3 red stripes (more or less thick) radiating from the eye to the cheeks and operculum, the highest continuing on the pectoral base. Eight to ten 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 continuous red line. Base of caudal fin with 3-4 red spots, preceded by a large red spot on caudal peduncle, all these spots resemble a cat’s paw print directed towards the posterior of the fish. The first dorsal fin is translucent with black zebra stripes in the medium part and a large whitish distal stripe. The second dorsal fin is slightly greyish with, on the lower part, yellow and red small spots, on the medium part a large brown band and with a large white stripe at the distal tip. Pectoral fins hyaline. Pelvic fins hyaline with a yellow distal margin. The anal fin is brightly coloured with alternating stripes from the base to distal part: red, yellow red, black and white. Caudal fin hyaline with red to orange lower distal margin ( Fig. 4A ). (2) with background of body brownish to greyish on the back, yellow on the flanks. Belly whitish to greyish. Top of head brown and lightly spotted. Lower lateral part of the head yellow with 3 reddish-brown stripes radiating from the eye to the cheeks and operculum, the highest continuing on the pectoral base. Eight to ten large alternating reddish-brown rounded patches along the flanks from pectoral base to hypural base. Base of caudal fin with 3-4 brownish spots, preceded by a large reddish-brown spot on caudal peduncle, all these spots resemble a cat’s paw print directed towards the posterior of the fish. The first dorsal fin is translucent. The second dorsal fin is translucent with a yellow stripe at the distal border. Pectoral fins hyaline. Pelvic fins hyaline with a yellow distal margin. The anal with alternating stripes from the base to distal part: yellow, black and yellow. Caudal fin hyaline ( Fig. 4B ).

Females ( Fig. 4C ). – Background of body brownish on the back. Top of head brownish with a few scattered black spots, lateral part beige-yellowish with 3 light reddish stripes radiating from the eye to the cheeks and operculum, the upper one continuing on the pectoral base. Eight to ten small alternating reddish to bluish rounded patches along the flanks from pectoral base to hypural base. Belly whitish as the lower part of the flanks. Base of caudal fin with one central brown spot. 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 yellowish to hyaline with a white distal margin. The anal fin is yellow or grey with a distal white stripe. Caudal fin hyaline.

Ecology

This species occurs in estuaries and lower parts of coastal streams, usually in riverbank vegetation and in shelters over rocky or gravel bottoms. It is mostly carnivorous and feeds on small shrimps, insects and fish. It is thought to be amphidromous as some other species of the family ( Marquet et al., 2003; Keith et al., 2010).

Distribution

This species is widespread and known from Mayotte in Indian Ocean to Indonesia (Java, Lombok, Ceram, Ambon, Halmahera, Sulawesi), Papua New Guinea, Salomon, Vanuatu, and New Caledonia in Pacific Ocean. Depending on the locality, it is sometimes found in sympatry with G. tolsoni or G. margaritaceus .

Etymology

The name of the species is derived from the latin word viator , meaning the traveller, the pilgrim, as the species has a large distribution from Indian Ocean to New Caledonia.

Comparison

Giuris viator n. sp., differs from the other species sequenced and present in the area by displaying reciprocal monophyly from its closest relatives and high K80+I genetic distances to its relatives at COI gene (0.1995 to its closest relative G. margaritaceus ). Moreover, it differs from G. tolsoni in having more scales around the eye (10-13 vs. 6-9), a greater body depth at anus (21-24 vs. 16-22% SL) and by the colourful pattern of the male. It differs from G. margaritaceus in having always 14 pectorals rays vs. 14 or 15 rays, more scales in backward series (10-12 vs. 9-10) and by the colourful pattern of the male.

Figures

Figure 1. – Most likely ML tree inferred using the K80+I model (–lnL = 1548.01608, Transition/tranversion ratio = 20.137, I = 0.776). Barcode Index Numbers (BIN) are given for each lineages.

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).

Figure 3. – A: Giuris tolsoni, RMNH 5180, holotype, male; SL 61.5 mm (Photo RMNH, P. Keith). B: G. tolsoni, MZB.25328, male, Bali; BIF 2283; SL 66 mm (Photo N. Hubert). C: G. tolsoni, in MZB.25329, female, Bali; BIF 2848; SL 34 mm (Photo N. Hubert).

Figure 4. – A: Giuris viator n. sp., MNHN 2019-0238, holotype, male; SL 122 mm New Caledonia (Photo N. Charpin). B: G. viator n. sp., MZB.25333, paratype, male; Moluccas, Ceram; BIF 5419; SL 90 mm (Photo N. Hubert). C: G. viator n. sp., in MZB.25337, paratype, female; Halmahera; BIF 6882; SL 79.5 mm (Photo N. Hubert).