Eleotris pellegrini Mauge 1984
Creators: name: Mennesson, Marion I.
name: Keith, Philippe
Publisher: name: Zenodo
Year: 2020
Subjects: Biodiversity
Taxonomy
Animalia
Chordata
Perciformes
Eleotridae
Eleotris
Eleotris pellegrini

description: Eleotris pellegrini Maugé, 1984
(Figs 1B, 2, 3; Tabs III-V)
Material examined
Syntypes. – MNHN-IC-1932-0108 from Madagascar (1 male and 2 females).
Others. – Fifteen males and five females collected from Seychelles and Madagascar with a size range of 29.3-64 mm SL. MNHN-IC-2007-0204, 2 specimens, Grande Anse, Mahé, Seychelles Islands, 20 Nov. 2004, Accouche et al. coll.; tags M-0204A & M-0204B. MNHN-IC-2020-0043, Silhouette, Anse Mondon, Seychelles Islands, 20 Nov. 2004, Accouche et al. coll.; tag 13970. MNHN-IC-2007-0200, 2 specimens (tags A, B) of 3, Mahé, Seychelles Islands, 22 Nov. 2004, Accouche et al. coll. MNHN-IC-2020-0049, Andrepona, Madagascar, 04 Jul. 08, Diamsoi coll.; tag 7546. MNHN-IC-2020-0050, same data as 2020-0049, tag 7547. MNHN-IC-2020-0051, same data as 2020-0049, tag 7548. MNHN-IC-2020-0052, Ambanizana, Madagascar, May 2010, Diamsoi coll.; tag 13015. MNHN-IC-2020-0053, Farambana, Madagascar, July 2008, Diamsoi coll.; tag 13007. MNHN-IC-2020-0054, Sahana, Madagascar, 07 Jul. 2008; Diamsoi coll.; tag 12947. MNHN-IC-2020-0055, same data as 2020-0053; tag 13001. MNHN-IC-1962-0172, 3 specimens, Madagascar, Lampahana, Kiener coll. MNHN-IC-2020-0056, Fond B’Offay, Praslin, Seychelles Islands, 22 Feb. 2020, Keith, Mennesson, Henriette et al., coll.; tag 12728. MNHN-IC-2020-0057, same data as 2020-0056, tag 12730. MNHN-IC-2020-0058, Grand St Louis River, Mahé, Seychelles Islands, 15 Feb. 2020, Keith, Mennesson, Henriette et al., coll.; tag 12593.
Diagnosis
The species is distinguished by: second and fourth suborbital free neuromast rows on cheek extending ventrally past horizontal row d (‘2.4’ pattern), row os not connected with row oi at ventro-posterior margin of operculum (‘open’ pattern); 15 pectoral fin rays; no teeth on vomer; scales in zigzag series 10-12, and 18-24 in transverse forward series.
Description
Scale and ray counts in Eleotris pellegrini and related species are given in tables III-IV, morphometrics in table V.
The body is elongated but stocky. The body depth at anus is 17-24 (% SL) and the caudal peduncle depth is 10-17 (% SL). Predorsal length 42-49 (% SL) and preanal length 62-70 (% SL). Size: up to 64 mm SL.
Head (32-37% SL) slightly depressed, the snout is pointed. Eyes high on head. The mouth is large, as jaw length is 9-14% SL, and oblique, the posterior margin of upper jaw reaches the vertical through the half of the eye. Upper and lower jaws with multiple rows of small inwardly curved teeth, larger on outer row; a few caniniform teeth in posterior position.
Dorsal fins mostly VI-I,8-9; D1 separate from and same height as D2; spines not elongated. Anal fin I,8-9 and directly opposite to second dorsal fin. Pelvic fins separate, I,5. Pectoral fins 15. Caudal fin rounded with 15 branched rays.
Cycloid scales on top of head, nape, cheek, operculum, pectoral fin base, prepelvic region, and abdomen. Ctenoid scales covering flanks. No lateral line canals. 48-56 scales in lateral series, 28-37 in predorsal series, 14-16 in transverse back series, 18-24 in transverse forward series and 10-12 in zigzag series.
A downward pointing spine at the posterior margin of the preoperculum is covered with skin. Gill opening is moderately broad, extending to below the preoperculum. Tubular anterior nares overhanging half upper lip, posterior nares open pits.
Cephalic lateralis: Adults with five transverse suborbital free neuromast rows of which second and fourth suborbital free neuromast rows on cheek extend ventrally past horizontal row d (‘2.4’ pattern); row os not connected with row oi at ventro-posterior margin of operculum (‘open pattern’) (Fig. 1B).
Urogenital papilla in females rounded, elongated and tapered in males.
Colour in life (Fig. 3)
Male and female similar. Body marbled from light to dark brown, more beige on the back and striped and spotty on the flanks, alternating dark brown and beige. Three horizontal dark brown to reddish stripes between eyes and preoperculum and three vertical white ones below the eye. First dorsal fin translucent with two large horizontal dark spotted stripes, one at fin base, one in the middle of the fin. Second dorsal and anal fins with 5-6 brownish wavy spotted horizontal stripes. Pelvic fins base yellowish. Caudal fin brown, with two brown spots anteriorly, several brownish vertical spotted wavy rows. Pectoral fins translucent.
Colour in preservation
Male and female similar. Body marbled brown, lighter on the back and striped on the flanks. Three horizontal dark brown stripes between eyes and preoperculum. First dorsal fin with two large horizontal dark stripes, one at fin base, one in the middle of the fin. Second dorsal and anal fins with 5-6 brownish wavy spotted horizontal stripes. Caudal fin brown, with two brown spots anteriorly, several brownish vertical wavy spotted stripes. Pectoral fins greyish.
Comparison
Eleotris pellegrini differs from the other species sequenced that occur in the area studied by having a high % of divergence in COI gene (9.4-15.2%).
Within the pattern ‘ 2.4 ’ group, E. pellegrini differs from E. acanthopoma in having 15 pectoral fin rays versus 16-17 and 28-34 scales in predorsal series versus 30-42. It differs from E. vomerodentata by the absence of teeth in the vomer versus presence. It differs from E. sahanaensis by a greater head length (31-37 versus 30-32% SL) and more scales in zigzag series (10-12 versus 10).
Distribution
Currently known only from Madagascar and the Seychelles Islands. It was found in Seychelles in sympatry with E. acanthopoma and in Madagascar with E. sahanaensis (this paper).
Ecology
The species is supposed to be mainly amphidromous (Mennesson and Keith, 2017). It lives in the lower part of the river. It lives in muddy to clear rivers with sandy to gravel bottom between 5 to 10 m in altitude. It is carnivorous.
description: Published as part of Mennesson, Marion I. & Keith, Philippe, 2020, Eleotris (Teleostei: Eleotridae) of the Indian Ocean: an overview with the description of three new species, pp. 185-203 in Cybium 44 (3) on pages 191-194, DOI: 10.26028/cybium/2020-443-002, http://zenodo.org/record/10493514