Eleotris vomerodentata Maugé, 1984

Mennesson, Marion I. & Keith, Philippe, 2020, Eleotris (Teleostei: Eleotridae) of the Indian Ocean: an overview with the description of three new species, Cybium 44 (3), pp. 185-203 : 194-196

Eleotris vomerodentata Maugé, 1984

( Figs 1B , 2, 4; Tabs III-V)

Material examined

Holotype. – MNHN-IC-1984-0803 from Madagascar (male).

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 and the presence of teeth in the vomer.

Description

Scale and ray counts in Eleotris vomerodentata and related species are given in tables III-IV, morphometrics in table V .

Jaw length Caudal peduncle depth 9 10 11 12 13 14 10 11 12 13 14 15 16 E. acanthopoma Males 2 3 6 5 1 1 1 8 1 6 Females 2 3 − 1 2 4 E. vomerodentata Males 1 1 E. pellegrini Males 3 1 3 2 4 3 1 4 3 1 4 1 1 Females 2 1 2 1 3 1 E. sahanaensis Male 1 1 Juv-Female 1 1 Body depth at anus origin 14 15 16 17 18 19 20 21 22 23 24 25 E. acanthopoma Males 1 2 2 2 1 2 2 1 Females 2 2 1 − − 1 E. vomerodentata Males 1 E. pellegrini Males 1 2 1 1 2 4 − 3 Females 1 − − − 1 E. sahanaensis Male 1 Juv-Female 1 Head length 26 27 28 29 30 31 32 33 34 35 36 37 E. acanthopoma Males 3 4 1 2 4 2 Females 1 2 1 1 1 E. vomerodentata Males 1 E. pellegrini Males 4 4 2 2 2 1 Females 1 2 2 E. sahanaensis Male 1 Juv-Female 1 Predorsal length 41 42 43 44 45 46 47 48 49 50 E. acanthopoma Males 1 3 4 1 2 2 − 1 − 1 Females 3 3 E. vomerodentata Males 1 E. pellegrini Males 1 2 2 4 3 3 2 Females 1 1 1 1 − 1 E. sahanaensis Male 1 Juv-Female 1 Preanal length 60 61 62 63 64 65 66 67 68 69 70 E. acanthopoma Males 1 − 3 3 3 1 2 1 1 − 1 Females 1 2 2 − − 1 E. vomerodentata Males 1 E. pellegrini Males 1 5 1 1 1 1 2 1 1 Females 2 1 1 − 1 E. sahanaensis Male 1

The head (35 % SL) is depressed, the snout is pointed. Eyes high on head. The mouth is large, as jaw length is 14% SL, and oblique, the posterior margin of upper jaw reaches the vertical through the two third of the eye. Upper and lower jaws with multiple rows of small inwardly curved teeth, larger on outer row in upper jaw, on inner row in lower jaw; a few caniniform teeth in posterior position. Presence of numerous well-marked teeth in half circle on the vomer, larger in the front part.

Dorsal fins VI-I,9; D1 separate from and same height as D2; spines not elongated. Anal fin I,8 and directly opposite to second dorsal fin. Pelvic fins separate, I,5. Pectoral fins 15. Caudal fin slightly 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. 51 scales in lateral series, 40 in predorsal series, 16 in transverse back series, 19 in transverse forward series and 11 in zigzag series.

A downward pointing spine at the posterior margin of the preoperculum is covered with skin. Gill opening 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 tapered in male.

Colour in life

Unknown.

Colour in preservation ( Fig. 4 )

Head, preoperculum, body and abdomen beige to light brown. Gular and isthmus clearer, rose to slightly whitish. Fins whitish beige.

Juv-Female 1

Comparison

Within the pattern ‘ 2.4 ’ Eleotris vomerodentata differs from all other species by the presence of teeth in the vomer versus absence.

Distribution Currently known only from Madagascar.

Ecology Unknown.

Description of the new species

Comparative material

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’).

Eleotris acanthopoma : MNHN-IC-2006-0617, 3 specimens, Mohéli, Mdjawaché, Comoros Islands, 31 Oct. 2005, Keith et al. coll. MNHN-IC-2020-0029, Mayotte, Kwale, Comoros Islands, 22 Apr. 2009, Feutry coll.; tag 12426. MNHN-IC-2020-0030, Comoros Islands, Mayotte, Apr. 2009, Feutry coll.; tag 12417. MNHN-IC-2020-0031, Mayotte, Ouroveni, Comoros Islands, 06 Sep. 2007, Marquet coll.; tag 13951. MNHN-IC-2020-0032, same data as 2020-0031, 06 Sep. 2007, Marquet coll.; tag 13952. MNHN-IC-2020-0033, same data as 2020-0031; tag 13953. MNHN-IC-2020-0034, same data as 2020-0031; tag 13954. MNHN-IC-2020-0041, Mayotte, Ouroveni, Comoros Islands, 06 Sep. 2007, Marquet coll.; tag 11817. MNHN-IC-2020-0035, Mayotte, Coconi, Comoros Islands, 06 Aug. 19, Valade et al. coll.; tag 14519. MNHN-IC-2020-0036, same data as 2020-0035, tag 14520. MNHN-IC-2020-0037, same data as 2020-0035, tag 14521. MNHN-IC-2020-0038, Comoros Islands, Mayotte, Ouroveni, 06 Aug. 2019, Valade et al. coll.; tag 14562. MNHN-IC-2020-0039, Comoros Islands, Mayotte, Longoni, 07 Aug. 2019, Valade et al. coll.; tag 14563. MNHN-IC-2020-0040, same data as 2020-0039, tag 14564. MNHN-IC-2007-0185, 2 specimens, Mahé, Seychelles Islands, 24 Nov. 2004, Accouche et al. coll. MNHN-IC-2007-0199, Mahé, Anse aux poules bleues riv., Seychelles Islands, 14 Oct. 2003, Keith et al. coll. MNHN-IC-2007-0205, Praslin, Fond B’Offay riv., Seychelles Islands, 10 Oct. 2003, Keith et al. coll.; tag 14509. MNHN-IC-2020-0042, Praslin, Nouvelle découverte, Seychelles Islands, 09 Oct. 2003, Keith et al. coll.; tag 13749. MNHN-IC-2007-0200, 1 (tag C) of 3, Mahé, Seychelles Islands, 22 Nov. 2004, Accouche et al. coll .

Eleotris vomerodentata Maugé, 1984 : holotype from Madagascar (MNHN-IC-1984-0803).

Eleotris pellegrini Maugé, 1984 : syntypes from Madagascar (MNHN-IC-1932-0108) and others (see above, E. pellegrini redescription).

Figures

Figure 1. – The five different cephalic neuromast patterns in Eleotris.

Figure4.– Eleotris vomerodentata, holotype MNHN-IC-1984-0803 (© M.I. Mennesson).

Tables

Table V. – Main morphometrics in Eleotris with a ‘2.4’ pattern in the Indian Ocean.

		Jaw length						Caudal peduncle depth
		9	10	11	12	13	14	10	11	12	13	14	15	16
E. acanthopoma	Males		2	3	6	5	1			1	1	8	1	6
	Females			2	3	−	1				2	4
E. vomerodentata	Males						1				1
E. pellegrini	Males	3	1	3	2	4	3	1	4	3	1	4	1	1
	Females		2	1	2					1	3	1
E. sahanaensis	Male			1						1
	Juv-Female	1							1
		Body depth at anus origin
		14	15	16	17	18	19	20	21	22	23	24	25
E. acanthopoma	Males					1	2	2	2	1	2	2	1
	Females						2	2	1	−	−	1
E. vomerodentata	Males								1
E. pellegrini	Males				1	2	1	1	2	4	−	3
	Females							1	−	−	−	1
E. sahanaensis	Male									1
	Juv-Female			1
		Head length
		26	27	28	29	30	31	32	33	34	35	36	37
E. acanthopoma	Males						3	4	1	2	4	2
	Females						1	2	1	1	1
E. vomerodentata	Males										1
E. pellegrini	Males							4	4	2	2	2	1
	Females						1	2	2
E. sahanaensis	Male							1
	Juv-Female					1
Predorsal length
		41	42	43	44	45	46	47	48	49	50
E. acanthopoma	Males	1	3	4	1	2	2	−	1	−	1
	Females				3	3
E. vomerodentata	Males							1
E. pellegrini	Males		1	2	2	4	3	3	2
	Females				1	1	1	1	−	1
E. sahanaensis	Male							1
	Juv-Female						1
		Preanal length
		60	61	62	63	64	65	66	67	68	69	70
E. acanthopoma	Males	1	−	3	3	3	1	2	1	1	−	1
	Females			1	2	2	−	−	1
E. vomerodentata	Males						1
E. pellegrini	Males			1	5	1	1	1	1	2	1	1
	Females			2	1	1	−	1
E. sahanaensis	Male				1
	Juv-Female		1

Predorsal length 47 (% SL) and preanal length 65