Hypseleotris agilis Herre, 1927

Keith, Philippe & Mennesson, Marion I., 2020, Review of Giuris (Teleostei: Eleotridae) from Indo-Pacific islands, with description of three new species, Cybium 44 (4), pp. 331-349 : 345-347

publication ID

https://doi.org/ 10.26028/cybium/2020-444-004

persistent identifier

https://treatment.plazi.org/id/03DA87DB-511A-D63E-FF3D-FEA510A79116

treatment provided by

Felipe

scientific name

Hypseleotris agilis Herre, 1927
status

 

Hypseleotris agilis Herre, 1927 View in CoL

Material examined

Holotype. – MNHN A-1690, Manila, Philippines.

Others. – MNHN 2019-0111 About MNHN , 4 specimens from Lake Taal , Luzon Is., Philippines ; tags 14580 to 14583. MNHN 2018-0719 About MNHN , 1 About MNHN spm from Alegre River , Panay Is., Philippines . MNHN 2020-0147 About MNHN , 5 About MNHN spms from Lake Mainit , Mindanao Is., Philippines ; tags 14592 to 14596.

Diagnosis

The species has 15 pectorals rays, a small eye diameter (5-6% SL), a small interorbital length (10-12% SL), few scales around the eye (6-8) and a great preanal length (64- 70% SL).

Description

The scale and ray counts are given in table III and morphometrics in table IV.

The body is more ovoid than elongated. The body depth at anus is 23-27 (% SL), at first dorsal fin 22-27 (% SL), and the caudal peduncle depth is 14-17 (% SL). Predorsal length 43-47 (% SL) and preanal length 64-70 (% 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 (8-11% SL) are small. Inwardly curved teeth set on both jaws and larger on outer row. Posterior end of maxillary not extending to below around anterior margin of eye. Lips with numerous internal short papillae. Eye small, diameter 5-6 (% SL) and interorbital length 10-12 (% SL).

Dorsal fins VI-I,8 without filamentous rays. The first dorsal fin is with, third, fourth and fifth rays longer. Anal fin I,9 directly opposite to the second dorsal fin. The caudal fin is with 14-15 branched rays and its posterior margin is round- ed. Pelvic fins separate, I,5. Pectoral fins 15, with the posteri- or margin rounded. Lateral scales 29-31, 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 of top of head and back bigger than those of belly. Scales in transverse back series 9-11, in transverse forward 12-14, in predorsal 15-18 and in zigzag 8-9. 6-8 scales around the eye (ENO). 25 vertebrae.

Absence of oculoscapular canal and supratemporals and presence of a short preopercular canal with the 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. The females have bulbous urogenital papilla with fimbriate projections around distal opening.

Colour in preservation

Males. – Background of body dark brown on the back and brown on the flanks. Top of head brownish to dark, lateral part of head with 3 brown stripes radiating from the eye to the cheeks and operculum. The belly is greyish. Flanks with 2 or 3 discontinuous and sinuous longitudinal lines of greyish spots. The first dorsal fin is brownish with several big greyish dots between rays. The second dorsal fin is brownish with several greyish dots between rays. Pectoral fins greyish. Pelvic fins greyish. The anal fin is brownish with two or three rows of greyish dots. Caudal fin brownish to dark with two rows of greyish dots.

Females. – Background of body brownish to greyish on the back. Top of head brownish, lateral part with 3 thin red stripes radiating from the eye to the cheeks and operculum. Flanks with several rows of greyish rounded patches from pectoral base to hypural base. Belly greyish. Caudal, first and second dorsal fins brownish. Pectoral, anal and pelvic fins greyish.

Colour in life

Males. – General pattern colourful and variable, two main patterns were observed: (1) Background of body more or less entirely greenish and orange or bright yellow. Top and lateral part of head greenish to greyish with 3 reddish stripes radiating from the eye to the cheeks and operculum, continuing or not on the pectoral base. The belly is yellowish to orange. About ten bluish rounded patches along the flanks from pectoral base to hypural base. These patches are underlined by more or less orange scales. The first and second dorsal fins are orange to yellowish with several blue dots; the upper part is greyish. Pectoral fins greyish hyaline, base of pectoral rays bright yellow. Pelvic fins hyaline to yellowish with a yellow distal margin. Anal fin greyish to yellowish with several blue dots and a red yellow margin. Caudal fin brownish with 4-5 brown dots at the hypural zone and orange parts at the base ( Fig. 6A View Figure 6 ). (2) Background of body brownish to black on the back to dark yellowish on the flanks. Top of head brownish to black, lateral part of head dark yellowish with 3 brown stripes radiating from the eye to the cheeks and operculum, the upper one continuing on the pectoral base. The belly is yellowish to bluish. Flanks with 2 or 3 discontinuous and sinuous longitudinal lines of bright yellow spots. The first and second dorsal fins brownish with several big bright yellow dots between rays and a yellow distal margin. Pectoral fins greyish. Pelvic fins greyish with a red distal margin. The anal fin is brownish to greyish with two or three rows of bright yellow dots and a red distal margin. Caudal fin brownish to dark with two rows of yellow dots ( Fig. 6B View Figure 6 ).

Females. – Background of body brownish to greyish on the back. Top of head brownish, lateral part yellowish with 3 thin red stripes radiating from the eye to the cheeks and operculum. Flanks with nine to eleven alternating bluish and yellowish rounded patches from pectoral base to hypural base. Belly orange to yellowish. Caudal fin brownish with 4-5 yellowish dots at the base. The first dorsal fin is yellowish with several dark blue dots on the last three rays; the upper part is greyish. The second dorsal fin is yellowish with several dark blue dots forming lines, on all rays, from median to basal parts; the upper part is greyish. Pectoral fins greyish to reddish. Pelvic fins yellowish with a red distal margin. The anal fin is yellowish with basal dark stripe underlined by a yellow one.

Ecology

The species occurs in vegetation of ponds, lakes, swamps, and in the lower parts of rivers. It is heavily fished in some lakes like Lake Taal in Luzon. It is omnivorous and feeds on small crustaceans and aquatic insects.

Distribution

The species occurs in several islands of the Philippines (Luzon, Lake Taal; Panay; Mindanao, Lake Mainit).

Comparison

Giuris laglaizei differs from the other species sequenced by having a significant percentage of divergence in COI gene (2.8-11.3%) (Tab. II) and by the colourful pattern of the male. Moreover it differs from G. yahayai by a combination of characters including fewer scales in transverse forward series (12-14 vs. 17-20) and fewer scales around the eye (6-8 vs. 11-14), a smaller body depth at anus (23-27 vs. 26-36% SL) and a smaller body depth at first dorsal fin (22- 27 vs. 26-39% SL). It differs from G. viator in having 15 pectorals rays vs. always 14 rays, fewer scales in transverse forward series (12-14 vs. 14-15) and zigzag series (8-9 vs. 9-10). It differs from G. tolsoni in having 15 pectorals rays vs. always 14 rays, a smaller eye diameter (5-6 vs. 6-7% SL) and a greater body depth at anus (23-27 vs. 16-22% SL). It differs from G. margaritaceus in having fewer scales in zigzag series (8-9 vs. 9-10), fewer scales around the eye (6-8 vs. 8-11), and 15 pectorals rays vs. 14-15. It differs from G. charpini in having 15 pectorals rays vs. 13-14, more scales in lateral series (28-31 vs. 27-29) and fewer scales around the eye (6-8 vs. 8-10). It differs from G. aporocephalus in having fewer scales around the eye (6-8 vs. 9-14) and a smaller interorbital length (10-12 vs. 13-16% SL). It differs from G. caussei in having fewer scales around the eye (6-8 vs. 11-12), a greater body depth at anus (23-27 vs. 16-22% SL) and a smaller interorbital length (10-12 vs. 13-15% SL).

NB. – Several specimens from Lake Mainit ( Philippines, Mindanao), type locality of Hypseleotris agilis Herre, 1927 ( Fig. 6E View Figure 6 ), were studied here and they are genetically includ- ed in the G. laglaizei clade. The percentage of divergence in COI gene is 1.4% between Lake Taal (Luzon)/Alegre River (Panay) and Lake Mainit (Tab. II) and the specimens of this last locality are a bit different: the specimens are stockier, with a taller body (%Hda 26-31 vs. 23-27) and 14-15 pectoral rays vs. 15. The colours are also slightly different (see below and Fig. 6C, D View Figure 6 ). This may be due to the specific life or trophic conditions in this lake. It could be interesting to verify if the individuals are all or always amphidromous; probably a different ESU.

MNHN

Museum National d'Histoire Naturelle

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