Hetereleotris psammophila, Kovačić, Marcelo & Bogorodsky, Sergey V., 2014

Kovačić, Marcelo & Bogorodsky, Sergey V., 2014, A new species of Hetereleotris (Perciformes: Gobiidae) from the Red Sea, Zootaxa 3764 (4), pp. 475-481 : 476-480

Hetereleotris psammophila sp. nov.

( Figs. 1–3 )

Holotype. PMR VP 3054, female, 26.9 + 7.3 mm, Red Sea, Gulf of Aqaba, Egypt, Dahab, “Lighthouse”, 28°29’55”N, 34°31’12”E, sand close to reef, 18 m, coll. Bogorodsky, S.V., 23 Nov. 2012.

Paratype. PMR VP 3049, female, 26.8 +7.0 mm, Red Sea, Gulf of Aqaba, Egypt, Dahab, “Lighthouse”, 28°29’54”N, 34°31’12”E, sand close to reef, 21 m, coll. Bogorodsky, S.V., 19 Nov. 2012.

Diagnosis. Dorsal-fin rays VI + I,10, no prolonged spines; anal-fin rays I,9; pectoral-fin rays 14 or 15, two upper rays with short free tips; pelvic-fin rays I,5, fifth ray unbranched or with one bifurcation; pelvic fins separated and without fraenum; no scales; no head canals; suborbital rows of papillae with 4 transversal rows; anterior nostril long tube without process from the rim, posterior nostril short tube, about 1/3 length of anterior nostril; gill opening restricted to pectoral-fin base; transparent in life, with scattered tiny whitish blue and brownish yellow spots on body aligned in vertical rows, and the vertical dark bar at the caudal-fin base; predorsal area mottled with brown; head with dark brown bar extending obliquely from eye to upper lip, and three iridescent bluish blotches on cheek; coloration pattern is mostly lost in preserved material except dark bar at caudal-fin base.

Description. Body moderately elongate, laterally compressed posteriorly, the depth at pelvic-fin origin 16.8– 18.2% SL, at anal-fin origin 16.0–17.5% SL, width at pectoral-fin origin 19.0–20.1% SL. Preanal length 56.1– 58.6% SL, predorsal length 36.2–37.2% SL and prepelvic length 30.1–32.8 % SL. Head length 30.1–31.0% SL, head moderately depressed (its depth 83.9%–85.2% width), head width 20.1–20.8% SL, head depth 17.2–17.5% SL. Snout with moderately sloping profile. Anterior nostril tubular, long, extending anteriorly to upper lip, lacking process from rim. Posterior nostril tubular and short about 1/3 length of anterior nostril. Eyes dorsolateral, eye diameter 9.7–10.1% SL. Interorbital very narrow. No tentacle above eye. Mouth terminal, oblique. Angle of jaws ending posteriorly below anterior margin of pupil. Rows of pointed teeth in both jaws, outer row the largest. Tip of tongue bilobed. No mental frenum, surface smooth along midventral from lower lip backwards. Branchiostegal membranes fused to isthmus, gill openings restricted to pectoral-fin base. Lower limb of first gill arch joined to gill cover by membrane. No opercular spines. Caudal-peduncle depth 11.9–13.0% SL, caudal-peduncle length 19.4– 20.4% SL.

Fins: first dorsal fin with VI spines, second with I spine and 10 rays; anal fin with I spine and 9 rays; pectoralfin rays 14 or 15 (holotype 14/15, paratype 14/14), all rays branched, upper two with short free tips; branched caudal-fin rays 15, segmented 17; pelvic-fin rays I,5, fins completely separate and without fraenum, 5th ray unbranched or with one bifurcation. Distance between first and second dorsal fin origins 18.3–18.6% SL; second dorsal-fin base 28.7–29.4% SL; anal-fin base 22.7–23.9% SL. Spines of first dorsal fin not elongate or filamentous, fourth to sixth spine of first dorsal fin reaching to origin of second dorsal fin when folded down; length of third spine in the first dorsal fin 13.0–13.1% SL. Fin membrane from sixth spine of first dorsal fin connected with base of spine of second dorsal fin. Origin of first dorsal fin behind vertical at pectoral-fin base. Origin of anal fin slightly posterior to vertical at origin of second dorsal fin (opposite second segmented ray of the second dorsal fin). Length of third from last segmented ray in second dorsal fin 14.6–15.2% SL, length of third from last segmented ray in anal fin 13.0–13.1% SL. Pectoral fins extending posteriorly to vertical through origin of anal fin, length 23.1– 24.5% SL. Pelvic fins reaching anus, length 23.8–24.3% SL. Caudal fin rounded, shorter than head, 84.3%–90.1% head length, 26.1–27.1% SL.

Squamation: no scales.

Cephalic sensory systems ( Fig. 3 ): no head canals or pores. Rows of head sensory papillae (studied on left side of stained paratype) reduced, with additional individual larger papillae where head canals normally present in other species. Preorbital: two larger papillae present on each side at middorsal between eyes and posterior nostrils, and lower row s3 as three longitudinally arranged papillae above upper lip. Lateral series c reduced to two papillae below posterior nostril; and two papillae behind anterior nostril and above upper lip. Suborbital rows: no row a. Row b (6) longitudinal, short, anteriorly beginning close to anterior edge of eye and transversal row 4. Four transverse suborbital rows (1–4) of sensory papillae, row 1 longer, reaching upper lip, rows 2 and 3 shorter, ending ventrally close to row d, row 4 long, extended below level of row d (1: 7, 2: 4, 3: 6, 4: 10). Row d (4 + 9) above upper lip, and on the cheek, ending backwards below posterior part of eye, near transversal row c4. Preoperculo - mandibular rows: external row e (14+15); and internal row i (7+9) longitudinal and uniserial, divided into anterior and posterior sections; mental row f longitudinal (4). Oculoscapular rows: larger papillae longitudinally arranged on the position of missing oculoscapular canal: two papillae anteriorly, four papillae forming reverse T shape in the middle and two papillae posteriorly; anterior upper longitudinal row x1 (4) short and distant from posterior upper longitudinal row x2 (3); anterior lower transversal row z (5); transversal axillary rows as1 (3), as2 (3), as3 (3) present; axillary row la1 (2) present above as2; axillary row la2 present as single papilla above and behind row as3. Opercular rows: two larger papillae transversally arranged on the position of missing preopercular canal; transverse row ot (13); superior longitudinal row os (6); and inferior longitudinal row oi (5). Anterior dorsal rows: single papilla behind eye, row n as three transversally arranged papillae, row o absent, row g (4) longitudinal; row m as single papilla; row h longitudinal, short and divided (3 + 2). Interorbital rows: single larger papillae present on each side at middorsal between posterior part of eyes.

Colour: in life ( Figs. 1 A, 2A), transparent, with small brownish yellow and whitish blue spots on body surface, the spots tending to lie in vertical rows; vertical black bar at caudal-fin base; an internal series of three large, horizontally-elongate, black blotches alternating with white along vertebral column; back with few irregular dark brown marks, first two extending onto third and fourth, and sixth dorsal-fin spines, respectively; predorsal area mottled with dark brown; head with few melanophores, oblique dark brown bar from upper lip to pupil, continuing faintly on iris dorsoposteriorly, and row of small dark brown spots extending obliquely from eye across cheek; iridescent whitish blue blotches on cheek, lower opercle and abdomen; red gills visible through thin gill cover; eyes whitish green, with dark green pupil; the dorsal fins mostly transparent, with scattered whitish and brown pigments basally and scattered melanophores along margin; anal fin transparent, with a few melanophores along the ray tips; caudal fin transparent with few melanophores along the fin edges, rays blackish basally; pectoral fins transparent, except for a brown spot at upper basal part and scattered melanophores on the fin and fin-lobe; pelvic fins whitish.

After death ( Fig. 1 B), specimens lost transparency and body became opaque, retaining surface coloration of live specimens. Scattered melanophores on membranes and rays on margin of median fins become more obvious.

In alcohol ( Figs. 1 C, 2B), body opaque white, with rare and reduced presence of melanophores only on the upper part of the body, mostly anteriorly. Eyes dark, including pupil. Head retains mottled pigmentation of predorsal area and dark band from upper lip to pupil of eye. Cheek and opercle with a few scattered melanophores. The dorsal fins transparent, the rare dark pigments still visible on dorsal fins at the base and tips. Anal fin transparent, with rare melanophores along the fin tips. Caudal fin transparent, with the vertical dark bar at the caudal-fin base and a few melanophores along the fin edges. Pectoral fins transparent, a few melanophores visible on the fin-lobe. Pelvic fins transparent to whitish.

Etymology. Named psammophila from the Greek psammos, meaning sand, and phila, meaning loving, in reference to the sand habitat in which this species was found.

Habitat. Species of the genus Hetereleotris are cryptic shallow-water species, except for H. exilis known from the depth of 53 m, and usually hidden in reefs or between rocks. Hetereleotris psammophila is active at night; it was observed on sand bottom close to coral reefs at depth of 18–21 m at the type locality; it was also observed in Naama Bay, Gulf of Aqaba, at night at depth of 8 m. When disturbed, gobies quickly retreated, not trying to hide or burrow in the sand.

Remarks. The new species resembles three other species of the genus ( H. caminata (Smith, 1958) , H. vulgaris (Klunzinger, 1871) and H. diademata (Rüppell, 1830)) in lacking head and body scales. It further differs from H. caminata and H. vulgaris by the absence of head pores. Therefore, the new species is unique among the species of the genus Hetereleotris , except for H. diademata , in the combination of absence of both scales and head canals (confirmed in the stained paratype). It clearly differs from H. diademata in having fewer soft rays in the second dorsal and anal fins, and in coloration: second dorsal-fin rays I,10 and anal-fin rays I, 9 in H. psammophila vs. second dorsal-fin rays I,12 and anal-fin rays I, 11 in H. diademata ; H. psammophila transparent in life with a scattered tiny white and brownish orange spots on body, with a vertical dark bar at the caudal-fin base, mottled pigmentation of predorsal area, and three iridescent bluish blotches on cheek vs. H. diademata ( Fig. 4 ) with intensively pigmented head, body, and fins, and with broad vertical dark bars on body (the bar under the first dorsal fin darker than other bars), and head with obvious oblique dark bar extending posteroventrally from eye to corner of preopercle.

Comparative material examined. Hetereleotris diademata : PMR VP 2479, 1 female, 27.2 + 7.2 mm, Hurghada, Egypt, Red Sea, coll. S.V. Bogorodsky, 22 Sep. 2009.

Figures

FIGURE 1. Hetereleotris psammophila sp. nov. Holotype: PMR VP 3054, female, 26.9 + 7.3 mm, Dahab, Egypt, Red Sea. A: live specimen; B: freshly collected specimen; C: preserved specimen. Photos by S. V. Bogorodsky (A, B), M. Kovačić (C).

FIGURE 2. Hetereleotris psammophila sp. nov. Paratype: PMR VP 3049, female, 26.8 + 7.0 mm, Dahab, Egypt, Red Sea. A: live specimen; B: preserved specimen. Photos by S. V. Bogorodsky (A), M. Kovačić (B).

FIGURE 3. Hetereleotris psammophila sp. nov., cephalic sensory papillae: paratype, PMR VP 3049, female, 26.8 + 7.0 mm. Terminology in text. Drawing by M. Kovačić.

FIGURE 4. Hetereleotris diademata, PMR VP 2479, 27.2 + 7.2 mm, Hurghada, Egypt, Red Sea. Photo by S. V. Bogorodsky.