Schindleria nigropunctata Fricke & El-Regal, 2017

Ahnelt, Harald, 2019, Redescription of the paedomorphic goby Schindleria nigropunctata Fricke & El-Regal 2017 (Teleostei: Gobiidae) from the Red Sea, Zootaxa 4615 (3), pp. 450-456 : 451-452

Schindleria nigropunctata Fricke & El-Regal, 2017

( Figures 1 –3; Tables 1–2 )

Material examined. Holotype, SMF 35956, 15.9 mm standard length (SL), female, Red Sea, Egypt, Magawish Island , reef lagoon, 27°10′02″N, 33°52′27″E, 23 April 2016 . Paratype, SMF 35957, male, 13.9 mm SL, otherwise same data as holotype .

Comparative material. Schindleria macrodentata , holotype ZMUC 77624 . Female, 16.5 mm SL. Molucca Sea, Indonesia, between the islands Sulawesi and Halmahera , 00°29′N, 125°54′E . Schindleria praematura , syntypes, NMW 99183. 9 females, 18.3–20.5 mm SL. North West Hawaiian Islands, USA, French Frigate Shoal, Tern Island , 23°52’12”N, 166°17’2”W. May 1928 .

Diagnosis. A Schindler’s fish with a slender, elongated body which lacks pigmentation (preserved). First dorsal and pelvic fins absent. Pectoral fin of larval character, i.e. the pectoral fin rays are attached to a large cartilaginous paddle-like pectoral-radial plate not differentiated into radials. Body depth at pectoral-radial origin 4.8% of SL, at anus 6.3% of SL and at anal-fin origin 5% of SL; predorsal length 61.1% of SL; preanal length 72.6%; pre-swim bladder length 53.5% of SL; tail length (excluding caudal fin) 26.7% of SL. Origin of dorsal fin distinctly anterior to origin of anal fin (LDF); dorsal-fin rays 17; anal-fin rays 11–12; first anal-fin ray below 8 th dorsal-fin ray; 23 + 14 (37) myomeres; premaxilla and dentary with tiny teeth; female urogenital papilla roundish with two horn-like projections; male urogenital papilla rod-like, lacking distinct lobes.

Description. Morphometrics ( Table 1 ) and meristics ( Table 2 ) are given separately for the holotype and the paratype respectively. The data of the paratype are given in parentheses. Dorsal-fin rays 17 (17); first fin rays short, gradually increasing in length, longest on the anterior half of tail and decrease in length rearwards; anal-fin rays 12 (12); first anal-fin rays longest, decreasing in length rearwards; last dorsal- and anal-fin rays opposite each other; pectoral-fin rays 16 (16); principle caudal-fin rays 13 (13), dorsal- and ventral-most 2 (2) segmented, unbranched, and in between 9 (9) segmented and branched rays; principle caudal-fin rays preceded by 5 (5) procurrent rays dorsally and ventrally respectively; posterior-most procurrent ray short (about 25% of length of first principle caudal-fin ray) and simple, with no additional spiny process at its base. First dorsal-fin ray at myomere 17, the last at myomere 34; first anal-fin ray on myomere 21, last opposite last dorsal-fin ray; all fin rays unsegmented and unbranched, except nine segmented and branched rays of the caudal fin; myomeres 37 (37), precaudal 23, caudal 14; the swim bladder positioned between myomeres 15–17; upper and lower jaws with very small teeth, premaxilla toothed along its entire edge,>20 teeth; dentary toothed only anteriorly; close to the symphysis, ~ 9 (8) tiny teeth; lower jaws form a rounded arch. Body elongate and slender; but increases slightly in height from base of pectoralradial plate to about middle of tail, and narrows rapidly rearwards to origin of hypural plate. Head short (12.2 % of SL), with short snout (21.6% in HL) and with relatively small (19.6 % in HL), slightly oval eyes; pectoral-radial plate longer (2.8% in SL) than wide (maximal width 1.7 % in HL). Anal fin originates ventral to 8 th dorsal-fin ray (preanal length 72.6% of SL) ( Tables 1 , 2 ). Gut straight; anus below 7 th dorsal-fin ray. Urogenital papillae of female and males conspicuous; rounded with two lateral projections in the female and tubular with no distinct lobes at the opening in the male; the anterior 20% of the ovaries are empty; the first egg at about half the distance between the head and the swim bladder, otherwise filled with 19 large and a series of small eggs irregularly distributed between the large eggs; due to the preservation the number of small eggs is not quantifiable; e.g. between the last egg (#19) and the penultimate egg (#18) three small eggs extend in a row, between the eggs #18 and #17 and #17 and #16 respectively one small egg is discernable.

Coloration in preserved specimens. Entire body uniformly greyish-white with conspicuous dark grey eyes; cornea of eyes silvery; dorsal part of cornea with many black melanophores (“leopard pattern”) in a sickle-shaped arrangement; no dark pigmentation on dorsal side of head and no black or dark pigment spots on the sides of the trunk.

Distribution. S. nigropunctata is so far only known from the type locality, the Magawish Island near Hurghada ( Egypt) in the northern Red Sea (see Fricke & El-Regal 2017b).

Figures

FIGURE 1. Schindleria nigropunctata, holotype, SMF 35956, 15.9 mm SL, female. Scale 1 mm. Head of same specimen enlarged. Note sickle-shaped arranged blackish melanophores dorsally on the eye. Long white arrow = origin of dorsal fin; short grey arrow = origin of anal fin. Scale 0.5 mm. Photo by Sven Tränker, SGN.

Tables

TABLE 1. Body proportions in mm and, in parentheses in % of standard length of Schindleria nigropunctata, holotype SMF 35956

Standard length (SL)	15.9 mm
Sex	female
Pre-dorsal fin length	9.72 (61.1)
Pre-anal fin length	11.55 (72.6)
Pre-swim bladder distance	8.50 (53.5)
Head length	1.94 (12.2)
Tail length (excluding caudal fin)	4.25 (26.7)
Head width	0.69 (4.3)
Caudal-fin length	1.11 (7.0)
Body depth at pectoral-fin base	0.76 (4.8)
Body depth at anus	1.00 (6.3)
Body depth at origin of anal-fin	0.80 (5.0)
Body depth at base of 4 th anal-fin ray	0.93 (5.8)
Caudal peduncle length	1.00 (6.3)
Caudal peduncle depth	0.28 (1.7)
Pectoral radial plate length	0.45 (2.8)
Pectoral radial plate width (at origin)	0.24 (1.5)
Pectoral radial plate width (max.)	0.29 (1.7)
Snout length	0.42 (2.6)
Eye diameter horizontal	0.38 (2.4)
Eye diameter vertical	0.42 (2.6)
Postorbital length	1.07 (6.7)
Interorbital width	0.29 (1.8)
% of caudal peduncle length
Caudal peduncle depth	28.0
% of head length
Snout length	21.6
Eye diameter horizontal	19.6
Eye diameter vertical	21.6
Postorbital length	55.2
Interorbital width	14.9
Head width	35.6
% of eye diameter
Interorbital width	69.0
% of pectoral radial plate length
Pectoral radial plate width (at origin)	53.3
Pectoral radial plate width (max.)	62.2