Koumansetta hectori ( Smith 1957 )

Kovačić, Marcelo, Bogorodsky, Sergey V., Mal, Ahmad O. & Alpermann, Tilman J., 2018, Redescription of the genus Koumansetta (Teleostei: Gobiidae), with description of a new species from the Red Sea, Zootaxa 4459 (3), pp. 453-481 : 466-468

Koumansetta hectori ( Smith 1957)

Hector’s goby

Fig. 5 , Table 1

Seychellea hectori Smith 1957: 726 (type locality: western Indian Ocean, Seychelles, Mahé; holotype: SAIAB 214)— Smith 1959: 204 (western Indian Ocean); Smith & Smith 1963: 47 (listed).

Amblygobius hectori — Masuda et al. 1980: 274 ( Japan, description); Masuda et al. 1984: 256 ( Japan, description); Winterbottom & Emery 1986: 5 (Chagos Archipelago, description); Randall & Goren 1993: 3 ( Maldives, description); Myers 1999: 242 ( Palau, Truk, Pohnpei, description); Larson & Murdy 2001: 3595 (western Pacific, listed); Senou et al. 2007: 66 (Ryukyu Islands, listed); Randall & Lim 2000: 635 (South China Sea, listed); Adrim et al. 2004: 126 (Anambas Island, listed); Kuiter & Tonozuka 2004: 338 (Bali, photo); Senou et al. 2004: 373 ( Japan, photo); Anderson 2005: 96 ( Maldives, photo); Shibukawa 2009: 261 (Andaman Sea, description); Seeto & Baldwin 2010: 52 ( Fiji, listed); Satapoomin 2011: 65 (Andaman Sea, listed); Chabanet et al. 2012 ( Maldives, listed); Yoshigou 2013: 110 (Ryukyu Islands, listed).

Koumansetta hectori— Allen & Adrim 2003: 59 ( Indonesia, listed); Shao et al. 2008: 262 (southern Taiwan, listed); Fricke et al. 2011 ( New Caledonia, listed); Allen & Erdmann 2012: 981 (East Indies, description, photo from the Philippines); Fricke et al. 2013: 270 (Europa Island, listed); Motomura & Harazaki 2017: 133 (Yaku-shima Island, photo); Fricke et al. 2018: 334 ( Madagascar, listed).

Diagnosis. Dorsal-fin rays VI + I,15–17; anal-fin rays I,15–16; pectoral-fin rays 16–17; longitudinal scale series 49–54; scales in transverse series 17–18; interorbital wide, 67–90 % of eye diameter*; rear margin of upper jaw ending posteriorly slightly behind or at vertical through anterior margin of eye; first two dorsal-fin spines filiform, elongate, remaining progressively shorter, the sixth dorsal-fin spine almost reaches the origin of the second dorsal; body covered with small ctenoid scales, cycloid at axil of pectoral fin, nape and entire belly, also in the area between first dorsal fin and pectoral fin; predorsal scales 16–22, scales not reaching to the vertical through the posterior edge of eye, ending at the level of pore G or H'*; cheek and opercle naked; scales cover the basal 1/3–1/4 of caudal fin, becoming rapidly smaller and cycloid; prepectoral area with about 4–9 vertical series of fine cycloid scales covering the entire base of the pectoral fin; prepelvic area with cycloid scales, 9–14 in the midventral row; width at anal-fin origin 9.9–10.7% of SL; caudal peduncle depth 75.4–88.9% of its length; head depth 47.3–54.4% of head length; length of 11th second dorsal-fin ray 11.8–14.2% of SL; length of 8th anal-fin ray 13.7–14.9% of SL.

Color in life ( Fig. 5 ). Upper two-thirds of head brown with reddish hue anteriorly, greyish ventrally; upper half of body dark brown above pale yellowish white stripe extending from posterior part of upper jaw across lower cheek, lower opercle, and middle of pectoral-fin base and ending at caudal-fin base; lower half of head and body above this demarcation stripe grey to dark grey, usually with bluish hue on abdomen. A large black spot (ocellus), rimmed by a semicircular white mark below, on back at middle of the second dorsal fin, the spot extending into fin, where rimmed above in yellow; the black spot on back appears an open eye, sometimes with dark red anteriorly and posteriorly; another black spot larger than pupil dorsally at posterior end of caudal peduncle, rimmed below in yellow. Head with straight middorsal stripe from the tip of snout reaching origin of the first dorsal fin. Two narrow longitudinal yellow dorsolateral stripes on each side of head and body between middorsal and demarcation stripes. Upper stripe with U-shaped continuation at the front of snout from one side of body to the other side and continuing across upper part of eye and inner surface of orbit (only upper edge of orbit is visible through stripe) backwards to black ocellus, the stripe then continuing behind ocellus, more or less visible, along the top of caudal peduncle, where it ends at another black spot. Lower stripe extending from the upper lip through the lower part of eye, upper part of opercle, and upper pectoral-fin base running along lateral midline to the caudal peduncle where it is bended or separate, continuing as slightly lower positioned pale yellow mark on caudal-fin base. First dorsal fin with a reddish brown band, rimmed above in yellow, along base; a black ocellus, a little larger than pupil, broadly rimmed with yellow over first three spines and adjacent third membrane at midlevel of fin; an indistinct narrow reddish brown stripe on membranes between fourth and sixth spines; and an obvious orange-red streak or series of 2 or 3 elongate spots in outer half of first membrane. The second dorsal fin with a broad reddish brown band rimmed above in yellow, circumflexing black ocellus, along base; narrow yellow margin and an indistinct reddish brown submarginal band, more obvious on posterior half; an indistinct narrow reddish brown stripe in the middle of anterior half of fin; and yellow rear edge. Anal fin with pale grey to dark grey membranes and with narrow pale bluish white margin on posterior half and rear edge. Caudal fin with curved white bar at base, rest of fin with transparent membranes. Pectoral and pelvic fins with translucent membranes.

Distribution and habitat. Widespread from islands of the western Indian Ocean ( Seychelles, Reunion, Mayotte Island, Europa Island, and Madagascar), Chagos Archipelago, Maldives, and Andaman Sea east to the Indonesia, Malaysia (Tioman), Papua New Guinea, the Philippines, New Caledonia, Solomon Islands, Micronesia, and Fiji, north to Taiwan and southern Japan (Ryukyu and Yaeyama Islands), no positive records from Australia. The record from Fiji (easternmost record of the species) is based on material from USNM collected by Springer & team (e.g. USNM 236679, USNM 235950). Usually seen solitary hovering a short distance above bottom near base of coral reefs at depth of 3– 30 m.

Remarks. Diagnosis of K. hectori is the combination of original description ( Smith 1957) and the data from the material examined. Some data therefore represent extended ranges based on both sources: dorsal-fin rays VI + I,15–17 (original description: 16–17, studied material: 15–17); pectoral-fin rays 16–17 (original description: 16, studied material: 16–17); longitudinal scale series 49–54 (original description: 50–54, studied material: 49–54); vertical rows of scales in prepectoral area 4–9 (original description: 9, studied material: 4–7). Despite the geographically distant origins of the comparative material of K. hectori ( Comoros, Seychelles, Maldives, Philippines), the found data match well the original description from Seychelles. Where the data observed for the examined material differed from the original description, only the observed characters where included in the diagnosis and marked with *. Two generic characters were obvious in examined material that were not mentioned in original description: anterior nostril tubular, short, lacking process from rim; posterior nostril slit-like, closer to anterior nostril than to anterior margin of eye; and gill rakers on lower limb of anterior arch slender, weak and soft, 6–7 in number. The differences could be caused by the less precise measuring or by a less precise account in the original description, by lower quality of techniques (stereomicroscope or caliper) and by lack of staining method in the original description. However, even excluding these characters, there are enough characters matching both the original description and results for the studied material, so that this species be can positively identified among congeners. Contrary to this, the published meristic data for this species that are clearly distant from both, the counts in the original description and in this study, should be taken with caution; e.g. Allen & Erdmann (2012) gave a range of longitudinal scale series of 65–70 and the count of first dorsal and anal fins I,14. Some ranges among morphometric characters in Table 1 from the presently studied material from Comoros, Seychelles, Maldives, and the Philippines are non-overlapping with the data in the original description based on material from the Seychelles. Unfortunately, the morphometric methods were not described in Smith (1957), contrary to the precise description of measurement methods in the present description. Considering that specimens from type locality ( Seychelles) were examined in the present study, noticed differences are probably results of different measurement methods.

Figures

FIGURE 5. Koumansetta hectori, underwater photographs. A: Reunion; B: Maldives; C: Philippines. Photos by A. Diringer (A), J. Greenfield (B), P. Poppe (C).