Black Spot Pygmy Goby

Eviota nigriventris Giltay

Eviota nigriventris Giltay, 1933:93, fig. 28 [type-locality: Banda Neira and Goenoeng Api].

MATERIAL EXAMINED.—133 specimens from 6 localities totaling 42 males, 54 females, and 37 juveniles; total size range 8.3–18.9; largest male 18.9, largest female 16.7; smallest gravid female 13.6.

Syntypes: ISNB 42, 2(12.5, 12.0), male and female; Entre Banda Neira et Goenoeng Api, 24 Feb 1929, S.A.R. le Prince Leopold de Belgique.

Other Material: INDONESIA: KARIMUNDJAWA ISLAND: USNM 219279, 1 (12.7), male; 29 Mar 1974, V. G. Springer, 74-28. USNM 219280, 2 (13.0, 13.6), females; 30 Mar 1974, V. G. Springer, 74-30. USNM 209680, 5 (10.6–13.2), 1 male (13.1), 4 females (13.2); Ceram, 10 Jan 73, V. G. Springer, 73-6. FIJI ISLANDS: BPBM 11584, 2 (14.2, 11.3), male and female; Nukulau I., 26 Apr 1970, M. Gawel, USP 1503. GREAT BARRIER REEF: ANSP 141218, 1 (10.7), juv., northern Escape Reef, 24 Jan 1969, J. Tyler, TS,A-30. AMNH 39069, 5 (8.3–14.3), 1 juv., 2 males (10.8), 2 females (14.3); northern Escape Reef, 24 Jan 1969, C. L. Smith, S69-33. PAPUA NEW GUINEA: BISMARCK ARCHIPELAGO, Hermit Is. (collected by V. G. Springer in 1978): USNM 219648, 64 (5.7–17.0), 25 juv., 20 males (17.0), 19 females (15.5); 1 Nov, VGS 78-13. USNM 219645, 17 (7.8–18.9), 4 juv., 6 males (18.9), 7 females (16.7); 2 Nov, VGS 78-16. USNM 219647, 4 (9.0–15.7), 1 juv., 1 male (14.5), 2 females (15.7); 31 Oct, VGS 78-12. USNM 219650, 26 (10.6–17.3), 5 juv., 9 males (17.3), 12 females (14.5); 5 Nov, VGS 78-20. USNM 219646, 2 (11.9, 12.1), females; 4 Nov, VGS 78-19. PHILIPPINE ISLANDS: USNM 219649, 2 (14.4, 15.1), females; Balicasag I., 10 Jun 1978, V. G. Springer, SP78-38.

DIAGNOSIS.—Pectoral rays simple; spinous dorsal fin elongate or filamentous in both sexes, the second or third spine longest; fifth pelvic fin ray well developed, five-tenths to seven tenths length of fourth ray; cephalic sensory pore system lacking IT and PITO pores; a broad, dark band on lower body, from snout to end of caudal fin, with an enlarged black spot at base of lower caudal fin rays, band may be variously reduced (Figure 66a–c).

DESCRIPTION.—Dorsal fin VI-I,9(14), VI-I, 10-(1); anal fin I,8(9), I,9(5); pectoral fin 15(3), 16(8), 17(3), 18(1); pelvic fin I,4 5/10(1), I,4 6/10(3), I,4 7/10(5); fourth ray of pelvic fin with 3–5 branches, averaging 3.8; segments between consecutive branches of the fourth pelvic fin ray number 3–6, averaging 4.3; pelvic fin membrane well developed; branched caudal fin rays 11(6); segmented caudal fin rays 17(16); lateral scale rows 21(1), 22(1), 23(1); transverse scale rows 5(1), 6(1); scales with 23–36 ctenii, 10–13 primary radii, 1–2 secondary radii; breast scaled.

The cephalic sensory pore system is pattern 3. The cutaneous papilla system is pattern B, as described for Eviota lachdeberei. The postocular area is considerably eroded in our specimens.

First four spines of dorsal fin may be elongate or filamentous in both sexes, the second or third spine longest in males, extending to end of second dorsal fin base, when depressed, and to the base of the eighth dorsal ray in females; pelvic fins long, extending beyond origin of anal fin.

Genital papilla in males not fimbriate, very long, slender, slightly flared, and bilobed at tip, extending, in some, to base of third anal fin ray; female papilla bulbous, extending to first anal fin ray, with 2–4 fingerlike projections on each side.

One female from Karimundjawa, 13.6 mm SL, was gravid.

Vertebrae 10(6), 11(1) precaudal and 15(7) caudal, total 25(6), 26(1).

COLOR IN PRESERVATION.—The prominent coloration is a broad, dark band from tip of snout, through tip of lower jaw, eye, cheek and opercle, base of pectoral fin, and, ventrolaterally, through trunk to end of caudal peduncle, where it terminates in an intense, black spot at the lower part of base of the caudal fin, the round portion of the spot directed posteriorly onto lower caudal rays; lower part of caudal fin dusky, with remnants of the dark band; anteriorly on body, the band is about as wide as the height of the pectoral fin base, and meets the upper and lower margins of the pectoral base, but becomes slightly narrower on caudal peduncle; the dorsal border of the band follows the midbody septum; lower portion of cheek and opercle dusky or pale; chin and breast pale; nape pale or with fine dark chromatophores; base of pectoral fin with a deep, dark mark, located mostly on posterior portion; anterior portion of pectoral base, especially centrally, usually pale; upper part of dark pectoral mark more intense than lower, the ventral portion of the base sometimes pale; belly, below ventrolateral dark band, slightly dusky to pale; upper part of trunk pale, with traces of fine chromatophores; no subcutaneous bars or caudal peduncle spot visible on trunk; first and second dorsal fins finely dusky; anal fin dusky to brown, the posterior portion more heavily brown and darker than the dorsal fins; upper part of caudal fin mostly pale with some fine chromatophores; pectoral and pelvic fins pale. Females somewhat paler than males.

GEOGRAPHIC DISTRIBUTION.—Known from 6 widely separated localities: Balicasag Island, Philippine Islands; Karimundjawa Island in the Java Sea; Ceram and Banda Islands, Indonesia; Bismarck Archipelago; northern Escape Reef, New South Wales, Australia; and the Fiji Islands (Figure 61).