EVIOTA NIGRIVENTRIS - (GILTAY, 1933)
Picture courtesy of: Alain Daoulas
Actinopterygii (Gigaclass) > Actinopteri (Class) > Teleostei (Subclass) > Gobiiformes (Order) > Gobioidei (Suborder) > Gobiidae (Family) > Gobiinae (Subfamily) > Eviota (Genus)
Redbelly dwarfgoby, Red-and-black eviota, Blackbelly pygmy goby, Blackbelly goby, Black-spot pygmy-goby, Somewake-isohaze, ソメワケイソハゼ, 黑腹矶塘鳢,
Description
Dorsal spines (total): 6-7; Dorsal soft rays (total): 9; Anal spines: 1; Anal soft rays: 8; Pectoral fin rays: 16-17 (usually: 16), all unbranched; Pelvic fin membranes well developed, almost reaching to the tips of the rays; Caudal fin rays: 12 branched and 17 segmented; Lateral scale rows: 22-23 (usually: 23); Transverse scale rows: 7; Scales on ventral surface of abdomen and embedded cycloid scales on the breast; First dorsal fin triangular in shape, first two spines of first dorsal fin may be filamentous in males, extending back past end of second dorsal fin in topotype; Genital papilla in male smooth, not fimbriate, with two lateral points at the end, extending to base first soft ray of anal fin in topotype; Female papilla bulbous with three fingers on each side at the end; Front of head rounded with an angle of about 65° from the horizontal axis; Mouth oblique forming an angle of about 45° to horizontal axis of body, lower jaw not projecting, maxilla extending to posterior third of pupil; Anterior tubular nares long and black, reaching to anterior edge of upper lip; Gill opening extending forward to posteroventral edge of preoperculum. Max. length: 2.5 cm TL. Depth range: 5 - 25 m.
Color
Body with a broad red stripe, covering most of the head and extending back on the ventral half of the body to the caudal-fin base, where it ends at a black semicircle at the caudal-fin base that extends onto the fin rays. There is a narrow white line running along the dorsal surface of the ventral red stripe from above the pectoral-fin base back to the caudal-fin base where it curves down around the posterior margin of the black semi-circular spot. Dorsal surface above this white line translucent cream, with red along the dorsal-fin bases. Nape with a slight yellowish tinge. Ventral side of head, breast, and abdomen white below red stripe. A short white stripe in a darker area under center of eye, angling forward to jaw. A similar white stripe behind the eye, at the level of the top of the pupil, extending back to above the preoperculum. Pupil of eye black, iris red, the same color as the red body stripe. A white stripe edged with black across and above top of the pupil. Another white stripe edged with black extending from snout, across interorbital area and onto top of head. Membranes of pectoral, pelvic, and first dorsal fin with a reddish tinge. Second dorsal fin with a wash of dark pigment on the membranes. Anal fin with a reddish wash on the anterior third, the remainder with a wash of dark pigment becoming black distally. The distal margin of the anal fin edged with sky blue. Caudal fin with reddish rays and membranes, the ventral margin sky blue.
Etymology
Eviota: from Greek prefix, ev-, eu-, = good or well, very + from Greek letter, iota = smallest letter in the Greek alphabet and often figuratively used to describe anything small or insignificant. Referring to Eviota epiphanes (Jenkins, 1903), which, at 1.0-1.9 cm in length, Jenkins claimed was the “smallest vertebrate that has up to this time been described”.
nigriventris: from Latin, nigrico = blacken, darken + from Latin, venter = the belly. Referring to black or dusky ventral half of body in alcohol (red in living specimens).
Original description: Eviota nigriventris Giltay, 1933 - Type locality: between Banda Neira and Goenoeng Api, Indonesia, 24 Feb. 1929, S.A.R. le Prince Leopold de Belgique, Institut royal des Sciences naturelles de Belgique.
Distribution
Eastern Indian Ocean, western Pacific: eastern Andaman Sea and Indonesia, east to New Ireland (Papua New Guinea), north to Ryukyu Islands (Japan), south to Chesterfield Islands and New Caledonia.
Biology
Lives among branching and encrusting corals in lagoon reefs. Forms groups among branches of Acropora coral.
Similar species
Eviota brahmi (Greenfield & Tornabene, 2014) - Reported from Western Pacific: Papua New Guinea.
Eviota dorsogilva (Greenfield & Randall, 2011) - Reported from Fiji.
Eviota dorsopurpurea (Greenfield & Randall, 2011) - Reported from Western Pacific: Papua New Guinea and d'Entrecasteaux Islands (Solomon sea).
Last update: 11, June 2023
Actinopterygii (Gigaclass) > Actinopteri (Class) > Teleostei (Subclass) > Gobiiformes (Order) > Gobioidei (Suborder) > Gobiidae (Family) > Gobiinae (Subfamily) > Eviota (Genus)
Redbelly dwarfgoby, Red-and-black eviota, Blackbelly pygmy goby, Blackbelly goby, Black-spot pygmy-goby, Somewake-isohaze, ソメワケイソハゼ, 黑腹矶塘鳢,
Description
Dorsal spines (total): 6-7; Dorsal soft rays (total): 9; Anal spines: 1; Anal soft rays: 8; Pectoral fin rays: 16-17 (usually: 16), all unbranched; Pelvic fin membranes well developed, almost reaching to the tips of the rays; Caudal fin rays: 12 branched and 17 segmented; Lateral scale rows: 22-23 (usually: 23); Transverse scale rows: 7; Scales on ventral surface of abdomen and embedded cycloid scales on the breast; First dorsal fin triangular in shape, first two spines of first dorsal fin may be filamentous in males, extending back past end of second dorsal fin in topotype; Genital papilla in male smooth, not fimbriate, with two lateral points at the end, extending to base first soft ray of anal fin in topotype; Female papilla bulbous with three fingers on each side at the end; Front of head rounded with an angle of about 65° from the horizontal axis; Mouth oblique forming an angle of about 45° to horizontal axis of body, lower jaw not projecting, maxilla extending to posterior third of pupil; Anterior tubular nares long and black, reaching to anterior edge of upper lip; Gill opening extending forward to posteroventral edge of preoperculum. Max. length: 2.5 cm TL. Depth range: 5 - 25 m.
Color
Body with a broad red stripe, covering most of the head and extending back on the ventral half of the body to the caudal-fin base, where it ends at a black semicircle at the caudal-fin base that extends onto the fin rays. There is a narrow white line running along the dorsal surface of the ventral red stripe from above the pectoral-fin base back to the caudal-fin base where it curves down around the posterior margin of the black semi-circular spot. Dorsal surface above this white line translucent cream, with red along the dorsal-fin bases. Nape with a slight yellowish tinge. Ventral side of head, breast, and abdomen white below red stripe. A short white stripe in a darker area under center of eye, angling forward to jaw. A similar white stripe behind the eye, at the level of the top of the pupil, extending back to above the preoperculum. Pupil of eye black, iris red, the same color as the red body stripe. A white stripe edged with black across and above top of the pupil. Another white stripe edged with black extending from snout, across interorbital area and onto top of head. Membranes of pectoral, pelvic, and first dorsal fin with a reddish tinge. Second dorsal fin with a wash of dark pigment on the membranes. Anal fin with a reddish wash on the anterior third, the remainder with a wash of dark pigment becoming black distally. The distal margin of the anal fin edged with sky blue. Caudal fin with reddish rays and membranes, the ventral margin sky blue.
Etymology
Eviota: from Greek prefix, ev-, eu-, = good or well, very + from Greek letter, iota = smallest letter in the Greek alphabet and often figuratively used to describe anything small or insignificant. Referring to Eviota epiphanes (Jenkins, 1903), which, at 1.0-1.9 cm in length, Jenkins claimed was the “smallest vertebrate that has up to this time been described”.
nigriventris: from Latin, nigrico = blacken, darken + from Latin, venter = the belly. Referring to black or dusky ventral half of body in alcohol (red in living specimens).
Original description: Eviota nigriventris Giltay, 1933 - Type locality: between Banda Neira and Goenoeng Api, Indonesia, 24 Feb. 1929, S.A.R. le Prince Leopold de Belgique, Institut royal des Sciences naturelles de Belgique.
Distribution
Eastern Indian Ocean, western Pacific: eastern Andaman Sea and Indonesia, east to New Ireland (Papua New Guinea), north to Ryukyu Islands (Japan), south to Chesterfield Islands and New Caledonia.
Biology
Lives among branching and encrusting corals in lagoon reefs. Forms groups among branches of Acropora coral.
Similar species
Eviota brahmi (Greenfield & Tornabene, 2014) - Reported from Western Pacific: Papua New Guinea.
Eviota dorsogilva (Greenfield & Randall, 2011) - Reported from Fiji.
Eviota dorsopurpurea (Greenfield & Randall, 2011) - Reported from Western Pacific: Papua New Guinea and d'Entrecasteaux Islands (Solomon sea).
Last update: 11, June 2023