TRIMMA KITRINUM - (WINTERBOTTOM & HOESE, 2015)
Picture courtesy of: Alain Daoulas
Gobie pygmée citron, Citron pygmygoby, Citron dwarfgoby,
Description
Dorsal spines (total): 7; Dorsal soft rays (total): 8, second spine longest and reaching to between base of second ray of D2 and middle of peduncle when adpressed, first ray of second dorsal fin branched, posterior margin of last ray to anterior third to mid-peduncle; Anal spines: 1; Anal soft rays: 8, first ray branched, last ray branched reaching posteriorly to anterior third to mid-peduncle; Pectoral fin rays (total): 13-14, all rays unbranched, fin reaching posteriorly to a point above urogenital papilla to anal spine; Pelvic fin rays: I 5, first four rays with one sequential branch each, fifth ray unbranched and 50–66 % the length of fourth, fourth ray reaching posteriorly to a point between bases of second to fifth anal ray; No fraenum; Basal membrane vestigial (< 5% length of fourth ray). Lateral line scales: 23–24; Transverse scales: 7–8; Predorsal scales in somewhat irregular rows: 11–12–14; Scales on cheek, opercle, pectoral-fin base, breast, anterior midline of belly and anterior predorsal cycloid, others ctenoid; Cheek, opercle and pectoral-fin base scales often abraded off and missing, cheek with 3 rows, 1–3 in upper row, 7–8 in middle row and 1–3 in lowermost row; Opercle usually with 3, 4 and 1 scales in three horizontal rows; Pectoral fin base with 3 vertical rows of 4–5 scales within each row, although anterior row may have fewer; Scales anterior to pelvic-fin base 5–9. Upper jaw teeth with an outer row of evenly spaced, straight, conical teeth extending to distal premaxilla, about twice the size of the inner teeth, which consist primarily of a single complete row with a few extra teeth near symphysis. Lower jaw teeth with an outermost row of 3–5 outwardly-flaring, enlarged, curved canines, a row of slightly smaller, straighter canines which decrease in size posteriorly and end on coronoid process of dentary, and 1–2 irregular rows of small conical teeth near symphysis, reduced to a single row posteriorly. Tongue truncately rounded, often with a slight central point at tip. Gill opening extends anteroventrally to below mid-pupil; Outer gill rakers on first gill arch: 4 + 16–18, total rakers: 20–22. Anterior nares in a short tube adjacent to upper lip, posterior opening a large pore with a rim; Nasal sac slightly raised; Nasal apparatus confined to anterior half of snout. Bony interorbital width: 70–80 100 % of pupil diameter in width, interorbital somewhat concave with a raised median ridge of soft tissue (forming a broad, gentle ‘W’ in cross section); Epaxialis reaching anteriorly in dorsal midline to above anterior to middle of pupil. Max. length: 2.7 cm SL. Depth range: 1 - 36 m.
Color
Background color light yellow-brown, somewhat darker over abdomen, with scale pockets more intensely outlined with dark chromatophores, particularly along dorsum. End of caudal peduncle lighter, grading into bright yellow caudal fin with streaks of violet-red in some interradial membranes, especially basally. Head, especially cheek and opercular regions, suffused with red. Iris mostly dark with yellow flecks, but with clear inner ring of yellow around lens aperture. Pectoral-fin rays red, with elements of pelvic, anal and dorsal varying between dirty yellow, red or brown. Fin membranes hyaline except for half-pupil diameter high basal band of melanophores in second dorsal fin. Specimens from Tonga, Solomons and Samoa are somewhat darker overall than Fijian examples.
Etymology
Trimma: from Greek, trimma, -atos = something crushed.
kitrinum: from Greek, kitrinos = citron-yellow, citron, in allusion to the distinctive yellow caudal fin of the new species.
Original description: Trimma kitrinum Winterbottom & Hoese, 2015 - Type locality: Great Astrolabe Reef, eastern side of offshore reef about level of Dravuni Island (178°33'42"E, 18°44'51"S), Fiji Islands, depth 10-15 meters, 29 Mar. 1983, Winterbottom et al.
Distribution
Western Pacific: Maluku (Indonesia) east to Marshall Islands, Tonga and Samoa, north to Guam, south to Queensland (Australia) and New Caledonia.
Biology
Inhabits crevices and caves of mostly dead coral rock and sandy rubble bottom. Solitary.
Description
Dorsal spines (total): 7; Dorsal soft rays (total): 8, second spine longest and reaching to between base of second ray of D2 and middle of peduncle when adpressed, first ray of second dorsal fin branched, posterior margin of last ray to anterior third to mid-peduncle; Anal spines: 1; Anal soft rays: 8, first ray branched, last ray branched reaching posteriorly to anterior third to mid-peduncle; Pectoral fin rays (total): 13-14, all rays unbranched, fin reaching posteriorly to a point above urogenital papilla to anal spine; Pelvic fin rays: I 5, first four rays with one sequential branch each, fifth ray unbranched and 50–66 % the length of fourth, fourth ray reaching posteriorly to a point between bases of second to fifth anal ray; No fraenum; Basal membrane vestigial (< 5% length of fourth ray). Lateral line scales: 23–24; Transverse scales: 7–8; Predorsal scales in somewhat irregular rows: 11–12–14; Scales on cheek, opercle, pectoral-fin base, breast, anterior midline of belly and anterior predorsal cycloid, others ctenoid; Cheek, opercle and pectoral-fin base scales often abraded off and missing, cheek with 3 rows, 1–3 in upper row, 7–8 in middle row and 1–3 in lowermost row; Opercle usually with 3, 4 and 1 scales in three horizontal rows; Pectoral fin base with 3 vertical rows of 4–5 scales within each row, although anterior row may have fewer; Scales anterior to pelvic-fin base 5–9. Upper jaw teeth with an outer row of evenly spaced, straight, conical teeth extending to distal premaxilla, about twice the size of the inner teeth, which consist primarily of a single complete row with a few extra teeth near symphysis. Lower jaw teeth with an outermost row of 3–5 outwardly-flaring, enlarged, curved canines, a row of slightly smaller, straighter canines which decrease in size posteriorly and end on coronoid process of dentary, and 1–2 irregular rows of small conical teeth near symphysis, reduced to a single row posteriorly. Tongue truncately rounded, often with a slight central point at tip. Gill opening extends anteroventrally to below mid-pupil; Outer gill rakers on first gill arch: 4 + 16–18, total rakers: 20–22. Anterior nares in a short tube adjacent to upper lip, posterior opening a large pore with a rim; Nasal sac slightly raised; Nasal apparatus confined to anterior half of snout. Bony interorbital width: 70–80 100 % of pupil diameter in width, interorbital somewhat concave with a raised median ridge of soft tissue (forming a broad, gentle ‘W’ in cross section); Epaxialis reaching anteriorly in dorsal midline to above anterior to middle of pupil. Max. length: 2.7 cm SL. Depth range: 1 - 36 m.
Color
Background color light yellow-brown, somewhat darker over abdomen, with scale pockets more intensely outlined with dark chromatophores, particularly along dorsum. End of caudal peduncle lighter, grading into bright yellow caudal fin with streaks of violet-red in some interradial membranes, especially basally. Head, especially cheek and opercular regions, suffused with red. Iris mostly dark with yellow flecks, but with clear inner ring of yellow around lens aperture. Pectoral-fin rays red, with elements of pelvic, anal and dorsal varying between dirty yellow, red or brown. Fin membranes hyaline except for half-pupil diameter high basal band of melanophores in second dorsal fin. Specimens from Tonga, Solomons and Samoa are somewhat darker overall than Fijian examples.
Etymology
Trimma: from Greek, trimma, -atos = something crushed.
kitrinum: from Greek, kitrinos = citron-yellow, citron, in allusion to the distinctive yellow caudal fin of the new species.
Original description: Trimma kitrinum Winterbottom & Hoese, 2015 - Type locality: Great Astrolabe Reef, eastern side of offshore reef about level of Dravuni Island (178°33'42"E, 18°44'51"S), Fiji Islands, depth 10-15 meters, 29 Mar. 1983, Winterbottom et al.
Distribution
Western Pacific: Maluku (Indonesia) east to Marshall Islands, Tonga and Samoa, north to Guam, south to Queensland (Australia) and New Caledonia.
Biology
Inhabits crevices and caves of mostly dead coral rock and sandy rubble bottom. Solitary.
Similar species
Trimma marinae (Winterbottom, 2005) - Reported from Eastern Indian Ocean, western Pacific: Bali (Indonesia) east to Palau, New Britain (Papua New Guinea) and Solomon Islands, north to Japan, south to Great Barrier Reef (Queensland, Australia). Trimma kitrinum may be distinguished from Trimma marinae, in possessing a complete nasal sac (vs. an open pit), more predorsal scales (11–14 vs. 6–8), in the presence of three rows of cheek scales (vs. none), and in coloration (yellow-brown body and yellow caudal fin vs translucent body above, red below, and a thin red bar at the base of an essentially hyaline caudal fin).
Trimma taylori (Lobel, 1979) - Reported from New Caledonia - Link to the species (here).
Trimma gigantum (Winterbottom & Zur, 2007) - Reported from New Caledonia - Link to the species (here).