Barred Clingfish

Dorsal spines (total): 0; Dorsal soft rays (total): 7 - 8; Analspines: 0; Analsoft rays: 6 - 8; Vertebrae: 30 - 33

Found on rock substratum close to shore (Ref. 13442).

Tomicodon fasciatus (Peters, 1859)

Sicyases fasciatus Peters, 1859:412 [type locality: Puerto Cabello, Venezuela; type specimen lost; neotype, USNM 365854, Panama, designated in “Nomenclatural Discussion,” below].

Arbaciosa minuta Meek and Hildebrand, 1928:928 [type locality: Colon, Panama; holotype, USNM 81523].

DESCRIPTION (Table 1).—Dorsal-fin rays 7 or 8 (mode 7). Anal-fin rays 6–8 (mode 7). Pectoral-fin rays 19 or 20 (mode 20). Caudal-fin segmented rays 10–12 (usually 10 or 12). Vertebrae 13–14+ 16–20 = 30–33 (mode 14 + 17 or 18 = 31); last rib on vertebra 13–15 (mode 14); last epineural on vertebra 20–25 (mode 21). Anal fin originating at vertical from base of dorsal-fin ray 2–4 (mode 3). Upper jaw with 2 canines, 8–11 incisors. Lower jaw with 2 or 4 canines (mode 2), 6 incisors. Anterior margin of pelvic disk crenulate, with flap complexity (referring to larger size and development of lateral cup-like concavities) of flap ornamentation increasing with specimen size. Pelvic disk region A with 5 irregular rows of papillae; region B with 6 or 7 irregular rows. Anus position varying from midway to near disk. Anterior nostril usually with well-developed dermal flap.

Head and body strongly depressed, head much wider than deep (width > 2× depth; head proportionally widest in specimens greater than 22 mm SL). Head length 26.3–29.4% SL (x = 27.7%). Head width 19.0%–25.6% SL (x = 22.9%). Pelvic disk small, length 20.4%–25.6% SL (x = 23.1%). Longest known specimen 31.2 mm SL.

Mature females with large, cigar-shaped ovaries extending through posterior three-fourths of body cavity. Two specimens, 16.8 and 18.0 mm SL (both USNM 365939), with well-developed ovaries, right ovary with about 20+ and 30+ eggs, respectively (number of eggs increasing with specimen length), largest eggs from these two specimens about 0.4 mm in diameter. Genital papilla of females short and conical with somewhat pointed tip; male papilla a slender, elongate tube.

ECOLOGICAL HABITAT AND DISTRIBUTION.—The ecological habitat is unknown for examined specimens of this species. The known distribution of T. fasciatus is St. Croix in the U.S. Virgin Islands, northern Venezuela, and Panama.

PRESERVED COLOR PATTERN (Figure 6).—Pigmentation apparently fades after preservation.

Males: Head and body with dark brown bars on tan background. Head with five diffuse dark bars radiating from eye: anteriormost bar radiating from eye to middle of upper lip, extending anteriorly and meeting similar bar from other side; bar beneath middle of eye bifurcating into anteriorly and posteriorly directed portions; remaining bars extending posteroventrally from eye to just below ventrolateral curvature of head. Underside of head pale, with patch of melanophores on fleshy lobes positioned laterally on each side of lower lip; Panama neotype with melanophores evenly distributed across entire lower lip; central portion of lower lip pale in St. Croix specimens. Approximately six hourglass-shaped, dark saddles along dorsal profile: anteriormost saddle on top of head, posteriormost saddle on top of caudal peduncle; anterolateral border of second saddle (above pectoral fin) forming elongate, somewhat crescent-shaped, and pupil-sized dark spot on either side of nape above pectoral-fin base. Body laterally bearing approximately six to eight diffuse dark bars: anteriormost bar behind pectoral-fin base, posteriormost bar on caudal peduncle. Dark lateral bars extending from anal-fin origin to caudal-fin base reaching ventral midline (anterior bars not reaching ventral midline). Belly and region anterior to anal-fin origin pale. Dorsal fin with small melanophores scattered over entire fin; melanophores somewhat concentrated over bases of anterior four or five rays. Anal fin unpigmented. Caudal fin with faint basal band of melanophores; Panama neotype with faint central bar of fine melanophores; this central bar absent in St. Croix specimens. Pelvic disk pale. Pectoral-fin base typically with large dark blotch covering entire base and extending posteriorly over about two-thirds length of pectoral fin.

Females: Similar to males except only examined Venezuela female with distinctive dark brown bar over basal one-fourth of caudal fin, and with dark blotch over basal one-third length of anterior three dorsal-fin rays.

FRESH COLORATION.—Unknown.

ETYMOLOGY.—The specific epithet is apparently based upon the Latin fascia, meaning banded, and presumably refers to the dark brown bars on the body of specimens of this taxon.

GEOGRAPHIC VARIATION.—Our limited data indicate slight modal shifts for some meristic characters. Caudal-fin ray counts are modally higher (12) for specimens from Venezuela and Panama than for those from St. Croix (10). There is a shift in the vertebral centrum bearing the last rib from 13 at St. Croix to 14 at Venezuela and Panama. Although the terminal epineural in the series is difficult to discern, the St. Croix and Venezuela specimens appear (Table 1) to have epineurals extending farther posteriorly (23–25) than do the Panama specimens (20–22). Although the total number of vertebrae is modally the same (31) for the St. Croix and Panama specimens, those from St. Croix have 13 precaudal vertebrae (versus 14 for Panama), and 18 or 19 caudal vertebrae (versus usually 16 or 17 for Panama). The position of the anus is usually closer to the disk for St. Croix specimens, whereas for Panama specimens the disk is usually midway.

NOMENCLATURAL