Meiacanthus cyanopterus, Smith-Vaniz, William F. & Allen, Gerald R., 2011

Smith-Vaniz, William F. & Allen, Gerald R., 2011, Three new species of the fangblenny genus Meiacanthus from Indonesia, with color photographs and comments on other species (Teleostei: Blenniidae: Nemophini), Zootaxa 3046, pp. 39-58 : 49-51

Meiacanthus cyanopterus new species

Figures 14‒16 , Table 1

Holotype. MZB 20021, male 45.3 mm SL, Alor Strait, Pura Island, 8°16.944'S, 124°19.543'E, 44 m, clove oil and hand-net, Mark V. Erdmann, 27 March 2011.

Paratypes. WAM P.33398-002 (3, 19.8-30.9 SL), Beang Abang, East Pantar I., 8°29.386'S, 124°10.736'E, 65 m, Mark V. Erdmann, 26 March 2011; USNM 402709 (34.8 SL) and WAM P.33400-002 (2, 37.5–40.8 SL), Alor Strait, Pancoran, Teluk Kalabahi (Kalabahi Bay), 8°17.451'S, 124°24.944'E, 40 m, Mark V. Erdmann, 28 March 2011.

Diagnosis. A species of Meiacanthus (subgenus Meiacanthus ) with major portion of dentary gland dorsally positioned and held in place laterally by dorsolateral flange of dentary; dorsal fin IV, 25 or 26; color pattern characterized by a pair of dark mid-lateral stripes that extend onto the caudal-fin base, and another dark stripe along the dorsal body contour and dorsal-fin base that encroaches onto the fin posteriorly; dorsal fin with black submarginal stripe bordered below by pale stripe, which is blue-violet in life and best developed in males.

Description. (values for the holotype are given first followed by the range of the paratypes). Dorsal fin IV, 25 (IV, 25–26). Anal fin II, 14 (II, 14–16). Pectoral fin 14-14 (13-13 to 15-15). Caudal fin: procurrent rays 4+4 (4– 5+5–6); segmented rays 11, inner rays not elongated or deeply incised. Vertebrae: precaudal 12 + caudal 21 (12– 13+21–22). A pair of canines posteriorly in each jaw, those in lower jaw very large with a deep frontal groove; incisor teeth in lower jaw 17 (16–17); in upper jaw 14 (15–16). Lateral line present, terminating below 5th (3–5) dorsal-fin ray; mandibular and posttemporal pores 3; single median supratemporal pore.

Sexual dimorphism well developed in pelvic and caudal fins (outer rays only) based on their relative lengths compared to other species of Meiacanthus . Values for two largest males, 45.3 holotype and 40.8 mm SL paratype, and two largest female paratypes, 37.5 and 34.8 mm SL, (values for females in parentheses) as follows: pelvic fin 27.2, 27.7% SL (11.7, 12.1% SL); longest caudal-fin ray 50.3, 38.2% SL (20.8, 21.3% SL); inner caudal-fin ray 20.3, 21.8% SL (19.8, 20.4% SL).

Color pattern in preservation. Male holotype with three dark stripes on head and body, separated by pale interspaces. The dorsalmost stripe extends along the dorsal body contour, base of the dorsal fin (distinctly encroaching onto the fin posteriorly), onto the dorsum of the caudal peduncle, and for a short distance onto the bases of several of the upper caudal-fin rays. A very narrow, pale, predorsal stripe separates the dorsalmost dark stripe from its counterpart and ends near or slightly forward of the anterior margin of the eye. The mid-lateral stripe extends across the snout, through the eye, completely enveloping the gill opening, encroaches slightly onto the upper margin of pectoral-fin base, and narrows posteriorly where it terminates on the caudal-fin base. In dorsal view the snout has a faint, V-shaped area (more distinct in life) that is a continuation of the pale stripe immediately above the dark mid-lateral stripe. The ventral stripe extends from the lower jaw, but does not meet at the mid-line of the chin, through the lower half of the pectoral-fin base and onto the caudal-fin base. The dorsal fin has a narrow, pale distal margin, followed by a relatively wide submarginal dark stripe, which extends the length of the fin, and is bordered by a similar pale stripe of equal length; posteriorly the pale proximal stripe abuts a second dark stripe that is a continuation of the dark stripe that follows the dorsal body contour. The other fins are without obvious markings.

Females differ from males primarily in having the dark submarginal dorsal-fin stripe narrower and indistinct posteriorly, and the dark stripe along the dorsal-fin base not as strongly encroaching onto the fin posteriorly.

Colour in life ( Figs. 15–16 ): The dark stripes on the body and dorsal fin are dark brown to black and the narrow intervening stripes on the body and head are white; the throat and belly are also white. The dorsal fin has a narrow blue distal margin anteriorly which gradually widens and changes to yellow posteriorly; in adult males the submarginal pale stripe in the dorsal fin is blue-violet the entire length of the fin but in females it becomes almost colorless near the end of the fin. In both sexes the anal fin is mostly pale blue-violet but the colour is lighter in females which also have a narrow, pale yellow, proximal stripe. The other fins are pale gray to nearly hyalin.

Comparisons. Among species of Meiacanthus with a pair of mid-lateral stripes M. cyanopterus is apparently unique in having a blue-violet stripe in the dorsal fin (best developed in males); life colors of M. abditus are unknown. Meristic characters of these two species broadly over-lap (Table I) and males of both species have elongate (sexually dimorphic) pelvic and outer caudal-fin rays (lengths of these fins are 25.7 and 41.8% SL, respectively, in the 48.3 mm SL and only adult male paratype of M. abditus ), but neither species has elongate inner caudal-fin rays. Despite the strong similarity of M. cyanopterus and M. abditus , at least in preserved specimens, and assuming their allopatric distributions are not a collecting artifact, we believe that two species are represented. The position of the dark body stripe along the dorsal body contour appears to be consistently different in M. abditus with the stripe not extending onto the base of the fin posteriorly ( Smith-Vaniz 1987: Figs. 7 b, 8b), versus distinctly encroaching onto the fin. Meiacanthus cyanopterus may also inhabit deeper reefs; its known depth range is 40– 65 m.

Habitat and distribution. Meiacanthus cyanopterus is known only from deep reef habitats. In addition to the Alor Strait localities, this species was observed by Mark Erdmann at Tulamben, off the north coast of Bali, 8°17.603'S, 115°36.599'E in 65 m.

Etymology. The name is a combination of the Greek Kyanos (blue) and pterus (fin) in reference to the blue dorsal-fin stripe.

Figures

FIGURE 7. Meiacanthus vicinus, WAM P. 31500 - 001, 35.0 mm SL, female, Indonesia, Banggai Is. (round blemish on lateral stripe is spear damage). Photo by S. J. Raredon.

FIGURE 14. Meiacanthus cyanopterus, holotype, MZB 20021, 45.3 mm SL, male, Indonesia, Alor Strait. Photo by H. L. Jelks.

FIGURE 15. Meiacanthus cyanopterus, male, Indonesia, Alor Strait. Photo G. R. Allen.

FIGURE 16. Meiacanthus cyanopterus, female, Indonesia, Alor Strait. Photo G. R. Allen.