Ecsenius niue, Victor G. Springer, 2002

Victor G. Springer, 2002, Ecsenius niue, new species of blenniid fish, and new distribution records for other species in the Opsifrontalis species group., Zootaxa 72, pp. 1-6 : 3-5

Ecsenius niue , new species

(Figure 2a)

Holotype: NMNZ P.35765 , male, 30.9 mm SL, Beveridge Reef, SW lagoon , Niue Island (20°01.13' S, 167°46.36' W), 7-13 m, collected by Clive Roberts and Terry Coe, 4 Oct 1998.

Paratypes. NMNZ P.35793 , 6 specimens: male, 28 mm SL; female 24.7 mm SL, and four sex indeterminate 18.2-22.7 mm SL. 500 m N of Alophi Wharf, Opaahi , Niue Island, 5-11 m, collected by Clive Roberts and Terry Coe, 6 Oct 1998.

Description (characters of holotype, if warranted, given in parentheses). Dorsal fin XII,13 or 14 (14). Anal fin II,15 or 16 (16). Pectoral-fin 13-13 (13-14). Precaudal vertebrae10, caudal vertebrae 22 or 23 (22). Caudal fin elements 8-13-7. Dentary incisor teeth 43-52 (50), lowest counts 43-46 are from smallest specimens, 18.2-21.9 mm; largest specimens, 22.7-30.9 mm, have counts of 49-52. Lateral line extending posteriorly to point between verticals from dorsal-fin spines 10 and 11.

All specimens have a preserved color pattern similar to that illustrated in Figure 2a. The main differences are in the intensity with which the dark markings are represented and, in the smaller specimens, the dorsal members of the pairs of spots tend to fuse into a stripe-like marking. The pattern on the anal fin, which is not clear in the Figure 2a, consists of a dusky sub-distal stripe, which is darkest distally, and very similar to that exhibited by E. fijiensis (Figure 2c).

Comparisons. Ecsenius niue will key to couplet 41 in Springer (1988:26), which differentiates E. tigris Springer (islands on the Queensland Plateau) from E. fijiensis (main Fijian and northern Lau islands) based on color pattern. E. tigris (Figure 2d) was stated to have four to six conspicuous dark spots on the dorsal body contour at the base of the spinous dorsal fin, as opposed to zero to two in E. fijiensis , and E. tigris was stated to have two vertical pairs of dark spots on the caudal peduncle, as opposed to three vertical pairs in E. fijiensis . In E. niue , there are zero to three very diffuse, dusky spots on the dorsal body contour at the base of the spinous dorsal fin and two vertical pairs of dark spots on the caudal peduncle (the dorsal members of the two pairs may fuse). Ecsenius niue , thus does not clearly key to one or the other of the two species in the key couplet.

The diffuse extension of the posteriormost pair of spots onto the caudal fin of E. niue is similar to the extensions in E. tigris (Figure2d); however, in E. tigris there are three or four conspicuous dark spots on the body ventral to those on the dorsal body contour below the spinous dorsal fin. These spots are absent in both E. niue and E. fijiensis . I believe that the color pattern of E. niue is most similar to that of E. fijiensis .

Distribution. Known only from Niue Island.

Etymology. Named niue in reference to the presumed endemicity of the species to Niue Island. The specific epithet is here used as a noun in apposition - thus, the Niue Ecsenius .