Taxonomic review of the deep water flathead genus Parabembras with description of the new species Parabembras multisquamata from the western Pacific Ocean (Teleostei, Parabembridae).

Yoshiaki Kai,Ronald Fricke

doi:10.3897/zookeys.740.21729

Abstract

Three valid species of Parabembras are recognized: P. curta, P. robinsoni, and the new species P. multisquamata. Parabembras robinsoni from the southwestern Indian Ocean (South Africa to Mozambique) is easily distinguishable from the other species in having eleven spines in the first dorsal fin, a distinct symphyseal knob on the lower jaw, two preocular spines, and a single lachrymal spine. Parabembras multisquamata from the southwestern Pacific (Vanuatu, Papua New Guinea) and the Philippines, and P. curta, known from the northwestern Pacific (southern Japan to South China Sea), are similar in sharing the absence of a symphyseal knob on the lower jaw, the presence of two lachrymal spines, and a single preocular spine, but the former is clearly distinguished from the latter in usually having 10 spines in the first dorsal fin (vs. eight or nine spines in P. curta), 9–11 supraocular spines (vs. 6–8 in P. curta), 40–44 pored lateral line scales (vs. 34–39 in P. curta), and the pectoral fin extending beyond the level of the anus (vs. not reaching to the level of the anus in P. curta).

Highlights

According to Imamura (1996), the family is diagnosed by the presence of spines and absence of tubercles on the dorsal surface of the head; the lower jaw projecting beyond the tip of the upper jaw; the separation of the ascending process and the remaining part of the premaxilla; the absence of free fin rays from the pectoral fin; three spines in the anal fin; about 35–40 scales in the lateral line; and the absence of a swim bladder
Body depths 1 and 2 are taken at the anterior insertions of the first and second dorsal fins, respectively; predorsal lengths 1 and 2 from tip the tip of the snout to the anterior insertion of the first and second dorsal fins, respectively; and the body width is measured between the uppermost part of the base of the right and left pectoral fins
Parabembras multisquamata is most similar to P. curta in having two lachrymal spines and no symphyseal knob on the lower jaw, but is clearly distinguished as described above

Summary

Introduction

The family Parabembridae, or deep water flatheads, comprises only two species, Parabembras curta (Temminck & Schlegel, 1843) from the northwestern Pacific Ocean, and P. robinsoni Regan, 1921, from the western Indian Ocean (Eschmeyer et al 2017). We examined four relatively recently collected (1980–2012) specimens of a species of Parabembras from the waters of Vanuatu, Papua New Guinea, and the Philippines These specimens differ from the two currently known species of the family by the spines on the head, number of dorsal-fin spines and pored lateral line scales, and several proportional measurements, and are described as a new species of Parabembras. The two congeneric species P. curtus and P. robinsoni are redescribed, and a key to the species of Parabembras is presented

Materials and methods

Discussion