Hapalogenys filamentosus, Iwatsuki & Russell, 2006

Iwatsuki, Yukio & Russell, Barry C., 2006, Revision of the genus Hapalogenys (Teleostei: Perciformes) with two new species from the Indo-West Pacific, Memoirs of Museum Victoria 63 (1), pp. 29-46 : 39

Hapalogenys filamentosus sp. nov.

New English name: Philippines Dark Velvetchin

Figures 1C–D , 3E–F

Type material. Holotype: MUFS 7666, 147 mm SL, off Iloilo, Panay I., Philippines, 10 Mar 1981, bottom trawl, 30–80 m, coll. M. Akazaki. Paratypes: MUFS 7654, 149 mm SL, off Iloilo, Panay I., Philippines, bottom trawl, about 40 m depth, 11 Mar 1981, coll. M. Akazaki ; MUFS 7667–7668 , 2 : 129–143 mm SL, same data as holotype .

Diagnosis. A species of Hapalogenys with the following combination of characters: fleshy lower lip with dense cluster of very short papillae (figs 3E–F), scaly posteriorly (on posterior abdominal part of angular of lower jaws, (fig. 3F); 10 unobstructed pores on and behind chin (fig. 3F; see Gloerfelt-Tarp and Kailola, 1984:197, fig. 2); no scales on maxilla (fig. 3E); 2 faint longitudinal dark stripes on body, 1st from nape to base of mid dorsal-fin soft rays, 2nd from eye to base of last dorsal-fin soft ray, their width below base of 5th and 6th dorsalfin spines clearly narrower than pupil diameter (see figs 2A–C in 65–158 mm SL and fig. 1B); soft rayed portions of dorsal and anal fins somewhat rounded posteriorly and slightly angulated posteriorly, respectively (fig. 1C); pelvic-fin tip almost reaching to or slightly beyond base of 1st anal-fin spine when depressed (figs 1C− D); 41 or 42 pored lateral-line scales; a procumbent spine-like process (exposed tip of 1st pterygiophore) apparent at origin of dorsal fin but covered by predorsal scales.

Description. Counts and proportional measurements as percentage of SL of the holotype and 5 paratypes are given in Table 2. Data for the holotype are presented first, followed by paratype material (if different) in parentheses. Characters given in the diagnosis are not repeated.

Body deep, 50% of SL (45–55% of SL), relatively compressed, covered with ctenoid scales, ctenii free on posterior margin of exposed area; lateral line continuous until on hypural plate; orbit diameter slightly larger than interorbital space; suborbital depth clearly less than eye diameter; head covered with scales, extending almost to snout tip; lips, chin and ventral part of urohyal naked; cheek and opercular bones fully scaled; jaws with bands of pointed conical teeth, outermost teeth generally much enlarged but no distinct canines; teeth absent on vomer and palatines; preopercle serrate; upper opercle with 2 short spines posteriorly; single notched dorsal fin; 4th dorsal-fin spine and 2nd dorsal-fin ray longest; 1st dorsal- and anal-fin soft rays not strongly bifurcated; 1st anal-fin spine short, 2nd very robust, longest, clearly longer than 3rd; dorsal and anal fins with high scaly sheath; pectoral-fin tip not reaching to vertical at anus or pelvic-fin tip when depressed; caudal fin slightly rounded.

Preserved colouration. Based on all type specimens: head and body generally dark-brownish; 2 faint longitudinal stripes on head and body.

Distribution. Hapalogenys filamentosus sp. nov. is currently known only off Iloilo, Panay I., Philippines. Efforts by the first author to collect other examples of the species from fish markets and trawl catches throughout the Philippine Is. (Luzon, Mindoro, Panay, Cebu and Mindanao Is.) have been in vain.

Apart from the type specimens, no examples are known to exist in museum collections.

Ecological note. The habitat of H. filamentosus sp. nov. is likely to be similar to that of H. kishinouyei and H. dampieriensis sp. nov.

Etymology. The name “ filamentosus ” refers to the filamentous 1st ray of the pelvic fin in this species.

Figures

Figure 1. The seven species of Hapalogenys. A), H. analis, MUFS 12258, 185 mm SL, East China Sea; B) H. dampieriensis sp. nov., CSIRO C4036-02, Holotype, 224 mm SL, N of Cape Lambert, north-western Australia; C), H. filamentosus sp. nov., MUFS 7666, holotype, off Iloilo, Panay Is., Philippines; D), Right pelvic-fin (reversed) of H. filamentosus sp. nov., MUFS 7666, holotype; E), H. kishinouyei, MUFS 12316, 266 mm SL, Miyazaki, Kyushu, Japan; F), H. merguiensis, PMBC 10985, paratype, 199 mm SL, off Satun Province near Phuket, Andaman Sea; G), H. nigripinnis, Kanagawa Prefectual Museumʼs photo database (KPM-NR0001009, photographed by T. Suzuki), about 180 mm SL, Moroyose, Hyogo, Sea of Japan; H), H. sennin, MUFS11649, holotype, 232 mm SL, Meitsu, Miyazaki, Japan. Arrow shows tip of pelvic-fin ray.

Figure 3. Head (left) and lower jaw ventral view (right) of 4 species, Hapalogenys analis (A–B), H. dampieriensis sp. nov. (C–D), H. filamentosus sp. nov. (E–F) and H. kishinouyei (G–H). A–B), HUMZ 106037, 113 mm SL, Saeki, Ooita, Japan; C–D), NTM S13510-010, 134 mm SL, Arafura Sea, Northern Territory, Australia; E–F), MUFS 7654, 134 mm SL, off Iloilo, Panay Is., Philippines; G–H), MUFS 20986, 131 mm SL, Meitsu, Miyazaki, Japan. Arrow indicates squamation on maxilla.