Pterophycis, Ho, 2019

Ho, Hsuan-Ching, 2019, A new genus and species of the cod fish family Moridae (Order Gadiiformes) from southwestern Taiwan, Zootaxa 4702 (1), pp. 32-40 : 32-40

Pterophycis gen. nov.

Type species. Pterophycis spatium Ho , sp. nov. (by monotypy), as described below.

Diagnosis. A genus of Moridae with a ventral light organ and differs from all other genera by having genital papilla separated from anus by several small scales, a large pelvic fin with all rays elongated ( Fig. 1A ), and the following combination of characters: snout broad and rounded, not shelf-like; palatines and vomer toothless; swimbladder with elongate projections that attached to openings at rear of the skull ( Fig. 2 ); pelvic fin with 7 rays; first dorsal fin short-based, with 8 rays; second dorsal and anal fins long-based, their margins not indented.

Etymology. From Latin pter means fin and phycis, a cod, in referring to the diagnostic large pelvic fin of the genus.

Relationship. The presence of the light organ and two dorsal fins suggest that Pterophycis gen. nov. is closely related to Physiculus , Gadella and Salilota belong to “ Physiculus ” subgroup (sensu Paulin, 1989a), which also includes Tripterophycis that has a light organ and three dorsal fins. It apparently shares many characters with the most specious genus Physiculus by the absence of vomerine teeth and similar fin elements and position. However, two diagnostic characters that distinguish these two genera are the large pelvic fins with all rays elongate and the position of genital papilla ( Figs. 1A , vs. 1B, C).

In addition to these two diagnostic characters mentioned above, it can be further distinguished from the monotypic genus Salilota , restricted in southern America, by lacking tooth patch on vomer (vs. small tooth patch on vomer in Salilota ) and 8 first dorsal-fin rays (vs. 9–12); and from the worldwide distributed genus Gadella , with 12 species currently, by having chin barbel (vs. absent in Gadella ) and origin of anal fin slightly behind a vertical of that of second dorsal fin (vs. origin of anal fin well behind that of second dorsal fin). Members of Tripterophycis , with 2 species restricted in the Southern Hemisphere, have their light organs situated at around the anus and three well-separated dorsal fins which can be easily distinguished from those of other genera.

Figures

FIGURE 1. Ventral view of abdominal region comparing with the pelvic fins, light organ (left arrow), anus (middle arrow) and genital papilla (right arrow). A. Pterophycis gen. nov., NMMB-P22891. B. Holotype of Physiculus dalwigkii, type species of Physiculus, MNHN 1996-1380, 190 mm SL. C. Physiculus chigodarana, NMMB-P16401, 118 mm SL.

FIGURE 2. Dorsolateral view of head showing the anterior extension of swimbladder (arrowed). A. Pterophycis gen. nov., NMMB-P22891. B. Physiculus dalwigkii, type species of Physiculus, MNHN A.4502, 197 mm SL.