Two new subscpecies of Antarctic horsefish (Zanclorhynchus, Scorpaeniformes: Congiopodidae) from Indian Sector of Southern Ocean

Abstract

The goal of this work is to revise the endemic South Ocean species Zanclorhynchus spinifer, one of the most numerous demersal fish species inhabiting waters off subantarctic islands. Despite its high abundance and significant role in trophic chains, the species remained poorly described. Morphological parameters were studied for the first time on a significant amount of material; individual variability was clarified for a number of parameters. Such variability, according to some characteristics, is beyond the range of values previously used in the description of the species, and the occurring break of the infraorbital canal was previously considered to be characteristic in the family Congiopodidae only for the sister genus Alertichthys. The two new subscpecies Zanclorhynchus spinifer armatus subsp. nov and Z. spinifer macquariensis subsp. nov. are described in this paper in addition to the nominative subspecies and the previously described subspecies from the seamounts of the Pacific Ocean sector of the Southern Ocean Z. spinifer heracleus. Type series were collected in the Indian sector of Southern Ocean off the Prince Edward Islands and the Crozet Islands from the depth 170–310 metres, and off the Macquarie Island from the depth 21–84 meters. New subscpecies well differs from other two subcpecies Z. spinifer spinifer and Z. spinifer heracleus with arming of the head and first dorsal fin, scales and body proportions. A key to the species and subspecies of the genus Zanclorhynchus is presented.