A new deepwater assfish, Bassozetus nielseni sp. nov. (Ophidiiformes: Ophidiidae), from the North Atlantic and West Indian oceans

First Record of the Rare Deepwater Assfish <i>Bassozetus mozambiquensis</i> (Ophidiiformes: Ophidiidae) from the Western South Atlantic

“…30), 63 total vertebrae (vs. 65) and short pelvic-fin, 9.0% SL (vs. 9.5%) (Table 1). The differences in other counts and measurements between the present specimen and B. mozambiquensis (within three and 2.6 points, respectively) are minor, and regarded here as intraspecific variations due to similar ranges existing in other species of Bassozetus (see Nielsen and Merrett 2000;Tomiyama et al 2015Tomiyama et al , 2018Tomiyama et al , 2021. There being no other signifi- (Tomiyama et al 2018(Tomiyama et al , 2021.…”

“…Counts of caudal-fin rays and vertebrae, and definitions of long and short rakers on the first gill arch follow Cohen and Nielsen (1978). Eye diameter and number of oblique scale (missing during or after collection) rows between the anus and dorsal-fin base followed Nielsen and Merrett (2000) and Tomiyama et al (2018). Preanus, prepelvic, preanal and tail lengths and distance between the pelvic and anal fins followed Tomiyama et al (2015Tomiyama et al ( , 2021, other counts and measurements following Hubbs and Lagler (1958).…”

“…The present specimen, the second only known of B. mozambiquensis and first Atlantic record of the species, is fully described below. In addition, an updated diagnosis of the species is provided on the basis of a detailed comparison of B. mozambiquensis with four other congeners, viz., Bassozetus nielseni Tomiyama, Takami, and Fukui, 2018, Bassozetus squamosus Tomiyama, Takami, and Fukui, 2021, Bassozetus trachibranchus Tomiyama, Takami, and Fukui 2021 robustus, which were newly described or redescribed after the original description of the former.…”

“…The deep-sea ophidiid genus Bassozetus Gill, 1883 currently comprises 16 valid species, excluding Bassozetus elongatus Smith and Radcliffe in Radcliffe, 1913, which has been synonymized under Bassozetus compressus (Günther, 1878) (Nielsen and Merrett 2000;Tomiyama et al 2015Tomiyama et al , 2018Tomiyama et al , 2021. Species of the genus are mainly benthopelagic, inhabiting depths of ca.…”

“…1000-5500 m in tropical to subarctic waters worldwide, although Bassozetus zenkevitchi Rass, 1955 is usually collected from the water column shallower than ca. 2000 m, an indication of its pelagic life style (Nielsen et al 1999;Nielsen and Merrett 2000;Tomiyama et al 2015Tomiyama et al , 2018Tomiyama et al , 2021.…”