Arctozenus Gill, 1864

Ho, Hsuan-Ching & Duhamel, Guy, 2019, A new species of the fish genus Arctozenus from the Kerguelen Islands, with comments on the lost teeth in adults (Aulopiformes: Paralepididae), Zootaxa 4651 (3), pp. 497-512 : 498-499

Arctozenus Gill, 1864

Diagnosis. Body covered by cycloid scales, moderately stout to slender; VFO behind vertical of DFO; gill rakers with multiple rows of short teeth, which never slender or needle-like; scales on body smaller than lateral-line scales; teeth on anterior portion of palatine enlarged and fang-shape; two rows of tooth pairs on lower jaw.

Note on synonymy of Paralepis risso Bonaparte, 1840 . Six available names are associated with Arctozenus and all are currently recognized as Arctozenus risso ( Bonaparte, 1840) ( Post, 1987) .

The original description of Paralepis risso Bonaparte, 1840 was based on description and a drawing by Cuvier in Cuvier & Valenciennes (1829:357–359, pl. fig. 66; reproduced in Fig. 1A ). The specimen was collected from Mediterranean Sea off Italy and apparently lost ( Post, 1972:143).

Richardson (1845:51, pl. 30, figs. 6–7) described Prymnothonus hookeri based on drawing of a figure “ provided by Dr. Hooker ” without voucher and locality. They also mentioned: “ It is evidently a Muraenoid fish, closely allied to the Congers. ” Post (1972:157) suggested that “ Dr. Hooker’s specimen cannot be assigned with any certainty to any nominal species. Apparently it was a postlarval paralepidid, probably either N. rissoi or P. coregonoides borealis or P. atlantica .” The species is treated herein as incertae sedis in Paralepididae .

Krøyer in Gaimard (1842 –1856) provided a drawing which he recognized as Paralepis borealis (although not specified, it is assumed to be Pl. 16B, fig. 1). However, the voucher appears not to have been retained. Gill (1864) established the new genus Arctozenus based on this drawing. Post (1972) recognized that the drawing was actually a Paralepis risso (as rissoi ). Paralepis borealis Reinhardt, 1837 he recognized as a subspecies of Paralepis coregonoides , and later synonymized with that species ( Post, 1973, 1987). Examination on the holotype of Paralepis coregonoides borealis Reinhardt, 1837 ( ZMUC P.2348432) has confirmed the synomyzation of these two names.

According to the Code ( ICZN, online version), the name Paralepis borealis of Krøyer in Gaimard (= A. risso ) is treated as available (Article 11.10), and should be the type species of Arctozenus (Article 69.2.4).

Jordan & Gilbert (1881) described Paralepis coruscans based on a single specimen collected from the northeastern Pacific Ocean. The fish is well described and illustrated. Rofen (1966) synonymized the species with N. rissoi (= A. risso ), a decision supported by Post (1972, 1987). The holotype has a relatively deep body (13 times in fork length in original description) and we concur with this decision.

Lütken (1892) described Paralepis kroyeri based on a drawing by Krøyer in Gaimard (1842 -1856, pl. 16B, fig. 1). This is evidently the same species described by Krøyer. The species has sometimes been treated as a valid subspecies (i.e. Rofen, 1966), however, Post (1968, 1987) has suggested latitude-related changes in morphometrics and meristics, and synonymized it with A. risso .

Whitley & Phillipps (1939) described Prymnothonoides regani , new genus and new species, based on a drawing of a juvenile collected at Cape Maria van Diem (northern tip of North Island, New Zealand) provided in Regan (1916: pl. VII, fig. 3). Harry (1953) placed the genus under Notolepis with a question mark and without further discussion. In his catalogue of types, Post (1972) records that “ Regan’s figure cannot be assigned with any certainty to any nominal species ” and “ The International Commission of Zoological Nomenclature has been requested to place the generic and specific name on the Official Index of ReJected and Invalid Names in Zoology. ” However, the later seems never been gazettes and published, and Post (1973) later suggested that the species is questionably a synonym of Notolepis risso ( Bonaparte, 1840) . The species is treated herein as incertae sedis in Paralepididae .

Figures

FIGURE 1. A–C. Arctozenus risso (Bonaparte, 1840).A. Original drawing which Paralepis risso Bonaparte, 1840, reproduced from Cuvier in Cuvier & Valenciennes, 1829: pl. fig. 66). B. Neotype of Paralepis risso Bonaparte, 1840, MNHN 2018-0246. C. MNHN uncat. (tissue no. BPS-1960), 199 mm SL, photo by Samuel Iglésias. D–E. Arctozenus australis sp. nov. D. Holotype, MNHN 2000-0260. E. Fresh condition, one of paratypes.