Nettenchelys dionisi Brito, 1989

Smith, David G., Lin, James, Chen, Hong-Ming & Pogonoski, John J., 2015, The eels of the genus Nettenchelys, with description of a new species from Taiwan (Teleostei: Anguilliformes: Nettastomatidae), Zootaxa 4060 (1), pp. 105-120 : 109

Nettenchelys dionisi Brito, 1989

Fig. 1 b

? Nettenchelys sp. B Smith & Castle 1982:18 (eastern Atlantic). Larva.

Nettenchelys dionisi Brito 1989:877 , figs. 2–4 (Canary Islands, eastern Atlantic, depth 350–400 m). Holotype. TFMC ZM-3 (female, 620 mm).

Material. Two specimens known, both gravid females. Holotype: TFMC ZM-3 (620 mm). Paratype: CCML 01/ 248 (446 mm).

Diagnosis. Anterior vomerine teeth uniserial but not enlarged; posterior nostril midway between eye and supratemporal canal. See Table 1 for additional characters.

Distribution. Known from the Canary Islands in the eastern North Atlantic.

Remarks. Smith & Castle (1982: 18) described a larva, Nettenchelys sp. B, based on two specimens collected in the eastern North Atlantic, one near the Azores and one near the Canary Islands ( Smith & Castle 1982: fig. 12). These larvae may belong to Nettenchelys dionisi , a species that was unknown in 1982. Both the holotype and paratype of N. dionisi appear to be incomplete; the vertebral counts of 165 and 132 respectively seem far too low for a nettastomatid. The preanal lengths of the two specimens given by Brito (1989:table 1) are 30.8 and 37.2 %TL for the holotype and paratype respectively. If the specimens are incomplete, and if the paratype has lost more vertebrae than the holotype, then it would be expected that any proportional measurement given as a percentage of TL would be greater in the paratype. This is indeed what we see, providing further evidence that both specimens have lost part of the tail. The two specimens of Nettenchelys sp. B larvae have 235–236 total myomeres ( Smith & Castle 1982:18); if these represent the larvae of N. dionisi , then the adults would have a comparable number of vertebrae.

Figures

FIGURE 1. Position of the posterior nostrils in nine species of the genus Nettenchelys (modified after Karmovskaya, 1999). (a) N. pygmaea, N. proxima; (b) N. gephyra and N. dionisi; (c) N. inion; (d) N. paxtoni; (e) N. exoria; (f) N. erroriensis; and (g) N. taylori.