Pycnocraspedum microlepis ( Matsubara, 1943 )

Schwarzhans, Werner W., Psomadakis, Peter N. & Nielsen, Jørgen G., 2025, Revision of the bathydemersal fish genus Pycnocraspedum (Ophidiidae; Teleostei), with description of two new species, Zootaxa 5636 (3), pp. 443-472 : 461

Pycnocraspedum microlepis ( Matsubara, 1943)

Itatius microlepis Matsubara, 1943: 40–43 , figs. 2–4, Kumano-Nada, Kii Peninsula, Japan.

Pycnocraspedum microlepis ( Matsubara, 1943) : Machida (1984), Nielsen et al. (1999), Nakabo (2000), Nielsen in Randall & Lim (2000), Shinohara et al. (2001), Nakabo (2002), Evseenko & Okiyama (2006),? Prokofiev (2022).

Remarks. Holotype apparently lost ( Fricke et al. 2024). No specimen identified that would reasonably match Matsubara’s detailed description. Matsubara (1943) gave a detailed description of P. microlepis and diagnostic features to distinguish the genus Itatius (syn. Pycnocraspedum ) from Neobythites . He compared P. microlepis with P. phyllosoma ( Parr, 1933) , which he considered related, and found that they shared “4 developed gill-rakers on the first gill-arch, dorsal fin inserted above the upper angle of gill-opening and 20 pyloric coeca (21 in P. phyllosoma ).” He found that P. microlepis differs from P. phyllosoma “at least in having slenderer body and lower arm of the gill-arch armed with 13 tubercular gill-rakers below the 4 developed ones” (vs. practically smooth). We can confirm the observation in respect to the gill rakers in P. phyllosoma but find this a rather variable and not very consistent character. From Matsubara’s description we find the combination of 25 scales rows above lateral line, 20 pyloric coeca and the absence of pseudobranchial filaments to represent the most characteristic features, which is not matched in any specimen studied by us (see also discussion to P. armatum ). In conclusion, we consider Phyllosoma microlepis as a nominally valid species and it is hoped that new findings matching Matsubara’s description will eventually resolve its taxonomic position.