Hydrops (Tachynectes) Fitzinger 1843

Subgenus:TachynectesFitzinger, 1843 Type species. Homalopsis leopardina Schlegel, 1837. Diagnosis. Members of the subgenus Tachynectes have short hemipenial lobes decorated with spinules. The hemipenial body is homogeneously covered with spinules (Fig. 4 A), occasionally a few enlarged spines may occur, e. g., in H. (T.) phantasma. Content. Five species, Helicops (Tachynectes) infrataeniatus Jan, 1865, H. (T.) leopardinus (Schlegel, 1837), H. (T.) modestus Günther, 1861, H. (T.) phantasma Moraes-da-Silva et al., 2021, H. (T.) tapajonicus da Frota, 2005. Comments. Tachynectes von der Mark, 1863, erected for a genus of fossil fishes, is a primary junior homonym of Tachynectes Fitzinger, 1843. As Tachynectes von der Mark, 1863 has only been used four times in the past 50 years according to our searches (Google Scholar, Zoological Record: Sepkoski 2002; Albert et al. 2009; Dietze 2009; Schwarzhans and Carnevale 2021), it fails to meet the criterion in Article 23.9. 2 of the International Code of Zoological Nomenclature (ICZN 1999) for prevailing usage and is therefore unavailable. As a replacement name for Tachynectes von der Mark, 1863, we propose Ichthyotachynectes nom. nov. to accommodate the fossil fish species previously assigned to Tachynectes von der Mark, 1863.