Sphaerocoryne Pictet, 1893

Maggioni, Davide, Schuchert, Peter, Arrigoni, Roberto, Hoeksema, Bert W., Huang, Danwei, Strona, Giovanni, Seveso, Davide, Berumen, Michael L., Montalbetti, Enrico, Collins, Richard, Galli, Paolo & Montano, Simone, 2021, Integrative systematics illuminates the relationships in two sponge-associated hydrozoan families (Capitata: Sphaerocorynidae and Zancleopsidae), Contributions to Zoology 90, pp. 487-525 : 496

Sphaerocoryne Pictet, 1893

Diagnosis: Colonies stolonal; hydrocauli unbranched or sparingly branched, with terminal hydranths; perisarc reaching hydranth; hydranth pyriform, with bulbous base and proboscis-like hypostome; no oral tentacles, but capitate tentacles in whorls around broadest part of body; gonophores arising above tentacles and released as free medusae.

Adult medusa with thick ovoid to bell-shaped umbrella; with or without apical projection, when present, conical or dome-shaped, with broad apical chamber; manubrium flask-shaped, quadrate, or cruciform, mouth simple, round or cruciform; four tentacles, when present, with adaxial, evenly distributed, or spirally arranged nematocyst clusters, with a terminal, ellipsoid or spherical capitation; with abaxial ocelli; gonads adradial, confluent in perradii in mature specimens.

Genetic diagnosis: 79 molecular diagnostic characters differentiate Sphaerocoryne from other genera in the family, specifically 16 in the 16S, 20 in the COX1, 22 in the COX3, 10 in the 18S, and 11 in the 28S ( table 2 ).

Remarks: The genus Sphaerocoryne comprises currently the following accepted nominal species: S. agassizii ( McCrady, 1859) , S. arcuata ( Haeckel, 1879) , S. bedoti Pictet, 1893 , S. coccometra ( Bigelow, 1909) , and S. peterseni Bouillon, 1984 . However, the genus shows some unresolved nomenclatural issues ( Calder, 2010). Indeed, the type species S. agassizii was initially ascribed to the genus Corynitis McCrady, 1859 , however this name is an invalid junior homonym of Corynitis Geyer, 1832 (Lepidoptera) and Corynitis Menge, 1854 (Araneae) . Linvillea Mayer, 1910 was then proposed as a replacement name for Corynitis , and synonymised to Sphaerocoryne . However, Corynetes Haeckel, 1879 (an unjustified emendation of Corynitis ) is an available name with priority over Linvillea and Sphaerocoryne . Therefore, if S. bedoti and S. agassizii are not congeneric, the latter should be transferred to the genus Corynetes and Sphaerocoryne will remain valid at least for S. bedoti . On the other hand, if the two species are demonstrated to be congeneric, the widely used generic name Sphaerocoryne will not be valid anymore, and a case should be submitted to the International Commission on Zoological Nomenclature (ICZN) to assess the merits of its conservation.