Bimeria Wright, 1859a

Calder, Dale R., 2010, Some anthoathecate hydroids and limnopolyps (Cnidaria, Hydrozoa) from the Hawaiian archipelago 2590, Zootaxa 2590 (1), pp. 1-91 : 19-20

Genus Bimeria Wright, 1859a

Bimeria Wright, 1859a: 109 .

Type species. Bimeria vestita Wright, 1859a , by monotypy.

Diagnosis. Bougainvilliid hydroids stolonal or erect and more or less alternately branched, arising from a creeping hydrorhiza. Erect colonies with monosiphonic hydrocaulus. Perisarc filmy to firm, covering hydrorhiza, hydrocauli, hydrocladia, and pedicels, enveloping hydranth and extending as a sheath over bases of tentacles and around periphery of hypostome. Hydranths ovoid to vasiform; tentacles filiform, in a distal whorl; hypostome dome-shaped.

Gonophores fixed sporosacs, arising from hydranth pedicels.

Remarks. Bimeria Wright, 1859a and Manicella Allman, 1859 have long been regarded as simultaneous synonyms because both were published in July issues of journals that year ( Calder 1988). Precedence was assigned to the name Bimeria by Hincks (1868), acting as First Reviser. Even Allman (1872) eventually accepted the relative priority of the two. However, Allman’s (1859) account of Manicella appeared in an issue of the Annals and Magazine of Natural History that can now be dated as 1 July 1859 ( Evenhuis 2003). The dating of Wright’s (1859a) account of Bimeria is less certain. In the journal itself, only the month of publication (July) is given, and publication date can only be taken here as 31 July 1859 (ICZN Art. 21.3.1). Wright’s (1859b) later claim of priority for Bimeria and the species name B. vestita Wright, 1859a was based on having found the hydroid first and having presented the names before a meeting of the Royal Physical Society of Edinburgh in January 1859. Such claims have no standing in zoological nomenclature, and the two names were not made available until they appeared in print in Wright’s (1859a) article. Nomenclatural stability is threatened when the virtually unknown Manicella and its type species by monotypy M. fusca Allman, 1859 become senior synonyms of the now widely used Bimeria and its type species B. vestita . Using Reversal of Precedence under the current code (ICZN Art. 23.9), Bimeria and B. vestita are designated here as valid and as nomena protecta, while Manicella and M. fusca are relegated to nomena oblita. First, the names Manicella and M. fusca have not been used as valid names in zoological nomenclature after 1899 (ICZN Art. 23.9.1). Meanwhile, Bimeria and the species name B. vestita have been used in at least 25 works by more than 10 authors in the past 50 years (ICZN Art. 23.9.2): Millard (1975), Calder (1988, 1993, 1998, 2009), Hirohito (1988), Medel & López-González (1996), Migotto (1996), Grohmann et al. (1997), Rajagopal et al. (1997), Genzano & Rodriguez (1998), Genzano & Zamponi (1999), Cairns et al. (2002), Migotto et al. (2002), Kelmo et al. (2003), Bouillon et al. (2004, 2006), Calder & Kirkendale (2005), Shimabukuro et al. (2006), Vervoort (2006), Altuna (2007), Galea (2007), Oliveira & Marques (2007), Schuchert (2007), Morri et al. (2009).

Hydroids of Bimeria and Koellikerina Kramp, 1939 are distinctive in having tentacles ensheathed basally in a tube of perisarc. While their trophosomes are similar, gonophores are fixed sporosacs in Bimeria and free medusae in Koellikerina . Both genera were assigned earlier to the subfamily Bimeriinae Allman, 1872 ( Calder 1988) . The hydroid stage is not reliably known in Thamnostoma Haeckel, 1879 , a related genus ( Petersen & Vannucci 1960; Schuchert 2007).

Taxonomic reviews of Bimeria have been given previously in reports by Calder (1988) and Schuchert (2007). The genus was also included in the synopsis of Bouillon et al. (2006), although its scope therein overlaps Garveia Wright, 1859a , assigned to a different subfamily (Bougainvilliinae Lütken, 1850). Of nine species listed under Bimeria in that work, at least three, Bimeria cerulea [= Calyptospadix cerulea Clarke, 1882 ], B. tunicata Fraser, 1943 , and B. robusta Torrey, 1902 , are referable to Garveia ( Vervoort 1964; Cairns et al. 2002). As well, the genus Calyptospadix Clarke, 1882 , included by Bouillon et al. (2006) as a synonym of Bimeria , has been combined instead with Garveia ( Calder 1971) . The type species of Calyptospadix , C. cerulea , may be conspecific with G. franciscana ( Torrey, 1902) ( Cairns et al. 2002) . Bimeria rigida Warren, 1919 , an outlier in the genus, has a preoral cavity in the hydranth and close-fitting perisarc around each tentacle instead of a loose tube. Its taxonomy merits closer study.