Rochinia A. Milne-Edwards, 1875

Lee, Bee Yan, Forges, Bertrand Richer De & Ng, Peter K. L., 2019, Deep-sea spider crabs of the family Epialtidae MacLeay, 1838, from Papua New Guinea, with a redefinition of Tunepugettia Ng, Komai & Sato, 2017, and descriptions of two new genera (Crustacea: Decapoda: Brachyura: Majoidea), Zootaxa 4619 (1), pp. 1-44 : 12-13

Genus Rochinia A. Milne-Edwards, 1875

Rochinia A. Milne-Edwards, 1875 [in 1873–1880]: 86 (footnote) [type species: Rochinia gracilipes A. Milne-Edwards, 1875 , by monotypy].

Remarks. There are currently 36 species recognised within this genus ( Ng et al. 2008; Richer de Forges & Ng 2013; Takeda & Marumura 2014; Tavares et al. 2015; Lee et al. 2017; Tavares & Santana 2018), with the species distributed across the Indo-Pacific and Atlantic Oceans (Griffin & Tranter 1986; Ng & Richer de Forges 2007; Lee et al. 2017).

The genus, Rochinia , has a complex history. It was being described as a footnote by A. Milne-Edwards (1875) and later two genera, Anamathia Smith, 1885 , and Scyramathia A. Milne-Edwards, 1880 , were synonymised under Rochinia by Rathbun (1925) for the AEP region. Subsequently, Griffin & Tranter (1986) synonymised Sphenocarcinus under Rochinia (see also “Remarks” for Oxypleurodon ). Tavares (1991) attempted to redefine Rochinia , and included 39 species. Ng & Richer de Forges (2007) in their study noted that the members of Rochinia are split in two distinct groups, those from the IWP region and the rest from the AEP region (see additional discussion by Richer de Forges & Poore 2008).

Ng & Richer de Forges (2013) attempted to separate the genus by suggesting preliminary groupings based on the shape of the male anterior thoracic sternum and pleon. However, the diagnoses provided by previous authors, such as Rathbun (1925), Garth (1958) and Griffin & Tranter (1986) are not accurate enough to allow many of the species to be grouped. Tavares & Santana (2018) attempted to redefine members of the genus from the AEP region, noting that only R. gracilipes belonged in Rochinia sensu stricto. They also transferred two AEP species to Scyramathia , which they recognised as a valid genus, transferred one AEP species to Anamathia , established Minyorhyncha Tavares & Santana, 2018 , for M. crassa (A. Milne-Edwards, 1879) , and referred the remaining four AEP and 31 IWP species to Rochinia sensu lato ( Tavares & Santana, 2018). As such, with the taxonomic problems of this genus having been discussed at length by various authors (see Ng & Richer de Forges 2007; 2013; Richer de Forges & Poore 2008; Lee et al. 2017; Tavares & Santana 2018), a revision of Rochinia is now in preparation (see also Lee et al., 2017). For the two new species described in this paper, they will both be provisionally placed in Rochinia sensu lato until a complete revision can be finished by the authors.

Therefore, with the description of two new species from PNG and the transfer of four species out of Rochinia (see Tunepugettia Ng, Komai & Sato, 2017 , and Crocydocinus n. gen.), there are currently 34 species in this genus.