Genus Callianopsis de Saint Laurent, 1973

Callianopsis de Saint Laurent, 1973: 515 (type species: Callianassa goniophthalma Rathbun, 1902, by original designation and monotypy, gender feminine)

Pleurocalliax Sakai, 2011: 480 –481 (type species: Callianassa caecigena Alcock & Anderson, 1894 by original designation and monotypy, gender feminine). Syn. nov.

Neocallianopsis Sakai, 2011: 482 (type species: Callianopsis anovalis Lin, Komai & Chan, 2007 by original designation and monotypy, gender feminine). Syn. nov.

Phaetoncalliax Sakai, Türkay, Beuck & FreiWald, 2015: 124 –128 (type species: Phaetoncalliax mauritana Sakai, Türkay, Beuck & FreiWald, 2015, by original designation and monotypy, gender feminine). Syn. nov.

Remarks. The type and only species of Pleurocalliax Sakai, 2011 was said to be “rather similar to the type species of the genus Callianopsis, C. goniophthalma ... but differs in that in Calliactites coecigena [sic] abdominal pleuron 2 is armed with a laterally directed acute projection posteroventrally, pleura 3–4 with a laterally-directed acute projection medioventrally, and pleura 5–6 with a laterally-directed acute projection anteroventrally; whereas in Callianopsis goniophthalma abdominal pleura 2–5 are unarmed and pleuron 6 is armed with a laterally-directed acute projection anteroventrally”. The only figures of Callianassa caecigena (Alcock & Anderson, 1896: pl. 26 fig. 2) illustrate the pleural spines. As well as the strong lateral tooth on pleuron 6, both C. goniophthalma (Rathbun 1904: 156, pl. 8) and C. anovalis (Lin et al. 2007: fig. 1) possess a spine or angle on pleura 1 and 5, while Phaetoncalliax mauritana has a spine on pleura 1 and 6 (Fig. 4F).

The synonymy of Neocallianopsis Sakai, 2011 with Callianopsis was discussed above.

Sakai et al. (2015b: 125) asserted that their new genus Phaetoncalliax differs from Callianopsis in that pleopod 1 is biramous (vs uniramous) and pleopod 2 has different relative lengths of appendix masculina and endopod. In addition, they listed the presence (Table 3) of a dorsal postcervical ridge on the carapace (present in Phaetoncalliax, absent in Callianopsis and Pleurocalliax).

Study of the holotype and male paratype of Phaetoncalliax mauritana shows, that the distal article of pleopod 1 is entire (Fig. 4C–F) and uniramous as in Callianopsis. The difference in the pleopod 2 is not convincing when comparing Sakai (2011: fig. 63I for C. goniophthalma) and Sakai et al. (2015b: fig. 6f for P. mauritana). Contrary to Sakai et al. ’s (2015b) statement, both C. goniophthalma and C. anovalis have an elevated mid-dorsal ridge near the posterior margin of the carapace as does P. mauritana (Fig. 4A). Given the similarity between all four species in the carapace, pleonite 6, uropods, chelipeds and elsewhere, the alleged differences are insufficient to warrant generic differentiation and the genera are therefore synonymous.