Guinotinia Forges & Ng, 2009, n. gen.

Guinotinia n. gen.

Diagnosis. Carapace pyriform. Rostrum bifid composed of 2 short flattened subparallel spines. Dorsal face of carapace with several raised plates with rounded surfaces. Supraocular eave forming sharp tooth anteriorly.

Antennae shorter than rostral spines, not visible from dorsal view. Carapace, ambulatory legs covered by short tomentum of cone-shaped setae. Gastric area with 4 plates touching each other or fused; cardiac plate distinctively heart-shaped; branchial plate elongated, separated into branchial, epibranchial portions. Cheliped shorter than P2. Propodi, dactyli of P3-P5 modified to form pseudochelae. Male abdomen with 7 free somites including telson. Male anterior thoracic sternal sutures incomplete.

Etymology. The genus honors the “queen” of modern carcinology, Danièle Guinot, Muséum national d’Histoire naturelle, Paris, for her outstanding influence on brachyuran taxonomy. The gender of the genus is feminine. The type species is Guinotinia cordis n. sp., by present designation.

Remarks. Superficially, Guinotinia n. gen. is similar to Rochinia, especially with regards to the pyriform carapace. The two genera, however, differ in the following characters: hepatic and branchial spines always prominent and very conspicuous in Rochinia (bearing only a plate on the carapace in Guinotinia n. gen.); the rostrum consisting of two long, slender and cylindrical spines in Rochinia (two short flat spines in Guinotinia n. gen.); the first pair of ambulatory legs are the longest in Rochinia (first pair of ambulatory legs shorter than the cheliped in Guinotinia n. gen.); and the propodi and dactyli of P3-P5 are normal in Rochinia (modified to form pseudochelae in Guinotinia n. gen.).

The characteristic shape of the extremity of the ambulatory legs of the two new species of Guinotinia n. gen. is probably an adaptation to its most common habitat, clinging onto and moving about the long and slender gorgonian branches growing on the hard bottom on seamounts (Fig. 11 C). The very long claw-like of the P3-P5 dactyli fold against the setose swelling on the propodus, forming pseudochelae similar to those of the P5 of Homolidae. Similar pseudochelae have been described in majoids of the genus Acanthonyx Latreille, 1828 (Epialtidae, Epialtinae), which live on large seaweeds (see Wu et al. 1999; Emparanza et al. 2007).