Gaeticinae Davie & Ng, 2007

Lasley Jr, Robert M., Anker, Arthur & Naruse, Tohru, 2024, Two new species and a new record of infaunal crabs (Decapoda: Brachyura: Pinnotheridae and Varunidae) from Oman and Saudi Arabia, Zootaxa 5476 (1), pp. 207-229 : 214-215

Subfamily Gaeticinae Davie & Ng, 2007

Remarks. At the time of its establishment, the varunid subfamily Gaeticinae , comprised two genera, Gaetice Gistel, 1848 and Sestrostoma Davie & Ng, 2007 ( Davie & Ng 2007). Shortly thereafter, Naruse & Clark (2009) described the gaeticine genus Gopkittisak Naruse & Clark, 2009 , for Asthenognathus gallardoi Serène & Soh, 1976 and compared it with the enigmatic species Paracleistostoma fossula Barnard, 1955 , which was considered a varunid but with uncertain subfamilial placement ( Ng et al. 2008). Števčić (2011) established the monotypic genus Brankocleistostoma Števčić, 2011 and family Brankocleistostomidae Števčić, 2011 for P. fossula , but without explanation as to why these taxa were necessary. Ng (2012) subsequently synonymised Brankocleistostomidae with Gaeticinae , but regarded Brankocleistostoma as a distinct, monotypic gaeticine genus. In his description of the genus Proexotelson Naruse, 2015 , Naruse (2015) provided a table of diagnostic characters of all gaeticine genera, except for Pseudopinnixa Ortmann, 1894 , which had been added to Gaeticinae by Komai & Konishi (2012). Naruse (2015) also added Acmaeopleura Stimpson, 1858 to Gaeticinae , which thus currently comprises seven genera: Acmaeopleura , Brankocleistostoma , Gaetice , Gopkittisak , Proexotelson , Pseudopinnixa , and Sestrostoma ( Guinot et al. 2018; Poore & Ahyong 2023).

Gaeticinae was initially differentiated from the other two varunid subfamilies by three characters: (1) Mxp3 adapted for filter feeding, with elongate palp (dactylus) bearing long setae; (2) presence of a longitudinal sulcus on the anterior thoracic sternites, lodging the afore-mentioned Mxp3 setae; and (3) fused male pleonites 3–6 ( Davie & Ng 2007). In summary, this varunid subfamily is unique in having Mxp3 and anterior sternites adapted for filter feeding. However, most gaeticine crabs have an anterior sternal depression, rather than a sulcus, to accommodate the long setae of the third maxillipeds ( Komai & Konishi 2012; Naruse 2015; Guinot et al. 2018). Species in almost all gaeticine genera also have relatively squarish or rounded carapaces (see examples in Davie & Ng 2007). Brankocleistostoma and Gopkittisak , which are treated here, are notable exceptions in having a carapace that is transversely rectangular or ovate, and much wider than long.