Platorchestiinae subfam. nov. (Amphipoda, Senticaudata, Talitridae) with the description of three new genera and four new species Author Lowry, J. K. Author Myers, A. A. 0000-0003-3256-2123 School of Biological, Earth and Environmental Sciences, University College Cork, Cork Enterprise Centre, Distillery Fields, North Mall, Cork, Ireland. bavayia @ gmail. com; https: // orcid. org / 0000 - 0003 - 3256 - 2123 bavayia@gmail.com text Zootaxa 2022 2022-02-17 5100 1 1 53 journal article 20608 10.11646/zootaxa.5100.1.1 cabdbbb1-1226-4c2e-b90b-fae0742b5091 1175-5326 6127681 F42DAC62-0E30-442E-A375-87FC02B2CC99 Cocorchestia fritzi ( Stebbing, 1903 ) comb. nov. ( Fig. 3 ) Talorchestia fritzi Stebbing, 1903: 925 , pl. 60.— Shoemaker, 1932: 184 , fig. 1.— Stephensen, 1948: 11 .— Ortiz, 1977: 9 .— Galan, 1984: 136 (PhD thesis).— Wakabara & Serejo, 1998: 583 (checklist).— Martin & Diaz, 2003: 339 .— Serejo, 2004: 25 , 26.— Ruffo & Krapp-Schickel, 2005: 37 .— García-Madrigal, 2007: 127 , Appendix, 188.— Foster et al ., 2009: 216 , Species List 21.1.— Ortiz & Lalana, 2010: 87 .— Barro et al ., 2013: 40 (checklist).— Herrera, 2012: 9 (checklist).— Martin et al., 2013: 1682 , 1716, Appendix 1.— Ortiz & Lalana, 2019: 67 . Not Talorchestia fritzi . — Schellenberg, 1938: 211 (= “ Talorchestia ” tucurauna ( Müller, 1864 )) .—Monod, 1970: 31, figs 55–69 (= Cocorchestia sp. , Santa Cruz Island, Galapagos ).— Peck, 1994: 61 , key. Non-Taxonomic Citations Talorchestia fritzi .— Ocaña et al ., 2012: 32 , 33, table 2 (ecology). Types. Syntypes , 5 specimens , USNM 28785 , Cocos Island , Costa Rica ( 5°31’45’’N 87°3’36’’W ) . Additional material. 10 specimens , USNM 106205 , about 200 specimens , USNM 106206 Type locality. Cocos Island , Costa Rica . Ecological type . Beach-hopper. Habitat. There is no information on habitat in the original description of Stebbing (1903) or in the subsequent description of Shoemaker (1932) , the first reviewer. According to Ocaña et al . (2012) C. fritzi is living on sandy beaches. Size. 5–9 mm . Diagnosis (male). Based on Stebbing (1903) and Shoemaker (1932) . Gnathopod 2 propodus palm transverse, rounded proximally, with large distal sinus, without proximal spine defining palm; dactylus not modified distally, blunt. Pereopod 7 not incrassate. Uropods 1 and 2 endopod each with marginal setae in one row. Telson with 4 robust setae per lobe. Remarks. Shoemaker (1932) had new material of this species from Costa Rica which indicated a very different morphology of the male gnathopod 2. However Shoemaker clearly indicated that his specimens were larger (and more mature) than those of Stebbing. Unfortunately Shoemaker only illustrated the anterior parts of his specimen. Both species ( C. fritzi and C. margaritae ) have an unmodified dactylus on male gnathopod 2 and uropods 1 and 2 with only one row of marginal setae on the endopods. Cocorchestia fritzi and C. margaritae each have a large distal sinus on the palm of male gnathopod 1. They differ in the distinctive proximal spine guarding the palm of male gnathopod 2 in P. margaritae . Species reported by Monod (1970) and Peck (1994) are not P. fritzi . However specimens from both records are available. The specimen which Monod (1970) illustrated has a differently shaped propodus on gnathopod 2, shorter and broader, almost round, with a shorter palm and dactylus and is similar to Platorchestia . Uropod 2 is also shorter than that of Stebbing (1903) and the ramus of uropod 3 is longer than the peduncle (shorter in illustration of Stebbing (1903)) . They don’t appear to be the same species. Stebbing’s male was apparently about 9 mm . Monod doesn’t appear to give a size for his male. Distribution. Costa Rica . Isla da Coca ( Stebbing 1903 ); Galapagos . Turtle Bay, Santa Cruz Island (Monod 1970), Isla Genovesa, Bahia Darwin ( Peck 1994 ).