Insularorchestia Lowry & Myers 2022, gen. nov.

• Main Authors: Lowry, J. K., Myers, A. A.
• Format: Text
• Language: unknown
• Published: Zenodo 2022
• Subjects: Biodiversity; Taxonomy; Animalia; Arthropoda; Malacostraca; Amphipoda; Talitridae; Insularorchestia; Thumb; Myers; Seta; Lowry; North Atlantic; South Atlantic Ocean
• Online Access: https://dx.doi.org/10.5281/zenodo.6312323; https://zenodo.org/record/6312323

Insularorchestia gen. nov. Type species. Orchestia ashmoleorum Stock, 1996, current designation. Included species. Insularorchestia includes 3 species: I. ashmoleorum (Stock, 1996) com. nov.; I. monodi (Mateus, Mateus & Afonso, 1986) com. nov. and I. susorum sp. nov. of Stock & Biernbaum, 1994 com. nov.. Ecological type. Beach-hoppers, field-hoppers. Habitat. Sand beaches and under stones at 762 m altitude (Stock & Biernbaum 1994). Etymology. From islands. Diagnostic description ( male ). Based on Mateus, Mateus & Afonso (1986), Stock (1996), Serejo (2004), Morino & Ortal (1995) and Stock & Biernbaum (1994). Head. Antenna 2 peduncular articles incrassate . Mandible left lacinia mobilis 5- or 6-cuspidate. Labium without inner lobes, with possible vestigial inner lobes. Maxilliped palp article 2 with distomedial lobe; article 4 reduced, button-shaped or fused with article 3. Pereon. Gnathopod 1 sexually dimorphic; subchelate; coxa much smaller that coxa 2; posterior margin of carpus and propodus each with lobe covered in palmate setae; propodus anterior margin with 3 or 4 groups of robust setae, subrectangular or ‘subtriangular’ with well-developed posterodistal lobe, palm transverse; dactylus simplidactylate . Gnathopod 2 subchelate; propodus palm acute , evenly rounded or irregular with small to large shallow midpalmar sinus or without distal palmar sinus with or without proximal spine or thumb defining palm; dactylus not modified distally, blunt or short, recurved distally or attenuated distally. Pereopods 3–7 dactyli bicuspidactylate. Pereopod 4 significantly shorter than pereopod 3 or subequal or slightly shorter than pereopod 3; carpus similar in length to that of pereopod 3 or significantly shorter than that of pereopod 3; dactylus amplidactylate, thickened proximally with notch midway along posterior margin or short, thickened. Pereopod 6 subequal in length to pereopod 7, not incrassate; basis moderately expanded; male merus and carpus not expanded or male merus expanded, carpus not expanded. Pereopod 7 not incrassate; basis broadly expanded; posterior margin with distinct minute serrations, each with a small seta, posterodistal lobe present or posterodistal lobe absent, shallow, broadly rounded; merus expanded distally, subtriangular, anterior margin slightly convex; carpus unexpanded or expanded, subrectangular, subequal to or shorter than propodus; propodus broad or propodus slender; length 4.7–7.3 × width; propodus without large distal tuft of setae. Oostegites (female) setae with simple smooth tips. Pleon. Pleopods 1–3 all well-developed. Uropod 1 peduncle distolateral robust seta absent; exopod without marginal robust setae; endopod with marginal robust setae in 2 rows. Uropod 2 exopod with marginal robust setae in 1 row; endopod with marginal robust setae in 2 rows. Uropod 3 ramus subequal in length to peduncle, or shorter than peduncle. Telson apically incised, with 3–6 robust setae per lobe . Remarks. Insularorchestia is most similar to Platorchestia . It differs in having a simplidactylate gnathopod 1 (cuspidactylate in Platorchestia ). Distribution. South Atlantic Ocean . Saint Helena (Stock 1996); Ascension Island (Stock & Biernbaum 1994). North Atlantic Ocean . Azores (Mateus, Mateus & Afonso 1986). : Published as part of Lowry, J. K. & Myers, A. A., 2022, Platorchestiinae subfam. nov. (Amphipoda, Senticaudata, Talitridae) with the description of three new genera and four new species, pp. 1-53 in Zootaxa 5100 (1) on pages 17-19, DOI: 10.11646/zootaxa.5100.1.1, http://zenodo.org/record/6127681 : {"references": ["Stock, J. H. (1996) The genus Platorchestia (Crustacea, Amphipoda) on the Mid-Atlantic islands, with description of a new species from Saint Helena. Miscellania Zoologica, 19 (1), 149 - 157.", "Stock, J. H. & Biernbaum, C. K. (1994) Terrestrial Amphipoda (Talitridae) from Ascension and Saint Helena (South Central Atlantic). Journal of Natural History, 28, 795 - 811. https: // doi. org / 10.1080 / 00222939400770411", "Serejo, C. S. (2004) Talitridae (Amphipoda, Gammaridea) from the Brazilian coastline. Zootaxa, 646 (1), 1 - 29. https: // doi. org / 10.11646 / zootaxa. 646.1.1", "Morino, H. & Ortal, R. (1995) Two Platorchestia species (Amphipoda, Talitridae) from Israel. Crustaceana, 68, 824 - 832. https: // doi. org / 10.1163 / 156854095 X 00971", "Miyamoto, H. & Morino, H. (2004) Taxonomic studies on the Talitridae (Crustacea, Amphipoda) from Taiwan. II. The genus Platorchestia. Publications of the Seto Marine Biological Laboratory, 40, 67 - 96. https: // doi. org / 10.5134 / 176317"]}