Seba Bate 1862
Creators: name: Ariyama, Hiroyuki
Publisher: name: Zenodo
Year: 2009
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Malacostraca
Amphipoda
Sebidae
Seba

description: Genus Seba Bate, 1862
Seba Bate, 1862: 159 (type species: Seba innominata Bate, 1862 by monotypy).— Stebbing, 1888: 782.— Della Valle, 1893: 773.— Stebbing, 1906: 162. – Walker, 1907: 37.— Schellenberg, 1931: 83.— J.L. Barnard, 1969: 436.— Karaman, 1971: 73.— Holman & Watling, 1983: 239.— Ledoyer, 1986: 944.— Shaw, 1989: 1885.—J.L.
Barnard & Karaman, 1991: 668.— Karaman, 1993: 681.— Lowry & Stoddart, 2003: 250. Teraticum Chilton, 1884: 257 (type species: Teraticum typicum Chilton, 1884).
Grimardia Chevreux, 1889: 284 (type species: Grimardia armata Chevreux, 1889).
Paravalettia K.H. Barnard, 1916: 112 (type species: Paravalettia chelata K.H. Barnard, 1916). Caribseba Shaw, 1989: 1885 (type species: Seba tropica McKinney, 1980).
Diagnosis [modified from J.L. Barnard & Karaman (1991)]. Body compressed, smooth or weakly carinate; urosomites 2 and 3 coalesced (except for Seba aloe Karaman, 1971). Rostrum obsolete, lateral lobes well developed, eyes absent [except for S. typica (Chilton, 1884)]. Antennae 1 and 2 of medium length, extending equally; peduncle of antenna 1 long, articles 1 and 2 longer than article 3; accessory flagellum present (except for S. tropica), 2-articulate, article 2 tiny; flagella of both antennae short. Mandibular incisor developed, toothed, molar reduced; palp long, with 3 articles, article 2 elongate, article 3 with 1–3 (mostly 2) apical setae. Labium with well-developed mandibular lobes, inner lobes indistinct. Maxilla 1 with blunt inner plate bearing 0–2 apical setae, outer plate with 7 apical setae; palp elongate, 1-articulate, with 1–4 apical setae. Maxilla 2 formed of weakly setose similar plate, outer plate bearing 3–5 setae. Plates of maxilliped moderately developed, poorly setose; palp stout, 4-articulate, dactylus unguiform. Coxae 1–4 of medium length, coxa 4 poorly excavate posteriorly; coxae 5–7 moderately shortened. Gnathopod 1 weakly chelate or subchelate; carpus short, lobed; propodus broad. Gnathopod 2 slender, strongly chelate; ischium elongate; carpus long, unlobed; propodus elongate, forming a chela with fitted dactylus. Pereopods 3 and 4 similar, ordinary; pereopods 5–7 relatively similar to each other, bases expanded, meri often expanded and lobate. Coxal gills present on pereopods 2 or 3 to 6, oostegites of female on pereopods 2–5. Pleopods ordinary. Uropods 1 and 2 biramous, stout, weakly spinose or almost naked, outer rami subequal or slightly shorter than inner rami; uropod 3 uniramous, peduncle short, ramus much longer than peduncle, 2-articulate. Telson linguiform, longer than broad, entire, poorly setulose. Sexual dimorphism often present in gnathopod 1 and pereopods 5–7.
Remarks. Walker (1907) proposed to call the genus Seba Stebbing, 1875, with Seba saundersi Stebbing, 1875 as the type species, because the existence of S. innominata had been questioned (Stebbing, 1888; Della Valle, 1893); Karaman (1971) approved of the proposal, and Holman & Watling (1983) also pointed out this taxonomic problem. However, referring the International Code of Zoological Nomenclature (International Commission of Zoological Nomenclature, 1999: Articles 50.1, 67.2), Bate’s (1862) nomenclature is valid.
Shaw (1989) presented the following characters for the diagnosis of the new genus Caribseba: (1) antenna 1 without accessory flagellum, (2) inner plate of maxilla 1 without apical seta, and (3) mandibular palp segment 3 with single apical seta. Although only Carib s eba tropica, the type species of the genus, actually has the character (1) in the species of the genera Seba and Caribseba, the characters (2) and (3) are shared with some of the Seba species as Winfield et al. (2009) stated [character (2): S. alvarezi, S. ekepuu J.L. Barnard, 1970 and S. robusta; character (3): S. ekepuu and S. robusta]. Moreover, there are wide morphological variations in the genus Seba [e.g. the presence of eyes in Seba typica, and the separated urosomites 2 and 3 in S. aloe]; therefore, Caribseba should be restored to Seba.
description: Published as part of Ariyama, Hiroyuki, 2009, Four species of the genus Seba from Japan, with descriptions of two new species (Crustacea: Amphipoda: Sebidae), pp. 44-68 in Zootaxa 2159 on pages 44-45, DOI: 10.5281/zenodo.188912