Sphaeromopsis Holdich and Jones, 1973

Anil, Pathan, 2022, Sphaeromopsis jayaraji sp. nov. (Crustacea: Isopoda), a new species of intertidal Sphaeromatidae from the Andaman Islands, northern Indian Ocean, Nauplius (e 2022009) 30, pp. 1-12 : 3

Genus Sphaeromopsis Holdich and Jones, 1973

Sphaeromopsis Holdich and Jones, 1973: 386 .— Holdich and Harrison, 1981: 287.— Kensley and Schotte, 1994: 502.— Kensley and Schotte, 1999: 707.— Storey, 2002: 142.— Ortiz et al., 2004: 1.— Schotte and Kensley, 2005: 1275 .— Khalaji-Pirbalouty and Wägele, 2009: 2305 .— Anil and Jayaraj, 2021: 37.

Type species. Sphaeromopsis amathitis Holdich and Jones, 1973 ; by monotypy; type locality: Watamu Marine Park , Kenya.

Diagnosis. Diagnoses to genus are found in Schotte and Kensley (2005) and Anil and Jayaraj (2021).

Remarks. Comparison of the new species to the different descriptions, figures, and specimens of Sphaeromopsis revealed some inconsistencies in what are usually considered generic character states. In the Sphaeromatidae pleon sutures are a critical and usually highly consistent character in genus definitions. This is not the case in Sphaeromopsis , as pleonal sutures differ in morphology and number. For example, in S. sulcifera the sutures are not clearly visible (see Schotte and Kensley, 2005: fig. 37A), whereas in Sphaeromopsis merohirsutus Ortiz et al., 2004 and S. persikolpos there is a single suture on either side of the posterior margin of the pleon rather than the more usual two sutures. The sutures of the coxal plate are similarly not visible in some species ( S. sei , S. persikolpos , S. sikata ). The pereon and pleon of most species in the genus do not exhibit any dorsal ornamentation. In S. heardi Kensley and Schotte, 1994 there is obvious sculpturing on the pleotelson, whereas in S. persikolpos , S. sikata , and S. jayaraji sp. nov., there are some scattered setae on the surface of these sclerites. Among all known Sphaeromopsis species, only S. sulcifera and S. sarii have a faint longitudinal, dorso-medial furrow on the pleotelson. Moreover, the pleotelson varies in shape from broadly truncate in S. amathitis to broadly rounded in S. minutus , to elongated with a narrow apex in S. persikolpos , S. sikata , and S. jayaraji sp. nov. Lastly, the relative length of the uropodal rami varies somewhat, with the exopod ranging from slightly shorter than the endopod to longer than the endopod. This variation at the species level is not of generic merit, and therefore not comparable to the endopod being reduced to a stub ( Paracilicaea Stebbing, 1910 ) or the exopod minute or even absent ( Cassidina H. Milne Edwards, 1840 ; Apemosphaera Bruce, 1994 ), for example.