Hexapleomera crassa ( Riggio, 1975 )

Bamber, Roger N., 2012, A re-assessment of Hexapleomera Dudich, 1931 (Crustacea: Tanaidacea: Tanaidae), with designation of three new species, Zootaxa 3583, pp. 51-70 : 68-69

Hexapleomera crassa ( Riggio, 1975) incertae sedis

Anatanais robustus forma crassus Riggio, 1975: 128

Anatanais robustus crassus Riggio, 1976: 503 , figs 6–8. Hexapleomera crassa .— Riggio, 1996: 648 –649, fig. 22.

Remarks: This taxon was first described as a “form” of “ Anatanais ” robusta ( Riggio 1975) , then as a subspecies ( Riggio 1976) and finally ( Riggio 1996) as a separate species (see Anderson 2012), based on material collected from the Italian coasts of Naples and Sicily. Hexapleomera crassa was distinguished from his H. robusta by Riggio (1996) on the basis of its being “more oval”, having a different “length/width ratio”—being about twice that of the “typical” form ( Riggio, 1976: 503) and being “significantly smaller, rarely exceeding one millimetre and a half”, on which basis he stated that “From these features it was considered a good species”. These cannot be adequate characters. It has not proved possible to find Riggio’s material.

As the published “description” is merely as above, coupled with three photographs ( Riggio 1976, figs 6–8) and one figure ( Riggio 1996, fig. 22), there is at present insufficient information from which to determine the validity, characteristics or even synonymy of this taxon. Riggio’s species may be synonymous with H. robusta sensu stricto. From its illustrated body proportions alone (female body 3.9 times as long as wide, male 2.9 times as long as wide, proximal article of male antennule 4.3 times as long as wide), Hexapleomera crassa is distinct from H. satella (4.5, 3.8 and 6.0 times as long as wide respectively) and only slightly closer to the proportions of H. robusta sensu Sieg (3.5, 3.2 and 5.0 times as long as wide respectively).