Genus Gesaia Kirtley, 1994

Gesaia Kirtley, 1994: 166 .

Type-species. Phalacrostemma elegans Hartman & Fauchald, 1971: 152 (not Fauvel 1911).

Remarks. This planktonic larva is provided with four parathoracic segments, simple (unbranched) feeding tentacles, nuchal hooks (with strongly bent sharp tips), and without limbations, operculum completely divided in two lobes, features that are characteristic for Gesaia species (Kirtley 1994; Capa et al. 2012; Capa & Hutchings 2015). The paleae morphology, with straight and cylindrical outer and inner paleae, and paleae arrangement, with outer paleae forming a semicircle and the inner paleae in an almost straight line between opercular lobes, is also most similar to benthic stages of members of this genus. However, the thecal ornamentation of the paleae, indicated to be the most important morphological trait for Gesaia species discrimination (Kirtley 1994: 166–167) observed in the larva described herein differs from other Gesaia species.