Swennenia, Buatip & Tan, 2020

Buatip, Somsak & Tan, Siong Kiat, 2020, A new genus Swennenia for Gascoignella jabae Swennen, 2001, a small rare mangrove dwelling sea slug in the Gulf of Thailand, with notes on the species (Gastropoda: Sacoglossa: Plakobranchoidea), Raffles Bulletin of Zoology 68, pp. 629-635 : 630

Swennenia , new genus

Type species. Gascoignella jabae Swennen, 2001: 78 , fig. 2 (type locality: mangrove area near Ban Di , southern Thailand, 06°52′17″N, 101°18′48″E) .

Diagnosis. Small, rather flat and elongate slugs without rhinophores or oral tentacles. Dorsum smooth with a pair of prominent rearward-facing cerata at the posterior end of the body. Other details of morphological characteristics are treated as the type species below.

Etymology. The new genus is named in honour of the late Dr Cornelis (Kees) Swennen (1929–2020) who discovered and described the type species. He was a revered collaborator and mentor of the first author. Gender feminine.

Remarks. Thus far monotypic. The animals look superficially similar to Limapontia Johnston, 1836 , but have a single pair of cerata at the posterior end of the body. Previously placed in Platyhedylidae Salvini-Plawen, 1973 , but rightly in the Limapontiidae based on similarities in anatomical characteristics (see Discussion), and molecular analyses that showed it to be sister to a clade comprising the limapontiid genera Limapontia Johnston, 1836 , Olea Agersborg, 1923 , and Calliopaea d’Orbigny, 1837 (see Krug et al., 2015, 2018; Filho et al., 2019).