Jukesena foveolata (Dell, 1964)

Zelaya Marina Güller, Diego G. & Ituarte, Cristián, 2020, Filling a blank in bivalve taxonomy: an integrative analysis of Cyamioidea (Mollusca: Bivalvia), Zoological Journal of the Linnean Society 190, pp. 558-591 : 582

WHAT ABOUT J. FOVEOLATA ?

Jukesena foveolata was described by Cooper & Preston (1910) based on specimens collected at the Falkland Islands. After its original description, only Dell (1964) reported additional material of this species, also coming from the type locality. Even when rarely sampled, the generic placement of J. foveolata has been controvertial. Originally placed in the genus Psephis (Veneroidea) by Cooper & Preston (1910), the species was subsequently mentioned under the Gomphina subgenus Acolus Jukes-Brown, 1913 (Veneroidea) by Melvill & Standen (1914). Iredale (1915) noticed that at the genus level Acolus Jukes-Brown, 1913 is preoccupied by Acolus Foerster, 1856 ( Hymenoptera ). Consequently, he proposed Jukesena as a replacement name for the former. However, the name Jukesena remained largely disregarded, and ‘ Gomphina (Acolus) ’ continued to be used in subsequent publications (e.g. Carcelles & Williamson, 1951; Powell, 1951). Powell (1960) recovered the usage of Jukesena (as a subgenus of Gomphina ), subsequently followed by Dell (1964). Despite the different (sub)generic placements for the species, until now its inclusion in Veneridae (Veneroidea) had never been questioned, probably because the species remained known only from its shell morphology for more than a century.

As part of the present study, we had the chance to study one live-collected specimen of this species from Patagonia. This specimen shows great morphological and anatomical similarities to Cyamioidea , particularly by the presence of the follicular epithelium, embryos attached to the gill filaments of the parental specimen by a stalk, and tentacles at the posterior part of the mantle margin. These characters, together with the molecular evidence obtained here (from both 16S and 28S markers), allow us to establish the placement of