Description of Brooksia lacromae sp. nov. (Tunicata, Thaliacea) from the Adriatic Sea

Brooksia lacromae sp. nov. is described from zooplankton material collected at a marine monitoring station in the South Adriatic in the autumn of 2014. The description of both solitary and aggregate forms is given along with 18S rRNA and mitochondrial cox1 sequence data that provides strong evidence that both forms belong to the same species. The described species is morphologically markedly different from B. rostrata (Traustedt, 1893) and B. berneri van Soest, 1975, previously the only two species in the genus Brooksia. Genetic analysis based on 18S rRNA gene confirmed distinctness of B. lacromae sp. nov. from B. rostrata (1.5% uncorrected pairwise distance). The appendicularian Fritillaria helenae Bückmann, 1924, so far known from the Atlantic only, was found in the same samples as B. lacromae sp. nov. Co-occurrence of B. lacromae sp. nov. with an Atlantic appendicularian suggests an Atlantic or Western Mediterranean origin for this new taxon.