Aglaja, RENIER, 1807 AND

AGLAJA RENIER, 1807 AND View in CoL THE NEW GENUS NIPARAYA

The type genus of Aglajidae , Aglaja Renier, 1807 (type species A. tricolorata Renier, 1807 ; type locality near Caesarea, Mediterranean coast of Israel; K. Jensen, pers. comm.) is distributed in the eastern Atlantic, Mediterranean Sea and eastern Pacific. This genus was validated by Lemche (1974) after conflicts with preoccupied names ( Lemche, 1972, 1974; Cernohorsky & Lemche, 1976; ICZN Opinion 1079, 1977). The genus is represented in our analyses by the type species A. tricolorata from the Mediterranean Sea, by the eastern Pacific species A. ocelligera , and at least five additional species ( Fig. 2A, B; Table 4).

However, a taxon usually ascribed to this genus ( A. regiscorona ) did not cluster together with the other species of Aglaja ( Fig. 2A, B; Supporting Information, Figs S1–S 4). Furthermore, Bertsch (1972) and Gosliner (1980) highlighted the presence of morphological characters distinguishing ‘ Aglaja ’ regiscorona and raised concerns about its taxonomic placement in Aglaja . Representatives of ‘ A. ’ regiscorona from the Pacific Ocean are small animals (up to 5 mm) with unique characters such as light-creamy coloration, numerous dark-tipped dorsal papillae along the body, cephalicanterior velum ( Fig. 3J), cephalic-posterior elevation in crown-like shape and a distinctive penial structure than the rest of the aglajid genera (see Gosliner, 1980: figs 1–12 and Marcus & Marcus, 1966: figs 22–27, for comparisons of the penial papilla and prostate of ‘ A. ’ regiscorona ). In contrast, slugs of the genus Aglaja are larger (up to 30 mm); devoid of dorsal papilla, velum, and upward projections of the cephalic/posterior shields; and their penial anatomy resembles that of Navanax ( Rudman, 1974) .

Camacho-García et al. (2014) previously hinted that ‘ A. ’ regiscorona could warrant a different phylogenetic affiliation, which is here confirmed by our results. No genus name is available for this new lineage, and therefore, we introduce the name Niparaya with type species N. regiscorona (type locality Las Cruces, Baja California, México) for eastern Pacific specimens with the aforementioned characteristics. Specimens identified in our work as ‘ Aglaja regiscorona ’ collected in Hawaii and western Pacific localities seem to belong to two distinct species ( Fig. 2A, B). Moreover, available images from field guides and specialized webpages clearly hint the possible existence of potential cryptic diversity in Niparaya regiscorona ( Gosliner, 2015: 49; Pittman & Fiene, 2015a).