Cryptoceloidea, Bahia, Padula & Schrödl, 2017

Superfamily Cryptoceloidea Bahia et al., 2017

Faubel (1983, 1984) erected the superfamily Ilyplanoidea to contain acotylean species that lack a true prostatic vesicle ( Fig. 1C; Table 1). Instead, their male tract is covered with a glandular lining or with prostatic-like glands called prostatoids ( Fig. 1D). Our results confirm the finding of Bahia et al. (2017) that Ilyplanoidea is not a valid taxon. We recovered monophyly of three species [ Adenoplana evelinae Marcus, 1950 View in CoL , Discocelis tigrina (Blanchard, 1847) View in CoL and Ilyella gigas ( Schmarda, 1859) View in CoL ] representing two families ( Discocelidae View in CoL and Ilyplanidae View in CoL ) in Ilyplanoidea , but our results show that a monophyletic group containing four species of Phaenocelis View in CoL plus Phaenoplana peleca ( Marcus & Marcus, 1968) form the immediate sister clade to these three ilyplanoid species. Using specimens of Adenoplana evelinae View in CoL and Phaenocelis medvedica Marcus, 1952 View in CoL , Bahia et al. (2017) also showed a paraphyletic Ilyplanoidea ( Table 1). Phaenocelis View in CoL belongs to Cryptocelidae View in CoL , prompting the authors to create the superfamily Cryptoceloidea , which they characterize by oval to elongate body shapes, a lack of tentacles and the presence of cerebral, nuchal and marginal eyespots. Given that body shapes and eyes can be unreliable taxonomic traits, we add the presence of unarmed, rod- or cylindrical-shaped penis papillae (e.g. found in Cryptocelis View in CoL , Phaenocelis View in CoL ) as a diagnostic character. Thus, our revised definition of Cryptoceloidea relies on the ‘absence of a true prostatic vesicle or, if an interpolated prostatic vesicle is present, an unarmed conical penis papilla’.

The phylogeny of Tsunashima et al. (2017), which included Ilyella gigas View in CoL , also does not resolve a monophyletic Ilyplanoidea . Instead, Ilyella gigas View in CoL clustered with Amemiyaia pacifica View in CoL . Amemiyaia View in CoL , a monospecific genus, was initially placed in Phaenocelidae by Kato (1944) and subsequently moved to Cryptocelidae View in CoL by Marcus & Marcus (1966). Currently, it belongs to Stylochoplanidae View in CoL , a leptoplanoid family that was established by Faubel (1983) and that also includes Phaenoplana View in CoL , among others. Based on its clustering with ilyplanoids ( Tsunashima et al. 2017), and when adding it to our phylogeny where it groups with Phaenocelis spp. , its position in the family Stylochoplanidae View in CoL (superfamily Leptoplanoidea View in CoL ) can no longer be supported. It clearly belongs to the superfamily Cryptoceloidea (sensu Bahia et al., 2017). Hence, we here return it to Cryptocelidae View in CoL .

Likewise, the original description of Phaenoplana peleca by Marcus & Marcus (1968) placed the species in Phaenocelis . However, Faubel (1983) moved it to Phaenoplana , a genus he erected in Stylochoplanidae . Based on strong molecular support, we here return Phaenoplana peleca to Phaenocelis , thus Phaenoplana peleca becomes a junior synonym of Phaenocelis peleca . The superfamily then contains, at minimum, Ilyplanidae , Discocelidae and Cryptocelidae . The inclusion of Euplanidae awaits testing.

Currently, several species of Phaenocelis are found in the greater Caribbean and the tropical western Atlantic. The type specimen of Phaenocelis purpurea ( Schmarda, 1859) is from Jamaica ( Schmarda, 1859), and the species is also known from the Florida Keys ( Hyman, 1954) and from Curaçao ( Marcus & Marcus, 1968). During our own surveys, we found Phaenocelis purpurea in Panama and Belize. Phaenocelis medvedica was originally described from the Island of São Sebastião in Brazil ( Marcus, 1952) and more recently it also has been found at Ponta Verde, Brazil ( Bahia et al., 2015). The type locality of Phaenocelis peleca is the same place in Curaçao that also contains Phaenocelis purpurea ( Marcus & Marcus, 1968) and our surveys extends its range to Belize and Jamaica.

Additionally, we found two other species of Phaenocelis . With regard to their external morphology, species in Phaenocelis are generally of elongate, slender form, with few distinguishing traits, and their colour may range from pale cream to pink. Consequently, species are difficult to identify, and conclusive identifications require sections of the internal reproductive system or DNA sequences. The D1–D2 expansion segment allows for species distinctions in the genus, because little intraspecific sequence variation exists, but distinct gaps can be recognized among species. Given that only Phaenocelis medvedica has been described from Brazil, it may be likely that the remaining four Phaenocelis species do not occur along that coast, thus facilitating the identification of Phaenocelis medvedica . With regard to the internal morphology, all five species ( Phaenocelis medvedica , Phaenocelis purpurea and Phaenocelis peleca , plus the two undescribed species) have distinctly shaped Lang’s vesicles and species-specific insertion points of the duct into Lang’s vesicles (S. Quiroga and M. Bolaños, unpublished data).