Ultraviolet vision in larval Neogonodactylus oerstedii

Stomatopod crustaceans have among the most complex eyes in the animal kingdom, with up to twelve different color detection channels. The capabilities of these unique eyes include photoreception of ultraviolet (UV) wavelengths (<400 nm). UV vision has been well characterized in adult stomatopods but has not been previously demonstrated in the comparatively simpler larval eye. Larval stomatopod eyes are developmentally distinct from their adult counterpart and have been described as lacking the visual pigment diversity and morphological specializations found in adult eyes. However, recent studies have provided evidence that larval stomatopod eyes are more complex than previously thought and warrant closer investigation. Using electroretinogram recordings in live animals we found physiological evidence of blue and UV sensitive photoreceptors in larvae of the Caribbean stomatopod species Neogonodactylus oerstedii. Transcriptomes of individual larvae were used to identify the expression of three distinct UV opsins transcripts, which may indicate the presence of multiple UV spectral channels. This is the first paper to document UV vision in any larval stomatopod, expanding our understanding of the importance of UV sensitivity in plankton. Similar to adults, larval stomatopod eyes are more complex than expected and contain previously uncharacterized molecular diversity and physiological functions.

Description of Aurelia pseudosolida sp. nov. (Scyphozoa, Ulmaridae) from the Adriatic Sea

Until 2021, the genus Aurelia contained eleven described species (WoRMS, 2020), with many genetic species still awaiting a formal description. In 2021, ten new species of Aurelia were described almost solely from genetic data in a novel attempt to use genetic characters as diagnostic characters for species descriptions, leaving seven genetic species still undescribed. Here we present the description of a new Aurelia species from the Adriatic Sea using an integrative taxonomy approach, i.e., employing molecular as well as morphological characteristics in order to describe this new Aurelia species. The species is described based on a single medusa sampled from the town of Rovinj (Croatia), North Adriatic, amidst combined blooms of the ctenophore Mnemiopsis leidy and cnidarian Aurelia solida in the summer of 2020. Based on genetic data, the newly described Aurelia pseudosolida sp. nov. has never been sequenced in any of the previous investigations of the molecular diversity of Aurelia. This is the second species belonging to Discomedusae described from the North Adriatic in little more than half a decade, which could be yet another indication of the susceptibility of the North Adriatic to proliferation of non-indigenous gelatinous species, especially if we take into account historical as well as recent blooms of suspected non-indigenous gelatinous species such as Muggiaea atlantica, Aurelia solida, Mawia benovici and Mnemiopsis leidy.