Juan Moles, Heike Wägele, Manuel Ballesteros, Alvaro Pujals, Gabriele Uhl, and Conxita Avila. 7/13/2016. “
The end of the cold loneliness: 3D comparison between Doto antarctica and a new sympatric species of Doto (Heterobranchia: Nudibranchia).” PLoS ONE, 11, 7, Pp. e0157941.
AbstractAlthough several studies are devoted to determining the diversity of Antarctic heterobranch sea slugs, new species are still being discovered. Among nudibranchs, Doto antarctica Eliot, 1907 is the single species of this genus described from Antarctica hitherto, the type locality being the Ross Sea. Doto antarctica was described mainly using external features. During our Antarctic research on marine benthic invertebrates, we found D. antarctica in the Weddell Sea and Bouvet Island, suggesting a circumpolar distribution. Species affiliation is herein supported by molecular analyses using cytochrome c oxidase subunit I, 16S rRNA, and histone H3 markers.We redescribe D. antarctica using histology, micro-computed tomography (micro-CT), and 3D-reconstruction of the internal organs. Moreover, we describe a new, sympatric species, namely D. carinova Moles, Avila & Wägele n. sp., and provide an anatomical comparison between the two Antarctic Doto species. Egg masses in both species are also described here for the first time. We demonstrate that micro-CT is a useful tool for non-destructive anatomical description of valuable specimens. Furthermore, our high resolution micro-CT data reveal that the central nervous system of both Doto species possesses numerous accessory giant cells, suggested to be neurons herein. In addition, the phylogenetic tree of all Doto species sequenced to date suggests a scenario for the evolution of the reproductive system in this genus: bursa copulatrix seems to have been reduced and the acquisition of a distal connection of the oviduct to the nidamental glands is a synapomorphy of the Antarctic Doto species. Overall, the combination of thorough morphological and anatomical description and molecular analyses provides a comprehensive means to characterize and delineate species, thus suggesting evolutionary scenarios.
Moles_et_al._2016_The_end_of_the_cold_loneliness_3D_comparison_between_Doto_antarctica_and_a_new_sympatric_species_of_Doto.pdf Juan Moles, Heike Wägele, Adele Cutignano, Angelo Fontana, and Conxita Avila. 1/28/2016. “
Distribution of granuloside in the Antarctic nudibranch Charcotia granulosa (Gastropoda: Heterobranchia: Charcotiidae).” Marine Biology, 163, 3, Pp. 1-11.
Abstract
The loss of the shell in nudibranch gastropods has been related to the acquisition of chemical defensive strategies during evolution, such as the use of natural products to deter predation. In the present study, we investigated the origin, location, and putative role of granuloside (1), a homosesterterpene lactone, recently isolated from the Antarctic nudibranch Charcotia granulosa Vayssière, 1906. Several adults, egg masses, and its bryozoan prey, Beania erecta Waters, 1904, were chemically analyzed by chromatographic and spectroscopic techniques. Light- and transmission electron microscopy of the mantle revealed complex glandular structures, which might be associated with the storage of defensive compounds in analogy to mantle dermal formations described in other nudibranchs. Although preliminary in situ repellence bioassays with live specimens of the nudibranch showed avoidance against the Antarctic generalist sea star predator Odontaster validus, the specific role of the terpene granuloside requires further investigation. The egg masses do not present granuloside, and the glandular structures are absent in the trochophore larvae. Our results suggest that C. granulosa synthesizes granuloside de novo in early stages of its ontogeny, instead of obtaining it from the prey. Considering the wide geographic area inhabited by this slug, this may be advantageous, because natural products produced by the slug will not be affected by fluctuant food availability. Overall, the Antarctic sea slug C. granulosa seems to possess defensive strategies that are similar, in terms of production and storage, to nudibranchs from other regions of the world. This species is one of the few cladobranchs investigated so far that present de novo biosynthesis of a defensive compound.
Moles_et_al._2016_Distribution_of_granuloside_in_the_Antarctic_nudibranch_Charcotia_granulosa.pdf Genoveffa Nuzzo, Adele Cutignano, Juan Moles, Conxita Avila, and Angelo Fontana. 1/6/2016. “
Exiguapyrone and exiguaone, new polypropionates from the Mediterranean cephalaspidean mollusc Haminoea exigua.” Tetrahedron Letters, 57, 1, Pp. 71-74.
AbstractTwo new polypropionates, named exiguapyrone (2) and exiguaone (3) along with the known haminol-1 (4) and -2 (5), have been isolated from the lipidic extract of the Mediterranean cephalaspidean mollusc Haminoea exigua. The regular propionate skeletons, structurally related to other polypropionates from the congener Haminoea fusari, have been elucidated by means of NMR techniques as natural (2 and 3) and α-/γ-pyrone methyl derivatives (2a and 2b). This is a further report showing the co-occurrence of alkyl-pyridines and polypropionates in Haminoea molluscs strenghtening the role of polypropionates as chemical markers among cephalaspideans.
Nuzzo_et_al._2015_Exiguapyrone_and_exiguaone_new_polypropionates_from_the_Mediterranean_cephalaspidean_mollusc_Haminoea_exigua.pdf