Publications

In Press
Conxita Avila, Laura Núñez-Pons, and Juan Moles. In Press. “From the tropics to the poles: chemical defensive strategies in sea slugs (Mollusca: Heterobranchia).” In Chemical Ecology: The Ecological Impacts of Marine Natural Products. Taylor & Francis Group.
Juan Moles, Conxita Avila, and Manuel António E Malaquias. In Press. “Systematic revision of the Antarctic gastropod family Newnesiidae (Heterobranchia: Cephalaspidea) with the description of a new genus and a new abyssal species.” Zoological Journal of the Linnean Society.
2017
Juan Moles, Guillem Mas, Irene Figueroa, Robert Fernández-Vilert, Xavier Salvador, and Joan Giménez. 10/2017. “As fast as a hare: Colonization of the heterobranch Aplysia dactylomela (Mollusca: Gastropoda: Anaspidea) into the western Mediterranean Sea.” Cahiers de Biologie Marine, 58, 3, Pp. 341-345.Abstract
The marine cryptogenic species Aplysia dactylomela was recorded in the Mediterranean Sea in 2002 for the first time. Since then, this species has rapidly colonized the eastern Mediterranean, successfully establishing stable populations in the area. Aplysia dactylomela is a heterobranch mollusc found in the Atlantic Ocean, and commonly known as the spotted sea hare. This species is a voracious herbivorous with generalist feeding habits, possessing efficient chemical defence strategies. These facts probably promoted the acclimatation of this species in the Mediterranean ecosystems. Here, we report three new records of this species in the Balearic Islands and Catalan coast (NE Spain). This data was available due to the use of citizen science platforms such as GROC (Catalan Opisthobranch Research Group). These are the first records of this species in Spain and the third in the western Mediterranean Sea, thus reinforcing the efficient, fast, and progressive colonization ability of this sea hare. We have demonstrated that citizen science is a valuable tool for the early awareness of new colonizations as well as for monitoring the advance and settlement of new populations of cryptogenic species.
Moles_et_al._2017_As fast as a hare.pdf
Blanca Figuerola, Carlos Angulo-Preckler, Laura Núñez-Pons, Juan Moles, L Sala-Comorera, C García-Aljaro, AR Blanch, and Conxita Avila. 8/2017. “Experimental evidence of chemical defence mechanisms in Antarctic bryozoans.” Marine Environmental Research, 129, Pp. 68-75.Abstract

Bryozoans are among the most abundant and diverse members of the Antarctic benthos, however the role of bioactive metabolites in ecological interactions has been scarcely studied. To extend our knowledge about the chemical ecology of Antarctic bryozoans, crude ether extracts (EE) and butanol extracts (BE) obtained from two Antarctic common species (Cornucopina pectogemma and Nematoflustra flagellata), were tested for antibacterial and repellent activities. The extracts were screened for quorum quenching and antibacterial activities against four Antarctic bacterial strains (Bacillus aquimaris, Micrococcus sp., Oceanobacillus sp. and Paracoccus sp.). The Antarctic amphipod Cheirimedon femoratus and the sea star Odontaster validus were selected as sympatric predators to perform anti-predatory and substrate preference assays. No quorum quenching activity was detected in any of the extracts, while all EE exhibited growth inhibition towards at least one bacterium strain. Although the species were not repellent against the sea star, they caused repellence to the amphipods in both extracts, suggesting that defence activities against predation derive from both lipophilic and hydrophilic metabolites. In the substrate preference assays, one EE and one BE deriving from different specimens of the species C. pectogemma were active. This study reveals intraspecific variability of chemical defences and supports the fact that chemically mediated interactions are common in Antarctic bryozoans as means of protection against fouling and predation.

Juan Moles, Heieke Wägele, Adele Cutignano, Angelo Fontana, Manuel Ballesteros, and Conxita Avila. 5/2017. “Giant embryos and hatchlings of Antarctic nudibranchs (Mollusca: Gastropoda: Heterobranchia).” Marine Biology, 164, Pp. 114.Abstract

Bathydoris hodgsoni and Doris kerguelenensis are two of the largest Antarctic nudibranchs. They are both common circumpolar species with broad bathymetric distributions, although B. hodgsoni is restricted to deep waters in the Antarctic high latitude. Egg masses and juveniles of these species were collected over multiple years (1998–2012) in the eastern Weddell Sea and the South Shetland Islands, and here new data are provided about egg mass characteristics and ontogeny using histological techniques. The egg mass of B. hodgsoni has a maximum length of 12.4 cm with one or two egg capsules with a mean diameter of 4.9 cm. The capsules either contained non-developing eggs or ready-to-hatch juveniles up to 2.9 cm long. The egg mass of D. kerguelenensis is a semicircular ribbon-like structure including 1,500–2,400 oval capsules (~1.7 × 1.2 mm) containing various stages of development up to ready-to-hatch juveniles 2.5 mm in length. Based on their morphology and development in egg masses maintained in the laboratory, the embryonic period for B. hodgsoni is estimated to be up to 10 years, and for D. kerguelenensis 13 months. Thus, B. hodgsoni has the largest egg capsules and probably the largest hatchlings of any mollusc. Chemical analyses of D. kerguelenensis egg masses showed no trace of terpenoid acylglycerols, although these compounds were present in field-collected juveniles and adults. None of four sponges that likely serve as food for D. kerguelenensis had the glycerides, or their precursors, found in the nudibranch.

Moles_et_al._-_2017_-_Giant_embryos_and_hatchlings_of_Antarctic_nudibranchs.pdf
Juan Moles, Heike Wägele, Gabriele Uhl, and Conxita Avila. 3/1/2017. “Bipolarity in sea slugs: a new species of Doridunculus (Mollusca: Nudibranchia: Onchidoridoidea) from Antarctica.” Organisms Diversity & Evolution, 17, 1, Pp. 101-109.Abstract

Bipolar distributions of benthic taxa have intrigued many biologists since the first Antarctic expeditions. Records of taxa, either at species or higher taxonomic levels, encompassing this peculiar distribution have been regularly reported since then. Moreover, the study of heterobranch mollusks from remote areas, such as Antarctica, often provides key taxa so far unknown, which might be essential for systematics. Here, we describe a new species of nudibranch from the eastern Weddell Sea using micro-computed tomography (micro-CT), namely, Doridunculus punkus n. sp. (Akiodorididae). Hitherto, the genus Doridunculus was only reported from the Arctic region. We provide an extensive description of morphological and anatomical characters of D. punkus n. sp., thereby offering new insights into the anatomyof the understudied Akiodorididae. A comparison of all Akiodorididae species shows that D. punkus n. sp. exhibits intermediate characters between some Onchidoridoidea families (i.e., hook-shaped innermost lateral teeth). Furthermore, the detailed study of its reproductive system suggests a close relationship of both Akiodorididae and Goniodorididae. We suggest an Antarctic origin of Akiodorididae followed by dispersion and a subsequent speciation in the Arctic.

Moles_et_al._2017_Bipolarity_in_sea_slugs_a_new_species_of_Doridunculus_from_Antarctica.pdf
Juan Moles, Heike Wägele, Michael Schrödl, and Conxita Avila. 2/10/2017. “A new Antarctic heterobranch clade is sister to all other Cephalaspidea (Mollusca: Gastropoda).” Zoologica Scripta, 46, 2, Pp. 127-137.Abstract
For a long time, Diaphanidae has been considered a basal family within Cephalaspidea, based on the presence of plesiomorphic morphological features within this taxon. Traditionally, the family contained the genera Bogasonia, Colobocephalus, Colpodaspis, Diaphana, Newnesia, Toledonia and Woodbridgea. Some phylogenetic analyses of several of these genera support the basal position of Diaphanidae within Cephalaspidea sensu stricto. However, the family is presently confirmed to be a polyphyletic taxon in which only the genus Diaphana is included. Several genera previously embraced within the family, such as the monotypic Newnesia, have never been previously analysed in molecular studies. Here, we provide an extensive morphological, anatomical and histological description of a new species of Newnesia from Antarctic deep waters (967–1227 m depth) in the Drake Passage. We also discuss the similarities to the traditional Diaphanidae genera to try to shed light into this phylogenetic conundrum. We sequenced cytochrome c oxidase subunit I, 16S rRNA, 28S rRNA and histone H3 markers of Newnesia antarctica and Newnesia joani n. sp. We analysed a comprehensive dataset of sequenced genera to evaluate the placement of both Newnesia species within the cephalaspidean families. Maximum-likelihood and Bayesian phylograms support the monophyly of N. joani n. sp. and suggest cryptic speciation in N. antarctica specimens. Newnesia is recovered as the most basal offshoot of Cephalaspidea, suggesting the establishment of a new family restricted to Antarctic waters, named Newnesiidae n. fam., to hold both species. The possible Antarctic origin of Cephalaspidea is discussed.
Moles_et_al._2017_A_new_Antarctic_heterobranch_clade_is_sister_to_all_other_Cephalaspidea.pdf
2016
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.Abstract
Although 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.Abstract
Two 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
2015
Juan Moles, Laura Núñez-Pons, Sergi Taboada, Blanca Figuerola, Javier Cristobo, and Conxita Avila. 8/12/2015. “Anti-predatory chemical defences in Antarctic benthic fauna.” Marine Biology, 162, 9, Pp. 1813-1821.Abstract

Antarctic benthic communities are largely structured by predation, which leads to the development of mechanisms of repellence. Among those mechanisms, chemical defences are quite extensive, yet poorly understood. To increase knowledge about the role of chemical defences in the Southern Ocean ecosystems, we assessed the incidence of feeding repellents in sessile and vagile invertebrates from nine phyla: Porifera, Cnidaria, Nemertea, Annelida, Mollusca, Bryozoa, Echinodermata, Hemichordata, and Tunicata (Ascidiacea). Samples were collected at depths of 120–789 m in the eastern Weddell Sea and Bouvet Island, and at depths ranging 0–100 m in the South Shetland Islands. When possible, specimens were dissected to study anatomical allocation of repellents. The common, eurybathic sea star Odontaster validus was chosen to perform feeding repellence bioassays, using diethyl ether (lipophilic) and butanol (hydrophilic) extracts from these samples. Among the 75 species tested, 52 % were studied for the first time for anti-predatory properties. Results provide further evidence of the prevalence of defensive metabolites in Antarctic organisms, with 47 % of the species exhibiting significant repellence within their lipophilic extracts. They also suggest a wider use of non-polar defensive chemicals. Sessile taxa displayed highest repellence activities, with ascidians, cnidarians, and sponges being the most chemically protected. Overall, the present study indicates that natural products by mediating trophic interactions between prey and their potential preda- tors play an important role in structuring Antarctic benthic ecosystems.

Moles_et_al._2015_Anti-predatory_chemical_defences_in_Antarctic_benthic_fauna.pdf
Adele Cutignano, Juan Moles, Conxita Avila, and Angelo Fontana. 7/15/2015. “Granuloside, a unique linear homosesterterpene from the Antarctic nudibranch Charcotia granulosa.” Journal of Natural Products, 78, 7, Pp. 1761-1764.Abstract

A new homosesterterpene with a unique linear skeleton, named granuloside (1), has been fully characterized from the Antarctic nudibranch Charcotia granulosa Vayssière, 1906 (Mollusca: Gastropoda). The planar structure of 1 was determined by extensive spectroscopic techniques on the methyl derivatives (1a and 1b), and the R absolute configuration at C-4 is suggested by comparison of experimental and calculated ECD spectra of 1b. Granuloside (1) is the first linear homosesterterpene skeleton ever reported and, despite the low molecular complexity, its chemical structure poses many questions about its biogenesis and origin in the nudibranch.

Juan Moles, Blanca Figuerola, Neus Campanyà-Llovet, Toni Monleón-Getino, Sergi Taboada, and Conxita Avila. 1/23/2015. “Distribution patterns in Antarctic and Subantarctic echinoderms.” Polar Biology, 38, 6, Pp. 799-813.Abstract

Echinoderms are the dominant megafaunal taxa in Antarctic and Subantarctic waters in terms of abundance and diversity, having a predominant role in structuring communities. The current study presents new data on the asteroids, holothuroids, and ophiuroids (three of the five extant classes of echinoderms) collected in seven scientific campaigns (1995–2012) from Bouvet Is., South Shetland Is., and the Eastern Weddell Sea, from a wide bathymetric range (0–1,525 m). Among the 316 echinoderms collected, we extended the bathymetric ranges of 15 species and expanded the geographic distribution of 36 of them. This novel dataset was analyzed together with previous reports in order to establish general patterns of geographic and bathymetric distribution in echinoderms of the Southern Ocean (SO). Nearly 57 % of the assembled-data species resulted endemic of the SO, although further taxonomic efforts in less accessible areas are needed. Interestingly, some islands presented high levels of species richness even comparable to large geographic areas. While generally exhibiting a wide range of eurybathy, there were differences in species composition across depths corre- sponding to sublittoral, upper and lower bathyal, and abyssal. Bathymetric distribution was analyzed considering biological aspects for each class. As expected, circumpolar trends were found, although hydrographic currents may be the cause of differences in species composition among SO areas. Our analyses suggest zoogeographic links between Antarctica and the adjacent ocean basins, being the Scotia Arc the most remarkable. This study contributes to the knowledge of large-scale diversity and distribution patterns in an Antarctic key group.

Moles_et_al._2015_Distribution_patterns_in_Antarctic_and_Subantarctic_echinoderms.pdf
Juan Moles, Conxita Avila, and Il-Hoi Kim. 2015. “Anthessius antarcticus n. sp. (Copepoda: Poecilostomatoida: Anthessidae) from Antarctic waters living in association with Charcotia granulosa (Mollusca: Nudibranchia: Charcotiidae).” Journal of Crustacean Biology, 35, 1, Pp. 97-104.Abstract

A new species of the genus Anthessius Della Valle, 1880 is described under the name A. antarcticus. It is ectosymbiont of the nudibranch Charcotia granulosa Vayssière, 1906 from the South Shetland Islands in the Southern Ocean. The female of the newspecies is distinguished from its congeners by the following combination of diagnostic morphological characters: 1) antenna with two terminal claws; 2) mandible with a seta between distal and outer lashes; 3) third exopodal segment of leg 4 with four spines and five setae (formula: III, I, 5); and 4) caudal ramus 2.40 times as long as wide. Its relationship with its congeners and other anthessiid genera are discussed. This is the first species of the genus found to be related to a nudibranch, and remarkably, it is also the only record of Anthessiidae from Antarctica.

Moles_2015_Anthessius_antarcticus_n._sp._from_Antarctic_waters.pdf
2014
Juan Moles, Anna Torrent, Ma José Alcaraz, Ramón Ruhí, and Conxita Avila. 7/22/2014. “Anti-inflammatory activity in selected Antarctic benthic organisms.” Frontiers in Marine Science, 1, Pp. 1-5.Abstract

Antarctic benthos was prospected in search for anti-inflammatory activity in polar benthic invertebrates, in two different geographical areas: deep-bottoms of the Eastern Weddell Sea and shallow-waters of the South Shetland Islands. A total of 36 benthic algae and invertebrate species were selected to perform solubility tests in order to obtain extracts thatwere soluble at an innocuous ethanol concentration (0.2%) for cell culture, and further test them for anti-inflammatory activity. From these, ethanol extracts of ten species from five different phyla resulted suitable to be studied in cell macrophage cultures (RAW 264.7). Cytotoxicity (MTT method) and production of inflammatory mediators (prostaglandin E2, leukotriene B4, interleukin-1β) were determined at three extract concentrations (50, 125, 250µg/mL). Bioassays resulted in four different species showing anti-inflammatory activity corresponding to three sponges: Mycale (Oxymycale) acerata, Isodictya erinacea, and I. toxophila; and one hemichordate: Cephalodiscus sp. These results show that Antarctic sessile invertebrates may have great value as a source of lead compounds with potential pharmaceutical applications.

Moles_et_al._2014_Anti-inflammatory_activity_in_selected_Antarctic_benthic_organisms.pdf
2013
Blanca Figuerola, Laura Núñez-Pons, Juan Moles, and Conxita Avila. 11/13/2013. “Feeding repellence in Antarctic bryozoans.” Naturwissenschaften, 100, Pp. 1069-1081.Abstract

The Antarctic sea star Odontaster validus and the amphipod Cheirimedon femoratus are important predators in benthic communities. Some bryozoans are part of the diet of the asteroid and represent both potential host biosubstrata and prey for this omnivorous lysianassid amphipod. In response to such ecological pressure, bryozoans are expected to develop strategies to deter potential predators, ranging from physical to chemical mechanisms. However, the chemical ecology of Antarctic bryozoans has been scarcely studied. In this study we evaluated the presence of defenses against predation in selected species of Antarctic bryozoans. The sympatric omnivorous consumers O. validus and C. femoratus were selected to perform feeding assays with 16 ether extracts (EE) and 16 butanol extracts (BE) obtained from 16 samples that belonged to 13 different bryozoan species. Most species (9) were active (12 EE and 1 BE) in sea star bioassays. Only 1 BE displayed repellence, indicating that repellents against the sea star are mainly lipophilic. Repellence toward C. femoratus was found in all species in different extracts (10 EE and 12 BE), suggesting that defenses against the amphipod might be both lipophilic and hydrophilic. Interspecific and intraspecific variability of bioactivity was occasionally detected, suggesting possible environmental inductive responses, symbiotic associations, and/or genetic variability. Multivariate analysis revealed similarities among species in relation to bioactivities of EE and/or BE. These findings support the hypothesis that, while in some cases alternative chemical or physical mechanisms may also provide protection, repellent compounds play an important role in Antarctic bryozoans as defenses against predators.

Figuerola_et_al._2013_Feeding_repellence_in_Antarctic_bryozoans.pdf