The relationships of the enigmatic gastropod Tritonoharpa (Neogastropoda): New data on early neogastropod evolution?

In this paper, the relationships of Tritonoharpa Dall, 1908, within Neogastropoda are discussed. Tritonoharpa is indeed similar to Colubraria in the morphology of its head-foot, pallial complex, reproductive and excretory systems, in the presence of an extremely long and coiled proboscis, and a very large stomach. However, it differs from Colubraria in the rest of its foregut anatomy, revealing a cancellariid affinity, and a typical nematoglossan radula. The molecular data confirms Beu and Maxwell's placement of Tritonoharpa in the Cancellariidae, close to Plesiotriton. It is also suggested that cancellariids may be the sister-group to the rest of neogastropods. Tritonoharpa has a rather large and well developed midgut gland, resembling the gland of Leiblein. As previously studied cancellarioideans have been shown to lack a well differentiated gland of Leiblein, the present study raises some interesting questions about the evolution of the foregut in Neogastropoda. In fact, if this glandular structure were confirmed as a true homologue of the gland of Leiblein, and the cancellarioideans proved to be the sister group to the remaining neogastropods, the possession of the gland should be considered a synapomorphy of the Neogastropoda

An assessment of the genus Columbella Lamarck, 1799 (Gastropoda: Columbellidae) from eastern Atlantic

Three species of the neogastropod genus Columbella Lamarck, 1799 are recognised from the northeastern Atlantic and the Mediterranean. One is the common Mediterranean C. rustica (Linnaeus, 1758), with paucispiral protoconch, extending its range in the Atlantic South to Senegal and North to Portugal. Columbella adansoni Menke, 1853, with multispiral protoconch is restricted to the Macaronesian archipelagoes. A third species, also with multispiral protoconch, from West Africa is recognised through molecular methods, and the name C. xiphitella Duclos, 1840 is employed by correcting the original erroneous locality (“Californie”) to Gabon. Except for protoconch features, no major morphological characters are available to separate the three species; however diagnostic species-level differences in specific positions in the cytochrome c oxidase I (COI) sequences are present between all three species

Editorial: Diversity and Evolution of Animal Venoms: Neglected Targets, Ecological Interactions, Future Perspectives

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Diversidad críptica en gasterópodos mediterráneos del género Aplus (Neogastropoda: Buccinidae)

Northeastern Atlantic and Mediterranean gastropods previously ascribed to the buccinid genus Pollia Gray, 1837 are more correctly classified in the genus Aplus de Gregorio, 1885. Using an integrative taxonomy approach combining molecular, morphological and geographic data, we revisit the limits of the extant species in the area, and propose a molecular phylogenetic hypothesis based on 66 specimens from various localities in the Mediterranean Sea, including type localities of some nominal taxa. We used a preliminary morphological inspection, followed by a DNA-barcoding approach to propose species hypotheses, subsequently consolidated using additional data (phylogenetic, geographic and refined morphological data). Seven species hypotheses were eventually retained within our molecularly assayed samples, versus three classical morphologically recognized species. Among these, three correspond to Aplus dorbignyi (Payreaudeau, 1826) with its hitherto unrecognized geographical cognates A. gaillardoti (Puton, 1856) (eastern Mediterranean) and Aplus nodulosus (Bivona Ant., 1832) (Sicily); two closely related, yet considerably divergent, lineages are treated as a single species under Aplus scaber (Locard, 1892); the classically admitted Aplus scacchianus (Philippi, 1844) is confirmed by molecular evidence; Mediterranean populations attributable to Aplus assimilis (Reeve, 1846) may represent either cryptic native populations or an ongoing invasion of the Mediterranean by what was hitherto considered to be a West African species; finally, specimens from the Strait of Gibraltar may represent an undescribed species, but we conservatively refrain from formally introducing it pending the analysis of more material, and it is compared with the similar Aplus campisii (Ardovini, 2014), recently described from Sicily and not assayed molecularly, and Aplus scaber.Los gasterópodos mediterráneos y del Atlántico nordeste previamente asignados al género Pollia Gray, 1837 deben ser más correctamente incluidos en el género Aplus de Gregorio, 1885. Se revisan aquí los límites de las especies recientes de este género en el área estudiada por medio de un enfoque de taxonomía integrativa. En base a ello se propone una hipótesis filogenética basada en 66 ejemplares procedentes de varias localidades del Mediterráneo, incluyendo las localidades tipo de algunos taxones nominales. Primero se realizó una diferenciación morfológica, seguida de la aplicación del marcador molecular COI para proponer las especies a modo de hipótesis, que finalmente fueron validadas con datos adicionales (filogenéticos, geográficos y detalles morfológicos). Como resultado se reconocieron siete especies válidas entre los ejemplares analizados molecularmente, en contraste con las tres especies previamente reconocidas morfológicamente. Tres de ellas corresponden a Aplus dorbignyi (Payreaudeau, 1826) y a sus afines geográficos no reconocidas hasta ahora A. gaillardoti (Puton, 1856) [del Mediterráneo oriental] y Aplus nodulosus (Bivona Ant., 1832) [de Sicilia]; dos linajes estrechamente relacionados, aunque divergentes, son considerados como una misma especie con el nombre de Aplus scaber (Locard, 1892); la especie tradicionalmente admitida Aplus scacchianus (Philippi, 1844) se confirma en base a evidencias moleculares; las poblaciones mediterráneas atribuibles a Aplusas similis (Reeve, 1846) pueden ser crípticas nativas o corresponder a una invasión en curso por parte de esta especie del noroeste africano; finalmente los ejemplares del Estrecho de Gibraltar pueden representar una especie no descrita, pero se ha preferido optar por una posición conservadora y no introducir un nuevo nombre a la espera del estudio de material adicional y compararla con Aplus campisii (Ardovini, 2014), especie descrita recientemente de Sicilia y pendiente de su análisis molecular, y con Aplus scaber

Molecular systematics and biogeography of the western Mediterranean stonefly genus Tyrrhenoleuctra (Insecta, Plecoptera)

The stonefly genus Tyrrhenoleuctra includes species living in western Mediterranean temporary freshwater streams, sometimes also at sea level, a very unusual habitat for most Plecoptera. Traditional morphological approaches proved unsuccessful in drawing both taxonomic and phylogenetic patterns, thus hampering discussion of biogeographical patterns for this interesting group. We aimed at: (a) assessing the taxonomic status of populations of Tyrrhenoleuctra covering the geographic range of the genus; (b) studying the phylogenetic relationships among the recognized species; and (c) describing biogeographic patterns. We used phylogenetic analyses to infer the phylogenetic history of this group of stoneflies based on a combined data set of 1666 bp including fragments of the 12S ribosomal (12S) and cytochrome oxidase I (CO-I) mtDNA genes, with maximum likelihood and Bayesian methods. Two main clades have been identified: a Sardo-Corsican one, including Tyrrhenoleuctra zavattarii, and an Ibero-Maghrebian one including four lineages of unkown taxonomic rank from the Balearic Islands (Maiorca), from northern Africa (Ceuta) and southernmost Spain (Algeciras), and a complex preliminarily referred herein to T. minuta (Klapálek, 1901), which includes two lineages, one from Cordoba, and one from Sierra de Grazalema (El Cerro) and Portugal (Tellhares) respectively. Dating the nodes by fixing the split of the Ibero-Maghrebian clade from the Sardo-Corsican one at 29 million years ago (Mya), yielded dates referring to the major geological events in the Mediterranean basin. Estimated molecular evolutionary rates ranged from 0.02-0.09% per million years (my) in the T. zavattarii lineages, to 0.2-0.7% per MY in the Ibero-Maghrebian clade. The phylogenetic pattern emerged from the present study is congruent with the known paleo-history of the western Mediterranean basin, with the divergence of the two main Tyrrhenoleuctra lineages corresponding to the split of the Sardo-Corsican microplate from the Iberian block. Vicariance events have characterized the history of this stonefly group along its entire biogeographical history. Surprisingly low evolutionary rates, previously supposed by Fochetti (1991, 1994) and Fochetti et al. (2004) based on nuclear markers (allozymes), have been herein found also in mitochondrial markers.L'articolo è disponibile sul sito dell'edditore http://onlinelibrary.wiley.com

Correlating Molecular Phylogeny with Venom Apparatus Occurrence in Panamic Auger Snails (Terebridae)

Central to the discovery of neuroactive compounds produced by predatory marine snails of the superfamily Conoidea (cone snails, terebrids, and turrids) is identifying those species with a venom apparatus. Previous analyses of western Pacific terebrid specimens has shown that some Terebridae groups have secondarily lost their venom apparatus. In order to efficiently characterize terebrid toxins, it is essential to devise a key for identifying which species have a venom apparatus. The findings presented here integrate molecular phylogeny and the evolution of character traits to infer the presence or absence of the venom apparatus in the Terebridae. Using a combined dataset of 156 western and 33 eastern Pacific terebrid samples, a phylogenetic tree was constructed based on analyses of 16S, COI and 12S mitochondrial genes. The 33 eastern Pacific specimens analyzed represent four different species: Acus strigatus, Terebra argyosia, T. ornata, and T. cf. formosa. Anatomical analysis was congruent with molecular characters, confirming that species included in the clade Acus do not have a venom apparatus, while those in the clade Terebra do. Discovery of the association between terebrid molecular phylogeny and the occurrence of a venom apparatus provides a useful tool for effectively identifying the terebrid lineages that may be investigated for novel pharmacological active neurotoxins, enhancing conservation of this important resource, while providing supplementary information towards understanding terebrid evolutionary diversification

Venom Diversity and Evolution in the Most Divergent Cone Snail Genus Profundiconus

Profundiconus is the most divergent cone snail genus and its unique phylogenetic position, sister to the rest of the family Conidae, makes it a key taxon for examining venom evolution and diversity. Venom gland and foot transcriptomes of Profundiconus cf. vaubani and Profundiconus neocaledonicus were de novo assembled, annotated, and analyzed for differential expression. One hundred and thirty-seven venom components were identified from P. cf. vaubani and 82 from P. neocaledonicus, with only four shared by both species. The majority of the transcript diversity was composed of putative peptides, including conotoxins, profunditoxins, turripeptides, insulin, and prohormone-4. However, there were also a significant percentage of other putative venom components such as chymotrypsin and L-rhamnose-binding lectin. The large majority of conotoxins appeared to be from new gene superfamilies, three of which are highly different from previously reported venom peptide toxins. Their low conotoxin diversity and the type of insulin found suggested that these species, for which no ecological information are available, have a worm or molluscan diet associated with a narrow dietary breadth. Our results indicate that Profundiconus venom is highly distinct from that of other cone snails, and therefore important for examining venom evolution in the Conidae family

Neither slugs nor snails: a molecular reappraisal of the gastropod family Velutinidae

The systematics of the marine mollusc family Velutinidae has long been neglected by taxonomists, mainly because their often internal and fragile shells offer no morphological characters. Velutinids are usually undersampled owing to their cryptic mantle coloration on the solitary, social or colonial ascidians on which they feed and lay eggs. In this study, we address the worldwide diversity and phylogeny of Velutinidae based on the largest molecular dataset (313 specimens) to date, accounting for > 50% of the currently accepted genera, coupled with morphological and ecological data. Velutinids emerge as a diverse group, encompassing four independent subfamily-level lineages, two of which are newly described herein: Marseniopsinae subfam. nov. and Hainotinae subfam. nov. High diversity was found at genus and species levels, with two newly described genera (Variolipallium gen. nov. and Pacifica gen. nov.) and ≥ 86 species in the assayed dataset, 58 of which are new to science (67%). Velutinidae show a remarkable morphological plasticity in shell morphology, mantle extension and chromatic patterns. This variability is likely to be the result of different selective forces, including habitat, depth and trophic interactions

Spicy food for the egg-cowries: the evolution of corallivory in the Ovulidae (Gastropoda: Cypraeoidea)

IntroductionHost-parasite associations provide very useful models to study adaptive processes. We investigated the interaction between carnivorous marine gastropods, the Ovulidae or egg-cowries, and their cnidarian food targets. Ovulidae (Fleming, 1828), is a family of specialized carnivorous caenogastropods that feed by browsing on octocorals (Anthozoa: Octocorallia: Malacalcyonacea and Scleralcyonacea) or, to a much lesser degree, on antipatharians (Anthozoa: Hexacorallia: Antipatharia) and Stylasteridae (Hydrozoa: Hydroidolina: Anthoathecata). Very scanty information is available on the phylogenetic relationships and the degree of specificity of the relationship with the cnidarians of this corallivorous lineage, especially for deep-water taxa.MethodsTo assess taxonomic identifications and investigate cnidarian/ovulid relationships in the context of their evolution, we generated an extensive molecular dataset comprising two mitochondrial (cox1 and 16S rDNA) and one nuclear gene (28S rDNA) from 524 specimens collected worldwide. The coral hosts of the ovulid species have been identified by integrating literature data with new records, employing morphological and/or molecular (the mitochondrial 16S rDNA and mtMSH, and the nuclear ITS2) markers.ResultsWe obtained a molecular phylogenetic framework for the Ovulidae, time-calibrated with nine reliable fossil records. An ancestral state reconstruction allowed to identify Hexacorallia or Hydroidolina as the most likely ancestral cnidarian host for the Ovulidae.DiscussionOur phylogenetic hypothesis revealed the existence of groups that do not completely correspond to the currently employed subfamilial arrangement. Concerning trophic ecology, while only pediculariines (Pedicularia and allied) are associated with hydrozoans (Stylasteridae), our results suggest that some ovulid lineages shifted independently between octocorals and hexacorals

Framing Cutting-Edge Integrative Deep-Sea Biodiversity Monitoring via Environmental DNA and Optoacoustic Augmented Infrastructures

17 pages, 1 figure, 1 tableDeep-sea ecosystems are reservoirs of biodiversity that are largely unexplored, but their exploration and biodiscovery are becoming a reality thanks to biotechnological advances (e.g., omics technologies) and their integration in an expanding network of marine infrastructures for the exploration of the seas, such as cabled observatories. While still in its infancy, the application of environmental DNA (eDNA) metabarcoding approaches is revolutionizing marine biodiversity monitoring capability. Indeed, the analysis of eDNA in conjunction with the collection of multidisciplinary optoacoustic and environmental data, can provide a more comprehensive monitoring of deep-sea biodiversity. Here, we describe the potential for acquiring eDNA as a core component for the expanding ecological monitoring capabilities through cabled observatories and their docked Internet Operated Vehicles (IOVs), such as crawlers. Furthermore, we provide a critical overview of four areas of development: (i) Integrating eDNA with optoacoustic imaging; (ii) Development of eDNA repositories and cross-linking with other biodiversity databases; (iii) Artificial Intelligence for eDNA analyses and integration with imaging data; and (iv) Benefits of eDNA augmented observatories for the conservation and sustainable management of deep-sea biodiversity. Finally, we discuss the technical limitations and recommendations for future eDNA monitoring of the deep-sea. It is hoped that this review will frame the future direction of an exciting journey of biodiscovery in remote and yet vulnerable areas of our planet, with the overall aim to understand deep-sea biodiversity and hence manage and protect vital marine resourcesThis research has been funded within the framework of the following project activities: ARIM (Autonomous Robotic Sea-Floor Infrastructure for Benthopelagic Monitoring; MarTERA ERA-Net Cofound); RESBIO (TEC2017-87861-R; Ministerio de Ciencia, Innovación y Universidades); JERICO-S3: (Horizon 2020; Grant Agreement no. 871153); ENDURUNS (Research Grant Agreement H2020-MG-2018-2019-2020 n.824348); Slovenian Research Agency (Research Core Funding Nos. P1-0237 and P1-0255 and project ARRS-RPROJ-JR-J1-3015). We also profited of the funding from the Spanish Government through the “Severo Ochoa Centre of Excellence” accreditation (CEX2019-000928-S) and Italian Ministry of Education (MIUR) under the “Bando premiale FOE 2015” (nota prot. N. 850, dd. 27 ottobre 2017) with the project EarthCruisers “EARTH’s CRUst Imagery for Investigating Seismicity, Volcanism, and Marine Natural Resources in the Sicilian Offshore”. Ocean Networks Canada was funded through Canada Foundation for Innovation-Major Science Initiative (CFI-MSI) fund 30199Peer reviewe