Morphological (shell) and molecular examination of a large suite of specimens of pleurotomariids from around New Caledonia and the Coral Sea reveals the existence of four species in the complex of Perotrochus caledonicus: Perotrochus deforgesi Métivier, 1990 and P. pseudogranulosus sp. nov. live allopatrically on the plateaus and guyots of the Coral Sea; Perotrochus caledonicus Bouchet & Métivier, 1982 and Perotrochus wareni sp. nov. live sympatrically - but essentially not syntopically on the slopes of New Caledonia, Norfolk Ridge and the Loyalty Ridge. All species live in the 300–500 m interval, and together form a significant component of the mollusc fauna living on hard bottoms in the SW Pacific, with individual dredge hauls containing up to 25 specimens of Perotrochus.

BATHUS 3, BATHUS 4, CONCALIS, EBISCO, LITHIST, MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, NORFOLK 1, NORFOLK 2, SMIB 5, SMIB 6, SMIB 8, TERRASSES, VOLSMAR

Characterizing speciation processes in the sea remains a highly contentious issue because geographic barriers to gene exchange, which are the initial conditions for the allopatric speciation model, are not obvious. Moreover, many benthic marine organisms have long-lived planktonic larvae that allow them to connect distant patches of habitats. We here analyse the pattern of speciation in the gastropod genus Bursa in which all species have long-lived and planktonic-feeding larvae. We use a large taxonomic and ecologic coverage of Bursidae from the Indo-Pacific. We use an integrative approach to taxonomy to give more support to available taxonomic hypotheses. This analysis revealed cryptic lineages and suggest that a taxonomic revision of the family should be performed. A molecular clock calibrated from the fossil record was used to estimate divergence times. We then focus on the three co-existing species living in the deep waters of New Caledonia. Over the wide sampled area, no genetic structure was detected for the three species. We show that among New Caledonia species, Bursa fijiensis and Bursa quirihorai are reciprocally monophyletic. These two species are the two more closely related species in the inferred phylogeny. The present biogeographic ranges of the two species and the estimated time of divergence make the scenario of geographic isolation followed by secondary contact unlikely.

AURORA 2007, CONCALIS, EBISCO, MAINBAZA, MIRIKY, NORFOLK 1, NORFOLK 2, PANGLAO 2004, PANGLAO 2005, SALOMON 2, TERRASSES

In shelled molluscs, assigning valid species names to independent evolutionary lineages can be a difficult task. Most original descriptions are based on empty shells and the high levels of variation in shape, color and pattern in some groups can make the shell a poor proxy for species-level identification. The deep-sea gastropod turbinid genus Bolma is one such example, where species-level identification based on shell characters alone is challenging. Here, we show that in Bolma both traditional and molecular taxonomic treatments are associated with a number of pitfalls that can lead to biased inferences about species diversity. Challenges derive from the few phylogenetically informative characters of shells, insufficient information provided in original descriptions and sampling artefacts, which at the molecular level in spatially fragmented organisms can blur distinctions between genetically divergent populations and separate species. Based on a comprehensive dataset combining molecular, morphological and distributional data, this study identified several cases of shell-morphological plasticity and convergence. Results also suggest that what was thought to be a set of distinct, range-restricted species corresponds instead to a smaller number of more widespread species. Overall, using an appropriate sampling design, including type localities, allowed us to assign available names to evolutionarily significant units.

ATIMO VATAE, AURORA 2007, BIOPAPUA, BORDAU 1, CONCALIS, EBISCO, EXBODI, MAINBAZA, MIRIKY, NORFOLK 2, PANGLAO 2004, PANGLAO 2005, SALOMON 2, SALOMONBOA 3, TAIWAN 2004, TERRASSES

Nassariidae are a group of scavenging, predominantly marine, snails that are diversified on soft bottoms as well as on rocky shores, and are the subject of numerous research papers in ecology, ecotoxicology or paleontology. A weak and/or apparently continuous variation in shell characters has resulted in an intimidating taxonomy, with complex synonymy lists. Over 1320 extant nominal species have been described, of which 442 are currently regarded as valid. Above species level, the state of the art is equally hazy, with four subfamilies and twelve genera currently accepted, and many other names in the graveyard of synonymy. A molecular analysis based on three mitochondrial (COI, 16S, 12S) and two nuclear (28S, H3) markers was conducted. Our dataset includes 218 putative nassariid species, comprising 9 of the 12 valid genera, and 25 nominal genera represented by their type species. The monophyly of the Nassariidae as classically construed is not confirmed. Species of Antillophos, Engoniophos, Phos, Nassaria, Tomlinia and Anentome (formerly considered Buccinidae) are included inside the Nassariidae clade. Within the Nassariinae, the tree unexpectedly demonstrates that species from the Atlantic and the Indo-Pacific form different clades which represent several independent diversification events. Through an integrative approach, the reconstruction of ancestral states was addressed for eight characters supposedly informative for taxonomy. Using numerous fossil calibration points, Nassariidae appear to have originated 120 MYA ago in Atlantic temperate waters during the Lower Cretaceous. Our results have a profound impact on nassariid taxonomy, especially with regard to the validity of subfamily- and genus-level names.

ATIMO VATAE, AURORA 2007, BIOPAPUA, CONCALIS, EBISCO, EXBODI, INHACA 2011, KARUBENTHOS 2012, LIFOU 2000, MAINBAZA, MIRIKY, PAKAIHI I TE MOANA, PANGLAO 2004, PANGLAO 2005, SALOMON 2, SALOMONBOA 3, SANTO 2006, TARASOC, TERRASSES

Cancellariidae, or nutmeg shells, is a family of marine gastropods that feed on the body fluids and the egg cases of marine animals. The 300 or so living species are distributed worldwide, mostly on soft bottoms, from intertidal to depths of about 1000 m. Although they are a key group for the understanding of neogastropod evolution, they are still poorly known in terms of anatomy, ecology and systematics. This paper reports the first mitochondrial multi-gene phylogenetic hypothesis for the group. Data were collected for 50 morphospecies, representative of 22 genera belonging to the three currently recognized subfamilies. Sequences from three genes (12S, 16S and COI) were analyzed with Maximum Likelihood analysis and Bayesian Inference, both as single gene datasets and in two partitioned concatenated alignment. Largely consistent topologies were obtained and discussed with respect to the traditional subfamilial arrangements. The obtained phylogenetic trees were also used to produce Robinson-Foulds supertrees. Our results confirmed the monophyly of the subfamily Plesiotritoninae, while Admetinae and Cancellariinae, as currently conceived, were retrieved as polyphyletic. Based on our findings we propose changes to the systematic arrangement of these subfamilies. At a lower taxonomic rank, our results highlighted the rampant homoplasy of many characters traditionally used to segregate genera, and thus the need of a critical re-evaluation of the contents of many genera (e.g. Nipponaphera, Merica, Sydaphera, Bivetia), the monophyly of which was not recovered.

AURORA 2007, CONCALIS, MAINBAZA, MIRIKY, NORFOLK 2, PANGLAO 2004, PANGLAO 2005, SALOMON 2, SALOMONBOA 3, SANTO 2006

BATHUS 3, MAINBAZA, MIRIKY, MUSORSTOM 3