The widespread and abundant brooding brittle-star ( Amphipholis squamata ) is a simultaneous hermaphrodite with a complex mitochondrial phylogeography of multiple divergent overlapping mtDNA lineages, high levels of inbreeding or clonality and unusual sperm morphology. We use exon-capture and transcriptome data to show that the nuclear genome comprises multiple (greater than 3) divergent (π > 6%) expressed components occurring across samples characterized by highly divergent (greater than 20%) mitochondrial lineages, and encompassing several other genera, including diploid dioecious species. We report a massive sperm genome size in A. squamata , an order of magnitude larger than that present in other brittle-stars, and consistent with our SNP-based measure of greatly elevated ploidy. Similarity of these genetic signatures to well-known animal systems suggests that A. squamata (and related taxa) is a hybrid polyploid asexual complex of variable subgenome origins, ploidy and reproductive mode. We discuss enigmatic aspects of A. squamata biology in this light. This putative allopolyploid complex would be the first to be reported from the phylum Echinodermata.

EBISCO, KANACONO, KANADEEP 2

Ophiuroid assemblages were successfully predicted from current museum sample data using presence-only modeling techniques and a multivariate classification on the resulting species occurrence probabilities across the Coral and Tasman Seas (20-37°S, 148-172°E). The classification involves two-stages. The first uses a non-hierarchical clustering technique to reduce the number of data points (map-pixels) to a manageable number that can be analysed in a second stage with a hierarchical classification method. For both steps, the Bray-Curtis similarity statistic is used.

BATHUS 3, BERYX 11, BIOCAL, BIOGEOCAL, CHALCAL 1, CHALCAL 2, HALIPRO 2, MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, SMIB 1, VOLSMAR

BATHUS 3, BERYX 11, BIOCAL, BIOGEOCAL, CHALCAL 1, CHALCAL 2, HALIPRO 2, MUSORSTOM 4, MUSORSTOM 5, SMIB 1, VOLSMAR

BATHUS 1, BATHUS 2, BIOCAL, BIOPAPUA, EBISCO, GEMINI, MUSORSTOM 6, SANTO 2006, SMIB 5

The large-scale spatial distribution of seafloor fauna is still poorly understood. In particular, the bathyal zone has been identified as the key depth stratum requiring further macro- ecological research [ 1 ], particularly in the Southern Hemi- sphere [ 2 ]. Here we analyze a large biological data set derived from 295 research expeditions, across an equator- to-pole sector of the Indian, Pacific, and Southern oceans, to show that the bathyal ophiuroid fauna is distributed in three broad latitudinal bands and not primarily differentiated by oceanic basins as previously assumed. Adjacent faunas form transitional ecoclines rather than biogeographical breaks. This pattern is similar to that in shallow water despite the order-of-magnitude reduction in the variability of environmental parameters at bathyal depths. A reliable biogeography is fundamental to establishing a representative network of marine reserves across the world’s oceans [1, 3].

AZTEQUE, BATHUS 1, BATHUS 2, BATHUS 3, BATHUS 4, BERYX 11, BIOCAL, BIOGEOCAL, BORDAU 1, BORDAU 2, CHALCAL 1, CHALCAL 2, CORAIL 2, CORINDON 2, GEMINI, HALIPRO 1, HALIPRO 2, KARUBAR, MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, MUSORSTOM 7, MUSORSTOM 8, NORFOLK 1, SALOMON 1, SALOMON 2, SALOMONBOA 3, SANTO 2006, SMIB 2, SMIB 4, SMIB 5, Restreint, VOLSMAR

There have been comparatively few large-scale studies on spatial genetic structure of bathyal sea floor fauna, despite the importance of these data to the successful management of the world's oceans.We use a comparative analysis of mitochondrial DNA from five bathyal (200–3500m) species of brittle-stars (Ophiuroidea) to assess phylogeographic structure along an extensive (8000km) longitudinal gradient at temperate latitudes (28–561S) from south-west Australia(113°E) to seamounts east of New Zealand (175°W). We found no evidence of a genetic discontinuity between Australia and New Zealand,either across the temperate Tasman Sea or across the Southern Ocean between the South Tasman Rise and the Macquarie Ridge. However, there were latitudinal phylogeographical breaks between tropical, temperate and polar regions; longitudinal breaks across the eastern Indian Ocean; and a bathymetric break at approximately 1700m. Although there was limited regional structure in the frequency of haplotype distributions within the major clades, and no clade appeared to be strictly panmictic, the regional structure in general was not concordant with a simple isolation-by-distance model. Demographic structure varied with three clades having a simplified haplotype network, low effective population sizes and no evidence of significant population expansion, and two clades having a high diversity of haplotypes, relatively high effective population sizes and signs of recent population expansion. These results are discussed with respect to putative dispersal strategies. We hypothesise that the ‘brooding’ species produce both brooded young and pelagic larvae, allowing for both the maintenance of local populations and long-distance dispersal.

ATIMO VATAE, BIOPAPUA, SANTO 2006

The power and throughput of next-generation sequencing is instigating a major transformation in our understanding of evolution and classification of life on our planet. The new trees of life are robust and comprehensive. Here we provide a landmark phylogeny of the living ophiuroids and use it as the basis for a major revision of the higher classification of this class of marine invertebrates. We used an exoncapture system to generate a 1484 exon (273 kbp) data-matrix from DNA extracted from ethanolpreserved museum samples. We successfully obtained an average of 90% of our target sequence from 576 species spread across the known taxonomic diversity. The topology of the major lineages was robust to taxon sampling, exon-sampling, models and methods. However, estimates of node age were much less precise, varying by about a quarter of mean age. We used a combination of phylogenetic distinctiveness and temporal-banding to guide our revision of the family-level classification. Empirically, we determined that limiting family crown age to 110 ± 10 Ma (mid Cretaceous) selected phylogenetically distinct nodes while minimising disruption to the existing taxonomy. The resulting scheme of 32 families and six orders considerably expands the number of higher taxa. The families are generally longitudinally widespread across the world’s oceans, although 17 are largely confined to temperate and equatorial latitudes and six to relatively shallow water (less than 1000 m depth).

ATIMO VATAE, BICOSE, BIOPAPUA, CEAMARC-AA, EBISCO, MUSORSTOM 7, SALOMON 2, SANTO 2006, TAIWAN 2000

The deep-seafloor in the tropical Indo-Pacific harbours a rich and diverse benthic fauna with numerous palaeoendemics. Here, we describe a new species, genus and family of brittle-star (Ophiuroidea) from a single eight-armed specimen collected from a depth between 360 and 560 m on Banc Durand, a seamount east of New Caledonia. Leveraging a robust, fossil-calibrated (265 kbp DNA) phylogeny for the Ophiuroidea, we estimate the new lineage diverged from other ophiacanthid families in the Late Triassic or Jurassic (median = 187–178 Myr, 95% CI = 215–143 Myr), a period of elevated diversification for this group. We further report very similar microfossil remains from Early Jurassic (180 Myr) sediments of Normandy, France. The discovery of a new ancient lineage in the relatively well-known Ophiuroidea indicates the importance of ongoing taxonomic research in the deep-sea, an environment increasingly threatened by human activities.

EXBODI

A short preliminary report ofan ongoing study of the New Caledonian deep-sea ophiuroid fatma is presented with a list of39 genera of79 species, including six previously undescribed species and a new gel1lls. Three species (Astrogynmotes hamishia Baker et al. , 2001, Astrothamnus sp., Ophioli/J/na antarctica (Lyman, 1879)) representing the main groups Ophiomyxidae, Euryalida, and Ophiacanthidae are presented briefly, illustrated with scanning electron micrographs, as examples of the Im·ger work that will be published elsewhere after the project will be finished.

BATHUS 1, BATHUS 3, BERYX 11, BIOCAL, CHALCAL 1, CHALCAL 2, HALIPRO 1, KARUBAR, MUSORSTOM 1, MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, MUSORSTOM 8, SMIB 4

Delineating biogeographical regions can provide important insights into the processes shaping large‐scale species distribution patterns. Here we aimed to 1) identify global marine benthic biogeographical regions for ophiuroids extending from shallow waters to the deep sea and 2) quantify the importance of contemporary environmental conditions and geological features in shaping the delineated biogeographical regions. We delineated marine benthic biogeographical regions using a bipartite network analysis applied to a historical dataset of brittle stars. We then examined the faunal exchanges between the regions, and applied random forest models to evaluate the relative role of contemporary environmental conditions and tectonic configuration underlying the proposed biogeographic scheme. We propose ten main large biogeographical regions across the benthos. The biogeographical regions with the highest species richness and endemicity rates were found in the Indo‐Pacific region, Tropical West Atlantic and Southern Ocean, and South America. The key transition regions fall within the subarctic areas of the Pacific and the waters surrounding Southern Australia and New Zealand. Tectonic configuration, surface temperature and salinity were found to be the most important predictors of the ten delineated biogeographical regions. Our biogeographic delineation, including the deep sea, is in partial agreement with those proposed in previous studies. Our results suggest that contemporary environmental conditions (sea water temperature and salinity) strongly influence the modern distribution of ophiuroids, but that plate tectonics left a marked imprint on regional species pools. Future work based on multiple benthic taxa, and with a better understanding of the environmental conditions in the deep sea, are needed to evaluate the robustness of our proposed division.

ATIMO VATAE, AURORA 2007, AZTEQUE, BATHUS 1, BATHUS 2, BATHUS 3, BATHUS 4, BENTHAUS, BERYX 11, BIOCAL, BIOGEOCAL, BIOPAPUA, BOA1, BORDAU 1, BORDAU 2, CHALCAL 1, CHALCAL 2, CORAIL 2, CORINDON 2, DongSha 2014, EBISCO, EXBODI, GUYANE 2014, HALIPRO 1, HALIPRO 2, KANACONO, KANADEEP, KARUBAR, KARUBENTHOS 2, LAGON, LITHIST, MIRIKY, MUSORSTOM 1, MUSORSTOM 10, MUSORSTOM 2, MUSORSTOM 3, MUSORSTOM 4, MUSORSTOM 5, MUSORSTOM 6, MUSORSTOM 7, MUSORSTOM 8, MUSORSTOM 9, NORFOLK 1, PALEO-SURPRISE, PAPUA NIUGINI, SALOMON 2, SALOMONBOA 3, SANTO 2006, SMIB 1, SMIB 2, SMIB 3, SMIB 4, SMIB 5, SMIB 6, TAIWAN 2000, TARASOC, VAUBAN 1978-1979, VOLSMAR, Walters Shoal