The phylogeny of extant starfish (Asteroidea: Echinodermata) including Xyloplax, based on comparative transcriptomics.

Multi-locus phylogenetic studies of echinoderms based on Sanger and RNA-seq technologies and the fossil record have provided evidence for the Asterozoa-Echinozoa hypothesis. This hypothesis posits a sister relationship between asterozoan classes (Asteroidea and Ophiuroidea) and a similar relationship between echinozoan classes (Echinoidea and Holothuroidea). Despite this consensus around Asterozoa-Echinozoa, phylogenetic relationships within the class Asteroidea (sea stars or starfish) have been controversial for over a century. Open questions include relationships within asteroids and the status of the enigmatic taxon Xyloplax. Xyloplax is thought by some to represent a newly discovered sixth class of echinoderms - and by others to be an asteroid. To address these questions, we applied a novel workflow to a large RNA-seq dataset that encompassed a broad taxonomic and genomic sample. This study included 15 species sampled from all extant orders and 13 families, plus four ophiuroid species as an outgroup. To expand the taxonomic coverage, the study also incorporated five previously published transcriptomes and one previously published expressed sequence tags (EST) dataset. We developed and applied methods that used a range of alignment parameters with increasing permissiveness in terms of gap characters present within an alignment. This procedure facilitated the selection of phylogenomic data subsets from large amounts of transcriptome data. The results included 19 nested data subsets that ranged from 37 to 4,281loci. Tree searches on all data subsets reconstructed Xyloplax as a velatid asteroid rather than a new class. This result implies that asteroid morphology remains labile well beyond the establishment of the body plan of the group. In the phylogenetic tree with the highest average asteroid nodal support several monophyletic groups were recovered. In this tree, Forcipulatida and Velatida are monophyletic and form a clade that includes Brisingida as sister to Forcipulatida. Xyloplax is consistently recovered as sister to Pteraster. Paxillosida and Spinulosida are each monophyletic, with Notomyotida as sister to the Paxillosida. Valvatida is recovered as paraphyletic. The results from other data subsets are largely consistent with these results. Our results support the hypothesis that the earliest divergence event among extant asteroids separated Velatida and Forcipulatacea from Valvatacea and Spinulosida.

New taxa and taxonomic revisions to the Poraniidae (Valvatacea; Asteroidea) with comments on feeding biology.

New molecular phylogenetic data and new specimens provide the basis for a revision of the family Poraniidae. We present molecular phylogenetic data for five out of 11 genera in the Poraniidae including a newly discovered taxon from the North Pacific. Bathyporania ascendens nov. gen., nov. sp., is described from Davidson Seamount (35º43'N, 122º43'W). Another newly discovered poraniid taxon, Clavaporania fitchorum nov. gen., nov. sp. is described from south of Macquarie Island (56º21'S, 158º 28'E) but was not included in the analysis. Revision of the Poraniidae has been undertaken. We present two new genera and reinstate the previously synonymized genus Glabraster and return Culcitopsis to genus level. The genus Porania sensu Clark (1993) and Clark and Downey (1992) is not monophyletic. Porania, Poraniomorpha and Poraniopsis are revised. In situ feeding observations of Bathyporania are described and compared with other poraniid feeding accounts.

Comments on "the phylogeny of post-Palaeozoic Asteroidea (Neoasteroidea, Echinodermata)" by A.S. Gale and perspectives on the systematics of the Asteroidea.

A new, morphologically based classification of extant asteroids with comments on select fossils was published by A.S. Gale. Research approaches used limited sampling, and much literature treatment is not accurate and therefore misleading. We review these concerns, seeking to clarify argumentation on differing interpretations.

New Taxa and Occurrences of Mesophotic and Deep-sea Goniasteridae (Valvatida, Asteroidea) from Okinawa and adjacent regions.

Thirteen new records of Goniasteridae showing mesophotic occurrence are presented, including a new species of Pseudoceramaster doto n. sp. from southern Japan and a new genus and species, Churaumiastra hoshi nov. gen. nov. sp. which occurs in southern Japan, the Philippines and Western Australia.

New Genera, Species, and observations on the biology of Antarctic Valvatida (Asteroidea).

Assessment of Antarctic taxonomic diversity for asteroids and other taxa for poorly studied or unknown regions, such as the deep-sea, will be important for our understanding of these understudied habitats. Eleven new species and a new genus are described from three families (Asterinidae, Goniasteridae, Solasteridae) within the Valvatida, nearly all of which were collected from deep-sea settings below 1000 m by the US Antarctic Research Program in the 1960s. A new subfamily, the Kampylasterinae subfam. nov. is designated for Kampylaster and Astrotholus nov. gen. which were supported as sister taxa on a monophyletic clade within the Asterinidae. Astrotholus nov. gen. is described to accommodate "Anseropoda" antarctica and four new bathyal and abyssal species, which are a significant morphological divergence from the typological definition of Anseropoda. New species of the goniasterid Notioceramus and the solasterid Paralophaster are also described from bathyal depths (2000-3000 m). Paralophaster ferax n. sp. is among the deepest asteroids known to brood, is the first brooding species within Paralophaster and the second species in the Solasteridae known to brood. Following examination of the type and molecular data, Lophaster densus is found to be included within Paralophaster. A review of Antarctic Lophaster species shows additional specimens of Lophaster abbreviatus which support it as a distinct species from Lophaster stellans. New occurrence data for bathyal Antarctic Asteroidea as well as unusual-gut content observations of shallower-water species are also included.

New Genera, Species and Occurrences of Deep-Sea Asteroidea (Valvatacea, Forcipulatacea, Echinodermata) collected from the North Pacific Ocean by the CAPSTONE Expedition.

Between 2015 and 2018, the NOAA ship Okeanos Explorer embarked on the CAPSTONE expedition, that collected video and specimen data from the Hawaiian Islands region and other American territories in the Central and South Pacific Ocean. Ultimately 20 species, 12 of which are newly described, from 14 genera in 3 families are described herein with one further undescribed species of Pythonaster currently in preparation. Okeanos Explorer collected a total of 17 sea star specimens, of which 9 represent new species and 4 new genera. Additionally, one species imaged by Okeanos Explorer during the campaign was discovered in a museum collection is described herein. Supplementary collections from the tropical Pacific by the R/V Nautilus resulted in a further 11th newly described species which had been originally observed by Okeanos Explorer. A total of 21 specimens were involved as part of this effort. Heligmaster n. gen. is the first new genus of the rarely encountered deep-sea Myxasteridae since Fisher (1906). The Goniasteridae, particularly the corallivorous subfamily Hippasterinae were most heavily represented in the collected material. Video imagery was extensive and provided new occurrence data for rarely seen species as well as several new records that likely represent undescribed species. Many of the new species collected were observed preying on of deep-sea octocorals and sponges.

A new genus and species of Goniasteridae, Peedeeaster sandersoni, and the first occurrence of Sclerasterias (Asteriidae) from the Cretaceous Peedee Formation of North Carolina.

Two new fossil asteroids are described from the Maastrichtian (Cretaceous) Peedee Formation in North Carolina. The first, a member of the Asteriidae, is identified as Sclerasterias sp. based primarily on the superomarginals, spination, and presence of transverse ribs on the distalmost armtip. This is the first occurrence of Sclerasterias in the Cretaceous of North America. The second asteroid taxon is based on a relatively well-preserved series of specimens described as a new genus and species, Peedeeaster sandersoni (Goniasteridae) which displays a pentagonal body shape similar to those of modern Peltaster and Sphaeriodiscus and is also comparable to such Cretaceous goniasterids such as Metopaster.

The East Pacific/South Pacific Boundary: New taxa and occurrences from Rapa Nui (Easter Island), New Caledonia and adjacent regions.

Recent expeditions to Rapa Nui (also known as Easter Island) and New Caledonia have revealed undescribed species from mesophotic and deeper depths. This includes three new species from Rapa Nui, Hacelia raaraa, Linckia profunda (Ophidiasteridae), Uokeaster ahi (Asterodiscididae) and two new species from New Caledonia, Astroglypha pyramidata n. gen. and Ophidiaster colossus (Ophidiasteridae). The new genus Astroglypha is described for A. pyramidata but the genus also includes the Atlantic Tamaria passiflora, which is reassigned herein. Pauliastra n. gen. is designated as a replacement for the homonym issue with Pauliella. New occurrences and synonymies are addressed for taxa related to New Caledonia, Rapa Nui and adjacent regions. A morphology based phylogenetic analysis agrees with prior work which placed Goniaster among the Asterodiscididae and posits biogeographic relationships among asterodiscidid genera. Implications for the Goniasteridae and placement of Goniaster among asterodiscidid genera are discussed. Biogeography and relationships among taxa from Rapa Nui and New Caledonia are reviewed. In situ observations from species observed from Rapa Nui are included.

The first complete mitochondrial genome of the Northern Pacific deep-sea goniasterid sea star Ceramaster japonicus (Sladen, 1889) determined using NGS-based shotgun sequencing.

The full mitogenome of an ethanol-preserved museum specimen of Ceramaster japonicus was determined using the NGS Illumina MiSeq platform. The specimen was collected from Tosa Bay, Japan, facing the Pacific Ocean (33.0781 N 134.0601 E), at 700 m depth in 2011. The mitogenome shows a typical metazoan genomic structure, with all of the 37 genes included in its 16,370 base-long mitogenome. We conducted phylogenetic analyses using a data set including 18 publicly available asteroids rooted against five ophiuroids as outgroups. The result confirms the position of C. japonicus in the order Valvatida. The complete mitogenome of C. japonicus reported here is the first reported for the family Goniasteridae Forbes, 1841.

Reef benthos of Seychelles - A field guide.

BACKGROUND: During the 2019 First Descent: Seychelles Expedition, shallow and deep reef ecosystems of the Seychelles Outer Islands were studied by deploying a variety of underwater technologies to survey their benthic flora and fauna. Submersibles, remotely operated vehicles (ROVs) and SCUBA diving teams used stereo-video camera systems to record benthic communities during transect surveys conducted at 10 m, 30 m, 60 m, 120 m, 250 m and 350 m depths. In total, ~ 45 h of video footage was collected during benthic transect surveys, which was subsequently processed using annotation software in order to assess reef biodiversity and community composition. Here, we present a photographic guide for the visual identification of the marine macrophytes, corals, sponges and other common invertebrates that inhabit Seychelles' reefs. It is hoped that the resulting guide will aid marine biologists, conservationists, managers, divers and naturalists with the coarse identification of organisms as seen in underwater footage or live in the field. NEW INFORMATION: A total of 184 morphotypes (= morphologically similar individuals) were identified belonging to Octocorallia (47), Porifera (35), Scleractinia (32), Asteroidea (19), Echinoidea (10), Actiniaria (9), Chlorophyta (8), Antipatharia (6), Hydrozoa (6), Holothuroidea (5), Mollusca (2), Rhodophyta (2), Tracheophyta (2), Annelida (1), Crinoidea (1), Ctenophora (1), Ochrophyta (1) and Zoantharia (1). Out of these, we identified one to phylum level, eight to class, 14 to order, 27 to family, 110 to genus and 24 to species. This represents the first attempt to catalogue the benthic diversity from shallow reefs and up to 350 m depth in Seychelles.

Megafauna of the German exploration licence area for seafloor massive sulphides along the Central and South East Indian Ridge (Indian Ocean).

BACKGROUND: The growing interest in mineral resources of the deep sea, such as seafloor massive sulphide deposits, has led to an increasing number of exploration licences issued by the International Seabed Authority. In the Indian Ocean, four licence areas exist, resulting in an increasing number of new hydrothermal vent fields and the discovery of new species. Most studies focus on active venting areas including their ecology, but the non-vent megafauna of the Central Indian Ridge and South East Indian Ridge remains poorly known.In the framework of the Indian Ocean Exploration project in the German license area for seafloor massive sulphides, baseline imagery and sampling surveys were conducted yearly during research expeditions from 2013 to 2018, using video sledges and Remotely Operated Vehicles. NEW INFORMATION: This is the first report of an imagery collection of megafauna from the southern Central Indian- and South East Indian Ridge, reporting the taxonomic richness and their distribution. A total of 218 taxa were recorded and identified, based on imagery, with additional morphological and molecular confirmed identifications of 20 taxa from 89 sampled specimens. The compiled fauna catalogue is a synthesis of megafauna occurrences aiming at a consistent morphological identification of taxa and showing their regional distribution. The imagery data were collected during multiple research cruises in different exploration clusters of the German licence area, located 500 km north of the Rodriguez Triple Junction along the Central Indian Ridge and 500 km southeast of it along the Southeast Indian Ridge.

Difference in larval type explains patterns of nonsynonymous substitutions in two ancient paralogs of the histone H3 gene in sea stars.

Paralogous genes frequently show differences in patterns and rates of substitution that are typically attributed to different selection regimes, mutation rates, or local recombination rates. Here, two anciently diverged paralogous copies of the histone H3 gene in sea stars, the tandem-repetitive early-stage gene and a newly isolated gene with lower copy number that was termed the "putative late-stage histone H3 gene" were analyzed in 69 species with varying mode of larval development. The two genes showed differences in relative copy number, overall substitution rates, nucleotide composition, and codon usage, but similar patterns of relative nonsynonymous substitution rates, when analyzed by the d(N)/d(S) ratio. Sea stars with a nonpelagic and nonfeeding larval type (i.e., brooding lineages) were observed to have d(N)/d(S) ratios that were larger than for nonbrooders but equal between the two paralogs. This finding suggested that demographic differences between brooding and nonbrooding lineages were responsible for the elevated d(N)/d(S) ratios observed for brooders and refuted a suggestion from a previous analysis of the early-stage gene that the excess nonsynonymous substitutions were due to either (1) gene expression differences at the larval stage between brooders and nonbrooders or (2) the highly repetitive structure of the early-stage histone H3 gene.

New species, occurrence records and observations of predation by deep-sea Asteroidea (Echinodermata) from the North Atlantic by NOAA ship Okeanos Explorer.

Exploratory cruises by the NOAA Ship Okeanos Explorer have resulted in a substantial contribution in our understanding of deep-sea echinoderm biodiversity, biology, and ecology in the North Atlantic. This includes the description and in situ feeding observations of two, new corallivorous goniasterid species, Evoplosoma nizinskiae n. sp. and Sibogaster bathyheuretor n. sp. Significant in situ observations include a synchronous feeding event including multiple goniasterid asteroids and a cidaroid urchin on a large demosponge, providing new data for understanding echinoderm feeding behavior, including agonistic behavior, in deep-sea settings and new, in situ feeding observations for 28 deep-sea species including the myxasterid Pythonaster atlantidis, the korethrasterid Remaster palmatus and the poorly understood hippasterine goniasterids, Gilbertaster caribaea and Sthenaster emmae.

New species and occurrence records of Japanese Solasteridae and Ganeriidae including a new species of Paralophaster from the North Pacific with an overview of Hyalinothrix.

Japanese waters contain a highly diverse echinoderm fauna including many undiscovered species, especially in deeper-water settings. Molecular phylogenetic data has shown a close relationship between three established families of asteroids, the Asterinidae, the Solasteridae and the Ganeriidae, which are three groups that are well-represented in the region. We present two undescribed species of solasterids, Lophaster cactorum n. sp. and Paralophaster gomo n. sp., the latter represents a genus which had previously been known primarily from Antarctic settings. New occurrence records of the tropical deep-sea Pacific solasterid Rhipidaster vannipes Sladen, 1889 has led to synonymy of Xenorias polyctenius Fisher, 1913. Three undescribed species of Hyalinothrix, Hyalinothrix diversus n. sp., Hyaliothrix enoki n. sp. and Hyalinothrix virtrispinum n. sp. are described. Nepanthia grangei McKnight, 2001 is transferred to Hyalinothrix. A new subfamily, the Hyalinothricinae is established within the Asterinidae, including Tarachaster and Seriaster, which was formerly assigned to the Solasteridae. Knightaster is reassigned to the Asterinidae from the Ganeriidae.

New genera, species and occurrence records of Goniasteridae (Asteroidea; Echinodermata) from the Indian Ocean.

Modern goniasterids are the most numerous of living asteroids in terms of described genera and species and they have important ecological roles from shallow to deep-water marine habitats. Recent MNHN expeditions and historical collections in the USNM have resulted in the discovery of 18 new species, three new genera and multiple new occurrence records from the western Indian Ocean region including Madagascar, Glorioso and Mayotte islands, Walters Shoal, South Africa, and Somalia. This report provides the first significant contribution to knowledge of deep-sea Asteroidea from the Indian Ocean since the late 20th Century. Several deep-sea species, previously known from the North Pacific are now reported from the western Indian Ocean. Gut contents from Stellaster and Ogmaster indicate deposit feeding. Feeding modes of this and other deep-sea species are discussed. Comments are made on fossil members of included taxa. A checklist of Indian Ocean Goniasteridae is also included.

Overview of the Ferdina-like Goniasteridae (Echinodermata: Asteroidea) including a new subfamily, three new genera and fourteen new species.

Recent assignment of some goniasterid-like Ophidiasteridae into the Goniasteridae has led to further re-evaluation of other ophidiasterids as possible goniasterids. This led to the discovery of new genera and species supported by a distinctive set of characteristics which support a new subfamily, the Ferdininae, a group originally outlined by Marsh and Price (1991) within the Goniasteridae. The historical Ophidiasteridae is paraphyletic and includes several nominal ophidiasterid genera (e.g., Fromia, Neoferdina, etc.). Newly described material has led to the inclusion of six genera,within this group, of which three, Bathyferdina n. gen., Eosaster n. gen., and Kanakaster n. gen., are newly described. Fourteen new species in five genera are described. This includes Bathyferdina aireyae n. gen., n. sp., Eosaster nadiae n. gen., n. sp., Ferdina mena n. sp., Kanakaster balutensis n. gen., n. sp., Kanakaster convexus n. gen., n. sp., Kanakaster discus n. gen., n. sp., Kanakaster larae n. gen., n. sp., Kanakaster plinthinos n. gen., n. sp., Kanakaster solidus n. gen., n. sp., Neoferdina annae n. sp., Neoferdina antigorum, n. sp., Neoferdina momo, n. sp., Neoferdina oni, n. sp., and Paraferdina plakos, n. sp. Identification keys, synopses, and description of these taxa are included.

Megafauna of the UKSRL exploration contract area and eastern Clarion-Clipperton Zone in the Pacific Ocean: Echinodermata.

BACKGROUND: There is growing interest in mining polymetallic nodules from the abyssal Clarion-Clipperton Zone (CCZ) in the tropical Pacific Ocean. Despite being the focus of environmental studies for decades, the benthic megafauna of the CCZ remain poorly known. In order to predict and manage the environmental impacts of mining in the CCZ, baseline knowledge of the megafauna is essential. The ABYSSLINE Project has conducted benthic biological baseline surveys in the UK Seabed Resources Ltd polymetallic-nodule exploration contract area (UK-1). Prior to these research cruises in 2013 and 2015, no biological studies had been done in this area of the eastern CCZ. NEW INFORMATION: Using a Remotely Operated Vehicle and Autonomous Underwater Vehicle, the megafauna within the UKSRL exploration contract area (UK-1) and at a site ~250 km east of the UK-1 area were surveyed, allowing us to make the first estimates of megafaunal morphospecies richness from the imagery collected. Here, we present an atlas of the abyssal echinoderm megafauna observed and collected during the ABYSSLINE cruises to the UK-1 polymetallic-nodule exploration contract area in the CCZ. There appear to be at least 62 distinct morphospecies (13 Asteroidea, 5 Crinoidea, 9 Echinoidea, 29 Holothuroidea and 6 Ophiuroidea) identified mostly by imagery but also using molecular barcoding for a limited number of animals that were collected. This atlas will aid the synthesis of megafaunal presence/absence data collected by contractors, scientists and other stakeholders undertaking work in the CCZ, ultimately helping to decipher the biogeography of the megafauna in this threatened habitat.

Deep-sea (>1000 m) Goniasteridae (Valvatida; Asteroidea) from the North Pacific, including an overview of Sibogaster, Bathyceramaster n. gen. and three new species.

Research cruises by the Monterey Bay Aquarium Research Institute (MBARI) have resulted in the discovery of three new species of asteroids from the lower bathyal/abyssal regions of the North Pacific. A new genus, Bathyceramaster is described to accommodate "Mediaster" elegans Ludwig 1905 and related species. New records and in situ observations are also presented. An identification key and taxonomic account of the deep-sea Goniasteridae known from this region including one new genus and two new species is included. An overview of the genus Sibogaster, including a new widely occurring species, is also included.

Covering Ground: Movement Patterns and Random Walk Behavior in Aquilonastra anomala Sea Stars.

The paths animals take while moving through their environments affect their likelihood of encountering food and other resources; thus, models of foraging behavior abound. To collect movement data appropriate for comparison with these models, we used time-lapse photography to track movements of a small, hardy, and easy-to-obtain organism, Aquilonastra anomala sea stars. We recorded the sea stars in a tank over many hours, with and without a food cue. With food present, they covered less distance, as predicted by theory; this strategy would allow them to remain near food. We then compared the paths of the sea stars to three common models of animal movement: Brownian motion, Lévy walks, and correlated random walks; we found that the sea stars' movements most closely resembled a correlated random walk. Additionally, we compared the search performance of models of Brownian motion, a Lévy walk, and a correlated random walk to that of a model based on the sea stars' movements. We found that the behavior of the modeled sea star walk was similar to that of the modeled correlated random walk and the Brownian motion model, but that the sea star walk was slightly more likely than the other walks to find targets at intermediate distances. While organisms are unlikely to follow an idealized random walk in all details, our data suggest that comparing the effectiveness of an organism's paths to those from theory can give insight into the organism's actual movement strategy. Finally, automated optical tracking of invertebrates proved feasible, and A. anomala was revealed to be a tractable, 2D-movement study system.

Abyssal fauna of the UK-1 polymetallic nodule exploration claim, Clarion-Clipperton Zone, central Pacific Ocean: Echinodermata.

We present data from a DNA taxonomy register of the abyssal benthic Echinodermata collected as part of the Abyssal Baseline (ABYSSLINE) environmental survey cruise 'AB01' to the UK Seabed Resources Ltd (UKSRL) polymetallic-nodule exploration claim 'UK-1' in the eastern Clarion-Clipperton Zone (CCZ), central Pacific Ocean abyssal plain. Morphological and genetic data are presented for 17 species (4 Asteroidea, 4 Crinoidea, 2 Holothuroidea and 7 Ophiuroidea) identified by a combination of morphological and genetic data. No taxa matched previously published genetic sequences, but 8 taxa could be assigned to previously-described species based on morphology, although here we have used a precautionary approach in taxon assignments to avoid over-estimating species ranges. The Clarion-Clipperton Zone is a region undergoing intense exploration for potential deep-sea mineral extraction. We present these data to facilitate future taxonomic and environmental impact study by making both data and voucher materials available through curated and accessible biological collections.