Patterns in deep-sea coral (DSC) diversity and distribution are described for a range of benthic habitat features including offshore banks, continental shelf and slope, and submarine canyons in three national marine sanctuaries off the coast of North-central California. Sixteen visual datasets of DSC observations collected using underwater vehicles from 2010 to 2021 across a wide depth range of 35-3317 m were analyzed for zonation by depth and seafloor feature type. A total of 36,670 DSC from at least 20 families were documented in the study area. Taxa displayed patterns corresponding to depth and seafloor feature type, such as broad distribution across multiple depths and features or narrower depth range and fewer features. Significant divergence in DSC assemblage diversity and density occurred between banks and canyons, representing the shallowest and deepest depth extents in the study area. One species of Stylasteridae coral primarily inhabited banks and accounted for the highest density of all DSC taxa. Diversity of soft corals and gorgonians (Octocorallia) and black corals (Antipatharia) was greatest on the slope and canyons. Other octocorals such as sea pens (Pennatuloidea) collectively spanned the largest depth ranges throughout the study area on all features other than banks. Comprehensively describing DSC communities in relation to seafloor features throughout an extensive depth range may have applications to other regions globally where similar habitats and DSC families are found. Our growing understanding of taxonomic diversity and zonation adds to existing knowledge of depth and geographic distributions on the U.S. West Coast and provides a crucial foundation for effective management and conservation efforts for DSC communities.

The genus Ceratocaulon Jungersen, 1892 was based on a single colony collected in NW Iceland, describing also the type species C. wandeli Jungersen, 1892. A few additional specimens were collected during the Danish Ingolf Expedition in 1891. The family placement of this genus was very controversial due to initial misinterpretation of internal anatomical features. Ceratocaulon was initially assigned to the family Xeniidae Ehrenberg, 1828, commonly found in temperate to tropical regions. However, this genus was later transferred to Alcyoniidae Lamouroux, 1812, after the correct interpretation of its internal anatomy. The lack of collections and studies that provide additional morphological details and molecular information for more than a century has surrounded this species with a halo of uncertainty and enigma. A recent phylogenomic study proposed its separation to an incertae sedis placement due to the lack of molecular information available. During the BIOICE Program ca. 1500, colonies of C. wandeli were collected, and a few additional samples provided by the BIOICE and IceAGE project allowed the extraction and successful amplification of mitochondrial genes. The present morphological and molecular study demonstrates an isolated placement of Ceratocaulon wandeli within the Order Malacalcyonacea McFadden, van Ofwegen and Quattrini, 2022, supporting the erection of a new family, Ceratocaulidae fam. nov.

The Magnuson-Stevens Fishery Conservation and Management Reauthorization Act of 2006 mandat¬ed the research and management of the nation’s deep-sea coral resources through establishment of the National Oceanic and Atmospheric Administra¬tion’s Deep Sea Coral Research and Technology Program. The challenge for Alaska was daunting, where expansive, world-class fisheries often coincided with extraordinarily rich coral habitats for a high-latitude region. The first chal¬lenge was to inventory known locations of deep-sea corals. Many coral records and some museum collections existed from Alaska, but the taxonomy of cor¬als was little studied and field iden¬tification of corals was problematic. Formal bycatch programs and research activities in recent decades provided many more specimens for taxonomic study, but guides to species were largely incomplete, inaccurate, and outdated given the fast pace of species discovery in Alaska. We provide a comprehen¬sive, up-to-date guide, detailing 161 coral taxa identified from museum collections, primary literature, and video records. Each profile includes a description, images for each taxon, taxonomic history, biology, ecology, geographical distribution, and habitat, including depth distribution. Corals are found in the six regions of Alaska but the coral fauna of the Aleutian Islands is by far the most species rich. The state of taxonomy for some coral groups is ex¬cellent, while others require additional collections and more taxonomic work. Construction of this guide resulted in descriptions of several antipatharian species, published separately from this guide (Alternatipathes mirabilis, Bathypathes alaskensis, B. ptiloides, B. tiburonae, and Parantipathes pluma) and the scleractinian Flabellum (Flabel¬lum) oclairi Cairns, sp. nov. described herein. The guide provides informa¬tion for targeting new collections and identifying areas of high abundance and indicator species of vulnerable marine ecosystems. Stakeholders can now more adequately assess Alaska’s coral resources and risks from natural and anthropogenic stressors.

The description in 1891 of the sea pen genus Gyrophyllum Studer, 1891 and also the type species G. hirondellei Studer, 1891 was based on a single colony collected in the Azores Archipelago. During the 19th and 20th centuries, the family placement of this genus became controversial as the set of morphological features present in Gyrophyllum could justify its assignation to both the families Pennatulidae Ehrenberg, 1834 and Pteroeididae Kölliker, 1880. Deliberations over this intermediate set of characters finally ended in the reunification of the genera and species of both families under Pennatulidae by principle of priority. The use of molecular sources of information based on a series of sequencing techniques presents a different but promising phylogenetic scenario in order to go further in the understanding of pennatulacean systematics. In this paper, a complementary morphological and molecular study (multiloci sequences with three mitochondrial and one nuclear markers) based mainly on newly collected material is carried out. This study re-confirms from a molecular point of view previously published results that indicate the position of Gyrophyllum as being distant from Pennatula Linnaeus, 1758 and Pteroeides Herklots, 1858 (type genera of the families Pennatulidae and Pteroeididae, respectively). This fact together with the results of a detailed morphological examination strongly supports the placement of the enigmatic genus Gyrophyllum in a separate family: Gyrophyllidae fam. nov. and resolves the nomenclatural uncertainty at family level for this genus. Moreover, the characters previously considered useful in the distinction of the two currently recognised species G. hirondellei in the Atlantic and G. sibogae Hickson, 1916 in the Indo-western Pacific are revisited.

. The description in 1891 of the sea pen genus Gyrophyllum Studer, 1891 and also the type species G. hirondellei Studer, 1891 was based on a single colony collected in the Azores Archipelago. During the 19 th and 20 th centuries, the family placement of this genus became controversial as the set of morphological features present in Gyrophyllum could justify its assignation to both the families Pennatulidae Ehrenberg, 1834 and Pteroeididae Kölliker, 1880. Deliberations over this intermediate set of characters finally ended in the reunification of the genera and species of both families under Pennatulidae by principle of priority. The use of molecular sources of information based on a series of sequencing techniques presents a different but promising phylogenetic scenario in order to go further in the understanding of pennatulacean systematics. In this paper, a complementary morphological and molecular study (multiloci sequences with three mitochondrial and one nuclear markers) based mainly on newly collected material is carried out. This study re-confirms from a molecular point of view previously published results that indicate the position of Gyrophyllum as being distant from Pennatula Linnaeus, 1758 and Pteroeides Herklots, 1858 (type genera of the families Pennatulidae and Pteroeididae, respectively). This fact together with the results of a detailed morphological examination strongly supports the placement of the enigmatic genus Gyrophyllum in a separate family: Gyrophyllidae fam. nov. and resolves the nomenclatural uncertainty at family level for this genus. Moreover, the characters previously considered useful in the distinction of the two currently recognised species G. hirondellei in the Atlantic and G. sibogae Hickson, 1916 in the Indo-western Pacific are revisited.

The recently described deep-sea pennatulacean genusPorcupinellawas previously known only by the type species,Porcupinella profundafrom the equatorial eastern Atlantic to the eastern North Atlantic Ocean. New data is provided on morphology, distribution, bathymetry, and related taxa. A second species is added here as well – a new species is described from the Tasman Sea in the southwestern Pacific. The new species,Porcupinella tasmanica, is distinguished fromP. profundaby its distinctive hook-shaped growth form, laterally compressed dorsal keel, and differing regions that are occupied by siphonozooids. A key to the species of the deep-sea pennatulacean family Chunellidae is included based on comparative morphology.

The pennatulacean genus Balticina has had a long and confusing taxonomic history, with serious nomenclatural problems that remain unresolved. Owing to disagreements about authorships and dates of publication, the names Pavonaria, Norticina and Halipteris have all been used as valid in place of Balticina, or else been regarded as its junior synonyms, even simultaneously. In this paper, after an extensive literature review, we determine the authorships and dates for all the taxa involved in accordance with the provisions of the International Code of Zoological Nomenclature and establish Balticina Gray, 1870 (=Halipteris) and Balticinidae Balss, 1910 (=Halipteridae) as the valid genus and family names, respectively, for this group of sea pens. We also propose the replacement name Rakollikeria for the preoccupied genus name Pavonaria Kölliker, 1870 (Balticinidae) (nec Schweigger, 1819 - Funiculinidae).

Sea pens (Cnidaria: Anthozoa: Pennatulacea) constitute a distinctive group of colonial marine invertebrates. They inhabit the world`s oceans, from shallow to deep waters. Studies about this group in Argentina are scarce, and no species have been described in the area in over a decade. Based on samples collected in Mar del Plata Submarine Canyon at about 3000 m deep we describe a new species of sea pen, Umbellula pomona Risaro, Williams & Lauretta sp. nov. This is a spiculate Umbellula that differs from other species of Umbellula with sclerites, by the number, development and distribution of the autozooids in its terminal cluster, as well as the shape of its axis. Molecular data also distinguishes it from other known species. Of the forty-three described species approximately ten are considered valid for the genus Umbellula, four of them are registered for the South Atlantic Ocean and only three are described for the Antarctic region. Since sampling efforts in this area have been scarce, the number of species of sea pens from the region is likely to increase substantially in the coming years.

A new genus and species of flagelliform gorgonian coral is described from mesophotic depth in the western Pacific Ocean. The new taxon exhibits calcaxonian morphological characters and shares affinities to both the clade that includes the Chrysogorgiidae, Primnoidae, and Isididae, as well as the clade that includes the Ellisellidae and the Pennatulacea. Based on morphology alone, placement in a new family is likely justifiable, since it exhibits some characters similar to several diverse calcaxonian taxa, and has unique features as well, but such an outcome awaits supporting molecular evidence. The new genus and species is remarkable among most octocorals in that it has an axis that is quadrangular in transverse section as in the calcaxonian Flagelligorgia gracilis and the pennatulacean Funiculina quadrangularis, and an apparently uniform, solid, highly calcified axial structure that lacks concentric layers or prismatic radiating wedges. In addition, it has distinctive sclerites of the surface coenenchyme that are predominantly elongate warty spindles with median waists, some of which superficially resemble sclerites found in some species of ellisellid gorgonians, but also exhibit ultrastructural features that differentiate them.

1 Department of Invertebrate Zoology and Geology, California Academy of Sciences, Golden Gate Park, 55 Music Concourse Drive, San Francisco, California 94118, USA.; 2 Centro de Investigación en Estructuras Microscópicas, Centro de Investigación en Ciencias del Mar y Limnología, Escuela de Biología, Universidad de Costa Rica. P.O. Box 11501-2060, San José, Costa Rica; 3 Smithsonian Tropical Research Institute, P.O. Box 0843-03092, Republic of Panama; 4 Corresponding Author: Gary C. Williams (gwilliams@calacademy.org)

Research Infrastructures (RIs) are facilities, resources and services used by the scientific community to conduct research and foster innovation. LifeWatch ERIC has developed various virtual research environments, which include many virtual laboratories (vLabs) offering high computational capacity and comprehensive collaborative platforms that supporting the needs of digital biodiversity science. Over its 250 years of history, the taxonomic research community has developed a system for describing, classifying and naming taxa across multiple levels. For the marine biota, taxonomic information is organized and made publicly available through the World Register of Marine Species (WoRMS) that records more than 250,000 described valid species. Although scientists tend to assign an equal status (in terms of contribution to overall diversity) to each taxon used in taxonomy, biogeography, ecology and biodiversity, the question “are all taxa equal?” has never been tested at a global scale. We present evidence that this question can be addressed by applying relatedness indices (Taxonomic Distinctness) over the entire WoRMS metazoan tree. The RvLab, developed by the LifeWatchGreece RI, operating on a high-performance computer cluster, has been used to meet the high computational demands required for such an analysis at a global scale.