We provide the first annotated checklist of ophiuroids from the continental shelf of the State of Paraíba, northeastern Brazil. Identification keys and taxonomic diagnoses for 23 species, belonging to 14 genera and 8 families, are provided. The material is deposited in the Invertebrate Collection Paulo Young, at the Federal University of Paraíba. Ophiopsila hartmeyeri represents the first recor...

Echinoderms are unique among animal phyla in having a pentaradial body plan, and their fossil record provides critical data on how this novel organization came about by revealing intermediate stages. Here, we report a spiral-plated animal from the early Cambrian of Morocco that is the most primitive pentaradial echinoderm yet discovered. It is intermediate between helicoplacoids (a bizarre grou...

Although eyes are generally considered necessary for image resolution, a diffuse photoreceptive system with directional sensitivity may also have this ability. Two species of the echinoid genus Echinometra were tested for spatial vision by examining their ability to locate and move towards targets of different sizes. The echinoids were significantly oriented (P<0.0001) towards a target with an ...

Aggregations of Oreaster reticulatus (L.) in a large sand patch amid an offshore seagrass bed (Syringodium filiforme) off St. Croix (US Virgin Islands) were characterized by protracted fronts of high density (2-7 individuals m-2). Fronts mlgrated across the sand patch at approximately 7 m d-l and were refracted and deflected at the grassbed border. Intensive microphagous feeding effected a 2-fo...

Five species of Caudinidae occur in New Zealandwaters. Two new species are described: Paracaudina alta sp. nov.; Paracaudina reductia sp. nov. Two species reported previously are discussed: Paracaudina chilensis (Müller) and Paracaudina coriacea (Hutton). A lectotype has been established for P. coriacea (Hutton). Hedingia albicans var. glabra (Théel) is raised out of synonymy with Hedingia albi...

Present communication reports the diversity of intertidal Ophiuroidea (Phylum: Echinodermata) from zones Saurashtra coastline, Gujarat state. coastlines were extensively surveyed January 2019 to March 2022 for diversity. A total nine species belonging eight genera and six families noted coastline. Amongst these, Macrophiothrix variabilis, Ophiothrix savignyi Ophiomaza cacaotica are newly observ...

The Valvatacea is one the most ecologically important, taxonomically diverse, and widespread groups of postPalaeozoic (i.e. modern) Asteroidea. Classification within the group has been historically problematic. We present a comprehensively sampled, three-gene (12S, 16S, early-stage histone H3) molecular phylogenetic analysis of the Valvatacea. We include five of the six families within the Paxi...

The unusual bathyal comatulid crinoid genus Atelecrinus is widespread in the Atlantic and tropical Pacific Oceans and currently includes three recognized species. A re-assessment based on examination of new and existing specimens requires establishment of two new genera and five new species, and returns three junior synonyms to species-level status. Paratelecrinus is erected to accommodate Atel...

Phylogenetic analysis has led to significant insights into the evolution of early life-history stages of marine invertebrates. Although echinoderms have been a major focus, developmental and phylogenetic information are relatively poor for ophiuroids, the most species-rich echinoderm class. We used DNA sequences from two mitochondrial genes to develop a phylogenetic hypothesis for 14 brittlesta...

Our understanding of the origin, evolution, and biogeography of seafloor fauna is limited because we have insufficient spatial and temporal data to resolve underlying processes. The abundance and wide distribution of modern and disarticulated fossil Ophiuroidea, including brittle stars and basket stars, make them an ideal model system for global marine biogeography if we have the phylogenetic f...