An increasing number of studies have forecast the potential responses of marine life to future climate change. This study predicts how the distributional range of temperate and tropical worm reefs (WRs) might respond to climate and environmental changes (CECs). Compared with current distributions, the tested hypotheses were: (i) under a low CO2 concentration and active atmospheric carbon capturing scenario (RCP2.6), both tropical and temperate WRs will maintain their current distributions and face only slight multi-directional biogeographic changes along the century; and (ii) under a high CO2 concentration scenario (RCP8.5) WRs will shift toward higher latitudes, with marked changes for tropical species and slight changes for temperate species, specifically at the end of the 21st century. The hypotheses were tested using species distribution modelling, and exploratory statistical analyses were performed to tune model settings. Under scenario RCP2.6, in the middle of the century, areas of suitable habitat are predicted to slightly increase for the temperate WRs and conversely contract for tropical WRs. At the end of the century, multi-directional shifts without range retraction were predicted for both species, but tropical WRs showed major changes in their distribution. Under scenario RCP8.5 and throughout the century, multi-directional shifts increased the areas of suitable habitat for temperate WRs, whereas tropical WRs experienced shifts toward high latitudes and significant retraction at low latitudes. Results indicate that biogeographic range shifts are idiosyncratic for temperate and tropical WRs depending on the CECs scenarios considered.

Larvae of ~100 species of benthic invertebrates were obtained from the vicinity of Tomales Bay and Dillon Beach, California, over a 6-year period (1971–1977). This study reports on larvae of 14 species in eight families of polychaetes: Micronereis nanaimoensis, Nereis vexillosa, Sthenelais fusca, Nephtys caecoides, Nephtys californiensis, Boccardia berkeleyorum, Polydora pygidialis, Polydora spongicola, Dipolydora cardalia, Mediomastus californiensis, Ampharete labrops, Phragmatopoma californica, Sabellaria cementarium and Pectinaria californiensis. Some species were cultured from embryos obtained from laboratory fertilizations or field-collected egg masses or capsules. Larvae of other species were obtained from meroplankton and some of these were cultured through metamorphosis. A summary table is presented documenting seasonal occurrence of 60 polychaete taxa in the meroplankton.

We aimed to verify the effects of local environmental hydrodynamics on the individual size of two sand-reef sabellariids (Sabellaria wilsoni and S. nanella) on a tropical intertidal beach in north-east Brazil. We also tested the hypothesis that the richness and abundance of their reef-building associated fauna would be influenced by environmental conditions related to the wind and wave action intensity. Individuals from three distinct intertidal levels at Cabo Branco beach (7o8′46″S 34°47′55″W), João Pessoa, Paraíba, Brazil, were sampled, identified, sexed, measured and the fauna associated with the reef samples was identified and quantified. Our statistical tests indicated that reef builders have distinct organization patterns which are related to environmental conditions. The aggregates exposed to the strongest wave and wind conditions presented reduced density and sabellariids of smaller sizes in comparison with the other aggregates. The associated fauna abundance and composition was also influenced by the local hydrodynamic regime.

Rhodoliths or maërl are calcareous nodules of coralline red algae growing unattached to the substrata. They sustain a high biodiversity, being one of the most important marine benthic environments dominated by macrophytes. Sabellariidae are tube-dwelling filter feeding marine polychaetes that build their tubes by secreting cement from their thoracic glands. Some species are solitary, while others build tubes together, forming large aggregates. This study analyses Sabellariidae collected in rhodolith beds along the subtidal zone of the coast of João Pessoa and Cabedelo, Paraíba, north-eastern Brazil. A total of 100 individuals of six species were identified. Four are reported for the first time for the north-east coast of Brazil: Phragmatopoma caudata Mörch (1863), Sabellaria bella Grube (1870), Sabellaria nanella Chamberlin (1919), and Sabellaria wilsoni Lana & Gruet (1989). The first occurrence of Sabellaria pectinata Fauvel (1923) along the western Atlantic is provided as well as the description of a new species of the genus Sabellaria.