The first open-sea (non-coastal) Marine Protected Area (MPA) in Argentina was created in 2013 (and named “Namuncurá”), at Burdwood Bank, an undersea plateau located about 200 km south from Malvinas/Falkland Islands, SW Atlantic Ocean. This contribution represents the most recent and complete checklist of benthic organisms (mainly mega and macrofauna) that summarized 240 taxa collected at three sites in the mentioned area. The benthic richness here documented largely exceeds the values coming from other productive areas in Argentinean waters. Faunistic composition was different among the sites, although several species were shared. Bryozoans presented the highest richness compared to the other groups, followed by mollusks and sponges. These data represent valuable information and a very helpful starting point for incoming research, conservation efforts and management. It is essential to establish the spatial distribution of indicator taxa, like corals, sponges and bryozoans, to better attempt at the protection of benthic biodiversity in this rich Argentinean marine system. This is a key issue considering the notable extension of the MPA compared to other areas in Argentina, the bathymetric variations, particular oceanographic conditions and different fishing circumstances within the area.

Deep-water octocorals (Cnidaria: Octocorallia) from Brazil: Family Chrysogorgiidae Verrill, 1883

Protopalythoa is a zoanthid that, together with thousands of predominantly marine species, such as hydra, jellyfish, and sea anemones, composes the oldest eumetazoan phylum, i.e., the Cnidaria. Some of these species, such as sea wasps and sea anemones, are highly venomous organisms that can produce deadly toxins for preying, for defense or for territorial disputes. Despite the fact that hundreds of organic and polypeptide toxins have been characterized from sea anemones and jellyfish, practically nothing is known about the toxin repertoire in zoanthids. Here, based on a transcriptome analysis of the zoanthid Protopalythoa variabilis, numerous predicted polypeptides with canonical venom protein features are identified. These polypeptides comprise putative proteins from different toxin families: neurotoxic peptides, hemostatic and hemorrhagic toxins, membrane-active (pore-forming) proteins, protease inhibitors, mixed-function venom enzymes, and venom auxiliary proteins. The synthesis and functional analysis of two of these predicted toxin products, one related to the ShK/Aurelin family and the other to a recently discovered anthozoan toxin, displayed potent in vivo neurotoxicity that impaired swimming in larval zebrafish. Altogether, the complex array of venom-related transcripts that are identified in P. variabilis, some of which are first reported in Cnidaria, provides novel insight into the toxin distribution among species and might contribute to the understanding of composition and evolution of venom polypeptides in toxiferous animals.

The present work records for the first time the association between ophiuroids and the octocoral Carijoa riisei. Carijoa riisei is a colonial octocoral very abundant in the littoral of Pernambuco (Brazil), with growth by creeping stolons with an arborescent structure creating an optimal environment for epibionts. The objectives of the work were to identify the species of Ophiuroidea associated with C. riisei, and to verify the existence of seasonality through the density, abundance and frequency of sampled taxa. Due to the known relationship between the ophiuroids and sponges related in the literature, the sponges founded associated with C. riisei were recorded. Seasonal samples of the beaches of Porto de Galinhas and Guadalupe were realized. In Guadalupe, 39 and 21 ophiuroids (dry and rainy seasons respectively) belonging to the families Ophiactidae (Ophiactis savignyi, Ophiactis lymani) and Ophiotrichidae (Ophiotrhix angulata) were identified. Ophiactis savignyi stood out in all the analysed stations (48.72% in dry season and 52.38% in rainy season). The average density of the ophiuroids was 10.74 ind/100 g of C. riisei, varying from 12.56 ind/100 g in the dry season to 8.92 ind/100 g, in the rainy season. Amongst the species of ophiuroids recorded in the samples, O. savignyi showed 80% and 100% frequency of occurrence in the dry and the rainy seasons, respectively, and O. lymani showed 80% during the dry season. The presence of O. lymani in Guadalupe constitutes the first record in Pernambuco state. Taking into account that all the ophiuroids collected in Guadalupe were considered juveniles (1–3 mm of disc diameter), the microhabitat created by C. riisei may be utilized as a recruitment place for some ophiuroids. No ophiuroids were found at Porto de Galinhas beach, just as for sponges. On the other hand, the ophiuroids were always found with sponges in Guadalupe beach. For this reason, the ecological relation of the ophiuroids with C. riisei could be observed as an occasional relation, in the way that the octocoral supplies a support structure to the growth of the many sponges that have given a favourable habitat to shelter ophiuroids.