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 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.

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Long non-coding RNAs (lncRNAs) have been shown to play regulatory roles in a diverse range of biological processes and are associated with the outcomes of various diseases. The majority of studies about lncRNAs focus on model organisms, with lessened investigation in non-model organisms to date. Herein, we have undertaken an investigation on lncRNA in two zoanthids (cnidarian): Protolpalythoa varibilis and Palythoa caribaeorum. A total of 11,206 and 13,240 lncRNAs were detected in P. variabilis and P. caribaeorum transcriptome, respectively. Comparison using NONCODE database indicated that the majority of these lncRNAs is taxonomically species-restricted with no identifiable orthologs. Even so, we found cases in which short regions of P. caribaeorum’s lncRNAs were similar to vertebrate species’ lncRNAs, and could be associated with lncRNA conserved regulatory functions. Consequently, some high-confidence lncRNA-mRNA interactions were predicted based on such conserved regions, therefore revealing possible involvement of lncRNAs in posttranscriptional processing and regulation in anthozoans. Moreover, investigation of differentially expressed lncRNAs, in healthy colonies and colonial individuals undergoing natural bleaching, indicated that some up-regulated lncRNAs in P. caribaeorum could posttranscriptionally regulate the mRNAs encoding proteins of Ras-mediated signal transduction pathway and components of innate immune-system, which could contribute to the molecular response of coral bleaching.

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The community associated with the zoanthid Palythoa caribaeorum on shores (Porto de Galinhas and Guadalupe) in northeastern Brazil were analysed. Seasonal samples (dry and wet) were made in both beaches throughout one year. This preliminary study identified 28 taxa and recognized two modes of existence, endobionts (three taxa) and hypobionts (25 taxa). Among hypobionts two patterns of ecological relationships were found: those fixed to the rocky substrata or on the base of the zoanthid colony (11 taxa) and the free-living (14 taxa). In some of these relationships, the organisms observed (Carijoa riisei and barnacles), were under the mat as victims of the zoanthid overgrowth (spatial competition). The more abundant taxa were: Mollusca (28%), Crustacea (25%), Nematoda (24%) and Polychaeta (16%). Among all samples species richness, abundance, similarity and diversity were different, especially the dry season of Porto de Galinhas. Porto de Galinhas in the dry season showed the lowest diversity with only one record. After evaluating the different ecological parameters of the P. caribaeorum-associated community, we conclude that the Guadalupe shore maintains annual homogeneity, while Porto de Galinhas shore is notably different during the year. The only environmental difference between them seems to be the effect of human activity from tourism (reef walkers, fishery and diving), that could be directly and indirectly affecting some ecological parameters of this zoanthid-associated community, such as abundance, richness and diversity of species.

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