Carlos Daniel Pérez

Brittle stars (Echinodermata: Ophiuroidea) associated with the octocoral Carijoa riisei (Cnidaria: Anthozoa) from the littoral of Pernambuco, Brazil

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.

The Transcriptome of the Zoanthid Protopalythoa variabilis (Cnidaria, Anthozoa) Predicts a Basal Repertoire of Toxin-like and Venom-Auxiliary Polypeptides

Abstract 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.

Growth of the tropical zoanthid Palythoa caribaeorum (Cnidaria: Anthozoa) on reefs in northeastern Brazil

In Brazilian reefs, zoanthids, especially Palythoa caribaeorum are fundamental for structuring the local benthic community. The objective of this study was to determine the growth rate of P. caribaeorum, and to assess the influence of the site (different beaches), season (dry and wet), location (intertidal or infralittoral zones), and human pressure associated with tourism. For one year we monitored the cover of P. caribaeorum in transects and focused on 20 colonies. We cut off a square (100 cm2) from the central part of the colony and monitored the bare area for four months in each season. The average growth rates varied from 0.015 and 0.021 cm.day(-1). The rate was homogeneous in all localities, and there was no influence from colony site, location, or touristic visitation, showing that the growth velocity may be an intrinsic characteristic of the species, with a strong genetic component. The growth rate of P. caribaeorum differed among months, and peaked in the first month after injury. The average cover varied from 6.2 to 22.9% and was lower on the reef visited by tourists. The present study corroborates the hypothesis that P. caribaeorum is important for coastal reef dynamics due to its fast and continuous growth.

Dolabellane Diterpenoids from the South Atlantic Gorgonian Convexella magelhaenica.

Two new dolabellane diterpenoids (1 and 2) were isolated from a small sample of the deep water gorgonian octocoral Convexella magelhaenica collected as a nontarget by-catch by dredging (-93 m) in commercial Patagonian scallop fishing grounds in the South Atlantic. The structures of the new compounds, which are major metabolites in the extract, were established by spectroscopic techniques and chemical transformations. Both compounds were cytotoxic against a human pancreatic adenocarcinoma cell line at micromolar concentrations.

Morphological Plasticity in the Reef Zoanthid Palythoa caribaeorum as an Adaptive Strategy

We compared morphology of Palythoa caribaeorum (number of polyps, area, diameter and height) occupying three sites located at different distances from a harbor area and with different environmental conditions, such as sedimentation. Seasonality was also considered by comparing morphology during the wet and dry seasons. GLM analyses showed significant main and first-order interaction effects between sites and seasons for each of the four morphological variables measured. Only at the site directly in front of the harbor area there was no seasonal variation. At the other two sites, no significant differences were found when the average pairwise distance of each morphological character was compared between seasons for each site. This indicates that these characters vary in a similar way and suggests growth conditions intrinsic to the species. Environmental homogeneity at the harbor area seems to promote homogeneous morphometry, which indicates different biological strategies and suggests that this species adapts to distinct environments.

Trophic ecology of the zoanthid Palythoa caribaeorum (Cnidaria: Anthozoa) on tropical reefs

This study examined the trophic ecology of the zoanthid Palythoa caribaeorum in tropical reefs and evaluated its role in the energy flow in that ecosystem. Colonies of this species were sampled in the infralittoral zone of reefs in north-eastern Brazil in 2008. We calculated the richness, total abundance, relative abundance and frequency of occurrence of prey items. The biovolumes and weighted biovolumes of prey were calculated to characterize the most important food items in terms of their biomasses. To evaluate the selectivity, zoanthid and plankton samples were collected in 2010. Pennate diatoms were the most abundant and most frequent prey and, together with invertebrate eggs, constituted the most important food items in terms of their biomasses. There were no significant differences in abundance or richness among the different beaches studied, nor between the different seasons. The mean size of prey items within the polyps was significantly smaller than of the general plankton, indicating that P. caribaeorum selected for (or limited) certain prey sizes. This species predominantly fed on diatoms, and did not take advantage of many other prey items abundant in the plankton. Our results indicate that P. caribaeorum is suspensivorous and feeds principally on small phytoplankton. As this species is prey for benthic organisms such as polychaetes and nektonic organisms, our results indicate the importance of this zoanthid in tropical reef ecosystems as a primary consumer that serves as an energy transfer link between the planktonic environment and the nektonic and benthic spheres.

New records of the genus Callogorgia (Anthozoa: Octocorallia) in the western Atlantic, including the description of a new species

Based on material collected during oceanographic campaigns in the western Atlantic from 1958 to 2011, two species of primnoid octocorals belonging to the genus Callogorgia were identified: Callogorgia americana and Callogorgia arawak sp. nov. These species are described and illustrated herein and their geographic and bathymetric are given. This is the first record of the genus in the south-western Atlantic. Additionally, the elevation of C. americana americana and C. a. delta to species level is proposed, keeping Callogorgia gilberti, C. delta and C. americana as separate species.

Identification of long non-coding RNAs in two anthozoan species and their possible implications for coral bleaching.

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.

Comparisons of sexual reproduction in Carijoa riisei (Cnidaria, Alcyonacea) in South Atlantic, Caribbean, and Pacific areas

Soft corals show a wide variety of reproductive strategies, including both asexual and sexual reproduction which can influence macro-evolutionary processes. The octocoral Carijoa riisei has an ample geographical distribution in Pacific and southern Atlantic and also in Caribbean region. This species was considered invasive in Hawaii, and its capacity for rapid proliferation is recognized, but recent studies, however, have indicated that it appears to be native to the Indo-Pacific region. The present study examined the reproductive biology of C. riisei in the Atlantic basin. The results were then compared to previous studies of the same species from the Pacific (Hawaii) and Caribbean (Puerto Rico) regions to examine the hypothesis that the reproductive patterns of C. riisei populations are the same throughout its geographical distribution, independent of its native or non-native status. Samples were collected on a monthly basis from May/2007 to April/2008 at Porto de Galinhas (Pernambuco State, Brazil). This species was found to have similar reproduction patterns in Brazil, the Caribbean, and in Hawaii (a gonochoric reproductive pattern and continuous and asynchronous gamete release). The similarities of their traits contribute to its rapid proliferation and occupation of spaces left by other species, independent of its native or non-native status.

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

Current knowledge about the Brazilian deep-water octocoral fauna remains scarce, fragmented, and mostly based on unpublished, regional scale surveys. The present work provides the first comprehensive study of the family Chrysogorgidae Verrill, 1883 in Brazil, based on morphological analysis of specimens collected in the last decade and those currently placed in museums. Members of this family are common mainly at great depths and remarkable for the iridescent aspect of their colonies. In Brazil, to the present, only four species were reported: Chrysogorgia elegans (Verrill, 1883), Chrysogorgia multiflora Deichmann, 1936, Stephanogorgia rattoi Castro, Medeiros & Loiola, 2010 and Trichogorgia brasiliensis Castro, Medeiros & Loiola, 2010-the last two are shallow-water species. In this study, three new deep-water species are described, Chrysogorgia tuberculata, Chrysogorgia upsilonia and Radicipes kopelatos, and a new record to Brazil is reported, Chrysogorgia fewkesii Verrill, 1883, as well as latitudinal expansions in distributions of Chrysogorgia elegans and Chrysogorgia multiflora are presented.