Physiological responses of Holothuria grisea during a wound healing event: An integrated approach combining tissue, cellular and humoral evidence.

Due to their tissue structure similar to mammalian skin and their close evolutionary relationship with chordates, holothurians (Echinodermata: Holothuroidea) are particularly interesting for studies on wound healing. However, previous studies dealing with holothuroid wound healing have had limited approaches, being restricted to tissue repair or perivisceral immune response. In this study, we combined tissue, cellular and humoral parameters to study the wound healing process of Holothuria grisea. The immune responses of the perivisceral coelom were assessed by analyzing the number, proportion and viability of coelomocytes and the volume and protein concentration of the coelomic fluid. Additionally, the morphology of the healing tissue and number of coelomocytes in the connective tissue of different body wall layers were examined over 30 days. Our results showed that perivisceral reactions started 3 h after injury and decreased to baseline levels within 24 h. In contrast, tissue responses were delayed, beginning after 12 h and returning to baseline levels only after day 10. The number of coelomocytes in the connective tissue suggests a potential cooperation between these cells during wound healing: phagocytes and acidophilic spherulocytes act together in tissue clearance/homeostasis, whereas fibroblast-like and morula cells cooperate in tissue remodeling. Finally, our results indicate that the major phases observed in mammalian wound healing are also observed in H. grisea, despite occurring at a different timing, which might provide insights for future studies. Based on these data, we propose a model that explains the entire healing process in H. grisea.

Echinodermata da Praia do Cabo Branco, João Pessoa, Paraíba, Brasil / Echinodermata from Cabo Branco Beach, João Pessoa, Paraíba, Brazil

Este estudo retrata a fauna de equinodermos encontrada na Praia do Cabo Branco, João Pessoa, Paraíba, Brasil. Esta praia é formada por um terraço de abrasão marinha do tipo arenito-ferruginoso e está localizada no ponto mais oriental das Américas. Foram identificadas 32 espécies de equinodermos pertencentes a quatro classes (Asteroidea, Ophiuroidea, Echinoidea e Holothuroidea), distribuídas em 18 famílias e 24 gêneros. O número de táxons identificados corresponde a 9,7 por cento das espécies registradas para o litoral Brasileiro e mostra a significativa diversidade das espécies de Echinodermata encontrada nesta área. A classe Ophiuroidea foi a mais diversa com 13 espécies, seguida por Holothuroidea (10 spp.), Asteroidea (5 spp.) e Echinoidea (4 spp). Do total de espécies registradas, as seguintes são novas ocorrências para o litoral do Estado da Paraíba: Ophiocnida scabriuscula, Ophiomyxa flaccida, Ophiactis lymani, Ophionereis reticulata, Ophioderma januarii, Ophiophragmus brachyatis, Thyone cognita, T. suspecta, Ocnus suspectus, Phyllophorus occidentalis, P. communis, Lissothuria sp. Holothuria grisea, H. arenicola, Chiridota rotifera, Synaptula hydriformis, Echinaster nudus, Linckia guildingii, Lytechinus variegatus, Mellita quinquiesperforata e Leodia sexiesperforata.

The present study examined the fauna of echinoderms at Cabo Branco Beach, João Pessoa, state of Paraíba, Brazil. The beach was formed by the erosion of a sandstone terrace. Thirty two species from four echinoderm classes (Asteroidea, Ophiuroidea, Echinoidea and Holothuroidea) distributed among 18 families and 24 genera were identified. The number of identified taxons corresponds to 9.7 percent of the total number of species registered for the entire Brazilian coast, and demonstrates the significant diversity of echinoderm species in this area. Class Ophiuroidea was the most diverse, with 13 species, followed by Holothuroidea (10 spp.), Asteroidea (5 spp.) and Echinoidea (4 spp.). Among the recorded species, the following were new occurrences for the state of Paraíba: Ophiocnida scabriuscula, Ophiomyxa flaccida, Ophiactis lymani, Ophionereis reticulata, Ophioderma januarii, Ophiophragmus brachyatis, Thyone cognita, T. suspecta, Ocnus suspectus, Phyllophorus occidentalis, P. communis, Lissothuria sp., Holothuria grisea, Holothuria arenicola, Chiridota rotifera, Synaptula hydriformis, Echinaster nudus, Linckia guildingii, Lytechinus variegatus, Mellita quinquiesperforata and Leodia sexiesperforata.