Colorless spherule cells and lysozyme contribute to innate immunological responses in the sea urchin Lytechinus variegatus, exposed to bacterial challenge.

The sea urchin Lytechinus variegatus is considered a good candidate for aquaculture, but bacterial diseases are a major challenge in culture conditions. The innate immunological defenses of L. variegatus to bacterial challenges were assessed through hematology parameters, in vitro phagocytosis, lysozyme activity and total plasma protein concentrations in cell-free coelomic fluid. Adult sea urchins were inoculated with Microccocus lysodeikticus, Escherichia coli and Vibrio parahaemolyticus in the cavity coelomic. Filtrated and sterile seawater (FSW) injected and non-injected sea urchins were used as control groups. Righting time, external aspects and behavior of sea urchins were evaluated. Twenty-four hours post-inoculation, we found an increase in the population of colorless spherule cells (CLS), phagocytosis, and humoral responses in sea urchins challenged by bacterial inoculations. Righting time was not affected by the treatments and apparent external signs of disease were not observed at least during 96h post-inoculation. The immunological system of L. variegatus quickly eliminated pathogenic microorganisms. CLS and lysozyme activity cooperate in the immune defenses of L. variegatus, showing an extraordinary efficiency for adjusting the immune defenses under stress caused by microbes. We recommend that the cellular and humoral markers serve as routine tests to monitor health status in sea urchins.

¿Hacia dónde va la acuicultura de equinodermos en América Latina? Potencial, retos y oportunidades / Where is echinoderm aquaculture heading in Latin America? Potential, challenges and opportunities

Introducción: La acuicultura de equinodermos en América Latina es incipiente, pero representa una nueva frontera para la producción de alimentos marinos altamente nutritivos, con especies nativas de alto valor comercial que ofrecen un gran potencial en comparación con las debilitadas pesquerías bentónicas artesanales. Metodología: Se revisó la literatura sobre pepinos de mar, erizos de mar y estrellas de mar hasta el año 2020. Resultados: Para el 2020, había 17 especies nativas con importantes avances en reproducción, larvicultura, crecimiento, tratamiento e identificación de enfermedades y nutrición en México, Belice, Panamá, Colombia, Ecuador, Perú, Brasil, Chile y Argentina. Conclusiones: La acuicultura de equinodermos en América Latina está avanzando y se beneficiaría de los sistemas multitróficos para expandirse y diversificarse, reduciendo la presión sobre las pesquerías agotadas.

Introduction: Echinoderm aquaculture in Latin America is incipient, but it represents a new frontier for the highly nutritious marine food production, with native species of high commercial value offering a vast potential when compared to the weakened artisanal benthic fisheries. Methodology: We reviewed the literature on sea cucumbers, sea urchins, and starfish up to the year 2020. Results: By 2020, there were 17 native species with important advances in reproduction, larviculture, growth, treatment and identification of diseases, and nutrition, in Mexico, Belize, Panamá, Colombia, Ecuador, Peru, Brazil, Chile and Argentina. Conclusions: Echinoderm aquaculture in Latin America is advancing and would benefit from multitrophic systems to expand and diversify, reducing the pressure on depleted fisheries.