Observaciones en cautiverio de la medusa Lychnorhiza aff. lucerna en el departamento del Magdalena / Observations in captivity of the jellyfish Lychnorhiza aff. lucerna in the department of Magdalena

RESUMEN En los últimos años se ha evidenciado un notable aumento en las poblaciones de la medusa Lychnorhiza aff. lucerna en el departamento del Magdalena, lo que ha tenido un impacto en la pesca artesanal y el turismo. El conocimiento que se tiene sobre la biología básica de estos organismos sigue siendo limitado, por lo que se hace necesario profundizar en la comprensión acerca de esta medusa y su historia de vida. El objetivo de esta investigación fue realizar ensayos preliminares para evaluar la viabilidad del mantenimiento en cautiverio de la medusa Lychnorhiza aff. lucerna, implementando sistemas de acuarios y estrategias de reproducción que han sido usados en otras especies de medusas. Se realizaron ensayos de fertilización in vitro y la fecundación fue exitosa con la observación de embriones en su primer clivaje. Las medusas fueron mantenidas en cautiverio en sistemas Kreisel por un periodo de 60 días, en este tiempo, las medusas disminuyeron hasta el 30 % de su tamaño. Se confirmó que los acuarios Kreisel y Pseudo-Kreisel son idóneos para el mantenimiento de esta especie filtradora, debido a que proporcionan las condiciones mínimas necesarias para estos organismos.

ABSTRACT In recent years, there has been a noticeable increase in the populations of the jellyfish Lychnorhiza aff. lucerna in the department of Magdalena, Colombia, impacting artisanal fishing and tourism. The understanding of the basic biology of these organisms remains limited, emphasizing the necessity to delve deeper into comprehending this jellyfish and its life history. The aim of this research was to conduct preliminary trials to assess the feasibility of maintaining the jellyfish Lychnorhiza aff. lucerna in captivity by employing aquarium systems and reproduction strategies used in other species of jellyfish. In vitro fertilization trials were conducted, resulting in successful fertilization observed through embryos in their first cleavage. The jellyfish were manteined in Kreisel systems for a 60 days period, during which their size decreased by up to 30%. It was confirmed that Kreisel and Pseudo-Kreisel aquariums are suitable for sustaining this filter-feeding species, as they provide the necessary minimum conditions for these organisms.

Aquaculture facilities promote populational stability throughout seasons and increase medusae size for the invasive jellyfish Cassiopea andromeda.

Cassiopea jellyfish have successfully invaded several marine ecosystems worldwide. We investigated if Cassiopea andromeda grows larger (umbrella size) and if their populations are more stable in shrimp farms than in mangroves in the Brazilian coast. Our results show that jellyfish abundance is higher in the shrimp farm during the rainy season and in the mangrove during dry season. The population is stable during both seasons in the shrimp farm, but unstable in the mangroves, as jellyfish are absent during rainy season. Shrimp farm-associated jellyfish are three times larger than those in the mangroves, regardless of season. We recorded the largest (49.2 cm of umbrella diameter) ever C. andromeda individual in the shrimp farm. Unlike the mangroves, the shrimp farm provides environmental intra-annual stability that promotes jellyfish growth and population persistence. Therefore, C. andromeda populations can be seasonally dynamic and artificial environments such as aquaculture facilities may facilitate the invasion process.

Regenerative Capacity of the Upside-down Jellyfish Cassiopea xamachana.

This study provides the first observation that umbrellar tissue can lead to the formation of virtually all body structures in jellyfish of the order Rhizostomeae. The regeneration process was observed in two specimens of the upside-down jellyfish Cassiopea xamachana Bigelow, 1892, one housed at the Vienna Zoo, Austria and the other in a laboratory at the University of São Paulo, Brazil. The process was triggered by an injury and ended with the formation of two new sets of body structures. Our observation offers evidence that C. xamachana has a hidden regenerative capacity exceeding that previously recorded.

Cubozoa e Scyphozoa (Cnidaria: Medusozoa) de águas costeiras do Brasil

Coastal species of Cubozoa and Scyphozoa occurring in Brazil are described, based on museum specimens and recently collected ones. Identification keys and a glossary are also presented. The listed species are: Aurelia sp.; Cassiopea xamachana Bigelow, 1892; Chiropsalmus quadrumanus (Müller, 1859); Chrysaora lactea Eschscholtz, 1829; Drymonema dalmatinum Haeckel, 1880; Linuche unguiculata (Swartz, 1788); Lychnorhiza lucerna Haeckel, 1880; Nausithoe aurea Silveira & Morandini, 1997; Phyllorhiza punctata von Lendenfeld, 1884; Stomolophus meleagris Agassiz, 1862; Tamoya haplonema Müller, 1859; and Tripedalia cystophora Conant, 1897.

As espécies de Cubozoa e Scyphozoa costeiras que ocorrem no Brasil são descritas, com base em espécimes de coleções de museus e exemplares recém-coletados. Chaves de identificação e um glossário também são apresentados. As espécies descritas são: Aurelia sp.; Cassiopea xamachana Bigelow, 1892; Chiropsalmus quadrumanus (Müller, 1859); Chrysaora lactea Eschscholtz, 1829; Drymonema dalmatinum Haeckel, 1880; Linuche unguiculata (Swartz, 1788); Lychnorhiza lucerna Haeckel, 1880; Nausithoe aurea Silveira & Morandini, 1997; Phyllorhiza punctata von Lendenfeld, 1884; Stomolophus meleagris Agassiz, 1862; Tamoya haplonema Müller, 1859 e Tripedalia cystophora Conant, 1897.

Cubozoa e Scyphozoa (Cnidaria: Medusozoa) de águas costeiras do Brasil

Coastal species of Cubozoa and Scyphozoa occurring in Brazil are described, based on museum specimens and recently collected ones. Identification keys and a glossary are also presented. The listed species are: Aurelia sp.; Cassiopea xamachana Bigelow, 1892; Chiropsalmus quadrumanus (Müller, 1859); Chrysaora lactea Eschscholtz, 1829; Drymonema dalmatinum Haeckel, 1880; Linuche unguiculata (Swartz, 1788); Lychnorhiza lucerna Haeckel, 1880; Nausithoe aurea Silveira & Morandini, 1997; Phyllorhiza punctata von Lendenfeld, 1884; Stomolophus meleagris Agassiz, 1862; Tamoya haplonema Müller, 1859; and Tripedalia cystophora Conant, 1897.

As espécies de Cubozoa e Scyphozoa costeiras que ocorrem no Brasil são descritas, com base em espécimes de coleções de museus e exemplares recém-coletados. Chaves de identificação e um glossário também são apresentados. As espécies descritas são: Aurelia sp.; Cassiopea xamachana Bigelow, 1892; Chiropsalmus quadrumanus (Müller, 1859); Chrysaora lactea Eschscholtz, 1829; Drymonema dalmatinum Haeckel, 1880; Linuche unguiculata (Swartz, 1788); Lychnorhiza lucerna Haeckel, 1880; Nausithoe aurea Silveira & Morandini, 1997; Phyllorhiza punctata von Lendenfeld, 1884; Stomolophus meleagris Agassiz, 1862; Tamoya haplonema Müller, 1859 e Tripedalia cystophora Conant, 1897.