Composição do bacterioma da pele e do ferrão das raias Gymnura altavela e Dasyatis hypostigma e influência do ambiente circundante, em um estuário eutrofizado e em um aquário público no Rio de Janeiro, sudeste do Brasil

Abstract

Bacterial communities are of significant importance to their hosts, facilitating nutrient absorption, regulating organism metabolism and defending against pathogen invasion. This study examines two important stingray bacteriomes present on the skin, which offers a first line of defense against external factors, and on stings, that displays the potential to cause lesions in both animals and humans. This is a first-time report of the bacterial composition of wild spiny butterfly rays (Gymnura altavela), sampled both from a Rio de Janeiro estuary and maintained in captivity in a public aquarium. In addition, the microbiome of groovebelly stingrays (Dasyatis hypostigma) living in captivity was also assessed. Statistically different communities were also noted when comparing the captive and estuary Spiny butterfly rays. The bacterial community of estuarine rays was similar to that present in the water and sediment of their capture sites, indicating significant influence of the surrounding environment on their microbiomes. However, concerning the captive samples, different bacterial communities were found between tank water and the animals. The most noteworthy bacteria phyla were Proteobacteria, Bacteriodetes and Actinobacteria. In captive rays, a high taxa biodiversity (e.g. Corynebacterium) was observed, with several taxa considered pathogens for both humans and fish. The presence of these pathogenic bacteria in ray stings confirms that the bacteria present in this stinger, in addition to the venom gland, also serve as a defense mechanism. This has been reported in previous studies concerning accidents with these animals, where subsequent bacterial infections were noted in injured people