Potentially dangerous fih of the Paraiba Estuary: Identifiation and envenomation mechanisms

Objective: To present venomous and poisonous fish species in the Paraiba Estuary, Paraiba State, Brazil, with a description of the envenomation mechanisms and characteristics of the toxins. Methods: Fishes were caught by beach seine in the dry and rainy season (November 2013 and June 2014) and bimonthly between May 2016 and March 2017. Results: Eight potentially dangerous species belonging to the families Batrachoididae, Ariidae and Tetraodontidae were identified. The representatives of the former two families, toadfish and catfish, respectively had specific venom inoculating apparatuses that could penetrate tissues, releasing toxins that caused injuries mainly to fishermen. The family Tetraodontidae had poisonous species, once the pufferfish could accumulate biotoxins (especially tetrodotoxin, which is a neurotoxin produced by bacteria). Despite being toxic for consumption, these fish were often consumed by fishermen and their families. Conclusions: The present study is the first record of venomous and poisonous species in the Paraiba Estuary and contributes to the knowledge of the identification of the species and the mechanisms that cause severe envenomation and even deaths in artisanal fishing communities. Such knowledge is fundamental to future campaigns aimed at the prevention of injuries involving fish in the region and in other estuarine environments, where such fishes are common