Molecular identification of poisonous pufferfishes and cross-atlantic genetic divergence patterns based on the mitochondrial COI gene

The Tetraodontidae is the most speciose family within the order Tetraodontiformes, being characterized by beak-like jaws and the presence of powerful neurotoxins Tetrodotoxin/Saxitoxin associated with soft tissues, inflation behavior under stress, a condition shared with its accepted sister-family Diodontidae. Although several studies, including both morphological and molecular analyses have been conducted in the last decade the phylogeny and biogeography of Tetraodontidae and its species remain under debate. Several fatal intoxication cases had been observed in the last years related with the ingestion of Tetraodontidae species all around the world. Although recent technological advances have facilitated the sequencing of an entire mitogenome (∼16Kb), increasing the use of mtDNA as a phylogenetic marker, several studies primarily focusing on small mtDNA regions are continuously conducted. Therefore, the aim of the present study was to investigate the molecular identification and the cross-atlantic genetic divergence patterns observed from the mitochondrial COI gene of the poisonous genus Sphoeroides based on newly determined and previously published sequences from both North and South Atlantic Oceans.