First Record of Malformation in Seahorses Attributed to the Oil Spill off the Brazilian Coast in 2019.

In 2019, there was an environmental catastrophe in Brazil, when more than 5000 tons of unknown origin crude oil invaded beaches and mangroves. Two years later, two monitoring areas were selected to study seahorses' offspring: Massangana River estuary (apparently healthy area) and Cocaia Island (affected area). Thirty-six reproductive events of Hippocampus reidi (Syngnathidae) couples from these two areas were monitored to analyze the offspring.

Morphological and molecular evidence for the occurrence of three Hippocampus species (Teleostei: Syngnathidae) in Brazil.

For many decades only two species of seahorses were recognized from Brazil: Hippocampus reidi Ginsburg, 1933, the long snout seahorse, and H. erectus Perry, 1810, the lined seahorse. The presence of a possible third species, recognized in 2002, brought about the need for a broad revision of the genus in Brazilian waters.