Human introduction or natural dispersion? Atlantic Ocean occurrence of the Indo‐Pacific whitetip reef shark Triaenodon obesus

Abstract

Occurrence of multiple whitetip reef sharks Triaenodon obesus in the Atlantic Ocean is reported for the first time from near a sunken ferry off the Paraná coast in south-eastern Brazil. This occurrence is hypothesized to have been caused by either a human introduction or a remarkably long oceanic displacement.

A network meta‐analysis of threats to South American fish biodiversity

“…Ten of the 14 species were non‐native, and most of the specimens were the Siamese fighting fish ( Betta splendens , Osphronemidae), which is much appreciated by aquarists. Aquarium trade is highlighted as a vital introduction pathway for some marine fish species (Essl et al., ) and the most plausible hypothesis to explain the record of four species on the Brazilian coast: red lionfish ( Pterois volitans , Scorpaenidae) (Ferreira et al., ), pennant coralfish ( Heniochus acuminatus , Chaetodontidae) (Adelir‐Alves, Soeth, Braga, & Spach, ; Luiz, Comin, & Madin, ), whitetip reef shark ( Triaenodon obesus , Carcharhinidae) (Bornatowski et al., ) and yellow bar angelfish ( Pomacanthus maculosus , Pomacanthidae) (Soeth, Adelir‐Alves, Loose, Daros, & Spach, ).…”

First sighting of a tropical benthic reef shark species at Rapa Nui: chance dispersal or a sign of things to come?

“…Active swimming across this current probably led to the occurrence of this species at the Kermadec Islands, possibly aided by the presence of seamounts that can act as stepping‐stones for the dispersal of shallow‐water species across oceanic divides (Duffy et al, ; Friedlander et al, ; Rogers, ). However, even with active dispersal, the observation of T. obesus in South Atlantic Ocean waters off the coast of south‐eastern Brazil (Bornatowski et al, ) is particularly anomalous. This Atlantic record was made in January 2013, well before the next nearest range expansion in the central east Pacific Ocean (Rapa Nui, present study, 2017), suggesting these specimens did not transit from the east.…”

“…Importantly, no other confirmation of this species has been made in the Atlantic Ocean (Whitney et al, ). As aquarium releases have occurred in this region before and no sighting of this species has been made in the years since (Bornatowski et al, ), we suspect that the Atlantic record of this species is most probably a consequence of human introduction.…”

Plectorhinchus macrolepis (Actinopterygii: Haemulidae) in the western Atlantic Ocean

“…90 km; nonetheless, its mangrove areas and sandy beaches and islands maintain a community of 272 species of fish (234 Actinopterygii and 38 Elasmobranchii; Spier et al ., ). In addition, non‐native species reported in this region can be added in the current list (Adelir‐Alves et al ., ; Bornatowski et al ., ; Caires et al ., ; Sampaio et al ., ; Soeth et al ., ). These records indicate that an important process driving introduction of non‐native reef fishes is taking place in Brazilian marine waters.…”