The State of Knowledge on Rhizoprionodon lalandii in Brazilian Waters Thomas Alves Vidal, João Henrique Alliprandini da Costa, Otto Bismarck Fazzano Gadig, Ursulla Pereira Souza

Abstract

The genus Rhizoprionodon comprises seven species, two of which occur in Brazil. Rhizoprionodon lalandii is a demersal neritic species that can reach 80 cm in length, common in shallow waters along the Brazilian coast, and of local commercial importance, which increases its vulnerability. Elasmobranchs such as R. lalandii play a crucial role in the ecological balance, and their excessive removal due to fishing can lead to collapses in food chains and environmental imbalances. A review of 24 studies on R. lalandii was carried out, the objective of which was to compile and evaluate the main knowledge gaps for the species. Most studies focused on the São Paulo Coast, highlighting gaps in other regions of Brazil. The most covered topics in research were reproduction and anthropogenic impacts, while areas such as age and growth, physiology, molecular biology, cell biology and anatomy were less explored. The most frequently addressed topics in the research were reproduction and anthropogenic impacts, while areas such as age and growth, physiology, molecular biology, cell biology, and anatomy were less explored. Similar to what was found in a review of another shark species, Galeocerdo cuvier, both species lacked data on age and growth, which are fundamental for the conservation of such a vulnerable group. We hope that, with the trends and gaps demonstrated in this work, new research efforts will be directed.