Age and growth of franciscana, Pontoporia blainvillei, and Guiana, Sotalia guianensis, dolphins from southeastern Brazil

Abstract

Life history is still poorly known for two small cetacean species found along the Atlantic coast of Latin America: the franciscana dolphin, Pontoporia blainvillei (Gervais & d'Orbigny, 1844) and the Guiana dolphin, Sotalia guianensis (Van Bénedén, 1864). For both species, the limited information available suggests there are likely distinct populations with different morphotypes identifiable by asymptotic length (Barreto & Rosas, 2006; Botta et al., 2010; Denuncio et al., 2017; Di Beneditto & Ramos, 2004; Ramos et al., 2000, 2002, 2010). As a result, precise estimates of growth and asymptotic length may be helpful in identifying potential stocks.