Journal of the Marine Biological Association of the UK



Research Article

Biology of the marine tucuxi dolphin (Sotalia fluviatilis) in south-eastern Brazil


Ana Paula Madeira  Di Beneditto a1c1 and Renata Maria Arruda  Ramos a2
a1 Universidade Estadual do Norte Fluminense, CBB, Laboratório de Ciências Ambientais, Avenue Alberto Lamego, 2000, Campos, RJ, 28013-600, Brazil
a2 Everest Tecnologia em Serviços Ltda., Avenue Nossa Senhora dos Navegantes, 675/1201, Vitória, ES, 29056-900, Brazil

Article author query
di beneditto ap   [PubMed][Google Scholar] 
ramos rm   [PubMed][Google Scholar] 

Abstract

Age, growth and reproductive parameters related to the marine tucuxi are presented, as well as feeding habits and parasitism. The specimens' age ranged from zero (newborn) to 21 years for males and 0·5 to 30 years for females. In relation to the body dimension, length distributions were bell-shaped for both sexes with male marine tucuxi ranging from 86·0 to 200·0 cm in length and females from 117·5 to 198·0 cm. The body length of new-born and calves varied between 86·0 to 117·5 cm and the postnatal growth curve an asymptotic reached length of 191·0 cm. According to the relationship between age, body length and reproductive characteristics, male and female specimens were considered sexually mature when [gt-or-equal, slanted]6 years and body length [gt-or-equal, slanted]180·0 cm and [gt-or-equal, slanted]6 years and body length [gt-or-equal, slanted]160·0 cm, respectively. Males and females up to six years old represented around 80% of the captures, indicating a bias towards juveniles and individuals that have yet to reach sexual maturity. The youngest specimen with solid contents in the stomach was 119·0 cm in length and seven months old. The marine tucuxi feeds on neritic prey, preferentially on the teleost fishes Trichiurus lepturus and Porichthys porossisimus, and on the cephalopods Loligo sanpaulensis and L. plei. Back calculation of prey lengths indicated that fish ranged from 1·2 to 106·9 cm and cephalopods from 3·4 to 22·2 cm. The barnacle Xenobalanus globicipitis was recorded attaching to the caudal fin and the helminths Braunina cordiformis, Anisakis typica, Halocercus brasiliensis and Nasitrema sp. were found in the internal organs.

(Received February 6 2004)
(Accepted July 8 2004)


Correspondence:
c1 e-mail: anapaula@uenf.br