1 research outputs found
Morphologie, croissance individuelle et dynamique des populations de la tortue verte (Chelonia mydas L.) au banc d'arguin (République islamique de Mauritanie)
The carapace morphology and growth of the Green turtle
(Chelonia mydas L.) has been studied in a large (n = 177) sample
of animals collected by the Imragen fishermen on the Banc d'Arguin
(lslamic Republic of Mauretania). The frequency of anomalies of the scales decreases with age
in this species, possibly due to a differentiai mortality between
normal and abnormal individuals.
The mathematical relation between length and width of the
carapace is discussed and the Mauretanian data are compared
with those of other areas. There are obvious differences in the
shape of the carapace between different breeding populations of
green turtles, which quite likely correspond to genetic differences
between various breeding populations. The Mauretanian green
turtles are quite similar to those breeding on the eastern coast of
South-America. Seven age classes can be recognized on the basis of the carapace
length.
A growth curve of the Mauretanian population of Chelonia
mydas L., based upon von Bertalanffy equation, is proposed. The
rate of growth decreases sharply after the first breeding season.
Sexual maturity takes place at 5.5 years of age, but age at first
reproduction apparently varies from one population to the other,
probably depending upon fishing pressure. The number of "bachelors" (mature individuals not taking part in reproduction) is
apparently greater in areas with the smallest fishing pressur