The growth of Aegla itacolomiensis (Crustacea, Decapoda) in an Atlantic forest stream in southern Brazil.

The growth of Aegla itacolomiensis (Crustacea, Decapoda) in an Atlantic forest stream in southern Brazil. To give more information about ecology and biology of Aegla itacolomiensis Bond-Buckup & Buckup, 1994 was analized its growth in the nature. Monthly samples were made from June 2005 to May 2006 in Solitaria Alta stream, tributary of Rio dos Sinos basin, district of Igrejinha, RS, Brazil (29 degrees 33'10,2 '' S; 50 degrees 50'57 '' W). The specimens were collected by dip net, sexed and after the cephalotorax measured, the animals were brought back to the stream. The growth estimated by cephalotorax length for males and females of A. itacolomiensis was analized by absolut distributional size-classes frequency. The modal frequency of cephalotorax lenght was calculated. The growth was estimated trought the modal progression. The growth curves in cefalotorax length for males and females are described respectively by the equations: C-t = 23.21[1-e(-0.0094(t + 7.03))] e C-t = 19.49 [1-e(-0.0065) ((t + 11.16))]. Were found juveniles in the spring and summer. The males attained larger sizes and a higher growth rate than females. The estimated longevity was 2.2 years for males and 2.5 years for females.