Resumo

DIAZ, Desiree et al. Sexual reproductive biology of Brachionus quadridentatus Hermanns (Rotifera: Monogononta). Hidrobiológica [online]. 2006, vol.16, n.1, pp.81-87. ISSN 0188-8897.

This study examined important aspects of the sexual reproductive biology of the monogonont rotifer Brachionus quadridentatus Hermanns. Observations on the following was made: 1) Morphological description of the male, 2) An analysis of mating behavior, 3) An analysis of female and male life-span at 25^oC, and 4) Morphometric characterization of the three types of eggs known in this species and determination of hatching percentages of sexual eggs at 20 and 25^oC. SEM photographs of the male are included, the female and parthenogenetic and sexual eggs. Some complementary photographs with the light microscope are also included. The mating behavior of B. quadridentatus is similar to those of other brachionids. Attempted copulations lasted on average 12.4 s, and completed copulations lasted on average 71.4 s. B. quadridentatus is the Brachionus species with the longest duration of copulation recorded so far. Photographs showing episodes of mating attempts and copulations are included. Mating attempts and copulations are similar to those of other members of Brachionus. A comparison of the mating of B. quadridentatus with that of other brachionids is also included.

Palavras-chave : Rotifer mating behavior; rotifer; evolution; taxonomy.