Biological aspects of Leptinaria unlamellata (d'Orbigny, 1835) were studied, such as: onset of sexual maturity, occurrence of self-fertilization and shell length measurement at different stages of development. In isolated specimens of L. unilamellata, sexual maturity was reached at 74 days (minimum time) and 104 days (maximum time). For the grouped specimens, the minimum time was 71 days. The occurrence of self-fertilization was observed in both species, 100% of specimens. The total numberof young per birth varied from one to 22 (average: 7,35 ± 5,78), the total number of offsprings per mollusc varied from two to eight (average: 4,1 ± 1,41) and total number of young per mollusc varied from five to 46 (average: 30,21 ± 8,08). As to the shell length in different growth stages, it was observed that in L. unilamellata, growth rhythm was similar until 15 days for age. After this period grouped specimens showed a high growth rhythm until 105 days after which the growth rhythm of grouped specimens became constant and the growth rhythm isolated specimens became greater. Grouped and isolated specimens reached a maximum size of 18,7 mm and 20,6 mm respectively. In the moment of the sexual maturity, the length of the shell in the individuals that were kept grouped was smaller than the isolated ones for L. unilamellata. In this specie individuals that were kept isolated reach larger length of shell.
Leptinaria unilamellata; biology; growth; reproduction