Efeito da densidade populacional sobre o crescimento e a reprodução de Bradybaena similaris (Férussac, 1821) (Mollusca, Xanthonychidae) e Leptinaria unilamellata (dOrbigny, 1835) (Mollusca, Subulinidae)

Nocelle de Almeida, MarceloCristina de Almeida Bessa, Elisabeth

For this study, 300 specimens of both species were divided in five different groups: G1: n=10, G2: n=20, G3: n=30; G4: n=40 and G5: n=50. The length of the shell was measured every 15 days for 180 days. The eggs and young were retired and counted daily. In Bradybaena similaris, the shells average length (mm) was: G1: 13,32; G2: 11,96; G3: 11,25; G4: 11,66 and G5: 10,18. The average number of eggs per group in B. similaris was: G1: 133,3; G2: 63,17; G3: 39,03; G4: 24,07 and G5: 25,44. In Leptinaria unilamellata, the shells average lenght (mm) was: G1: 17,06; G2: 18,44; G3: 14,8; G4: 12,2 and G5: 14,22. The average number of offspring per group in L. unilamellata was: G1: 24,75; G2: 23,55; G3: 16,13; G4: 10,31 and G5: 20,69. The population density influence the growth and the reproduction in B. similaris, and it just influence the growth in L. unilamellata.