Development of the escargot Helix aspersa Muller [Gastropoda, Stylommatophora) with employment of different sources of calcium

Abstract

The present study is an attempt to evaluate, in two phases (A) and (B), the growth of Helix aspersa confined and fed with: 67% of poultry ration supplemented with 33%  of different calcium sources (meals): (A1) = bones; (A3) and (B1)=oyster valves; (A4) and (B2) = egg rinds; (A5) = shrimp carapaces; and associations, in the proportion of 1:1, in (A2) and (B3) = oyster valves + bones; (B5) = egg rinds + bones; and (B4) = egg rinds + oyster valves. The graphical analysis of weight increase in the phase (A) indicates that the best results were obtained in treatments (A2) and (A4). In the phase (B), the analysis of variance for weight gain shows that there were no significant differences between treatments (B2) to (B4), but significant differences between treatment (B5) and the others, at the 5% level. Considering the time necessary to reach the adult phase, the analysis of variance indicates no significant differences between treatments (A2) to (A4) and (B1) to (B4), but significant differences between these and treatments (A5) and (B5), at the 1% level. No adults were found in treatment (A1). The food conversion was determined for treatments (B1) to (B5); treatment (B4) showed the best result (4.18:1). The results indicate that oyster valves and egg rinds are the best calcium sources for the growth of this species of escargot.