Bulimulus tenuissimus (d'Orbigny, 1835) is a land snail of parasitological importance with a poorly understood biology. The goal of this laboratory study was to determine development and reproductive patterns in B. tenuissimus. Recently hatched individuals in seven groups of 10 were maintained in the laboratory for two years. To test for self-fertilization, 73 additional individuals were isolated. After 180 days the isolated snails showed no signs of reproduction. Subsequently, 30 of these snails were paired to test fertility. We noted the date and time of egg-laying, the number of eggs produced, the number of egg-layings per individual, the incubation period and hatch success. This species shows indeterminate growth. Individuals that were maintained with others, as compared to isolated individuals, laid eggs sooner, laid more eggs and had a greater hatching success. This species can self-fertilize, however, with lower reproductive success. Bulimulus tenuissimus has a well-defined reproductive period that is apparently characteristic for this species.

Habroconus semenlini is a micro-terrestrial gastropod native to South America. There are no previous studies on its biology. We studied its pattern of growth, fertility and lifespan under laboratory conditions. For this purpose, 80 snails were either grouped or kept isolated (40 animals in each condition) during their lifetime. Growth is indeterminate and the species is capable of self-fertilization with high reproductive success. Grouped snails had lower fecundity than the animals that were kept in isolation. This species has a short lifespan and only one reproductive period, which characterizes the occurrence of semelparity.

Feed influences directly growth and survival in land snails. Here, we investigate the influence of diet and isolation on growth and survival in Bulimulus tenuissimus (d'Orbigny, 1835) in the laboratory. Animals were maintained individually and in groups and three different types of diets: lettuce, ration and both lettuce and ration (mixed diet) for 210 days. Isolated animals, in all diet types, grew more rapidly than grouped animals. Also, snails fed with lettuce grew most slowly in isolated or grouped treatments. Within isolated or grouped treatments, growth rates were similar for the ration and the mixed diet. Mortality rate was higher in animals fed on lettuce only, in both density treatments. Thus, diet and density are important components of the population dynamics of B. tenuissimus.

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The objective of this study was to evaluate the variation of energy substrates in different seasons in Bulimulus tenuissimus. For this evaluation, substrates were collected from the digestive and albumen glands and foot tissues, which were processed to obtain the concentrations of glucose and galactose. There was seasonal variation in energy reserves in both the digestive gland and the foot of Bulimulus tenuissimus, with a tendency to accumulation from spring to winter. There was greater use of energetic reserves in the spring and summer, being the glycogen stored in the digestive gland the first source consumed. In addition, mobilization of reserves of glycogen in the muscle in summer was observed. The reduction of glycogen coincides with the reproductive cycle of the species, and the expenses generated for the processes of mating and gametogenesis was the cause of this reduction. The concentration of galactogen also varied according to the reproductive period. It was suggested that variations in temperature and photoperiod that occur during the year would act as regulatory mechanisms of energy metabolism of B. tenuissimus.