Estudié el efecto de agregar calcio al alimento sobre el desarrollo del caracol pulmonado africano Limicolaria flammea (Müller). La cantidad de calcio tuvo una correlación positiva con el peso corporal (T de Student, p < 0.01; r = 0.96, p < 0.0001) y la longitud de concha (T de Student, p < 0.01; r = 0.96, p < 0.00001). Los caracoles que no recibieron calcio murieron en gran cantidad y no produjeron huevos. En un experimento a largo plazo, hubo picos de consumo del calcio y el mayor aumento de peso fue en los seis meses iniciales. Los picos de producción de huevos fueron entre los seis y los ocho meses (535 huevos), entre los diez y once meses (350 huevos) y en los meses 13 y 14 (310 huevos).

In an attempt to elucidate the role of calcium in the life of the edible Achatinid snail, Limicolaria flammea (Müller) I investigated short and long term effects of calcium added to the food. The short term experiments lasted for 18, 30 and 32 weeks respectively, while the long term experiment to determine life time utilization of calcium carbonate lasted for 15 months. In the short term experiments, hatchlings were divided into densities of one, ten and 50 snails. In the 10 snail group, there was a positive correlation between calcium provision, body weight (t test, p < 0.01; r = 0.96, p < 0.0001) and shell length (t test, p < 0.01; r = 0.96, p < 0.00001). There was also a positive correlation between increase in shell length and availability of calcium in the 1 snail group (t test, p< 0.01; r = 0.99, p < 0.00001). In the 50-snail group, the correlation was positive for shell length of the snails (t test, p < 0.05; r = 0.99, p < 0.0001) and body weight (t-test, p < 0.05; r = 99, p < 0.00001). Mortality was very high in the snails deprived of calcium and they did not produce eggs. In the long term experiment, there were three feeding peaks in L. flammea. In the first feeding peak, amount of food and calcium ingested by the snails increased in the first three months of life. The second feeding peak occurred at six months of age, while the last occurred at 10 months of age. The amount of calcium ingested during the second peak decreased gradually in the 4th and 5th month. The amount of calcium ingested was lowest during the 3rd feeding peak. The period of highest weight gained by the snails was between the 1st and 6th month and then dropped at between six and 12 months of age which corresponds to the period of egg production. There were also three peaks of egg production; the first was between six and eight months (535 eggs), the second at between 10 and 11 months (350 eggs) and the third at 13 to 14 months (310 eggs) respectively. Rev. Biol. Trop. 56 (1): 333-343. Epub 2008 March 31.

Os estágios finais da embriogênese do caracol Limicolariaflammea (Müller, 1774) foram descritos por meio de observações a partir de microscopia óptica e eletrônica. Embriões em vários estágios de desenvolvimento estavam presentes em ovos durante a primeira hora ou logo após a desova, de blástulas tetra celulares a mórulas e estágios avançados. Embriões avançados, totalmente desenvolvidos no segundo dia, apresentaram uma longa base cefálica, a primeira a desenvolver-se, aderida ao embrião e um podocisto aderido ao pé do embrião. Ambas estruturas reduziram de tamanho à medida que a embriogênese progrediu, até finalmente desaparecer próximo do sétimo dia após a oviposição. A concha embriogênica foi evidenciada no segundo dia e o enrolamento espiral foi aparente próximo ao quinto. A concha espiralada possuia uma volta quando formada e mais espirais foram adicionadas e assim, quando da eclosão, o jovem tinha três voltas.

The late stages of embryogenesis in the achatinid land snail Limicolariaflammea (Müller, 1774) were described using light and electron microscopy. Embryos at various stages of development were present in the eggs during the first hour after they were laid, from 4-cell blastulae to morulae and fairly advanced stages. The advanced embryo which was fully developed on the second day bears a long cephalic sac, first to be developed, attached to the embryo and a podocyst which is attached to the foot of the embryo. Both of these structures are reduced in size as embryogenesis progresses until they finally disappear at about the 7th day after the egg was deposited. The embryonic shell was apparent on the second day and spiral coiling was apparent at about day 5. The spiral shell had one whorl when formed and more spirals were added so that at hatching the young snails had three whorls.