Lipids analysis in hemolymph of African giant Achatina fulica (Bowdich, 1822) exposed to different photoperiods

Abstract

The influence of different photophases (0, 6, 12, 18 and 24 hours) on the triglycerides and total cholesterol contents in the hemolymph of A. fulica was evaluated, since there is no information in the literature about the influence of this factor on lipids metabolism in mollusks. After 2 and 4 weeks of exposure the snails were dissected. The cholesterol content at the 2 nd and 4 th weeks post exposure only varied significantly in the groups exposed at 24 hours and 0 hour of photophase, respectively. Probably, such increase may be a result of a rise in cholesterol biosynthesis and/or remodelling of cell membranes. There were no significant differences among the content of triglycerides in the snails exposed to 6, 12, 18 and 24 hours of photophase during two weeks. The snails exposed to intermediate photophase (6 and 12 hours) had the triglycerides content increased, ranging over values near to those observed in the group exposed to 0 hour. Results showed that triglycerides metabolism in A. fulica are more influenced by photoperiod than cholesterol metabolism. A negative relation is maintained between the triglycerides content in the hemolymph and the different photophases, with lower mobilisation of triglycerides under shorter photophases.Keywords: Achatina fulica, cholesterol, photoperiod, triglycerides, snail. Análises dos lipídeos no gigante africano Achatina fulica (Bowdich, 1822) expostos a diferentes fotoperíodos ResumoA influência de diferentes fotofases (0, 6, 12, 18 e 24 horas) sobre os conteúdos de triglicerídeos e de colesterol total na hemolinfa de A. fulica foi avaliada, uma vez que não há na literatura informações sobre a influência deste fator sobre o metabolismo de moluscos. Após 2 e 4 semanas de exposição, os moluscos foram dissecados. O conteúdo de colesterol até a 2 a e 4 a semanas pós exposição somente variou significativamente nos grupos expostos a 24 horas e 0 horas de fotofase, respectivamente. Provavelmente, tal aumento pode ser resultado de uma elevada biossíntese de colesterol e/ou remodelamento de membranas celulares. Não houve diferenças significativas entre o conteúdo de triglicerídeos nos moluscos expostos a 6, 12, 18 e 24 horas de fotofase até a segunda semana. Os moluscos expostos a fotofases intermediárias (6 e 12 horas) tiveram o conteúdo de triglicerídeos aumentados, levando seus valores próxi-mo àqueles observados para o grupo exposto a 0 hora de fotofase. Isto mostra que o metabolismo de triglicerídeos em A. fulica é mais influenciado pelo fotoperíodo do que o metabolismo de colesterol. Uma relação negativa é mantida entre o conteúdo de triglicerídeos na hemolinfa e as diferentes fotofases, com menor mobilização de triglicerídeos sob fotofases curtas.

Changes in the reproductive biology of Biomphalara glabrata infected with different doses of Echinostoma paraensei miracidia

“…However, this divergent result could have been due to the use of different doses of miracidia, because Sluiters et al (1980) and Sluiters (1981) found a negative correlation between the number of eggs laid and the miracidial dose. Besides this, the influence of various environmental factors must be considered, such as food availability, photoperiod and population density (Sandland and Minchella, 2003;Gomot, 1990;Oliveira et al, 2008;Lustrino et al, 2010).…”

Distribution of cysts of Strongyluris sp. (Nematoda) in the pallial system of Achatina fulica Bowdich, 1822 from Vila Dois Rios and Vila do Abraão, Ilha Grande, Angra dos Reis, Rio de Janeiro

“…Hemolymph in A. fulica also features high cholesterol levels, a result of the metabolism of lipids in these animals (Lustrino et al, 2010). This factor can also explain the preference of larvae allocation in the mantle organs, as for filling the cysts and folding the larvae, are necessary amounts of fat that possibly were easily acquired from hemolymph flowing in this region.…”

Management of Achatina fulica (Bowdich, 1822) (Pulmonata: Achatinidae) in lettuce (Lactuca sativa L.)

“…Changes in the metabolism of carbohydrates and protein in snails in response to parasitism, starve, population density and photoperiod were observed (LUSTRINO et al, 2010). Nevertheless, there are few studies on changes in lipid metabolism PINHEIRO, 2007).…”

“…In freshwater snail Lymnaea stagnalis, the photoperiod exerts an influence on the neuronal control of the cells of the lateral lobes of the cerebral ganglia (VAN MINNEN; REICHELT, 1980). But there is no information in the literature about the influence of this factor on the metabolism of lipids (triglycerides and cholesterol) of molluscs (LUSTRINO et al, 2010). Lipids have many functions in biological, energetic and structural systems (LUSTRINO et al, 2010).…”

“…But there is no information in the literature about the influence of this factor on the metabolism of lipids (triglycerides and cholesterol) of molluscs (LUSTRINO et al, 2010). Lipids have many functions in biological, energetic and structural systems (LUSTRINO et al, 2010). In snails, it was identified that the lipids are involved in survival in saline stress conditions, such as food restriction in long period, parasitism, depletion of carbohydrate and lipids stores, besides the different types of alterations lipids (BANDSTRA et al, 2006).…”