EFFECTS OF MAINTENANCE TEMPERATURE ON THE GLUCOSE AND MALTOSE CONTENT OF BIOMPHALARIA GLABRATA SNAILS AS DETERMINED BY HIGH PERFORMANCE THIN-LAYER CHROMATOGRAPHY-DENSITOMETRY

Abstract

High performance thin-layer chromatography-densitometry was used to determine the glucose and maltose content of the digestive-gland gonad complex (DGG) of adult Biomphalaria glabrata snails maintained at 17, 24, and 31°C as well as the whole bodies of juvenile B. glabrata snails maintained at the same temperatures. Sugars were extracted in ethanol-water (70:30) from the snails. The major sugars detected in both experimental groups were glucose and maltose. Sugars were separated on silica gel preadsorbant plates with the mobile phase 1-butanol-glacial acetic acid-diethyl ether-deionized water (27:18:5:3). The sugars were detected using an α-naphthol-sulfuric acid reagent and quantified by densitometry at 515 nm. One week after the study was initiated, adult snails maintained at 31°C had a significantly higher glucose content than those maintained at the lower temperatures. An elevated metabolic rate of the adult snails maintained at the highest temperature probably accounted in part for the high glucose content in the DGG. The juvenile snails showed considerable variation in sugar content as a result of snail maintenance at the different temperatures. Each week data were collected, there were significant differences in both the glucose and maltose content of the juveniles as a factor of temperature. This difference in sugar content in the juveniles relative to the adults as a response to temperature extremes can probably be attributed, in part, to the higher metabolic rate of juveniles compared to adult snails. Moreover, whole bodies of the juveniles were used for sugar analysis compared to only the DGG of the adult snails. Such differences in sample type could explain, in part, the difference in sugar content between the two groups as a factor of temperature.

Keywords:

• Biomphalaria glabrata
• densitometry
• DGG
• digestive-gland gonad complex
• glucose
• maltose
• sugars
• temperature
• thin layer chromatography

ACKNOWLEDGMENTS

We are grateful to Dr. Fred A. Lewis, Head, Schistosomiasis Laboratory, Biomedical Research Institute, Rockville, MD, USA, for supplying the B. glabrata snails used in this work through NIH-NIAID Contract N01-AI-55270.

Notes

^a Temp = Temperature.

^a S.E. = Standard Error.

^b There was a statistically significant difference (P < 0.05) in glucose content at week 1 in snails maintained at 31°C compared to the snails maintained at the two lower temperatures.

^c n = 2 samples; n = 3 for all other samples.

^a n = 2 samples; n = 3 for all other samples.

^a Refer to TABLE 1 for sample size.

^b There was a statistically significant difference between groups A and B (P < 0.05).

^c There was a statistically significant difference between group C and the other 2 groups (P < 0.05).

^d There was a statistically significant difference between group A and the other 2 groups (P < 0.05).