EFFECTS OF INCREASED SALINITY ON GLUCOSE AND MALTOSE COMPOSITION OF BIOMPHALARIA GLABRATA SNAILS AS DETERMINED BY HIGH PERFORMANCE THIN-LAYER CHROMATOGRAPHY-DENSITOMETRY

Abstract

High performance thin-layer chromatography was used to analyze the glucose and maltose concentrations of the digestive gland-gonad complex of mature adult uninfected Biomphalaria glabrata snails maintained in laboratory cultures containing various dilutions of artificial ocean water (AOW) as well as the whole bodies of young adult B. glabrata snails maintained in laboratory cultures at the same dilutions of AOW for up to 4 weeks. Controls for both groups consisted of snails of the same size maintained identically in deionized water and artificial spring water. Sugars were extracted from the snails in ethanol-water (70:30). Random samples from both experimental groups were tested to detect the presence of different types of carbohydrates; the major sugars detected in the snails were glucose and maltose. These sugars were separated on EMD Millipore silica gel preadsorbent plates with mobile phase 1-butanol-glacial acetic acid-diethyl ether-deionized water (27:18:5:3), detected using α -naphthol-sulfuric acid reagent, and quantified by densitometry with a CAMAG TLC Scanner 3 at 515 nm. The mature adult snails showed high survival rates in most salinities, and only in 25% salinity was the survival lower than in the other cultures. In the experimental group of young adult snails, the survival was lower, especially in 25% salinity where only 40% of the snails survived up to 4 weeks. No significant statistical differences in the carbohydrate composition as a function of salinity were found in either of the two experimental groups.

Keywords:

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

ACKNOWLEDGMENT

We thank Dr. Fred A Lewis, Head, Schistosomiasis Laboratory, Biomedical Research Institute, Rockville, Maryland, USA, for supplying the B. glabarta snails used in this work through NIH–NIAID Contract NO1-AI-55270. We thank Dr. Charles Holiday for assistance in using the osmometer. Nevena Popovic was supported by a Camille and Henry Dreyfus Foundation Senior Scientist Mentor Program award to Professor Joseph Sherma and the Lafayette College EXCEL Scholars Program. The authors thank David Lentz of EMD Millipore for providing the HPTLC plates.

Notes

^a SD, Standard deviation.

^b Percent salinity.