Attraction to amino acids by Lymnaea acuminata, the snail host of Fasciola species

Abstract

Adult Lymnaea acuminata (average length 20-22 mm) were collected locally from lakes and low-lying submerged fields from Gorakhpur. The chemoattraction studies were made in round glass aquaria measuring 30 cm in diameter and filled to a depth of 10 mm with 500 ml dechlorinated tap water. Each aquarium was divided into four concentric zones. At the starting time of the assay 10 snails were placed on the circumference of outermost zone 0. Snail attractant pellets (SAP) were added simultaneously in the center of central zone 3. SAP of different amino acids were prepared at concentrations of 10, 20, 50, 80 and 100 mM/2% agar solution and, subsequently, spread to a uniform thickness of 5 mm. After cooling, SAP were cut in small pieces of 5 mm in diameter. Lymnaea acuminata's attraction to amino acids was studied using different amino acid concentrations in SAP. Pellets containing amino acids with non-polar R groups (proline and tryptophan), a charged polar group (arginine) and uncharged polar R groups (serine, citrulline and asparagine) were tested. The snails were more attracted to the uncharged polar R group amino acid serine than to other groups of amino acids. The preferred amino acid concentration was 80 mM. The attraction of snails to different amino acids was concentration dependent. Snails could discriminate amongst the different amino acids at ≥50 mM.

Enzyme Activity in the Nervous Tissue of <i>Lymnaea Acuminata</i> Fed to Different Bait Formulations

“…Concentrations of amino acids were based on the earlier reports of Tiwari and Singh [16,17]. These solutions were spread at a uniform thickness of 5mm.…”

“…The bioassay was performed by the method by Tiwari and Singh [16,17]. The bioassay chamber consists of a clean glass aquarium having a diameter of 30 cm.…”

Bait formulations of molluscicides and their effects on biochemical changes in the ovotestis of snail Lymnaea acuminata (Mollusca; Gastropoda:Lymnaeidae)

“…Concentrations of amino acids were based on the earlier reports of TIWARI & SINGH 25,26 . These solutions were spread at a uniform thickness of 5 mm.…”

“…The bioassay was performed by the method by TIWARI & SINGH 25,26 . The bioassay chamber consists of a clean glass aquarium having a diameter of 30 cm.…”

“…It is therefore important to identify strong attractant and effective molluscicides for preparing bait formulations. Snails, like other gastropod molluscs, use chemical clues to locate food sources 2,3,6,17,25,26,27 . The freshwater snails inhabit an environment containing macrophytes algae and bacteria 23 .…”