Snail Egg clutch collection
Author Fred Lewis, PhD
Introduction
The egg clutches (masses) of Biomphalaria glabrata and Bulinus truncatus truncatus typically contain a variable number of embryos. From the time the egg clutches are deposited by the adult snails, embryos begin to emerge in about 2 weeks. Snails prefer to deposit egg clutches on any hard surface, including the shells of other snails. Plastic strips, or pieces of styrofoam, placed in an aquarium containing adult snails serve as convenient materials on which to collect and manipulate the egg clutches.
Equipment
Small spatula or flat forceps
Materials
Small, clear plastic strips or pieces of styrofoam (~100 mm x 100 mm)
Aerated “Pond H20”
Procedure
- Place the plastic strips or styrofoam on the surface of the water containing adult B. glabrata snails.
- After a few days remove the plastic/styrofoam strips.
- Gently lift the egg clutches with a small spatula, and place them in a container of aged tap water (photos – clutch 1 and clutch 2).
Follow-up comments/recommendations
Removal of egg clutches from the adult snails allows the embryos to hatch and grow unimpeded by crowding (or other effects) due to the presence of the adult snails. One can also treat the surface of the egg clutches with a sodium hypocholorite solution (1% commercial bleach in aged tap water) for 10 minutes to eliminate most contaminating commensals such as rotifers.
References
Standen, O.D. 1951. Some observations upon the maintenance of Australorbis glabratusin the laboratory. Annals of Tropical Medicine and Parasitology 45: 80-83.
Pimental, D. 1957. Life history of Australorbis glabratus, the intermediate snail host of Schistosoma mansoni in Puerto Rico. Ecology 38: 576-580.
Olivier, L. and W.T. Haskins. 1960. The effects of low concentrations of sodium pentachlorophenate on the fecundity and egg viability of Australorbis glabratus. American Journal of Tropical Medicine and Hygiene 9: 199-205.
Chernin, E. 1957. A method of securing bacteriologically sterile snails (Australorbis glabratus). Proceedings of the Society for Experimental Biology and Medicine 96: 204-210.
Nov. 2016
