MATERIALS
- Proper PPE: disposable gloves and lab coat (face shield may also be necessary).
Patent B.truncatus are cercariae positive and at biosafety level 2 status (BSL-2). Cercariae can penetrate exposed skin and therefore, protocols for handling positive snails require personal protective equipment. Please check with your institute’s Biosafety Officer for a current protocol. - Featherweight forceps
- 250mL glass beakers
- Artificial Pond Water (water). See APW recipe on the BRI website. Commercial spring water can be substituted (e.g., Poland Spring or Deer Park)
Featherweight forceps
METHODS
- Remove B. truncatus from the aquaria using featherweight forceps. Using a deck sprayer, gently rinse the snails with water to remove debris and commensals.
- Place the B. truncatus in the beaker. <40 snails per beaker is a good density.
- Keep snails dry for 1 hour under ambient light.
- Add water to the beaker, enough to cover the snails. Leave for 1-2 hours under direct light. Check the beaker every 20—30 min for cercariae activity. Pour the contents of the beakers into one bigger container. Repeat this step until enough cercariae have been collected.
- Collect cercariae with a glass pipet.
- If more cercariae are required, the snails can be left under the light longer.
- After “shedding” the cercariae, the snails can be returned to their housing and maintained in the dark.
NOTES
- The optimal timepoint for collecting cercariae from infected B. truncatus is 5-6 weeks following exposure to miracidia.
- Avoid changing the housing or water of the patent B. truncatus less than 4 days prior to shedding
- A minimum of 50 patent B. truncatus will provide a mix of male and female cercariae. >100
snails are desirable to ensure a ratio of male: female cercariae that will promote a higher percentage of pairing, and thus, female egg production - The light source can be LED or fluorescent lighting
