Animal care

• Each Helobdella species has its own optimal culture condition. Described below is a general culture condition for H. austinensis and is perhaps applicable to all species in the H. triserialis-robusta-europaea complex.
• 2-liter pyrex bowl is used as a standard container each holds up to ~200 individuals. Keep the animals at room temperature (20-28°C) and under shade. Direct light exposure does not kill the leech, although the leech seems happier in a shaded environment. For an extended period of nonattendance, animals can be kept at 15°C for up to 2 weeks (with some loss).
• Artificial pond water (1-2% of reconstituted Instant Ocean stock; stock = 32 g/L Instant Ocean salt in distilled water) is replaced daily.
• Feed the leech at least 3-4 times a week with frozen bloodworms (larvae of chironomid midge) and/or living physid or planorbid pond snails.
• For bloodworm feeding, change water and remove food materials after 2-3 hours. The leeches should have finished their dinner by then.
• Snails can be left with the leeches until the decomposing carcasses begin to foul the water (~2 hours for physids and overnight for planorbids).
• A mixed diet is OK (might be beneficial).
• Rub the leech bowl once a week to scrub off the slime on the wall. Change the bowl every 1-2 months (depending on how bad the slime builds up).
• Chemicals, soap, skin lotion, perfume and cigarette stain are strictly forbidden on the leech-contacting surface (such as your hands and the container) and liquid. If you are not sure whether it is safe with your bare hand, please wear gloves while handling the leeches.
• Pathogens such as bacteria, fungi and protozoans come along with bloodworms and snail may be detrimental to the health of the lab leech population. However, leech does not take cooked food, and sterilization by heating is impossible. One way to manage pathogen contamination is to expose the food materials to UV-C irradiation before feeding. It is also a good practice to keep several completely separated stocks of leeches.

Additional Readings

Shankland, M., Bissen, S.T., Weisblat, D.A., 1992. Description of the Californian leech Helobdella robusta sp. nov. and comparison with Helobdella triserialis on the basis of morphology, embryology and experimental breeding. Can. J. Zool. 70, 1258-1263.

Kutschera, U., Langguth, H., Kuo, D.-H., Weisblat, D.A., Shankland, M., 2013. Description of a new leech species from North America, Helobdella austinensis n. sp. (Hirudinea: Glossiphoniidae), with observations on its feeding behaviour. Zoosyst. Evol. 89, 239-246.

Kutschera, U., Weisblat, D.A., 2015. Leeches of the genus Helobdella as model organisms for Evo-Devo studies. Theor. Biosci. 134, 93-104.

Weisblat, D.A., Kuo, D.-H., 2009. Handling of Helobdella (leech) embryos. Cold Spring Harb. Protoc. 2009, doi:10.1101/pdb.prot5189.