Please download and read the general MacLab guidelines thoroughly and make sure that they are followed when attempting to culture Macrostomum.
Avoiding inbreeding and minimising selection
In order to avoid inbreeding, we keep our Macrostomum cultures in populations started each generation with approximatedly 100 individuals. We try to minimise selection by allowing the worms to reproduce for some time before starting a new generation (so we avoid selecting for early reproduction), and then choosing the offspring by picking them individually from all parts of the dish (and thus avoiding selection for e.g. phototacticity)
Food
When collecting specimens in the field, the gut contents should be determined (this is particularly easy with small, transparent species). The species we keep at the moment (see table below) mainly eat diatoms, and we feed them with Nitzschia curvilineata. Predacious species should be preferably fed with preys similar to the natural ones. Alternatives like liver are also used.
Journaling
Keeping a record of the origin (location and date), regime (transfer rate, light and temperature conditions, etc), and state (population size, general age structure, diseases) of the cultures will allow not only an optimization of the procedures by the culturing lab, but also other labs to start culturing the same or similar species with relative ease.
Cleaning of cultures
Macrostomum cultures contain a variety of unicellular species -beside algae. In some cases, these creatures compromise our cultures and experiments. One example are thraustochytrids, a species of which parasitizes -at least- M. lignano (see pdf). Cultures have been successfully cleaned of thraustochytrids by reducing salinity (pdf soon) or by treating eggs with Triton (pdf). Keep a vigilant eye over your cultures, thraustochytrids can be devastating!
| line | species | salinity | transfer rate |
| LS1 | Macrostomum lignano | 32‰ | 4 weeks |
| Origin of our cultures The LS1 culture (also known as EEE and outbred culture) stems from worms from different locations which were pooled together in 2004, and since then kept in a metapopulation of 6 paired populations. We no longer keep older cultures of M. lignano. Before we had worms collected in 2003, in two locations in the Adriatic Sea, Isola di Martignano and Bibione, near Lignano Sabbiadoro (Italy). Within each location, three sites were sampled. From each sample, different replicates were produced in the lab and kept as independent populations. Another culture originated from worms collected in 2006, at the southern Pump Station in the Laguna di Marano (also near Lignano Sabbiadoro), and again in Bibione. Proceedings The worms are kept in f/2 to allow for the growth of algae, at 20° C, with a 12:8 light:dark cycle. Each four weeks (the worms have a generation time of about 18 days), a new generation is founded. To do so, at least 100 hatchlings or juveniles are pipetted into a small petri dish with ASW, in order to wash them. After 2-3 hours, 100 worms are transferred to fresh glass petri dishes with algae and fresh medium. The dishes with the parents are kept as a back-up, and the present back-up (with the grand-parents) is discarded. |
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| line | species | salinity | transfer rate |
| Macrostomum pusillum |
32‰ | 4 weeks | |
| Origin of our cultures Worms were collected in 2006 at the Pump Station in the Laguna di Marano, near Lignano Sabbiadoro, in different sites. Lines from several of those sites have since been kept independently. Proceedings (same as for M. lignano) The worms are kept in f/2 to allow for the growth of algae. Each four weeks (the worms have a generation time of about 18 days), a new generation is founded. To do so, at least 100 hatchlings or juveniles are pipetted into a small petri dish with ASW, in order to wash them. After 2-3 hours, 100 worms are transferred to fresh glass petri dishes with algae and fresh medium. The dishes with the parents are kept as a back-up, and the present back-up (with the grand-parents) is discarded. |
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| line | species | salinity | transfer rate |
| Macrostomum spirale |
6‰ | 5 weeks | |
| Origin of our cultures Worms were collected in 2004 at the Etang de Biguglia, near Bastia, Corsica (France) Proceedings The worms are kept in ASW (but would probably also do well in f/2). Each five weeks (the worms have a generation time of about 24 days), a new generation is founded. To do so, more than 100 hatchlings or juveniles are pipetted into a small petri dish with ASW, in order to wash them. After 2-3 hours, 100 worms are transferred to fresh glass petri dishes with algae and fresh medium. The dishes with the parents are kept as a back-up, and the present back-up (with the grand-parents) is discarded. The cultures are monitored in a log, recording how the algae, the medium, and the worms look, as well as a rough estimate of the quantities of adults and hatchling, and the number of worms used as founders of the next generation. |
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| line | species | salinity | transfer rate |
| SR1 | Macrostomum hystrix |
6‰ | 3-4 weeks |
| Origin of our cultures Worms were collected in 2010 in a brackish pond in San Rossore, near Pisa, Italy Proceedings The worms are kept in 6‰ ASW (but would probably also do well in f/2). The actual proceedings are still being developed, but will likely resemble those of M. lignano |
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