I hope it is successful!
Regarding crossbreeds, my main question is why haven't snail farms opted for this? They tend to keep breeders separate to the ones that get sold so you would think they would want the robustness and growth rate of aspersa but with the size and taste of pomatia seeing as they are considered more desirable. Perhaps the issue is reliability.
Anyway, I've been thinking about a way for us to try and test this crossbreeding theory so I'd like all your opinions and suggestions and level of interest.
I was reading about what defines a species, for example:
research.amnh.org/ornithology/crossbills/species.htmlIt is all based on species being reproductively isolated from each other. That doesn't mean they can't crossbreed but in most cases the babies will be infertile; this is the mechanism that stops the merging of two distinct species. In some cases this can happen such as in the case of coyotes and wolves, where some coyotes now have stable wolf genes and vice-versa.
It seems to me that snails will be more likely to create fertile crossbred offspring than mammals, with them being so prolific, so I've been devising a simple experiment we can conduct to answer a few fairly elementary questions for snails:
1. Can similar species crossbreed successfully?
2. Are the resultant offspring fertile?
3. Which pairing provides success, CROSSBREED x CROSSBREED or CROSSBREED x ORIGINAL?
4, Is it possible to breed one species' genes into another species?
I was gonna suggest aspersa because they are so readily available though they may not be compatible with other Helix snails seeing as they as classed in some places (CLECOM) as not Helix snails. Anyway, here is the idea. In this example I will use aspersa and pomatia but pomatia and lucorum are equally viable.
Stage 1We take one baby of both species and confine them together. They will stay with each other indefinitely and it is important that they never come into contact with members of their own species, or other snails for that matter. It is also vitally important we start with babies to ensure there has been no previous mating. The idea is to get quite a few people with this set up so we have plenty available for study and to help ensure more success.
Assuming stage 1 results in viable eggs we move on to Stage 2
Stage 2If stage 1 has been successful the resulting offspring should be either:
A. All very similar obvious crossbreeds.
B. A varying level of crossbreed, some looking more like one parent, some more like the other and some inbetween.
Scenario A is more desirable because it gives us a simpler experiment and is easier to standardise. Scenario B on the other hand merits a more complex experiment as the disparity shows that the sexual compatibility and viability could vary greatly from one individual to the next. If this case, the later stages of the experiment would need to be revised to allow a wider selection of pairings to assess this.
For now we will assume Scenario A is likely and revise should the results be suited to Scenario B.
So, at this point we should have the following babies available; pomatia, apsersa and the resulting crossbreeds. We organise them into new groups:
1 Helix pomatia + 1 apsersa/pomatia crossbreed
1 Helix aspersa + 1 apsersa/pomatia crossbreed
2 apsersa/pomatia crossbreeds.
These will be kept in the same way as snails from Stage 1 until viable eggs are hatched.
The resulting offspring should tell us if crossbreeds can breed and if they can breed back into the original population. It is to be assumed that if a 50/50 crossbreed can breed successfully a 75/25 crossbreed can also. By comparing the characteristics of each group of offspring at each step it should be possible to assess the likelihood of stabilising one species' genes back into the others if throwbacks occur after reintegration back into the parent population.
Requirements to take partEach person taking part would need a tank about 20x15x15 cm. minimum so a large tupperware tub is ideal. This is large enough for two 5 cm. snails to live happily. Both stages are to be looked at as handing over points for those who do not wish to continue, although it is likely that stage2 will need a lot more people than stage 1. The ideal solution is for a large group of people to take part and look after 1 or 2 groups each. The offpsring can be sent to a few people when extra analysis is required. The bulk of the experiment is the extra tank and time needed to conduct it.
I currently have about 30 Helix pomatia eggs and I'm sure I will get more. Aspersa are also readily available and both species come with the advantage of us being able to return any excess offspring to the wild in countries where they are native. That said, if there is a compatibility issue with apsersa and pomatia, and it seems more likely that lucorum will crossbreed with pomatia, we do have European members who could take the offpsring to return to their native country. Ideally, if enough people are willing to take part we could arrange to try all 3 species and the various permutations that will allow.
It could be done with Achatinids but with them being large combined with us not being able to release excess offspring to the wild, smaller European snails will be much more convenient.
The only real stumbling block is identifying cases of self-fertilisation although while it is accepted that for some species it is possible it is now regarded as rare after the discovery of how long they can store sperm. It now seems likely that Hodasi who commented on how commonly tiger snails self-fertilise was duped by this. I've never been clear on this but that recent S. African book raised the same question. The British ID book by Robert Cameron suggests some species can do it. I'm hoping self-fertilised batches will be obvious as they grow and can be released.
What do you reckon? If we do it, we can calculate the numbers of snails and pairings involved to see how many people we would need and a rough time frame.
