How do I care for the Pea clam Sphaerium corneum?

[Simon Cole]

I was just about to set-up a tank for culturing the blackworm Lumbriculus variegatus - and it has occurred to me that I might consider bivalves.
The conditions will be a very good match for bivalve filter-feeders.

If I did keep the two together then what springs to mind is:
1. Whether the clams might suck-in the blackworm for food?
2. Might I expect them to opportunistically eat the boiled vegetables that I feed the blackworm?

Assuming I just kept the bivalves on their own, I was thinking of a spirulina, pollen, powder-food type recipe. Does anybody know of a recipe?
3. What are their dietary requirements, like, are they going after algae, plant debris, micro-fauna?

Thank you, Simon

 

[Dr. White]

I don't have experience of keeping Sphaerium, but I take invert samples all over the country in ponds, lakes and all types of river. Pea mussels are almost exclusively found in fine silt, so for the best results you'd probably want to replicate that. I'd be interested to hear how you get on.

 

[Simon Cole]

@Dr. White Thank you. I was chatting with Lucas from LBR Aquatics yesterday and he just happened to be looking more closely at their filtration benefits. He mentioned milk, but I seem to recall that it drastically raises the BOD. The good news is that they really do not seem to require especially basic water; I was looking at the NBN records for north Wales, and indeed they are in the streams and rivers surrounding Snowdon, which surprised me; the UK-endemic River nerite does not share the same extensive habitat range. Breeding also looks, well, rather easy I should expect.

They are coming at a good price from a licensed supplier, so if anybody fancies some... shout me up. It would be fantastic to share the adventure. I suspect that they could be almost the perfect companion for Californian blackworms, feeding from proteins released from their slime perhaps.

 

[Simon Cole]

Will what I choose to feed the clams contain too many toxins? I am mindful that spirulina has more copper and sodium than chlorella, and something does make me wonder about lead and mercury.
Spirulina vs Chlorella:

Pollen seems to be a big winner in terms of proteins, carbohydrates and sugars, vitamins, not to mention all the other wonderful biological molecules., but here is the minerals <info>, which could be more relevant to toxicity depending upon which green powder I end-up choosing:

Any thoughts most welcome? Should I just go ahead and buy all three feeds? Other suggestions?
My current thinking is a chlorella-pollen mix, but then what about the vitamin K (absent but found in spirulina)?

Edit: I have just ordered ingredients, for this recipe: 1 part pollen, 1 part kale powder, 3 parts chlorella powder. It would seem that kale is packed with vitamin K, whereas the other two have none.​

I discounted weightlifting proteins (a.k.a. badger milk), stuff like that would cloud the water.​

 

[Simon Cole]

With relation to diet and breeding... I have found a great <document> and it makes a few interesting points:

"Sphaerium corneum is mainly a filter feeder but can also deposit feed. It prefers diatoms but also ingests other types of phytoplankton. Sphaerium corneum is capable of climbing up aquatic macrophytes, which aids it to filter feed."​

"S. corneum is hermaphroditic and ovoviviparous. Eggs incubated in a brood-sac in the parent; embryos develop and are released as miniature adults. Sexually mature adults can carry 1–20 embryos, occasionally more. Parturition in the St. Lawrence River usually occurs in the spring." ​

There seem to be a few <instances> where it does quite well on gravel (picture below), so it looks like I can probably keep the adults in fine pea gravel for now. I will set up a duel experiment with something like sand or clay substrate in a couple of months time. But overall, breeding sounds a lot more feasible because they are ovoviviparous (give birth to live young) and not subject to getting sucked into filters.
I think the photograph below possibly shows spawning activity (sperm exchange) over gravel.

 

[Dr. White]

Nice to see a pea mussel more than just a shell. I love the translucence of their foot, it's almost cnidarian.