Featured Content - Feb/March - 2025

The Four Nematodes: Micro Worm (MW) - Banana Worm (BW) - Walter Worm (WW) - Vinegar Eels (VE)

These four nematode worms are indispensable as first or second foods for the fry of almost all freshwater aquarium fish. They are simple to culture and maintain and all but the vinegar eels get started very quickly. The MW, BW and WW are all cultured on solid medium like oatmeal, and the VE are cultured in a jug of cider vinegar and water.

They differ mainly in terms of size, reproductive rate, and how long they stay alive in water. The differences are not visually apparent at the level of individual worms. They become apparent at the level of a whole culture.

You should always plan ahead and have cultures going before fry arrive, especially with vinegar eels that usually take four to six weeks to get going. Once a VE culture does start producing though, it can last up to a year! With little to no maintenance required, it is a good idea to just start and keep a jug or two of vinegar eels running just in case.

All four have about the same high nutritional value, a close second in many respects to newly hatched baby brine shrimp (BBS). The comparison table here below summarizes the important differences. If you are hatching really tiny fry like bettas, you want walter worms and vinegar eels. You can start larger fry that are still too small for BBS right away on banana worms or micro worms. Micro worms are also good for fry growing out and even smaller fish like neons, juvenile guppies, or badis.

Nematode Comparison Chart