"Reading in the web about European nigthcrawlers, one seller says:
Hortensis is a prolific breeder...Each worm will lay one to two capsules per week. Each capsule will hatch out between 4 and twenty worms."

Carlos, my experience with EH is limited, but here's a summary of information I gathered about Euros. My impression is that EHs can be prolific under conditions ideal for them. The 1-2 cocoon per week rate sounds right, but the 4-20 worms per cocoon sounds wrong. It's probably more like 1-2 worms per cocoon. Do the math and it still comes out to be prolific.

"The researchers found D. veneta (E. hortensis) to be a large worm with a low reproductive rate and slow maturity rate compared to Eisenia fetida."

Here you are quoting Kelly Slocum, who in turn is referring to studies by scientists who tested the composting worms for the processing of cattle manure. Those are a very different set of environmental conditions than either commercial vermicomposting or home vermicomposting bins. AFAIK, no one has done a scientific study of EH in a home worm bin. So all we can do is rely on anecdotal accounts, but it's doubtful any of the growers had the time to do a rigorous study to find how many worms hatched out of each cocoon.

If you follow the link I posted above, you'll see that I just started a Euro bin this past week. I'll be able to add my own account, but I won't be able to quantify any of it. Right now I'm assuming the truth lies between the two extremes. My first observations are that EH babies are big right out of the cocoon and grow fat very quickly. I'm feeding mainly worm chow for now and they eat that faster than EEs. Lastly, they're a beautiful worm.

Cheers,
Andrew