The European Nightcrawler is a larger cousin of the Red Worm, and while certainly useful as a composting worm, is widely known for its potential as a bait worm.
Not only is it the perfect size – larger than a Red Worm, and smaller than a Canadian Nightcrawler (Lumbricus terrestris) – but it is also very durable, and tolerant of a wide range of conditions. I’ve read that these worms can even be used successfully in brackish waters and for ice fishing!
Unlike Canadian Nightcrawlers (also known as ‘Dew Worms’), this species also does not need to be refrigerated during storage – although doing so may help to increase their shelf life even longer since it slows down their metabolism.
Research seems to indicate that European Nightcrawlers aren’t as prolific in the breeding department as Red Worms, nor are they as effective when it comes to processing organic wastes. Many worm farmers disagree – some indeed consider the Euro to be the “perfect” worm.