The burrows ofNephrops norvegicus(L.)

Abstract

The highly fluctuating catches of Norway lobster, Nephrops norvegicus (L.), wherever it is exploited, have prompted investigators to postulate that the animal has a burrowing habit. However, no direct observations from the Norway lobster's natural habitat revealing the nature of the burrows or the categories of Norway lobsters making them, have been made so far. — Observations made by divers, combined with aquarium experiments, show that the Norway lobster digs burrows with, usually, two openings in the bottom sediment. These tunnels very often occur in groups of about 5–10, the groups generally being well separated from each other. The dimensions of the burrows are in approximate proportion to the sizes of the animals inhabiting them. Individuals of both sexes and of most size classes (including berried females and large males) are found in such burrows. The decisive factor inducing the animals to retire into and stay in their burrows seems to be light conditions but little is known of the exact way these conditions affect the Norway lobster.