The Norway lobster, Nephrops norvegicus, also called Dublin Bay prawn, langoustine or scampi (in Italian the last is properly scampo singular, scampi plural), is a slim, orange-pink lobster which grows up to 24 cm long (9-10 in). It is found in the north-eastern Atlantic Ocean and North Sea as far north as Iceland and northern Norway, and south to Portugal. It is not common in the Mediterranean Sea except in the Adriatic Sea, notably the north Adriatic.

Habitat requirements

It is a preference of Nephrops to inhabit muddy seabed sediments, with > 40% being of silt and clay.

Nephrops burrows are of semi-permanent nature, and vary in structure and size. Typical burrows are 20 cm to 30 cm deep, with a distance of 50 cm to 80 cm between the front and back entrances. Nephrops spend most of their time either lying in their burrows, or by the entrance. They only leave their shelters to forage or mate.

Reproduction

The reproductive cycle of Nephrops varies depending on geographical position - "The periods of hatching and spawning, and the length of the incubation period, vary with latitude and the breeding cycle changes from annual to biennial as one moves from south to north".

Incubation of eggs is temperature-dependent, and in colder climates, the duration of the incubation period increases. This means that, by the time the hatching occurs, it is too late for the females to take part in that year’s breeding cycle.

In warmer climates, the combined effects of recovery from moulting and ovary maturation mean that spawning can become delayed. This, in turn, has the effect of the female missing out a year of egg carrying.

Adult male Nephrops moult once or twice a year (usually in late winter or spring) and adult females moult up to once a year (in late winter or spring, after hatching of the eggs). In annual breeding cycles, mating takes place in the spring or winter, when the females are in the soft, post-moult state. The ovaries mature throughout the summer and spring months, and egg-laying takes place in early autumn or late summer. After spawning, the buried females return to their burrows and remain there until the end of the incubation period. Hatching takes place in early spring or late winter. Soon after hatching, the females moult and mate again, resuming the cycle.

Food and feeding

Nephrops is a scavenger and predator, who makes short foraging excursions mainly during periods of subdued light. They capture active prey with chelipeds and walking legs, and food is conveyed to the mouth using the anterior walking legs, assisted by the maxillipeds. Nephrops are solitary predators, feeding on other animals such as worms and fish.

In December 1995, the commensal Symbion pandora was discovered attached to the mouthparts of a Norway lobster, and was found to be the first member of a new phylum, the Cycliophora.

As food

The tail is muscular and is frequently eaten under the name "scampi". Norway lobster is eaten on special occasions in Spain and Portugal, where it is less expensive than the European lobster. Usual in paellas. The Norway lobster is an important species for fisheries, being caught mostly by trawling. Around 60,000 tonnes are caught annually, half of it in the United Kingdom's waters.

Discards from Nephrops fishery may account for up to 37% of the energy requirements of certain marine scavengers, such as the hagfish Myxine glutinosa. Boats involved in Nephrops fishery also catch a number of fish species such as plaice and sole, and it is thought that without that revenue, Nephrops fishery would be economically unviable.

Gallery

Image:Shrimp in scotland.jpg|Freshly caught Norway lobsters in ScotlandImage:Nephrops norvegicus (cooked tails).jpg|Steamed Norway lobsters tailsImage:GrilledShrimp.jpg|Grilled Norway lobstersImage:Cañas-Madrid-2009.jpg|Steamed in Madrid (tapas)

References

1. Phillips, B. (ed) (2006)Lobsters, Biology, Management, Aquaculture and Fisheries
2. Dybern, B.I. & Hoisaeter, T. (1965) The burrows of Nephrops Norvegicus, Sarsia
3. Bailey, N. (1984) Some Aspects of Reproduction in Nephrops
4. Farmer, A.S.D. (1975) Synopsis of data on the Norway lobster Nephrops Norvegicus FAO Fisheries Synopsis
5. Thomas, H.J. & Davidson, C. (1962) The food of the Norway lobester Nephrops norvegicus, Marine Research
6. Chapman, C.J. & Rice, A.L. (1971) Some direct observations on the ecology and behaviour of the Norway Lobster Nephrops norvegicus using different methods, Marine Biology
7. Chapman, C.J., Johnstone, A.D.F. & Rice, A.L. (1975) The behaviour and ecology of the Norway lobster, Nephrops norvegicus In H. Barnes (Ed.) Proceedings of the 9th European Marine Biological Symposium