Norway lobster

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Norway lobster
Langoustine Nephrops norvegicus 07062010 2.jpg

Norway lobster ( Nephrops norvegicus )

Systematics
Order : Decapods (decapoda)
Subordination : Pleocyemata
Partial order : Large crayfish (Astacidea)
Family : Lobster-like (Nephropidae)
Genre : Nephrops
Type : Norway lobster
Scientific name of the  genus
Nephrops
Leach , 1814
Scientific name of the  species
Nephrops norvegicus
( Linnaeus , 1758)

The Norway lobster ( Nephrops norvegicus ), also langoustine or scampi called, is one in the continental shelf of the North-East Atlantic , the Mediterranean and the North Sea live local crayfish . He has a lobster-like build and can reach overall lengths of over 20 centimeters and an age of more than 10 years. Norway lobsters are mostly found in self-dug caves at a depth of 20 to 800 meters, which they leave only for reproduction and usually once a day to forage. In their entire range, they are mostly fished with bottom trawls, because their abdomen is a delicacy in particular . Despite this intensive fishing, the Norway lobster is not endangered according to species protection criteria, although some stocks are overfished.

features

Adultus

Norway lobsters have an elongated body that is typical of lobster-like species , which is divided into cephalothorax and abdomen . The cephalothorax is covered by the so-called carapace , which ends in a rostrum at the front . They are smaller and slimmer than lobsters , but have longer claws relative to their height. They have a light to reddish orange color. The first three pairs of striding legs are chelated , so they have scissors, with those of the first being very large and unequal.

Carapace

Side view of the Norway lobster
Dorsal view of the anterior carapace with rostrum, eyes

The anterior process of the carapace, the rostrum, has lateral and an abdominal tooth. There is a tubercle just behind the rostrum . Starting from this, a median ridge runs over the entire length of the carapace, which has two rows of granules and is only interrupted by a transverse furrow (postcervical groove). Two ridges running to the side of this median ridge are provided with small points, which are particularly evident in the middle of the ridges. Two spines just behind the eyes are well defined, but not very large. They are followed by further spines running backwards in a row, which are not on a ridge like other lobster-like species. Two more spines below the row of spines are well defined.

On the anterior part of the carapace there are some distinct furrows (postcervical, hepatic, cervical, antennal groove); an approximately central, transverse groove (intercervical groove) is only visible in its rear area. Shortly behind the transverse depression there are four spikes, but no more. On the rear area of ​​the carapace, two longitudinal ridges are clearly pronounced, while the lateral ridge located approximately in the middle is missing (branchial carina).

Abdomen and telson

Dorsal view of the uropods and telsons

The individual tergites of the abdomen show a pattern of transverse and longitudinal ridges and depressions. The latter are relatively wide and have short hairs. A median ridge is present on the second through sixth abdominal segments. A wide ridge separates the tergites from the pleura . The sixth abdominal segment has no spines.

The telson is trapezoidal and becomes narrower towards the rear. The rear edge is arched outward and the back and side spines are well defined. There are no peaks on the two diverging ridges on the upper side of the Telson.

Eyes and antennae

The eyes are fully developed, relatively large, and kidney-shaped. The first segment of the antenna tubes is comparatively long. The stylocerite is clearly visible as a large club. The base of the antennae (antennal peduncle) carries a long thorn, roughly at the base of the exopodites of the antennae (scaphocerite). The latter are well developed, relatively narrow, with a convex inner edge.

Limbs

"Scissors" of the Norway lobster

The exopodite of the second pair of maxillipeds is a multi-segmented flagellum . On the third pair of maxillipedes, there are no tips or teeth on the carpus and merus.

The large scissors on the first pair of striding legs are unequal. One has some large, round teeth and a few small teeth; they are called K or crack scissors. It can no longer be completely closed, especially with larger animals. The other scissors always close and have a few smaller teeth and are therefore called tooth or Z scissors, as with the lobster. Some specimens have the Z scissors on the left, some on the right. The segments of the first pair of legs have long, clearly visible ridges with strong thorns. On the small scissors of the second and third pair of legs there are hair fringes at the top and bottom.

The first pair of pleopods in males is hardened and consists of two immobile segments. The appendices masculina on the second pair of legs are elongated and more than half as long as the endopodites. The uropods have one ridge on the endopodite and two on the exopodite. The diaeresis of the exopodites is very clear and has a few teeth on its front edges.

larva

Norway lobsters go through three larval stages. They hatch as Zoealarve and are about 6.5 millimeters long in their first stage. The walking legs are present with their respective exopodites, and there are already scissors on the first three pairs of legs. The segments of the abdomen each have a conspicuous spine, the last abdominal segment has a paired spine. The telson consists of two long, serrated thorns. The second stage of zoeal larvae, at which the Norway lobster show pleopods for the first time, is reached by moulting. They are then about 8 millimeters long. In the third larval stage, the uropods are also developed, the body length is about 10 millimeters.

ecology

distribution and habitat

Norway lobster in a cave, image from the Monaco Oceanographic Museum

The Norway lobster is common in the eastern North Atlantic, in the North Sea and in the western and central Mediterranean. It lives there on the continental shelf or continental slope at depths of 20 to 800 meters. Its distribution area in the Atlantic extends in the north from Iceland and Norway, for example, from the Lofoten to Morocco in the south. In the Mediterranean, the distribution extends to around 25 ° E. The Norway lobster is therefore not native to the Levantic Sea, the Baltic Sea, the Baltic Sea, the Black Sea or the Bosporus. The occurrence of the Norway lobster is strictly linked to the nature of the seabed, which is why its range is discontinuous. At least 30 separate populations are known to exist in European waters. The population of Norway lobster is considered stable. In the IUCN Red List it is therefore classified as not at risk (“least concern”).

Norway lobsters live on a rather muddy seabed, which consists of over 40% clay and silt . He digs caves that he uses as a hiding place. Cave passages extend 20 to 30 centimeters below the ground surface. These caves are mostly U-shaped, with a main entrance and a narrower, second entrance. The tunnel between the entrances can reach lengths of 50 to 80 centimeters. Caves with only one entrance, as well as complex cave systems with several entrances and vertical shafts are observed less often. The number of caves ranges from 0.1 to 1.6 per square meter. This density seems to depend on the grain size distribution of the soil. For example, in Scottish waters with very fine soils, i.e. with a low proportion of sand, lower population densities were found.

Reproduction

Female with eggs

Females of the Norway lobster become sexually mature between 2 and 3.5 years of age . Depending on age and geographical location, they then have a carapace length of 21 to 36 millimeters. Males are 3 years old at sexual maturity and their carapace is between 24 and 27 millimeters.

Mating takes place in winter or spring shortly after the female has molt. The fertilization of the eggs as well as the spawning take place in late summer to autumn. The number of eggs a female can spawn depends on her size. With a carapace of 25 millimeters, the number of eggs is 600 to 1200; With a carapace of 45 millimeters, up to 4800 oocytes can be counted. The volume of an egg, which is around 1.5 cubic millimeters, does not depend on body size. The female attaches the fertilized eggs to her pleopods . From this point onwards, an egg-bearing female will no longer leave her cave. The duration of the incubation, i.e. the time between the eggs spawning and the larvae hatch, is heavily dependent on the water temperature. It is about 5.5 months at 15 ° C and 10 months at 8 ° C. Females in northern waters near Iceland and Norway therefore spawn only every two years, while annual spawning can be observed in the rest of the range. With increasing age of the female it can happen that it spawns only every two years, even in the southern distribution area. The color of the eggs is initially dark green, becomes lighter over time and is brownish-pink shortly before hatching. During incubation, up to 75% of the eggs can be lost due to predation, cannibalism, incomplete embryonic development, and insufficient adhesion to the pleopods. The larvae hatch in late winter to early spring, after which the female sheds its skin and mating can take place again.

The freshly hatched zoo larvae are about 6.5 millimeters long. In contrast to adults, they are free swimming and therefore part of the plankton. Young Norway lobsters go through three larval stages before they change to a benthic way of life as post larvae with a body length of around 16 millimeters . The duration of the planktonic phase depends on the temperature and can range from three weeks at 15 ° C to seven weeks at 8 ° C. During their first year of life, Norway lobsters rarely leave their burrows.

growth

As with all decapods, an increase in size occurs through moulting . The moulting frequency decreases with age. Annual Norway lobsters, for example, shed their skin once a month, while in the second and third year of life only three to four molts per year occur. With sexual maturity, the molting frequency decreases further to once or twice a year for males and zero to once a year for females. Because of this, the largest Norway lobsters are mostly male. Terminal anecdysis, a stage in which moulting no longer takes place, is not known. In the laboratory, the moulting took 20 to 30 minutes. The exoskeleton is completely hardened about two weeks after moulting.

The increase in length per molt is absolutely 1 to 2.5 millimeters carapace length. This corresponds to a relative growth of 3 to 12%. However, significant deviations from these values ​​are not atypical. In addition, growth rates can differ significantly between individual populations. These cannot be explained simply because several factors such as temperature, grain size distribution of the sediments, food availability, population density and fishing could have an influence on growth.

Norway lobster can reach an age of 10 years, an age of up to 15 years seems to be possible. Maximum body lengths are probably 25 centimeters and therefore the maximum carapace lengths are 80 millimeters. As a rule, they are smaller, with body lengths of 18 to 20 centimeters and carapace lengths of up to 60 millimeters.

Behavior and migration

Norway lobsters live as solitary animals and stay mainly in their caves. These are usually only left very briefly for foraging or reproduction. The changing of as well as fighting for caves was observed. Ritualized battles also take place to establish a hierarchy between individuals. Fights always contain threatening gestures, in which the large scissors are spread horizontally and a very upright posture is assumed. Combatants use the scissors to try to hit and push the opponent as well as to grab limbs. In the laboratory, such fights usually lasted no more than a minute, and none of the observed fights resulted in injuries. In the case of Norway lobsters, the order of precedence is maintained through urine excretion. It is possible that the animals recognize themselves by the smell of urine or that it can convey their social status.

The daily leaving of the cave depends on the populated sea depth. In rather shallow waters up to a depth of 40 meters, Norway lobsters usually only leave their cave once a night. At medium depths between 40 and 100 meters, caves are usually left twice, at sunrise and sunset. At greater depths, Norway lobsters usually leave their burrows once a day. The reasons for this behavior are not fully understood. In addition to exogenous influences such as the availability of light, endogenous factors, such as individual activity rhythms, are suspected in the Norway lobsters.

Norway lobsters tend to be sedentary. They do not migrate more than a few hundred meters, so that there is no genetic exchange between individual populations. This is only conceivable during their planktonic larval stage, when greater distances can be overcome.

nutrition

The Norway lobster is an opportunistic predator and scavenger . The composition of the food depends primarily on the availability of the prey and not on dietary preferences, which is why there may be differences in diet between populations of Norway lobster. The main part of the diet is made up of crustaceans, polystyrene , molluscs and, to a lesser extent, echinoderms . Norway lobsters are also filter feeders and are therefore able to filter detritus or plankton from the water and use them as food. This could be an important contribution to the diet of egg-bearing females who do not leave their den for months. Cannibalism is not uncommon.

It is also not uncommon to find grains of sand or mud in the digestive tract. An examination of the stomach contents of Norway lobster on the west coast of Scotland, on the Firth of Clyde , found plastic, mostly in the form of threads, in 83% of the caught specimens. These could have been recorded with sediments or with prey. Norway lobsters have also been observed picking up stones and using the maxillipedas to move them in front of the mandibles and maxillae . In addition, filtering the water could help absorb plastic. According to the study, at least some of the plastic threads can accumulate in the digestive tract because they cannot be excreted.

Predators

Most important predator of the Norway lobster in the Atlantic: Cod

Norway lobsters are prey of some species. In the Atlantic and North Sea, the most important predator by far is the cod ( Gadus morhua ). Thornback ray ( Raja clavata ), lesser spotted dogfish ( Scyliorhinus canicula ), American plaice ( Hippoglossoides platessoides ), Blackmouth dogfish ( Galeus melastomus ) Fourbeard Rockling ( Enchelyopus cimbrius ), dog tongue ( Glyptocephalus cynoglossus ) and haddock ( Melanogrammus aeglefinus ) are also known predators of the emperor garnet. The knowledge of predators in the Mediterranean is somewhat poorer. Customers, including anglers fish of the genus Lophius , some elasmobranchii (Elasmobranchii), the hake ( Merluccius merluccius ), gurnard ( Trigla spp.), Scorpionfish ( Scorpaena spp.) And small cod , such as the poor cod ( Trisopterus minutus ).

Parasites and diseases

Compared to other decapods, only a few ectoparasites of the Norway lobster are known. One of them is the Symbion pandora , a species of the Cycliophora found on the mouthparts of Norway lobsters from the Kattegat . The barnacles Balanus crenatus is known to affect the exoskeleton and is mostly found on older specimens. The foraminifera genus Cyclogyra was also found on pleopods . Kaisergrante also have hardly any symptoms of shell disease , a degeneration of the exoskeleton in decapods caused by bacteria. Only about 1% of the examined individuals in Italian fish markets showed the typical lesions. Brownish necroses could, however, be observed on the edges of injuries, which were probably caused by chitin-degrading bacteria.

A systemic infection may by ciliates of the genera Mesanophrys or Orchitophyra done. The digestive tract of Norway lobsters can be infested with the gregarine species Porospora nephropis and one stage of the sucking worm, Stichocotyle nephropis . Histriobdella homari , a multi- bristle of the Eunicida , is rarely observed in the respiratory chambers of the host animals.

Species of the genus Hematodinium of the dinoflagellates can attack Norway lobsters, which then show abnormally lethargic behavior and an opaque, yellowish-orange color and milky-white hemolymph . The prevalence of the infestation in Scotland was 10 to 15%, although this is probably overestimated because diseased Norway lobsters are not only more difficult to swim, but also stay outside their burrows for much longer and can thus be caught to a greater extent than healthy ones. An infestation with Hematodinium inevitably leads, directly or indirectly, to death.

A idiopathic muscle necrosis at the abdomen was from trawlers observed caught scampi. Already shortly after the catch, areas and later the entire abdomen can turn whitish. It is then elongated and no longer slightly curved. The cause is not fully understood. One suspects a stress-induced, lower resistance to pathogens in connection with injuries, which can be caused by constant "tail flipping", the escape reaction of lobsters during the catching process.

Taxonomy and systematics

Carl von Linné named the Norway lobster Cancer norvegicus in the 10th edition of his Systema Naturae in 1758 . The later generic name Nephrops refers to the kidney-shaped eye, the specific epithet to the location of the type species on the Norwegian coast. The Norway lobster was subsequently described again several times. In 1814 Constantine Samuel Rafinesque referred to a specimen caught near Sicily as Astacus rugosus . In 1880 Charles Spence Bate and Joshua Brooking Rowe described a Norway lobster caught off Cornwall as Nephropsis cornubiensis . The genus Nephrops established William Elford Leach in 1814, which was monotypical of his time with the Norway lobster .

The Norway lobster belongs to the lobster-like family (Nephropidae Dana, 1852) and is considered a close relative of the lobster , either this or the genus Metanephrops is the most likely sister group . Within the genus Nephrops it is the only recently known species. While seven fossil species were previously assigned to the genus, only one of them is still listed here today: Nephrops kvistgaardae from the Miocene of Jutland, Denmark. The closely related genera Palaeonephrops from North America and Paraclytia from western Eurasia are from the Cretaceous period , three species of Paraclytia were also found in Germany.

Norway lobsters from the Mediterranean are delimited by some authors and referred to as Nephrops norvegicus var. Meridionalis or Nephrops norvegicus meridionalis Zariquiey Cenarro, 1935. They differ from northern Norway lobsters to a very small extent in the morphology of the second maxillipedas. This distinction is considered controversial.

Economic use

Fideuà with Norway lobsters
Freshly caught Norway lobster (front)

The Norway lobster is fished throughout its range and is considered to be the most commercially important cancer in Europe. The value of the Norway lobster landed in 2001 is put at EUR 208 million. Between 1985 and 2005 around 60,000 tons of Norway lobster were landed annually. In 2007 over 75,000 tons were fished, in 2010 it was 66,544 tons. The north-east Atlantic is considered the main fishing area.

Two Norway lobsters caught in a trap in Portugal during scientific observations in Dec. 2014

Since its habitat is mostly accessible for fishing with trawlers , fishing with trawls dominates . Before 1950, Norway lobster was more of a bycatch and the vast majority of landings were then in France . Later, the Norway lobster became a target of the fishery and special, selective trawls were developed. Today there is also a mixed fishery, whereby the catch is not aimed at a target species. The Norway lobster is then u. a. Caught together with cod and haddock in the continental shelf of Northern Europe and together with flatfish , anglerfish or cod in deeper waters of Scotland and Ireland.

There may be regional differences in the fishing methods. The Norway lobster is caught almost exclusively with traps in the Faroe Islands or in regions of Sweden. In general, traps are used wherever the sea floor is not suitable for trawls. Or where fishing with trawlers is prohibited, such as in the northern Aegean and parts of the Adriatic. Due to the development in demand for live Norway lobsters, the percentage of fishing with traps is increasing. One advantage of trapping is that mostly larger specimens are caught. Females and smaller specimens mostly stay in or near their burrows, while the larger, males move further away from their burrows in search of food and reproductive possibilities and are more likely to fall into traps. In addition, the bycatch is much lower and the impact on the seabed is much lower.

The catch of Norway lobsters is subject to restrictions. In most cases, the carapace must not fall below a certain length. This varies regionally, is around 20 millimeters for catches around Ireland and 40 millimeters in the Kattegat. Since there is a high mortality when fishing with trawls, these lower limits of the lengths are achieved with the prescribed mesh sizes of the nets. In addition, catch quotas are defined.

Nephrops trawls have relatively small meshes, which is why the proportion of bycatch is relatively high. This is either landed or thrown overboard if the catch quotas for bycatch have already been exceeded, the quality is poor or the fish species in the bycatch are not desired.

The Norway lobster is usually sold frozen or fresh on ice, mostly only the abdomen. The Norway lobster is offered under various, sometimes misleading names. In France it is called "langoustine", which brings it linguistically close to the (much more expensive) lobster . In the German-speaking world, the tails of the Norway lobster are often offered as "lobster tails" for the same reason. The term "Kaiser Lobster" is just as misleading. In Italy the animal is called "scampo" (plural " scampi ").

Web links

Commons : Nephrops norvegicus  - collection of images, videos and audio files

Individual evidence

  1. ^ A b c Lipke B. Holthuis : Marine Lobsters of the World. An Annotated and Illustrated Catalog of Species of Interest to Fisheries Known to Date . Ed .: Food and Agriculture Organization (=  FAO Fisheries Synopsis . Volume  125 ). Rome 1991, ISBN 92-5103027-8 , pp. 84 ( fao.org ).
  2. ↑ a b c d Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 412 .
  3. ^ Marisa Sabatini, Jacqueline Hill: Norway lobster - Nephrops norvegicus - General information. Marine Life Information Network [MarLIN], 2008, accessed June 25, 2019 .
  4. ^ A b Lipke B. Holthuis : The Lobsters of the Superfamily Nephropidea of ​​the Atlantic Ocean (Crustacea: Decapoda) . In: Bulletin of Marine Science . tape  24 , no. 4 , 1974, p. 820 ( decapoda.nhm.org [PDF; 16.0 MB ; accessed on June 30, 2012]).
  5. ↑ a b c d e f g Lipke B. Holthuis : The Lobsters of the Superfamily Nephropidea of ​​the Atlantic Ocean (Crustacea: Decapoda) . In: Bulletin of Marine Science . tape  24 , no. 4 , 1974, p. 821 ( decapoda.nhm.org [PDF; 16.0 MB ; accessed on June 30, 2012]).
  6. ^ A b Lipke B. Holthuis : The Lobsters of the Superfamily Nephropidea of ​​the Atlantic Ocean (Crustacea: Decapoda) . In: Bulletin of Marine Science . tape  24 , no. 4 , 1974, p. 822 ( decapoda.nhm.org [PDF; 16.0 MB ; accessed on June 30, 2012]).
  7. ↑ a b Nephrops norvegicus. In: Zooplankton and Micronekton of the North Sea. Marine Species Identification Portal, accessed July 26, 2012 .
  8. ^ A b c Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 413 .
  9. ↑ Nephrops norvegicus in the endangered Red List species the IUCN 2012. Posted by: Bell, C., 2011. Accessed July 26, 2012 found.
  10. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 415 .
  11. ↑ a b c d e Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 424 .
  12. ^ A b FG Howard: The Norway Lobster . In: Department of Agriculture and Fisheries for Scotland (Ed.): Scottish Fisheries Information Pamphlet . tape 7 , 1989, pp. 3 ( scotland.gov.uk [PDF; 1.7 MB ; accessed on August 4, 2012]).
  13. ↑ a b c d e FG Howard: The Norway Lobster . In: Department of Agriculture and Fisheries for Scotland (Ed.): Scottish Fisheries Information Pamphlet . tape 7 , 1989, pp. 6 ( scotland.gov.uk [PDF; 1.7 MB ; accessed on August 4, 2012]).
  14. ↑ a b c d Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 420 .
  15. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 419 .
  16. ^ A b Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 422 .
  17. ↑ Mario Mori, Milena Modena, Franco Biagi: Fecundity and egg volume in Norway lobster (Nephrops norvegicus) from different depths in the northern Tyrrhenian Sea . In: Scientia Marina . tape 65 , no. 2 , 2001, p. 111-116 .
  18. ^ A b Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 421 .
  19. ^ A b Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 423 .
  20. ^ A b c Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 416 .
  21. ^ A b Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 417 .
  22. ^ FG Howard: The Norway Lobster . In: Department of Agriculture and Fisheries for Scotland (Ed.): Scottish Fisheries Information Pamphlet . tape 7 , 1989, pp. 7 ( scotland.gov.uk [PDF; 1.7 MB ; accessed on August 4, 2012]).
  23. ^ Marisa Sabatini, Jacqueline Hill: Norway lobster - Nephrops norvegicus - Reproduction and longevity. Marine Life Information Network [MarLIN], 2008, accessed June 25, 2019 .
  24. ^ Marisa Sabatini, Jacqueline Hill: Norway lobster - Nephrops norvegicus - General biology. Marine Life Information Network [MarLIN], 2008, accessed June 25, 2019 .
  25. ↑ Emi Katoh, Magnus Johnson, Thomas Breithaupt: Fighting behavior and the role of urinary signals in dominance assessment of Norway lobsters, Nephrops norvegicus . In: Behavior . tape 145 , no. 10 , 2008, p. 1447-1464 .
  26. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 425 .
  27. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 426 .
  28. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 427 .
  29. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 428 .
  30. ^ A b Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 429 .
  31. ^ Fiona Murray, Phillip Rhys Cowie: Plastic contamination in the decapod crustacean Nephrops norvegicus (Linnaeus, 1758) . In: Marine Pollution Bulletin . tape 62 , 2011, p. 1207-1217 , doi : 10.1016 / j.marpolbul.2011.03.032 .
  32. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 430 .
  33. ^ A b c Grant D. Stentiford, Douglas M. Neil: Diseases of Nephrops and Metanephrops: A review . In: Journal of Invertebrate Pathology . tape 106 , 2011, pp. 92-109 , doi : 10.1016 / j.jip.2010.09.017 .
  34. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 431 .
  35. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 432 .
  36. ^ A b Lipke B. Holthuis : Marine Lobsters of the World. An Annotated and Illustrated Catalog of Species of Interest to Fisheries Known to Date . Ed .: Food and Agriculture Organization (=  FAO Fisheries Synopsis . Volume  125 ). Rome 1991, ISBN 92-5103027-8 , pp. 83 ( fao.org ).
  37. ^ William E. Leach: Crustaceology . In: David Brewster (Ed.): The Edinburgh Encyclopaedia . tape 7 , 1830, p. 383-437 .
  38. ↑ a b Sammy De Grave, N. Dean Pentcheff, Shane T. Ahyong et al: A classification of living and fossil genera of decapod crustaceans . In: Raffles Bulletin of Zoology . Suppl. 21. 2009, p. 1–109 ( rmbr.nus.edu.sg [PDF; 7,8 MB ]).
  39. ↑ Dale Tshudy, Rafael Robles, Tin-Yam Chan, Ka Chai Ho, Ka Hou Chu, Shane T. Ahyong, Darryl L. Felder: Phylogeny of marine clawed lobster families Nephropidae Dana, 1852, and Thaumastochelidae Bate, 1888, based on mitochondrial genes . In: Joel W. Martin, Keith A. Crandall, Darryl L. Felder (Eds.): Decapod Crustacean Phylogenetics . CRC Press, 2009, ISBN 1-4200-9258-8 , pp. 357-368 ( decapoda.nhm.org [PDF; 1,2 MB ; accessed on June 24, 2012]).
  40. ^ Nephrops at WoRMS World Register of Marine Species , accessed September 29, 2015.
  41. ↑ Dale Tshudy: Systematics and position of Nephrops among the Lobsters . In: Magnus L. Johnson, Mark Johnson (Eds.): The Ecology and Biology of Nephrops norvegicus. Advances in Marine Biology 64 . CRC Press, 2013, ISBN 978-0-12-410533-1 , pp. 2-25 .
  42. ^ A b Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 434 .
  43. ^ A b The Nephrops fisheries of the Northeast Atlantic and Mediterranean - A review and assessment of fishing gear design . In: N. Graham, RST Ferro (Ed.): ICES Cooperative Research Report, No. 270 . 2004, p.  40 .
  44. ↑ Species Fact Sheets Nephrops norvegicus. Food and Agriculture Organization of the United Nations, accessed July 26, 2012 .
  45. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 435 .
  46. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 436 .
  47. ↑ Ana Maria Leocádio, David Whitmarsh, Margarida Castro: Comparing Trawl and Creel Fishing for Norway lobster (Nephrops norvegicus): Biological and Economic Considerations . In: PLOS ONE . tape 7 , no. 7 , July 25, 2012, ISSN  1932-6203 , p. e39567 , doi : 10.1371 / journal.pone.0039567 , PMID 22848357 , PMC 3405070 (free full text) - ( plos.org [accessed September 15, 2016]).
  48. ^ N. Clare Eno, David S. MacDonald, Jim AM Kinnear, S. Chris Amos, Colin J. Chapman: Effects of crustacean traps on benthic fauna . In: ICES Journal of Marine Science: Journal du Conseil . tape 58 , no. 1 , January 1, 2001, ISSN  1054-3139 , p. 11-20 , doi : 10.1006 / jmsc.2000.0984 ( oxfordjournals.org [accessed September 15, 2016]).
  49. ↑ Mike C. Bell, Frank Redant, Ian Tuck: Nephrops Species . In: Bruce F. Phillips (Ed.): Lobsters: Biology, Management, Aquaculture and Fisheries . Wiley-Blackwell, Oxford, UK / Ames, Iowa 2006, ISBN 1-4051-2657-4 , pp. 444 .
  50. ↑ Food and Agriculture Organization of the United Nations [FAO] (ed.): Processing Norway lobsters (=  Torry Advisory Notes . No. No. 29 ). (English, fao.org [accessed July 26, 2012]).