Wednesday, 22 August 2012

Marine Fauna of Norway

Norway Post  has issued the stamp series features their marine fauna such as : shrimp, lobster, and crab on September 21, 2007. The issue stamps consist of 4 single stamps depicted Pink shrimp (Pandalus montagui), European lobster (Homarus gammarus), Edible brown crab (Cancer pagurus), Squat lobster (Galathea strigosa). 
Pink shrimp

Pandalus montagui  is a species of cold-water shrimp in the family Pandalidae. It is the type species of the genus Pandalus and is variously known as the pink shrimp, Aesop shrimp and Aesop prawn . Its range extends from Greenland and Iceland, the Arctic Ocean and northern Atlantic Ocean, south to Rhode Island and the British Isles.

Pandalus montagui is an omnivore, predator and scavenger. The diet consists mainly of small crustaceans such as copepods, hydroids and polychaete worms. Pandalus montagui is a translucent, pinkish shrimp, generally growing to about 5 centimetres  long. The colour is due to a number of red chromatophores and there are also a few short red streaks running obliquely on the carapace.

Most individuals start life as males but change sex to females at 12–15 months. It prefers hard substrates but can be found on rock, gravel, sand and mud. It is most common at depths between 20 metres and 100 m  but sometimes occurs near low water mark or at depths down to 700 m .
European lobster

Homarus gammarus, known as the European lobster or common lobster, is a species of clawed lobster and found across the north-eastern Atlantic Ocean from northern Norway to the Azores and Morocco, not including the Baltic Sea.

It may grow to a length of 60 cm  and a mass of 6 kilograms , and bears a conspicuous pair of claws. In life, the lobsters are blue, only becoming "lobster red" on cooking. Homarus gammarus is a highly esteemed food, and is widely caught using lobster pots, mostly around the British Isles
Mating occurs in the summer, producing eggs which are carried by the females for up to a year before hatching into planktonic larvae. The diet of Homarus gammarus mostly consists of other benthic invertebrates. These include crabs, molluscs, sea urchins, starfish and polychaete worms.

It is also present in most of the Mediterranean Sea, only missing from the section east of Crete, and along only the north-west coast of the Black Sea. The northernmost populations are found in the Norwegian fjords Tysfjorden and Nordfolda, inside the Arctic Circle.

Adult Homarus gammarus live on the continental shelf at depths till 150 metres , although not normally deeper than 50 m . They prefer hard substrates, such as rocks or hard mud, and live in holes or crevices, emerging at night to feed.
Edible brown crab

Cancer pagurus, commonly known as the edible brown crab, is a species of crab found in the North Sea, North Atlantic Ocean and perhaps in the Mediterranean Sea. It is a robust crab of a reddish-brown colour, having an oval carapace with characteristic "pie crust" edge and black tips to the claws.

Males typically have a carapace 60 millimetres  long, and females 98 mm  long. Carapace width is typically 150 mm, or exceptionally up to 250 mm . A fold of the carapace extends ventrally to constitute a branchial chamber where the gills lie.

Cancer pagurus is a nocturnal predator, targeting a range of molluscs and crustaceans.Its  hiding buried in the substrate during the day, but foraging at night up to 50 metres from their hideouts. Their diet includes a variety of crustaceans

Cancer pagurus is abundant throughout the northeast Atlantic as far as Norway in the north and northern Africa in the south, on mixed coarse grounds, mud and sand from the shallow sub-littoral to depths of about 100 metres . It is frequently found inhabiting cracks and holes in rocks but occasionally also in open areas. 
Squat lobster

Galathea strigosa is a species of squat lobster found in the northeast Atlantic Ocean, from the Nordkapp to the Canary Islands, and in the Mediterranean Sea and Red Sea. It is edible, but not fished for commercially. It is the largest squat lobster in the northeast Atlantic, reaching a length of 90 mm  or a carapace length of 53 mm ,and is easily identified by the transverse blue stripes across the body.

Squat lobsters are decapod crustaceans of the families Galatheidae, Chirostylidae, Munididae, Munidopsidae and Kiwaidae, including the common genera Galathea and Munida. They are not lobsters, but are more closely related to porcelain crabs, hermit crabs and then, more distantly, true crabs. They are distributed worldwide in the oceans, and occur from near the surface to deep sea hydrothermal vents. There are currently 870 described species.

The body of a squat lobster is usually flattened, the abdomen is typically folded under itself, and the first pereiopods (front legs) are greatly elongated and armed with long chelae (claws). The fifth pair of pereiopods is usually hidden within the gill chamber, under the carapace, giving squat lobsters the appearance of having only eight pereiopods.

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