Considérations générales sur Liocarcinus vernalis (Risso, 1827) et remarques sur sa présence en Mer du Nord (Crustacea, Decapoda, Brachyura, Portunidae)
d'Udekem d'Acoz, C. (1991). Considérations générales sur Liocarcinus vernalis (Risso, 1827) et remarques sur sa présence en Mer du Nord (Crustacea, Decapoda, Brachyura, Portunidae). De Strandvlo 11(4): 84-100
In: De Strandvlo: Driemaandelijks Tijdschrift van De Strandwerkgroep België. De Strandwerkgroep België: Ursel. ISSN 0773-3542, more
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Keywords |
Distribution records Liocarcinus vernalis (Risso, 1827) [WoRMS] ANE, North Sea [Marine Regions] Marine/Coastal |
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- d'Udekem d'Acoz, C., more
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Abstract |
The Grey Swimming Crab Liocarcinus vernalis has been recorded since 1989 in the Southern North Sea where it may be locally quite common. It is not known if its occurrence in this sea is temporary or not but the population survived after the rather severe winter 1990-1991. lts geographical distribution and ecology are discussed and compared with other species. The three Liocarcinus of the holsatusgroup may be distinguished as follows: 1. Two tubercles (sometimes very faint) on the external margin of chelipeds carpus. Pereiopods II-IV slender (Mainly the propodus)................... 2-External margin of chelipeds carpus regularly rounded and without any trace of tubercles. Pereiopods II-IV robust (mainly the propodus). Carapace narrow. Crabs usually with a rough and very contrasted marbled pattern: Liocarcinus marmoreus (LEACH, 1814). 2. Fifth pereiopods merus very short (1.4-1.6 longer than wide). Median frontal tooth always overreaching the levelof the two submedian teeth (usually strong- ly). Carapace usually smooth or with few granules. Carapace often plain pale brown or plain blueish grey. Often larger than 39 mm accross: Liocarcinus holsatus ( F A8RICIUS , 1798 )-Fifth pereiopods merus long (2.0-2.5 longer than wide). Median frontal tooth usually not overreaching the level of the two submedian teeth. Carapace usu- ally (but not always !) with many faint granules. Carapace usually grey or greyish and minutely speckled. Very seldom larger than 39 mm accross: Liocarcinus vernalis (RISSO, 1816) |
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