| Summary: | Har ett hummerfredningområde någon betydelse som avelsbank? Av Mats Ulmestrand, Havsfiskelaboratoriet, Lysekil Since 1989 a lobster (Homarus gammarus) fishing area of 1.05 km2 was closed and protected from all fishery except experimental fishery carried out by the Institute of Marine Research in Lysekil. All caught lobster were tagged and released in the area again. This paper gives an estimation of the change in egg production while the fishing mortality on H. gammarus stops. Mundelarnas funktionella morfologi hos havskräfta. Av Anders Sellbom The Norway lobster (Nephrops norvegicus ) can be a suspension feeder, and the lobster use its mouth parts as a "landing-net". A feeding current was produced by the exopodite of the third maxillipeds and with the pleopods. This paper describes the morphology of the mouthparts with respect to suspension feeding. The activity of the mouthparts were tested during aquaria experiments. Crushed shrimps (Pandalus borealis) and nauplii of brine shrimps (Artemia salina) were used asprey. All mouthparts of N. norvegicus are covered with setae in different lenght and size. There are also different shapes among them. In general speaking there are long, serrate setae on the anteriormouthparts and short, stiff setae on the inner mouthparts. Food particles are trapped on the long, serrated setae on the outer mouthparts (mostly the third maxillipeds) and are transported by combing movements of the inner mouthparts to oesophagus. There was no significant difference in beatspeed of the exopodites. Three different sources were tested against each other: food (crushed shrimp or nauplii of brine shrimp), treatment (before, under and after addition of food) and the interaction food/treatment. Very large variance differences occurred within the same food group when tested for the interaction food/treatment. The explanation is that the exopodites do not beat simultanously and there are large speed differences between left and right exopodite. A two factor ANOVA analysis of variance was used as ...
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