Аge structure and fecundity of the noble crayfish populations in abandoned quarries

The population of noble crayfish ( Astacus astacus ) was researched in quarries an old brick plant Molodechno district Minsk region. Rare disappearing found 10 closed quarries. presence that are not connected with watercourses indicates these populations were created by man. the factory is characterized a high number. average catch eel traps 1.31 ± 0.77 individuals/trap/day. Crayfish first and second year life grew faster than other habitats, but subsequently size individuals quarry smaller comparison general model growth Belarus. Individuals older 6 years have been This there factors determine mortality rate age groups. However, favorable conditions for juveniles allow to maintain their numbers at level. reason this phenomenon remains unknown. reaching puberty fertility comparable those from habitats. In quarry, minimum length oviparous female 7.2 cm. Egg-laying females 7.0-7.9 cm class 16.7 %, 8.0-8.9 - 38.8, 9.0-9.9 70.6 10.0-10.9 all oviparous. should be considered as donor carrying out resettlement into water bodies river Neman.