Alien aquatic invertebrates of Republic of Karelia: Eriocheir sinensis (Edwards, 1853)

Study Extent

Different waterbodies in borders of Republic of Karelia, in the volume of samples during the study period.

Sampling

Collecting on different lakes and rivers and visual observations

Method steps

1. Collecting or observing specimens, identification of collected specimens, digitizing the data with MS Access and MS Excel, carrying out statistical analysis of data set.

Republic of Karelia Chinese mitten crab observed in lake Onega, located in the South of the Republic of Karelia (Lake Onega: 61.5816666666666/34.7736111111111; 62.1886111111111/34.2505555555555; 62.852968/34.608028; 61.4119444444444/ 35.3397222222222). The studied species is caught by single specimens. It has no commercial value. Chinese mitten crab (Chinese freshwater edible crab) was accidentally introduced with ballast water in Europe from China in 1912. In 1993 it was registered in Lake Onega, the path of penetration - with ballast water from the White sea. The crab lives on hard surfaces of littoral in rivers, lakes, estuaries. It migrates to the sea to spawn. It is a euryhaline, eurythermal species. Crab reaches sexual maturity on 4 th-5 th year. The crab spawns in late autumn or winter in estuaries. Fecundity ranges from 250,000 to one million eggs, which hatch in brackish or seawater. Adult crabs die after breeding. Larvae appear in summer. After hatching, the larvae have seven stages of development. At these stages, the larvae begin to move from brackish to fresh water.