ABUNDANCE OF NARROW-CLAWED CRAYFISHES (Astacus leptodactylus Eschscholtz, 1823) AND ITS TRENDS IN LAKE SEVAN, ARMENIA

Abstract

The narrow-clawed crayfish (Astacus leptodactylus Eschscholtz, 1823) is an indigenous species in Armenia. In 1980s it was occasionally introduced in Lake Sevan where its population started to grow. There is a large scale fishery of the crayfish in the Lake, as its demand remains high. Industrial stock of crayfishes at the Lake monitored annually, shows statistically significant decline in the 2004-2011 period. This decline can be described by logarithmic model y = -577.5ln(x) + 2158, F = 50.27, P