Abstract
The round crucian carp (Carassius auratus glandoculis) is an endemic species, which is categorized as endangered in Lake Biwa, Japan, by the Ministry of the Environment. The spawning behavior of the species has not been fully studied. We analyzed triggers for the spawning migration from Lake Biwa to the paddy field drainage area at Shimokasa of Kusatsu city, in Shiga Prefecture. Observations were conducted between May 14 and July 9, 2008. In the field, numbers of carp were surveyed daily, and statistical data on environmental factors were also collected and analyzed by canonical discriminant analysis. Results showed that spawning migration triggers included water level fluctuations in Lake Biwa and Chemical Oxygen Demand (COD). We discuss the implications of our findings in relation to conservation strategies for the species.
