Red crayfish of the Blue Lakes

 

They are called Blue because of their bright blue, even ultramarine color, which can be seen during the period of rapid snow melting in June. Part of the ice covering the water surfaces is flooded, as a result of which the ice takes on a bright, beautiful color in reflected light.

 

In September, the water level in the lakes dropped sharply and the smaller lakes dried up. One lake was bright green, the second was blue. But the third turned into a small puddle of bright red color. Upon closer examination of this phenomenon, it was found that the color of the reservoir is given by numerous small red crustaceans.

 

Scientists from the Kamchatka branch of the Russian State Research Center “All-Russian Research Institute of Fisheries and Oceanography” (VNIRO) collected water samples with plankton from the Blue Lakes and delivered them to the laboratory of fisheries ecology for research.

 

As the head of the laboratory, Ekaterina Lepskaya, said, in 2024, only nauplii (immature stages of copepods) of the red calanid were found in the samples, and in the fresh sample there were both males and females, which made it possible to conduct a taxonomic identification and confidently attribute the found red crustacean to Arctodiaptomus kamtschaticus.

 

“This species was first described by E.V. Borutsky in 1953 in a plankton sample from Lake Zelenoe (Kurenkov, 2005). In 2024, our research confirmed its presence in this reservoir. The crustaceans get their red color from pigments from the astaxanthin group, which the animals receive with food. However, the algal flora of the Green and Blue Lakes is very poor, and it is still unclear how the calanids could accumulate such a quantity of lipids and lipophilic pigments that protect the crustaceans from dying at low temperatures,” explained Ekaterina.

 

The answer to this question may appear after an analysis of the composition of fatty acids, which will be conducted by colleagues from the biophysics laboratory of the Krasnoyarsk Federal University.

 

Press service of VNIRO