Finding of Previously Extinct Population of Brackish Water Crustacean Calanipeda aquaedulcis (Copepoda, Calanoida) in the Middle Caspian

In the spring of 2024, in the Middle Caspian off the coast of the Republic of Dagestan from Makhachkala to Kaspiysk, a massive development of the population of the copepod was discovered, which was absent here for almost 20 years. It again entered the group of dominant species and formed an average of 92% of the total biomass of zooplankton. Mature males (45% of the total number), females (47%) and immature crustaceans of copepodic stages of development (8%) were recorded in the population. In the early 2000s, was badly damaged by the introduction of the copepod and the ctenophore Mnemiopsis leidyi into the reservoir. Currently, there is hope for the restoration of the population in the Middle Caspian.