An extraordinary discovery was made by researchers from the Volga-Caspian branch of the Russian Federal Research Institute Of Fisheries and Oceanography. During their annual monitoring of the waters of the Middle Caspian, they found a living organism that had been considered extinct for 20 years.

The discovery concerns a brackish water crustacean — a copepod. Scientists reported the encounter with this zooplankton species this year, although it was first observed in the spring of last year near the coast of Dagestan, about 200 meters from shore.

The copepod’s fate has not been an easy one, as many species attempted to displace it — and some even succeeded for a time. This copepod was once one of the three main genera that made up the bulk of zooplankton in the Middle and Southern Caspian. It served as a key food source for local sprat populations — a pattern that persisted through the 1970s.

However, in the 1990s, the comb jelly, a marine invertebrate, invaded the Caspian Sea, leading to the disappearance of this crustacean species from the waters of the Middle and Southern Caspian. Now, scientists report that the species, once thought lost for two decades, has reappeared and regained its position among the dominant zooplankton of the region.

Source: arbuztoday.ru