Goby Lake that the diversity of species in the lake is greatly reduced from the nearby lagoon. The golden jellyfish "Mastigias" cf. "papua nakamurai" and possibly other species in the lake have evolved to be substantially different from their close relatives living in the nearby lagoons. The lake is rich with several species of fish, including goby, giving to lake its name. The deepest - north-eastern - part of Goby Lake is stratified into two layers, an oxygenated upper layer (mixolimnion) and a lower anoxic layer (monimolimnion). The oxygen concentration in the lake declines from about 6 mg/l at the surface to
Monkey goby as amphipods and shrimp. In the Danube lakes Yalpug and Kugurluy, the diet of the monkey goby consists of amphipods, molluscs, and Oligochaeta. In the Khadzhibey Estuary a dozen species of prey make up the diet of monkey goby. Polychaetes, larvae of insects, and shrimp are present in the diet year round. Seasonal dietary additions include crabs such as "Rhithropanopeus harrisii", sea weed such as "Zostera marina", and amphipods such as "Marinogammarus olivii". Certain planktonic crustaceans are also present in the diet of adult gobies. In the northwestern Black Sea, twelve parasite species are known to infect the monkey goby.