The specificities of round goby fecundity (Neogobius melanostomus) in different ecological conditions
AbstractWe conducted a comparative analysis of the absolute and relative fecundity of round goby (Neogobius melanostomus (Pallas, 1984)) females in the Kakhovskyy Reservoir and the Azov Sea. We analysed the indicators of salinity, pH and oxygen levels in the waterbodies investigated. We determined the dependence of fertility of round gobies on body weight, length and age. This article presents the results of a comparative analysis with the works of other authors, including the results of a similar study conducted 40-years ago. We conducted cameral processing of the results by standard methodology. We counted the oocytes at varying stages of maturity. All oocytes were grouped by their diameter. We visually identified four groups of oocytes: 1700–2500 mkm – the large, mature oocytes (ІV stage of maturity); 400–1200 mkm – light yellow oocytes, which are ripening (ІІІ stage); 100–300 mkm (ІІ stage) whitish eggs, and the smallest (I stage) – up to 100 mkm. Stages II–IV were subjected to statistical processing. The differences between the indicators of fertility of fishes from saltwater and freshwater waterbodies show an increase in the relative and the absolute fecundity of fishes from the sea (saltwater) and decrease in the fecundity of the fishes in freshwater. The correlation analysis between the waterbodies and the length of the fishes showed 0.81 at the Kahovskyy Reservoir and0.62 in theAzovSea. The correlation analysis between the same waterbodies and the weight of the fishes was 0.63 and 0.74 respectively. This could indicate that conditions for the fishes’ existence were more favourable in the sea. The comparison analysis between our data and the 40-year old data for theAzovSea depending on length and weight show a significant increase in oocyte numbers. This increase was noted for all size groups of fish. Nevertheless, the greatest differences were between fish in theAzovSea (all data) and those in the Kahovskyy Reservoir. These results should be studied in the context of the nutrition spectrum and calorific objects of the round goby in these water bodies. It would be interesting to analyse data on gobies of theAzovSea according to gradation in salinity levels.
Gutowsky, L.F.G., Fox, M.G., 2012. Intra-population variability of life-history traits and growth during range expansion of the invasive round goby, Neogobius melanostomus. Fisheries Manag. Ecol. 19, 78–88. >> doi:10.1111/j.1365-2400.2011.00831.x
Koshelev, B.V., 1966. Nekotoryye osobennosti polovykh tsiklov u ryb s sinkhronnym i asinkhronnym rostom ootsitov v vodoyemakh razlichnykh shirot [Some features of sexual cycles in fish with synchronous and asynchronous oocyte growth in the reservoirs at different latitudes]. Sevastopol, 21–54 (in Russian).
Kovtun, I.F., 1971. O plodovitosti bychka-kruglyaka Gobius melanostomus Pallas Azovskogo morya [About fertility round goby Gobius melanostomus Pallas from Azov Sea]. Journal of Ichthyology 1, 642–649 (in Russian).
Kulikova, N.I., Fandeyeva, V.N., 1975. O portsionnosti ikrometaniya azovskogo bychka-kruglyaka Neogobius melanostomus (Pallas) [The portioned spawning Azov round goby Neogobius melanostomus (Pallas)]. VNIRO 96, 18–27 (in Russian).
Mikhman, A.S., 1963. O plodovitosti azovskikh bychkov – kruglyaka i sirmana [The fertility Azov steers – sticks and sirman]. AzNIIRKH 6, 105–109 (in Russian).
Moskvin, B.S., 1940. Nablyudeniya za razmnozheniyem nekotorykh vidov Gobiidae, Blennidae, Gobiosocidae v Chernom more [Observations of the breeding of some species Gobiidae, Blennidae, Gobiosocidae in the Black Sea]. Novorossiysk 3, 25–40 (in Russian).
Nikol’skiy, G.V., 1974. Teoriya dinamiki stada ryb kak biologicheskaya osnova ratsional’noy ekspluatatsii i vosproizvodstva rybnykh resursov [The dynamics theory became fish as the biological basis of rational exploitation and reproduction of fish resources]. Moskow (in Russian).
Nolte, A.W., 2011. Dispersal in the course of invasion. Molecular ecology. >> doi:10.1111/j.1365-294X.2011.05083.x
Piria, M., Šprem, N., Jakovlić, I., 2011. First record of round goby, Neogobius melanostomus (Pallas, 1814) in the Sava River, Croatia. Aquatic Invasions 6(1), 153–157. >> doi:10.3391/ai.2011.6.S1.034
Polačik, M., Janáč, M., Vassilev, M., Trichkova, T., 2012. Morphometric comparison of native and nonnative populations of round goby Neogobius melanostomus from the River Danube. Folia Zool. 61(1), 1–8.
Ray, W.J., Corkum, L.D., (2001). Habitat and site affinity of the round goby. J. Great Lakes Res. 27(3), 329–334. >> doi:10.1016/S0380-1330(01)70648-X
Sapora, M.R., Mariuzs, R., 2012. Neogobius melanostomus. Invasive Alien Species Fact Sheet 11.
Smirnov, A.I., 1986. Fauna Ukrainy. Ryby [Fauna of Ukraine. Fish]. Kyiv, 8 (in Russian).
Verreycken, H., Breine, J.J., Snoeks, J., Belpaire, C., 2011. First record of the Round goby, Neogobius melanostomus (Actinopterygii: Perciformes: Gobiidae) in Belgium. Acta Ichthyologica et Piscatorial 41(2), 137–140. >> doi:10.3750/AIP2011.41.2.11
Yoganzen, B.G., Zagorodneva, D.S., 1951. Plodovitost’ sibirskogo yel’tsa i faktory, yeye opredelyayushchiye [Fecundity of siberian dace and its determining factors]. Memoirs of the Tomsk State University 2, 117–140 (in Russian).