Seasonal changes of development and reproduction cycle of Microdeutopus gryllotalpa Costa, 1853 (Crustacea, Amphipoda) in the ouling community of the Odessa Bay, Black Sea
Investigations of development of Microdeutopus gryllotalpa under conditions of the fouling community in Odessa Bay, Black Sea were carried out for two years from January 2013 to December 2014. Monthly samples were taken from the underwater surface of solid substrates located in the coastal zone of the Odessa Bay. In addition to quantitative parameters of these invertebrates, the characteristics of their reproduction, absolute fecundity, the total number of egg-laying during the life cycle, as well as the relationship between their body size, weight, and fecundity parameters were studied. The reproductive process of these crustaceans proceeded throughout the year, but its intensity increased synchronously with the increase the quantitative parameters of invertebrates in spring and autumn during periods of sharp changes in sea water temperature. The maximum absolute fecundity of female 8 mm in size was 64 eggs. The relationship between the wetweight and body length of oviparous females is isometric. The parameter of absolute fecundity is directly proportional to the body weight of the female. Under the conditions of the fouling community in the Odessa Bay, the female M. gryllotalpa can produce about 7 egg-laying during her life cycle.