Breeding characteristics of the sand goby (Pomatoschistus minutus) - one of the most abundant goby species in the costal waters of the Gulf of Gdańsk region (southern Baltic Sea)

The reproduction aspect of the biology of Pomatoschistus minutus was investigated on fish collected in the Gulf of Gdańsk from March to October 2002. The study zone was from the shore to a depth of about 1 m. The sand goby is common in the investigated area from July to October, but it migrates to deeper water in the colder months. The highest numbers of individuals were observed in September. The spawning season of the sand goby in the Gulf of Gdańsk is from April to August. It is so long because this species is batch spawner. The study confirmed a dependence between the HSI and GSI indexes as well as the dependence between relative fecundity and fish length.