Variability of body weight and morphometry of the Chinese mitten crab (Eriocheir sinensis) was studied on a total of 142 individuals (68 females and 74 males) found within 15 October – 15 November 2000 in fyke nets deployed in the northern part of Lake Dąbie and in the southern part of the Szczecin Lagoon, a southern Baltic estuarine area where the non-indigenous crab had established an abundant population. The body weight, carapace length, and carapace width of the crabs were found to range within 30.1-458.9 g, 36.1-85.4 mm, and 41.1-98.4 mm, respectively, the male crabs being significantly heavier than the females. The comparative analysis of 11 metric characters of males and females revealed other indicators of sexual dimorphism in the population studied; of those, particularly pronounced differences were recorded in the relative claw length (significantly higher in males) and the relative length and width of abdomen (significantly higher in females).

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