In this study, the relative growth, size–weight relationships and size at onset of maturity of the brown crab Cancer pagurus were investigated in the Isle of Man. For the analyses of relative growth and size at onset of maturity, the samples were collected seasonally between autumn 2012 and spring 2013 using several methods: pot surveys, dredge and trawl surveys, market surveys and shore surveys. Results showed that allometric growth occurred in the chelipeds of males (n = 87) and in the abdomen of females (n = 222). Four different measures of maturity (behavioural, functional, morphometric and physiological) were examined. With respect to the behavioural maturity, the smallest female crab found with a sperm plug measured 110 mm CW, whereas in terms of functional maturity the smallest ovigerous female had a CW of 134 mm. Based on direct observations of gonad maturity, 50% of females were mature at 108 mm CW, whereas 50% of males were mature at 89 mm CW. The size at the onset of maturity measurements of female and male C. pagurus based on gonad development is smaller than the current minimum landing size (130 mm), and therefore this suggests that the current minimum landing size is an adequate management measure.

This study provides information on the distribution and ecology of Callinectes sapidus in Turkey, as well as its maximum daily catch in set nets (trammel nets and gillnets), and its commercial fishery in lagoons. Data were collected in 2020 by utilizing a telephone based questionnaire survey. Responses were gathered from fishers (n = 6) who fish in the lagoons and the head of fishery cooperatives or its members (n = 104) in 28 cities, including the coastal regions of the Mediterranean Sea (Levantine), Aegean Sea, Sea of Marmara and the Black Sea in Turkey. Results indicated that C. sapidus is commonly distributed along the Levantine and Southern Aegean coasts of Turkey, whilst it is rarely observed in the Sea of Marmara and the Black Sea. It has been reported by fishers that this species has been seen in the Black Sea for the last decade. The maximum daily catch of blue crab in set nets showed a significant difference in the Levantine and Aegean coasts. The species is mainly produced in the lagoons, whereas many coastal fishers returned it as discard and 79% of fishers emphasized that C. sapidus shred the nets and caused an economic loss. Ovigerous females have been observed between March and October and we have discussed related management issues including current fishery season.