Distribution and allometry of the knobby swimcrab, Macropipus tuberculatus (Roux, 1830) (Brachyura, Portunidae) in the Strait of Sicily (Mediterranean Sea)

Distribution and biometric information for Macropipus tuberculatus of the Strait of Sicily were obtained via an experimental bottom trawl survey carried out in 2000. The species occurred with low frequency (20%) and abundance (365 specimens), showing a scattered spatial distribution, split in 2 preferential depth levels (90-160 m and 230-460 m). Males were larger and more abundant than females. The carapace length width relationship was allometric positive (b 1), and the carapace length weight relationship was isometric (b = 3).