Growth of immature false southern king crab, Paralomis granulosa (Anomura, Lithodidae), in the Beagle Channel, Argentina
Gustavo A. Lovrich, Julio H. Vinuesa

We studied the growth of the immature false southern king crab, Paralomis granulosa (10-57 mm carapace length, CL) from the Beagle Channel, Argentina during 1988-1991. Crabs were kept in laboratory tanks or in a pen submerged in the Beagle Channel. One hundred and thirty two moulting individuals were studied and neither tagging nor the place of captivity had a detectable effect on the growth of immature crabs. Also, no differences in growth between sexes were found. Increment at moult and its variability increased with premoult size. Growth factor, or percent increment, for healthy crabs was constant and was about 12.5% (SD=4.0%). Increment per moult and growth factor for crabs with injured limbs were significantly lower than those for healthy crabs. Moulting was clearly seasonal: 75% of the observed moults occurred during the late spring - early summer, i.e. November to January. Crabs < 40 mm CL were observed also to moult during winter. Males and females begin to moult annually 2 and 3 years before reaching gonadal maturity at 50.2 and 60.6 mm CL, respectively. Aided by our moult increment function for crabs that moulted in captivity, 14 moult instars were required to explain the size frequency distribution of crabs collected in the field. Paralomis granulosa takes about 8 years to growth from ca. 12 to 57 mm CL.

Keywords: Lithodidae, immature growth, Paralomis, king crabs, Tierra del Fuego, Southwestern Atlantic.
Contents of this volume Sci. Mar. 59(1) : 87-94 Back PDF
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