Publication Abstract

Damage, autotomy and arm regenerstion in starfish (Asterias rubens L.) caught by fishing gears

K. Ramsay, M. Bergmann, L. O. Veale, C. A. Richardson, M. J. Kaiser, S. J. Vize, and S. W. Feist

Arm damage and loss were examined in the starfish Asterias rubens that had been caught in a variety of towed and demersal fishing gears deployed on different sea bed types. Between 7% and 38% of the starfish in each catch lost one or more arms, and arm loss was positively correlated with the volume of the catch for two fot eh fishing gears examined. Subsequent monitoring of the damaged animals showed that the arms were autotomised for at least three weeks following capture. Mortality was highest in starfish with damaged or missing arms, compared with those that appeared intact after fishing. Arm regeneration was delayed in a small proportion of the animals caught by commercial gears. In a parallel study, 17% of the starfish caught by a 4 m beam trawl had a damaged ambulacral ossicle at the point of autotomy (cf. none from a control group thsat were induced to autotomise under controlled conditions). there was no difference in regeneration rates between the animals caught by commercial gears and a control set (caught by a small trawl and forced to autotomise an arm in the laboratory) once the animals that delayed regeneration were excluded from the dataset. After 1 year under laboratory conditrions the starfish had, on average, regenerated the missing arm to 75% of the length of the other four arms. During this time period the lengths of the undamaged arms increased by ca. 50%. The implications of this study for using arm loss in starfish as an indicator of fishing disturbance are discussed.

Reference:

K. Ramsay, M. Bergmann, L. O. Veale, C. A. Richardson, M. J. Kaiser, S. J. Vize, and S. W. Feist, 2001. Damage, autotomy and arm regenerstion in starfish (Asterias rubens L.) caught by fishing gears. Marine Biology, 138(3): 527-536