PROMOTING ACCESS TO AFRICAN RESEARCH

African Journal of Marine Science

The AJOL site is currently undergoing a major upgrade, and there will temporarily be some restrictions to the available functionality.
-- Users will not be able to register or log in during this period.
-- Full text (PDF) downloads of Open Access journal articles will be available as always.
-- Full text (PDF) downloads of subscription based journal articles will NOT be available
We apologise for any inconvenience caused. Please check back soon, as we will revert to usual policy as soon as possible.





Discrepancy between otolith and tag-recovery estimates of growth for two South African surf-zone teleost species

CG Attwood, L Swart

Abstract


Growth rates determined from recovered tagged galjoen Dichistius capensis and white steenbras Lithognathus lithognathus were compared to predictions from growth models based on otolith ring counts. Galjoen could not
be sexed externally, but it was assumed that all fish >450 mm total length were females, which grow faster than males. Those smaller than this were assumed to include mostly males and were treated as a “male” sample. Male
and female white steenbras grow equivalently. Tagged “male” (n = 322), and female galjoen (n = 34) and white steenbras (n = 14) grew more slowly than the model predictions. The discrepancy is likely attributable to the physiological effect of external tags on growth.



AJOL African Journals Online