Short Communication

Validation of growth zone deposition rate in otoliths and scales of flathead mullet Mugil cephalus and freshwater mullet Myxus capensis from fish of known age

  • BR Ellender
  • GC Taylor
  • OLF Weyl

Abstract

Flathead mullet Mugil cephalus and freshwater mullet Myxus capensis are important components in South African estuarine fish communities and fisheries, but there is little information on their age and growth or age validation. This study validated the periodicity of growth zone formation in sectioned sagittal otoliths and scales of fish of known age that had been at liberty for 10 years. For both M. cephalus and M. capensis, the number of growth zones counted on otolith sections did not differ significantly from the known age of the fish. There were significantly fewer growth zones on scales than the known age of both M. cephalus and M. capensis. Growth zone deposition rate could therefore be validated as annual for otoliths but not for scales of the two species. It is recommended that future ageing studies focus on otoliths rather than scales.

Keywords: age validation, growth zones, sagittal otoliths, South Africa

African Journal of Marine Science 2012, 34(3): 455–458

Author Biographies

BR Ellender
Department of Ichthyology and Fisheries Science, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
GC Taylor
Department of Ichthyology and Fisheries Science, Rhodes University, PO Box 94, Grahamstown 6140, South Africa
OLF Weyl
South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown 6140, South Africa; Centre for Invasion Biology, South African Institute for Aquatic Biodiversity, Private Bag 1015, Grahamstown 6140, South Africa
Section
Articles

Journal Identifiers


eISSN: 1814-2338
print ISSN: 1814-232X