Premium
The use of otoliths as indicators of Little Penguin Eudyptula minor diet
Author(s) -
GALES R. P.
Publication year - 1988
Publication title -
ibis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 80
eISSN - 1474-919X
pISSN - 0019-1019
DOI - 10.1111/j.1474-919x.1988.tb00999.x
Subject(s) - otolith , fish <actinopterygii> , digestion (alchemy) , biology , ingestion , zoology , fishery , portion size , meal , chemistry , food science , biochemistry , chromatography
The validity of using otoliths from stomach contents quantitatively to determine the number and size of fish consumed was tested on Little Penguins. They were fed different meal sizes of known number and size of fish and the stomach contents were recovered after various time intervals. There were no differences in estimates of original fish size when calculated from otolith length or weight. Rate of digestion of otoliths tended to decrease with increased meal size but increased with time after ingestion. Digestion of otoliths proceeds rapidly and, if ignored, estimates of numbers of fish consumed and of original fish size can be significantly underestimated. This problem can be partially solved by inspection of otolith condition and restricting calculations of fish size to otoliths unaffected by digestion. Many factors introduce variations into rate of otolith degradation and further species‐specific studies are required before appropriate correction factors can be applied.