Show simple item record  

dc.contributor.authorHicks, Brendan J.
dc.contributor.authorWest, David William
dc.contributor.authorBarry, B. J.
dc.contributor.authorMarkwitz, A.
dc.contributor.authorBaker, Cindy F.
dc.contributor.authorMitchell, C.P.
dc.identifier.citationHicks, B. J., West, D. W., Barry, B. J., Markwitz, A., Baker, C. F. & Mitchell, C. P. (2005). Chronosequences of strontium in the otoliths of two New Zealand migratory freshwater fish, inanga (Galaxias maculatus) and koaro (G. brevipinnis). International Journal of Particle Induced X-ray Emission 15(3-4), 95-101.en
dc.description.abstractHalf of the freshwater fish fauna in New Zealand is diadromous (i.e., migrates between the sea and freshwater); unimpeded access to and from the sea is important for the conservation of diadromous fish. The genus Galaxias (Galaxiidae: Osmeriformes) contains five diadromous species that spawn in freshwater, migrate to sea as larvae, and then migrate back into freshwater as 50-55-mm juveniles. Microchemistry of the otolith, a calcified structure in the fish's head, allows an independent test of assumptions about these migrations. Concentric layers of CaCO3 with some Sr as SrCO3 comprise the otolith, creating a chronosequence that reflects a fish's migratory history. More Sr accumulates in the otolith when a fish is in seawater than when it is in freshwater. High-resolution nuclear microscopy was used to measure the molar ratios of Sr/Ca in two galaxiid species. Otoliths of inanga (G. maculatus) caught in freshwater all showed a central zone of 100-200 μm in radius with Sr/Ca of 0.008-0.012, indicating early rearing in the sea. Sr/Ca values decreased to 0.001-0.002 as the fish moved into freshwater. Of six adult koaro (G. brevipinnis) caught in a river with sea access and no lakes, five had migrated to sea but one had not, raising questions about the generalized assumptions of migration.en
dc.publisherWorld Scientific Publishing Co. Pte. Ltd.en_NZ
dc.rightsFull text of this article may be requested by emailing AProf Brendan J. Hicks:
dc.subjectotolith microchemistryen
dc.subjectmigratory historyen
dc.subjectfreshwater fishen
dc.titleChronosequences of strontium in the otoliths of two New Zealand migratory freshwater fish, inanga (Galaxias maculatus) and koaro (G. brevipinnis)en
dc.typeJournal Articleen
dc.relation.isPartOfInternational Journal of PIXEen_NZ

Files in this item


There are no files associated with this item.

This item appears in the following Collection(s)

Show simple item record