Hello Fellow list members,
following my request last week for information on using chemicals to stain larval fish otoliths, I am forwarding a summary of the responses that I have received. I would like to thank all those who kindly took time out of their schedules to reply to my request.
The two most recommended stains both in responses from list members and in the literature are tetracycline and alizarin complexone. Both have the potential of creating reliable, consistent (among fish) stains, and both have minimal impact on growth and mortality. Immersion in the chemicals appears to be the most efficient and reliable method of staining. However, tetracycline in full strength seawater can be problematic as the divalent ions in the water bind to the chemical. This problem can be circumvented by using diluted seawater (10 ppt) or artificial seawater (leaving out the divalent cations).
Another marker, manganese, which can be detected by cathodoluminescence spectroscopy was also suggested, as it has been used to mark mollusc shell increments (see Hawkes et al. 1996. Journal of Shellfish Res. 15: 659-666).
Respondents to my request did not forsee a problem with repeatedly marking the otoliths of my larvae, as long as sufficient time was allowed between stainings to allow distinct bands to form. Others recommended alternating stains (tetracycline and alizarin) to create alternating bands of different colors. This has apparently been used to given hatchery larvae unique marks before being released.
Some useful references include (in no order what so ever...oh well):
Stevenson and Campana (eds.). 1992. Otolith microstructure examination and analysis. Can. Spec. Publ. Fish. Aquat. Sci. 117.
Secor et al. (eds.) 1995. Recent developments in fish otolith research. University of S. Carolina Press, Columbia, S. Carolina.
Secor et al. 1991. Trans Am Fish Soc 120: 261-266.
Ahrenholz et al. 1994. Fish Bull 93: 209-216.
Hettler 1984. Trans. Am. Fish. Soc. 113: 370-373.
Nagiec et al. 1995. Fisheries Management and Ecol. 2:185-195.
Brooks et al. 1994. North Am J Fish Management 14: 143-150.
Blom et al. 1994. Aquaculture and Fisheries Management 25 (Suppl1): 229-243
Beckman et al. 1996. Trans Am Fish Soc 125: 146-149
Dabrowski and Tsukamoto. 1986. J. Fish Biol 29: 691-698
Hope that this helps, and thanks again to those which responded to my request.
Cheers,
Hugues
*********************************************** Hugues Benoit
Ocean Sciences Center Memorial University of Newfoundland St.-John's, Newfoundland, Canada (709) 772-6184
e-mail: [log in to unmask] ***********************************************
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