Skip to main content

The effects of handling time, ambient light, and anaesthetic method, on the standardized measurement of fish colouration

Buy Article:

$50.00 plus tax (Refund Policy)


The effects of handling time, ambient light intensity, and anaesthetic method, on the collection of spectral reflectance data were assessed in two species of Malawi cichlids (Melanochromis auratus and Metriaclima zebra). Using spectrometry, colour patches were measured over 10min, under increasing ambient light levels, and using three anaesthetic methods. As time elapsed, maximum percent reflectance (Rmax) decreased across all anaesthetic methods and species, suggesting that measurements should be taken immediately after capture and anaesthetization. With increasing light intensity, Rmax increased significantly, suggesting that measurements should be taken under natural ambient conditions when possible. Finally, we found that anaesthetizing fish using an ice bath produced significantly higher Rmax than using either MS-222 (tricaine methanesulphonate) or clove oil (eugenol). However, the highest proportion of ultraviolet (UV) colouration was recorded while fish were anaesthetized with clove oil. Our results highlight the variation involved in measuring fish colour patterns using two related species, and thus indicate the need for a standardized approach to collecting spectral reflectance data in fish.

Nous avons évalué les effets du temps de manipulation, de l'intensité lumineuse ambiante et de la méthode d'anesthésie sur la récolte de données de réflectance spectrale chez deux espèces de cichlidés du Malawi (Melanochromis auratus et Metriaclima zebra). Nous avons mesuré par spectrométrie des taches de couleur pendant 10 minutes sous des intensités croissantes de lumière ambiante et en employant trois méthodes d'anesthésie. À mesure que le temps passe, le pourcentage maximum de réflectance (Rmax) décroît sous toutes les méthodes d'anesthésie et pour les deux espèces, ce qui indique que les mesures devraient être faites immédiatement après la capture et l'anesthésie. Sous une intensité lumineuse croissante, Rmax augmente de manière significative, ce qui laisse croire que les mesures devraient se faire, si possible, dans les conditions ambiantes naturelles. Enfin, l'anesthésie des poissons dans un bain de glace produit un Rmax significativement plus élevé que l'utilisation de MS-222 (méthanesulfonate de tricaïne) ou de l'huile de clou (eugénol). Cependant, la plus grande proportion de coloration ultraviolette (UV) est enregistrée lorsque les poissons sont anesthésiés avec de l'huile de clou. Nos résultats soulignent la variation qui existe dans la mesure des patrons de coloration de deux poissons apparentés et démontrent donc la nécessité d'une méthode standardisée pour la récolte de données de réflectance chez les poissons.

Document Type: Research Article

Publication date: February 1, 2011

More about this publication?
  • Published continuously since 1901 (under various titles), this monthly journal is the primary publishing vehicle for the multidisciplinary field of aquatic sciences. It publishes perspectives (syntheses, critiques, and re-evaluations), discussions (comments and replies), articles, and rapid communications, relating to current research on cells, organisms, populations, ecosystems, or processes that affect aquatic systems. The journal seeks to amplify, modify, question, or redirect accumulated knowledge in the field of fisheries and aquatic science. Occasional supplements are dedicated to single topics or to proceedings of international symposia.
  • Information for Authors
  • Submit a Paper
  • Subscribe to this Title
  • Terms & Conditions
  • Sample Issue
  • Reprints & Permissions
  • ingentaconnect is not responsible for the content or availability of external websites

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
Cookie Policy
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more