Environmental Biology of Fishes

, Volume 86, Issue 3, pp 427–441 | Cite as

Why is the neon tetra so bright? Coloration for mirror-image projection to confuse predators? “Mirror-image decoy” hypothesis

Article

Abstract

The neon tetra (Paracheirodon innesi), which inhabits blackwater streams of the Amazon basin, has extremely bright coloration characterized by metallic blue-green stripes. To clarify the ecological function of this coloration, we examined the appearance of living neon tetra. They changed color in response to lighting and background conditions, and became less conspicuous under each condition to the human eye. Although they appeared bright in colorless clear water, their stripes appeared darker in blackwater. In addition, the visible area of their stripes was small and their brightness decreased, unless they were observed within a limited viewing angle (approximately 30° above the horizon). The results show that from the viewpoint of approaching submerged predators, a bright mirror image of the stripes is projected onto the underside of the water’s surface, providing a dramatic visual target while the real fish remains less conspicuous. Based on these results, we hypothesize that the neon tetra’s bright coloration is an effective predator evasion strategy that confuses predators using bright mirror images.

Keywords

Anti-predation Camouflage Iridophore Aposematic 

Abbreviations

θ

the angle between the horizontal and the line of measurement/sight

References

  1. Brooks JL (1968) The effects of prey-size selection by lake planktivores. Syst Zool 17:272–291CrossRefGoogle Scholar
  2. Clothier J, Lythgoe JN (1987) Light-induced colour changes by the iridophores of the neon tetra, Paracheirodon innesi. J Cell Sci 88:663–668PubMedGoogle Scholar
  3. Endler JA (1990) On the measurement and classification of colour in studies of animal colour patterns. Biol J Linn Soc 41:315–352CrossRefGoogle Scholar
  4. Fernald RD, Liebman PA (1980) Visual receptor pigments in the African cichlid fish, Haplochromis burtoni. Vision Res 20:857–864CrossRefPubMedGoogle Scholar
  5. Geisler R (1979) Exploding the habitat of the neon tetra. Aquar Dig Int 24:24–27Google Scholar
  6. Géry J (1966) A review of certain Tetragonopterinae (Characoidei), with the description of two new genera. Ichtyol Aquar J 37:211–236Google Scholar
  7. Hayashi H, Sugimoto M, Oshima N, Fujii R (1993) Circadian motile activity of erythrophores in the red abdominal skin of tetra fishes and its possible significance in chromatic adaptation. Pigment Cell Res 6:29–36CrossRefPubMedGoogle Scholar
  8. Hooper PL, Miller GF (2008) Mutual mate choice can drive costly signaling even under perfect monogamy. Adapt Behav 16:53–70CrossRefGoogle Scholar
  9. Janssen J (1981) Searching for zooplankton just outside Snell’s window. Limnol Oceanogr 26:1168–1171CrossRefGoogle Scholar
  10. Kasai A, Oshima N (2006) Light-sensitive motile iridophores and visual pigments in the neon tetra, Paracheirodon innesi. Zool Sci 23:815–819CrossRefPubMedGoogle Scholar
  11. Kobayashi S (1990) Tsuchi no 100 fushigi (100 Questions about soil). Tokyo Shoseki, Tokyo, Japan, pp 122–123 in JapaneseGoogle Scholar
  12. Levine JS, MacNichol EF Jr (1979) Visual pigments in teleost fishes: effects of habitat, microhabitat and behavior on visual system evolution. Sens Process 3:95–130Google Scholar
  13. Li-Cor (1982) Radiation measurements and instrumentation. Publication 8202-LM, Lincoln, NebraskaGoogle Scholar
  14. Lythgoe JN, Shand J (1982) Changes in spectral reflections from the iridophores of the neon tetra. J Physiol 325:23–34PubMedGoogle Scholar
  15. Lythgoe JN, Shand J (1983) Diel colour changes in the neon tetra Paracheirodon innesi. Environ Biol Fishes 8:249–254CrossRefGoogle Scholar
  16. Muntz WRA (1982) Visual adaptations to different light environments in Amazonian fishes. Rev Can Biol Exp 41:35–46PubMedGoogle Scholar
  17. Myers GS (1936) A new characid fish of the genus Hyphessobrycon from the Peruvian Amazon. Proc Biol Soc Wash 49:97–98Google Scholar
  18. Nagaishi H, Oshima N (1989) Neural control of motile activity of light-sensitive iridophores in the neon tetra. Pigment Cell Res 2:485–492CrossRefPubMedGoogle Scholar
  19. Nagaishi H, Oshima N (1992) Ultrastructure of the motile iridophores of the neon tetra. Zool Sci 9:65–75Google Scholar
  20. Nagaishi H, Oshima N, Fujii R (1990) Light-reflecting properties of the iridophores of the neon tetra, Paracheirodon innesi. Comp Biochem Physiol 95A:337–341Google Scholar
  21. National research council (1996) Guide for care and use of laboratory animals. National Academy Press, Washington, D.CGoogle Scholar
  22. Neudecker S (1989) Eye camouflage and false eyespots: chaetodontid responses to predators. Environ Biol Fishes 25:143–157CrossRefGoogle Scholar
  23. Oshima N, Nagaishi H (1992) Study of the motile mechanism in neon tetra (Paracheirodon innesi) iridophores. Comp Biochem Physiol 102A:273–278CrossRefGoogle Scholar
  24. Shultz H (1962) The kingdom of the neon tetra. N J Trop Fish Hobbyist 20:60–65Google Scholar
  25. Stevens M, Parraga CA, Cuthill IC, Partridge JC, Troscianko T (2007) Using digital photography to study animal coloration. Biol J Linnean Soc 90:211–237CrossRefGoogle Scholar
  26. Thimijan RW, Heins RD (1983) Photometric, radiometric, and quantum light units of measure: a review of procedures for interconversion. Hort Sci 18:818–822Google Scholar
  27. Weizman SH, Fink WL (1983) Relationships of the neon tetras, a group of South American freshwater fishes (Teleosti, Characidae), with comments on the phylogeny of New World characiforms. Bull Mus Comp Zool 150:339–395Google Scholar

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  1. 1.Graduate school of Bioscience and BiotechnologyTokyo Institute of TechnologyTokyoJapan
  2. 2.Wildlife Research CenterKyoto UniversityKyotoJapan

Personalised recommendations