Swimming patterns associated with foraging in phylogenetically and ecologically diverse American weakly electric teleosts (Gymnotiformes)

Priya Nanjappa, Lance Brand, Michael Lannoo

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The backwards swimming behavior exhibited by American weakly electric fishes (Gymnotiformes) is thought to be an important component of foraging, particularly in the electrolocation of prey items. Previous studies of Eigenmannia virescens and Apteronotus albifrons have shown that backwards swimming appears to allow a fish to scan a potential prey item across its cutaneous electroreceptor array, then put itself in position for a short, forward lunge preceding ingestion. Adult gymnotiforms exhibit considerable variation in size, shape, and electric organ characteristics. For example, gymnotiforms produce either a wave or a pulse electric organ discharge (EOD). Given this variation, we ask whether the results reported previously can be completely generalized to all gymnotiforms. To address this question we observed the foraging patterns of phylogenetically and ecologically distinct gymnotiforms: three wave species, E. virescens, A. albifrons and Sternopygus macrurus; and three pulse species, Gymnotus carapo, Brachyhypopomus cf. brevirostris, and Rhamphichthys rostratus. Electric organ placement and body-shape were also noted in these species to determine if morphological differences correlate with variations in foraging behaviors. Results demonstrate that following prey detection the wave species examined primarily swim backwards during prey approach, prior to lunging forward and ingesting prey. This result is similar to previous findings. In contrast, the pulse species examined detect, approach, and ingest prey primarily in the forward direction, swimming backwards only to reposition themselves.

Original languageEnglish
Pages (from-to)97-104
Number of pages8
JournalEnvironmental Biology of Fishes
Volume58
Issue number1
DOIs
StatePublished - 2000

Fingerprint

teleost
foraging
animal morphology
fish
swimming behavior
ingestion
body shape
foraging behavior
Gymnotiformes
Apteronotus albifrons
Eigenmannia virescens
organ

Keywords

  • Backwards locomotion
  • Electrolocation
  • Electroreception
  • Foraging behavior
  • Reverse swimming

ASJC Scopus subject areas

  • Aquatic Science
  • Ecology

Cite this

Swimming patterns associated with foraging in phylogenetically and ecologically diverse American weakly electric teleosts (Gymnotiformes). / Nanjappa, Priya; Brand, Lance; Lannoo, Michael.

In: Environmental Biology of Fishes, Vol. 58, No. 1, 2000, p. 97-104.

Research output: Contribution to journalArticle

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