Prey Capture Ecology of the Cubozoan Carukia barnesi

PLoS One. 2015 May 13;10(5):e0124256. doi: 10.1371/journal.pone.0124256. eCollection 2015.

Abstract

Adult Carukia barnesi medusae feed predominantly on larval fish; however, their mode of prey capture seems more complex than previously described. Our findings revealed that during light conditions, this species extends its tentacles and 'twitches' them frequently. This highlights the lure-like nematocyst clusters in the water column, which actively attract larval fish that are consequently stung and consumed. This fishing behavior was not observed during dark conditions, presumably to reduce energy expenditure when they are not luring visually oriented prey. We found that larger medusae have longer tentacles; however, the spacing between the nematocyst clusters is not dependent on size, suggesting that the spacing of the nematocyst clusters is important for prey capture. Additionally, larger specimens twitch their tentacles more frequently than small specimens, which correlate with their recent ontogenetic prey shift from plankton to larval fish. These results indicate that adult medusae of C. barnesi are not opportunistically grazing in the water column, but instead utilize sophisticated prey capture techniques to specifically target larval fish.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Australia
  • Bites and Stings / physiopathology
  • Body Size
  • Cnidarian Venoms / metabolism
  • Cnidarian Venoms / toxicity*
  • Cubozoa / anatomy & histology
  • Cubozoa / pathogenicity
  • Cubozoa / physiology*
  • Feeding Behavior / physiology
  • Fishes
  • Larva / drug effects
  • Light
  • Nematocyst / anatomy & histology
  • Nematocyst / physiology*
  • Organ Size
  • Predatory Behavior / physiology*

Substances

  • Cnidarian Venoms

Grant support

NGS aquatic provided support in the form of salaries for author NS, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section.