Diving beetle offspring oviposited in amphibian spawn prey on the tadpoles upon hatching

John Gould*, Jose W. Valdez, John Clulow, Simon Clulow

*Corresponding author for this work

Research output: Contribution to journalArticle

Abstract

In highly ephemeral freshwater habitats, predatory vertebrates are typically unable to become established, leaving an open niche often filled by macroinvertebrate predators. However, these predators are faced with the challenge of finding sufficient food sources as the rapid rate of desiccation prevents the establishment of extended food chains and limits the number of prey species present. It could therefore be advantageous for predators to synchronize their phenology with that of their prey within sites of extreme ephemerality. We report the first case of adult diving beetles (Hydaticus parallelus) ovipositing their eggs within spawn of an amphibian species (sandpaper frog, Lechriodus fletcheri). This behavior was found among several pools used by L. fletcheri for reproduction. Beetle eggs oviposited in frog spawn were found to hatch within 24 h of the surrounding L. fletcheri eggs, with the larvae becoming voracious consumers of the hatched tadpoles. Although it has yet to be established experimentally whether this is an adaptive behavior, the laying of eggs among potential future tadpole prey in this instance should confer significant fitness benefits for the offspring upon hatching, ensuring that they are provided an immediate source of food at the start of their development and potentially throughout. This oviposition behavior might be common among diving beetles and could form a significant predatory threat for amphibians with a free-swimming larval stage in ephemeral freshwater habitats.

Original languageEnglish
Pages (from-to)393-397
Number of pages5
JournalEntomological Science
Volume22
Issue number4
Early online date7 Oct 2019
DOIs
Publication statusPublished - Dec 2019

Keywords

  • Anura
  • Coleoptera
  • Dytiscidae
  • ephemeral
  • Hydaticus parallelus
  • invertebrate
  • predator-prey interaction

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