Fish larval recruitment to reefs is a thyroid hormone-mediated metamorphosis sensitive to the pesticide chlorpyrifos

Elife. 2017 Oct 30:6:e27595. doi: 10.7554/eLife.27595.

Abstract

Larval recruitment, the transition of pelagic larvae into reef-associated juveniles, is a critical step for the resilience of marine fish populations but its molecular control is unknown. Here, we investigate whether thyroid-hormones (TH) and their receptors (TR) coordinate the larval recruitment of the coral-reef-fish Acanthurus triostegus. We demonstrate an increase of TH-levels and TR-expressions in pelagic-larvae, followed by a decrease in recruiting juveniles. We generalize these observations in four other coral reef-fish species. Treatments with TH or TR-antagonist, as well as relocation to the open-ocean, disturb A. triostegus larvae transformation and grazing activity. Likewise, chlorpyrifos, a pesticide often encountered in coral-reefs, impairs A. triostegus TH-levels, transformation, and grazing activity, hence diminishing this herbivore's ability to control the spread of reef-algae. Larval recruitment therefore corresponds to a TH-controlled metamorphosis, sensitive to endocrine disruption. This provides a framework to understand how larval recruitment, critical to reef-ecosystems maintenance, is altered by anthropogenic stressors.

Keywords: Acanthurus triostegus; Chlorpyrifos; Coral reef fish; Metamorphosis; Thyroid hormones; developmental biology; ecology; stem cells.

MeSH terms

  • Animals
  • Behavior, Animal*
  • Chlorpyrifos / toxicity*
  • Coral Reefs*
  • Ecosystem
  • Fishes / physiology*
  • Larva / physiology
  • Metamorphosis, Biological*
  • Pesticides / toxicity*
  • Thyroid Hormones / metabolism*

Substances

  • Pesticides
  • Thyroid Hormones
  • Chlorpyrifos

Grants and funding

No external funding was received for this work