Spindly leg syndrome in Atelopus varius is linked to environmental calcium and phosphate availability

PLoS One. 2020 Jun 29;15(6):e0235285. doi: 10.1371/journal.pone.0235285. eCollection 2020.

Abstract

Spindly leg syndrome (SLS) is a relatively common musculoskeletal abnormality associated with captive-rearing of amphibians with aquatic larvae. We conducted an experiment to investigate the role of environmental calcium and phosphate in causing SLS in tadpoles. Our 600-tadpole experiment used a fully-factorial design, rearing Atelopus varius tadpoles in water with either high (80mg/l CaCO3), medium (50mg/l CaCO3), or low calcium hardness (20mg/l CaCO3), each was combined with high (1.74 mg/l PO4) or low (0.36 mg/l PO4) phosphate levels. We found that calcium supplementation significantly improved tadpole survival from 19% to 49% and that low calcium treatments had 60% SLS that was reduced to about 15% at the medium and high calcium treatments. Phosphate supplementation significantly reduced SLS prevalence in low calcium treatments. This experimental research clearly links SLS to the calcium: phosphate homeostatic system, but we were unable to completely eliminate the issue, suggesting an interactive role of other unidentified factors.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Animals
  • Bufonidae / abnormalities*
  • Bufonidae / growth & development
  • Calcium / administration & dosage
  • Calcium / adverse effects*
  • Environment
  • Musculoskeletal Abnormalities / etiology
  • Musculoskeletal Abnormalities / pathology*
  • Phosphates / administration & dosage
  • Phosphates / adverse effects*
  • Syndrome

Substances

  • Phosphates
  • Calcium

Grants and funding

We are grateful for financial support for this study from the Morris Animal Foundation D18ZO-040. The experiments were conducted in a laboratory facility established by the National Science Foundation Field Stations and Marine Laboratories Improvement Grant # 1227005. The Panama Amphibian Rescue and Conservation Project is a collaborative project between the Cheyenne Mountain Zoo, the Houston Zoo, Zoo New England and the Smithsonian Institution who collectively provide core operational support for this project. RI, and JG were supported in part by a grant from First Quantum Minerals, E.L. was supported by a grant from the Woodtiger Fund. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.