The thermal range of the cushion sea star, Culcita novaeguineae, distribution and its behavioral response to warmer waters
- Published
- Accepted
- Subject Areas
- Animal Behavior, Conservation Biology, Ecology, Ecosystem Science, Marine Biology
- Keywords
- Culcita novaeguineae, temperature, distribution, ocean warming, behavior, tropical marine ecosystems, thermal tolerance, cushion star, Mo'orea, French Polynesia
- Copyright
- © 2016 Yokley
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ Preprints) and either DOI or URL of the article must be cited.
- Cite this article
- 2016. The thermal range of the cushion sea star, Culcita novaeguineae, distribution and its behavioral response to warmer waters. PeerJ Preprints 4:e2653v1 https://doi.org/10.7287/peerj.preprints.2653v1
Abstract
Overproduction of greenhouse gases is driving climate change and increasing the average temperature of oceans worldwide. As a result, organisms are exhibiting behavioral changes and species are shifting their natural distribution. This study aimed to assess the effects of temperature on C. novaeguineae distribution and movement in order to predict the effects of rising sea temperature on this echinoderm’s behavior and ecology. The distribution study measured the temperature gradient of the cushion star’s current habitat in order to determine how temperature changes with respect to depth. Additionally, the cushion star’s distribution range in relation to depth and sea temperature was examined to demonstrate how temperature influences cushion star range. The field experiment was conducted to determine the effects of increased temperature on C. novaeguineae behavior. Movement, a common mechanism used by ectotherms to escape heat stress, was measured as the response variable in cushion stars heat shocked in ocean waters 3°C above their expected upper thermal limit and in control organisms kept in ambient ocean waters of 31°C. The results of the distribution survey found that temperature decreased as depth increased. And cushion stars were generally found at 1, 2, and 3 meters and in temperatures between 29°C and 31°C. The field experiment revealed that the heat shocked individuals moved 3.2 times further than the control organisms and twice the number of heat shocked cushion stars moved into deeper waters than control organisms. This study suggests that temperature is the major factor affecting cushion star distribution and increased temperature promotes movement into greater depths. Consequently, as the ocean continues to warm, cushion stars may move into deeper waters to find relief from the heat stress, altering the structure of the shallow, coral reef ecosystem in which cushion stars are currently abundant.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Raw data
Raw data of field study and experimental data.