The University of Southampton
University of Southampton Institutional Repository

Impact of temperature on an emerging parasitic association between a sperm-feeding scuticociliate and Northeast Pacific sea stars

Impact of temperature on an emerging parasitic association between a sperm-feeding scuticociliate and Northeast Pacific sea stars
Impact of temperature on an emerging parasitic association between a sperm-feeding scuticociliate and Northeast Pacific sea stars
Global warming has important implications for the dynamics and ecological impacts of emerging diseases. We investigated temperature effects on scuticociliate, Orchitophrya cf. stellarum, infections in ripe testes of two Pacific northeast sea stars (Asterina miniata Brandt and Pisaster ochraceus Brandt) using laboratory and field approaches. We predicted that a small increase in temperature would result in higher ciliate growth rates and heightened infection intensities. To test this we (1) cultured free-living O. stellarum at 10 and 15 °C and quantified ciliate abundance after 3 days, and (2) housed sea stars of both species at 10 and 15 °C for durations varying from 4 to 21 days and then measured the infection intensity. Ciliate densities in cultures were two orders of magnitude higher in the warmer treatment. Infection intensity was also temperature sensitive: greater proportions of testes were infected and infection stage was more advanced at 15 versus 10 °C, leading to a reduction in spermatozoa and regression of the germinal layer within three weeks. In seven field populations surveyed, we found a tight linear correlation between infection prevalence (percent infected sea stars) and infection intensity (proportion of infected testes per individual and mean infection score). However, 45% of P. ochraceus testes exhibited heavy infections versus 8% of A. miniata testes, which may relate to the different thermal habitat of each species: P. ochraceus occurs higher on the shore and likely reaches higher body temperatures at low tide. While the sex ratio of A. miniata is unbiased, P. ochraceus populations are consistently female-biased and show no relationship to infection prevalence (ranged from 30 to 90%). O. cf. stellarum infections of testes of both sea stars are prevalent in field populations, are highly temperature sensitive, and lead to rapid loss of reproductive potential.
Asterina miniata, Pisaster ochraceus, Orchitophyra stellarum, Host, Parasite, Temperature
0022-0981
44-50
Bates, Amanda E.
a96e267d-6d22-4232-b7ed-ce4e448a2a34
Stickle, William B.
eb32699f-b020-4d49-b2a7-7cd9425f6942
Harley, Christopher D.G.
ebd1b1b2-2b3d-4086-bdab-f644d1d09af5
Bates, Amanda E.
a96e267d-6d22-4232-b7ed-ce4e448a2a34
Stickle, William B.
eb32699f-b020-4d49-b2a7-7cd9425f6942
Harley, Christopher D.G.
ebd1b1b2-2b3d-4086-bdab-f644d1d09af5

Bates, Amanda E., Stickle, William B. and Harley, Christopher D.G. (2010) Impact of temperature on an emerging parasitic association between a sperm-feeding scuticociliate and Northeast Pacific sea stars. Journal of Experimental Marine Biology and Ecology, 384 (1-2), 44-50. (doi:10.1016/j.jembe.2009.12.001).

Record type: Article

Abstract

Global warming has important implications for the dynamics and ecological impacts of emerging diseases. We investigated temperature effects on scuticociliate, Orchitophrya cf. stellarum, infections in ripe testes of two Pacific northeast sea stars (Asterina miniata Brandt and Pisaster ochraceus Brandt) using laboratory and field approaches. We predicted that a small increase in temperature would result in higher ciliate growth rates and heightened infection intensities. To test this we (1) cultured free-living O. stellarum at 10 and 15 °C and quantified ciliate abundance after 3 days, and (2) housed sea stars of both species at 10 and 15 °C for durations varying from 4 to 21 days and then measured the infection intensity. Ciliate densities in cultures were two orders of magnitude higher in the warmer treatment. Infection intensity was also temperature sensitive: greater proportions of testes were infected and infection stage was more advanced at 15 versus 10 °C, leading to a reduction in spermatozoa and regression of the germinal layer within three weeks. In seven field populations surveyed, we found a tight linear correlation between infection prevalence (percent infected sea stars) and infection intensity (proportion of infected testes per individual and mean infection score). However, 45% of P. ochraceus testes exhibited heavy infections versus 8% of A. miniata testes, which may relate to the different thermal habitat of each species: P. ochraceus occurs higher on the shore and likely reaches higher body temperatures at low tide. While the sex ratio of A. miniata is unbiased, P. ochraceus populations are consistently female-biased and show no relationship to infection prevalence (ranged from 30 to 90%). O. cf. stellarum infections of testes of both sea stars are prevalent in field populations, are highly temperature sensitive, and lead to rapid loss of reproductive potential.

Full text not available from this repository.

More information

Published date: 1 March 2010
Keywords: Asterina miniata, Pisaster ochraceus, Orchitophyra stellarum, Host, Parasite, Temperature
Organisations: Ocean and Earth Science

Identifiers

Local EPrints ID: 361238
URI: https://eprints.soton.ac.uk/id/eprint/361238
ISSN: 0022-0981
PURE UUID: 3e9b2512-81c0-4ef3-8e8f-f47a9e892f73

Catalogue record

Date deposited: 15 Jan 2014 15:02
Last modified: 16 Jul 2019 21:14

Export record

Altmetrics

Contributors

Author: Amanda E. Bates
Author: William B. Stickle
Author: Christopher D.G. Harley

University divisions

Download statistics

Downloads from ePrints over the past year. Other digital versions may also be available to download e.g. from the publisher's website.

View more statistics

Atom RSS 1.0 RSS 2.0

Contact ePrints Soton: eprints@soton.ac.uk

ePrints Soton supports OAI 2.0 with a base URL of https://eprints.soton.ac.uk/cgi/oai2

This repository has been built using EPrints software, developed at the University of Southampton, but available to everyone to use.

We use cookies to ensure that we give you the best experience on our website. If you continue without changing your settings, we will assume that you are happy to receive cookies on the University of Southampton website.

×