Using a thermistor flowmeter with attached video camera for monitoring sponge excurrent speed and oscular behaviour

Brian W Strehlow; Damien Jorgensen; Nicole S Webster; Mari-Carmen Pineda; Alan Duckworth

doi:10.7717/peerj.2761

Using a thermistor flowmeter with attached video camera for monitoring sponge excurrent speed and oscular behaviour

PeerJ. 2016 Dec 13:4:e2761. doi: 10.7717/peerj.2761. eCollection 2016.

Authors

Brian W Strehlow¹, Damien Jorgensen², Nicole S Webster³, Mari-Carmen Pineda³, Alan Duckworth³

Affiliations

¹ Centre for Microscopy, Characterisation and Analysis, School of Plant Biology, and Oceans Institute, University of Western Australia, Crawley, WA, Australia; Western Australian Marine Science Institution, Crawley, WA, Australia; Australian Institute of Marine Science, Townsville, QLD, Australia.
² Australian Institute of Marine Science , Townsville , QLD , Australia.
³ Western Australian Marine Science Institution, Crawley, WA, Australia; Australian Institute of Marine Science, Townsville, QLD, Australia.

Abstract

A digital, four-channel thermistor flowmeter integrated with time-lapse cameras was developed as an experimental tool for measuring pumping rates in marine sponges, particularly those with small excurrent openings (oscula). Combining flowmeters with time-lapse imagery yielded valuable insights into the contractile behaviour of oscula in Cliona orientalis. Osculum cross-sectional area (OSA) was positively correlated to measured excurrent speeds (ES), indicating that sponge pumping and osculum contraction are coordinated behaviours. Both OSA and ES were positively correlated to pumping rate (Q). Diel trends in pumping activity and osculum contraction were also observed, with sponges increasing their pumping activity to peak at midday and decreasing pumping and contracting oscula at night. Short-term elevation of the suspended sediment concentration (SSC) within the seawater initially decreased pumping rates by up to 90%, ultimately resulting in closure of the oscula and cessation of pumping.

Keywords: Behaviour; Contraction; Flowmeter; Pumping; Sponge; Thermistor.

Grants and funding

This research was funded by the Western Australian Marine Science Institution (WAMSI) as part of the WAMSI Dredging Science Node, and made possible through investment from Chevron Australia, Woodside Energy Limited, BHP Billiton as environmental offsets and by co-investment from the WAMSI Joint Venture partners. The views expressed herein are those of the authors and not necessarily those of WAMSI. NSW was funded by an Australian Research Council Future Fellowship FT120100480. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.