Integrating a thermistor flowmeter and time lapse imagery to monitor sponge (Porifera) behaviour

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1 School of Plant Biology; Centre for Microscopy, Characterisation and analysis; and Oceans Institute, Universtiy of Western Australia, Crawley, WA, Australia
2 Western Australian Marine Science Institution, Crawley, WA, Australia
3 Australian Institute of Marine Science, Townsville, QLD, Australia
4 Sustainable Coastal Ecosystems & Industry in Tropical Australia, Australian Institute of Marine Science, Townsville, QLD, Australia
DOI
10.7287/peerj.preprints.2137v1
Published
Accepted
Subject Areas
Animal Behavior, Marine Biology
Keywords
Flowmeter, Sponge, Thermistor, Pumping, Behaviour, Contraction
Copyright
© 2016 Strehlow et al.
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
Strehlow BW, Jorgensen D, Webster NS, Pineda M, Duckworth A. 2016. Integrating a thermistor flowmeter and time lapse imagery to monitor sponge (Porifera) behaviour. PeerJ Preprints 4:e2137v1

Abstract

A digital, four-channel thermistor flowmeter was developed as an experimental tool for measuring pumping rates in marine sponges, particularly those with small excurrent pores (oscula). The flowmeter is integrated with time lapse cameras and has an accuracy of ±5 mm s-1 over the range of 5–200 mm s-1, a spatial resolution of 1.4 mm, and an adjustable temporal resolution of 5 seconds. Combining flowmeters with time lapse imagery yielded valuable insights into the contractile behaviour of oscula in Cliona orientalis, revealing four distinct oscula states: (1) osculum open with extended papilla, (2) osculum closed with extended papilla, (3) osculum closed with papilla retracted, and (4) osculum closed with papilla retracted and contraction of region surrounding osculum. Osculum area was positively correlated to measured excurrent velocities, indicating that sponge pumping and osculum contraction are coordinated behaviours. 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 within the seawater initially decreased pumping rates by up to 90%, ultimately resulting in closure of the oscula and cessation of pumping. The thermistor flowmeter developed here will be a valuable tool to monitor behaviour, physiology and ecophysiology of sponges.

Author Comment

This is a submission to PeerJ for review.

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