The application of optical coherence tomography to image subsurface tissue structure of antarctic krill Euphausia Superba

• Published in: PLoS ONE
• Main Authors: Bellini, Nicola, Cox, M.J., Harper, D.J., Stott, S.R., Ashok, P.C., Dholakia, K., Kawaguchi, S., King, R., Horton, T., Brown, C.T.A.
• Other Authors: European Commission, EPSRC, University of St Andrews.School of Physics and Astronomy, University of St Andrews.Biomedical Sciences Research Complex
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2014
• Subjects: QC Physics; QH301 Biology; SDG 14 - Life Below Water; QC; QH301; Antarctic; Antarc*; Antarctic Krill; Antarctica; Australian Antarctic Division; Euphausia superba
• Online Access: https://hdl.handle.net/10023/5794; https://doi.org/10.1371/journal.pone.0110367; http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0110367#s5

The collection and rearing of krill specimens was funded by Australian Antarctic Division science programme Project 4037 (Experimental Krill Biology: Response of krill to environmental change), and Project 4050 (Assessing change in krill distribution and abundance in Eastern Antarctica). MJC is funded by Australian Research Council grant FS110200057. The OCT imaging was funded in part by the U.K. Engineering and Physical Sciences Research Council grant EP/G061688/1, the European Union European Union project FAMOS (FP7 ICT, contract no. 317744) and the CR-UK/EPSRC/MRC/DoH (England) imaging programme. DH was funded by a School of Physics and Astronomy Student Staff Council Vacation Award research studentship. Many small open ocean animals, such as Antarctic krill, are an important part of marine ecosystems. To discover what will happen to animals such as krill in a changing ocean, experiments are run in aquaria where conditions can be controlled to simulate water characteristics predicted to occur in the future. The response of individual animals to changing water conditions can be hard to observe, and with current observation techniques it is very difficult to follow the progress of an individual animal through its life. Optical coherence tomography (OCT) is an optical imaging technique that allows images at high resolution to be obtained from depths up to a few millimeters inside biological specimens. It is compatible with in vivo imaging and can be used repeatedly on the same specimens. In this work, we show how OCT may be applied to post mortem krill samples and how important physiological data such as shell thickness and estimates of organ volume can be obtained. Using OCT we find an average value for the thickness of krill exoskeleton to be (30±4) µm along a 1 cm length of the animal body. We also show that the technique may be used to provide detailed imagery of the internal structure of a pleopod joint and provide an estimate for the heart volume of (0.73±0.03) mm3. Peer reviewed