The accurate observation of physiological changes on in vivo samples of important animal species such as Euphausia superba (Antarctic krill) is an important goal in helping to understand how environmental changes can affect animal development. Using a custom made ‘krill trap’, live un-anaesthetized krill were confined for seven hours, during which three hours of optical imaging were obtained and no subsequent ill effects observed. The trap enabled two imaging methods to be employed: optical coherence tomography (OCT) and microscopy. OCT enabled internal structure and tissues to be imaged to a depth of approximately 2 mm and resolution of approximately 12 μm. Microscopy was used to observe heart rate. During our experiments, we imaged a range of internal structures in live animals including the heart and gastric areas. The trap design enables a new generation of mixed modality imaging of these animals in vivo. These techniques will enable detailed studies of the internal physiology of live krill to be undertaken under a wide range of environmental conditions and have the potential to highlight important variations in behaviour and animal development.
Bibliographical noteFunding Information:
The collection and rearing of krill specimens was funded by the 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 an Australian Research Council grant FS110200057. CTAB acknowledges support for instrument development and shipping costs from the United Kingdom Engineering and Physical Sciences Research Council Grant EP/M000869/1 (Shaped Light at the Interface). Live wild krill were caught in the Southern Ocean under permits issued by the Australian Department of Environment and Heritage under the Environment Protection and Biodiversity Conservation Act 1999, permit WT2005-8619, and under the Antarctic Marine Living Resources Conservation Act 1981, permit AMLR 05-06_2655.
This work was supported by the Australian Antarctic Division Science Programme [project 4037], [project 4050]; Australian Research Council [grant FS110200057]; United Kingdom Engineering and Physical Sciences Research Council [grant EP/M000869/1].
All Science Journal Classification (ASJC) codes
- Aquatic Science