Understanding the complex visual system of Mantis Shrimps (Stomatopods); a new form of colour processing?
University of Queensland, Queensland Brain Institute, Australia
National Cheng Kung University, Taiwan
Mantis shrimps have one of the most complex visual systems in the world, with 12 different spectral channels separated into 6 rows of enlarged ommatidia termed the midband. Why mantis shrimps have so many spectral sensitivities is not known, but it is unlikely that they have a “12-dimensional” colour space. Humans and other animals with known colour vision use an opponency system where colour is processed in an antagonistic manner recording the differences in activity from the photoreceptors. If Mantis shrimps were to use the same system it would require a highly complex network of neuronal wiring, and previous work on the neural connections beneath the retina does not suggest such a complexity. We propose instead that they either use a simpler system where information is “binned” and transmitted linearly and in parallel from the photoreceptors without any complex processing or that each mid band row processes colour from a narrow spectral window separately in six dichromatic sub-sets. Either system would be a completely new way of processing colour, never before seen in any other animal. A variety of methods have been employed to investigate how the mantis shrimps colour processing works; Intracellular electrophysiological recordings of each individual photoreceptor have been performed to determine the exact spectral sensitivities of the stomatopod species Haptosquilla trispinosa. Novel associative learning experiments have been used to test the spectral discrimination abilities of H. trisponosa and to obtain a spectral discrimination curve. Preliminary results from these tests indicates a much poorer spectral discrimination than you would expect from an animal with dichromatic comparisons and suggests that a form of parallel spectral binning is used to distinguish colours. We are now using various fluorescent imaging techniques to determine the neuronal morphology and connections to understand this system at the sub-retinal level.
Tenth International Congress of Neuroethology, College Park. Maryland USA, USA, 5 Aug - 10 Aug, 2012.
Poster (but consider for student poster award)
(2012). Understanding the complex visual system of Mantis Shrimps (Stomatopods); a new form of colour processing?.
Front. Behav. Neurosci.
Tenth International Congress of Neuroethology.
30 Apr 2012;
07 Jul 2012.
Mrs. Hanne H Thoen, University of Queensland, Queensland Brain Institute, St Lucia, Brisbane, QLD, 4072, Australia, email@example.com