Electrophysiological evidence for linear polarization sensitivity in the compound eyes of the stomatopod crustacean Gonodactylus chiragra.
Gonodactyloid stomatopod crustaceans possess polarization vision, which enables them to discriminate light of different e-vector angle. Their unusual apposition compound eyes are divided by an equatorial band of six rows of enlarged, structurally modified ommatidia, the mid-band (MB). The rhabdoms of the two most ventral MB rows 5 and 6 are structurally designed for polarization vision. Here we show, with electrophysiological recordings, that the photoreceptors R1-R7 within these two MB rows in Gonodactylus chiragra are highly sensitive to linear polarized light of two orthogonal directions (PS=6.1). They possess a narrow spectral sensitivity peaking at 565 nm. Unexpectedly, photoreceptors within the distal rhabdomal tier of MB row 2 also possess highly sensitive linear polarization receptors, which are in their spectral and polarization characteristics similar to the receptors of MB rows 5 and 6. Photoreceptors R1-R7 within the remainder of the MB exhibit low polarization sensitivity (PS=2.3). Outside the MB, in the two hemispheres, R1-R7 possess medium linear polarization sensitivity (PS=3.8) and a broad spectral sensitivity peaking at around 500 nm, typical for most crustaceans. Throughout the retina the most distally situated UV-sensitive R8 cells are not sensitive to linear polarized light.
Kleinlogel
Sonja
S
Vision Touch and Hearing Research Centre, School of Biomedical Sciences, University of Queensland, Brisbane QLD 4072, Australia. S.Kleinlogel@uq.edu.au
Marshall
N Justin
NJ
D000818:Animals; D003445:Crustacea / Q000166:cytology / Q000502:physiology*; D004594:Electrophysiology; D005260:Female; D008027:Light; D008297:Male; D017956:Photoreceptor Cells, Invertebrate / Q000166:cytology / Q000502:physiology*; D013057:Spectrum Analysis; D014785:Vision, Ocular / Q000502:physiology*