Behavioural red-light sensitivity in fish according to the optomotor response

Abstract

Various procedures have been adopted to investigate spectral sensitivity of animals, e.g. absorption spectra of visual pigments, electroretinography, optokinetic response, optomotor response (OMR) and phototaxis. The use of these techniques has led to various conclusions about animal vision. However, visual sensitivity should be evaluated consistently for a reliable comparison. In this study, we retrieved behavioural data of several fish species using a single OMR procedure and compared their sensitivities to near-infrared light. Besides cavefish that lack eyes, some species were not appropriate for the OMR test because they either stayed still or changed swimming direction frequently. Eight of 13 fish species tested were OMR positive. Detailed analyses using medaka, goldfish, zebrafish, guppy, stickleback and cichlid revealed that all the fish were sensitive to light at a wavelength greater than or equal to 750 nm, where the threshold wavelengths varied from 750 to 880 nm. Fish opsin repertoire affected the perception of red light. By contrast, the copy number of long-wavelength-sensitive ( LWS ) genes did not necessarily improve red-light sensitivity. While the duplication of LWS and other cone opsin genes that has occurred extensively during fish evolution might not aid increasing spectral sensitivity, it may provide some other advantageous ophthalmic function, such as enhanced spectral discrimination.

The Role of Vision and Lateral Line Sensing for Schooling in Giant Danios (Devario Aequipinnatus)

“…The spectral sensitivity for vision in near infrared in giant danios is not known, but their visual sensitivity is at between 50 and 150 times lower at 750 nm than at 500 nm (van Roessel, 1997), suggesting that they have even lower sensitivity at 850 nm. Similarly, closely related zebrafish (Brachydanio rerio) have a substantial drop in optomotor responsiveness at 840 nm (Matsuo et al, 2021), suggesting that zebrafish, and by extension giant danios, have much reduced vision at wavelengths greater than 840 nm. For the experiments with lateral line ablation, the giant danios were placed into gentamicin treated water (0.001% for 24 h, 5 litres, Sigma-Aldrich, St Louis, MO) following previously established protocols (Mekdara et al, 2018).…”

Kinematics and behaviour in fish escape responses: guidelines for conducting, analysing, and reporting experiments

“…If possible, we recommend using infrared illumination (>800nm). In our experience, fish respond more naturally in these conditions than under the bright light of a visible laser, even if many species are capable of seeing and responding to infrared light (Matsuo et al, 2021).…”

Predators and habitat association of post‐settlement snapper (Chrysophrys auratus)

“…To reduce infrared light reflectance, the GoPro Hero 3 camera was mounted on an additional aluminium bar (54 cm long) oriented to the side, but pointing towards the jar containing the post‐settlement snapper 64 cm away (Figure 2 ). The infrared illuminator provided a high‐powered (35 watt) 140° wide beam of light at 850 nm [and therefore not visible to many fish (Kobayashi et al ., 2002 ; Matsuo et al ., 2021 )] and was pointed at the restrained post‐settlement snapper c . 60 cm away.…”

“…In this way camera deployments covered a range of times and tidal states. The infrared illuminator provided a high-powered (35 watt) 140 wide beam of light at 850 nm [and therefore not visible to many fish (Kobayashi et al, 2002;Matsuo et al, 2021)] and was pointed at the restrained post-settlement snapper c. 60 cm away. To enable the camera to see this infrared light source, the authors removed the infrared filter contained within each GoPro Hero 3 used for night-time camera work.…”