- Open Access
Fluorescence characterisation and visual ecology of pseudocheilinid wrasses
Frontiers in Zoology volume 13, Article number: 13 (2016)
Wrasses represent the second largest family of marine fishes and display a high diversity of complex colours linked to ecological functions. Recently, red autofluorescent body colouration has been reported in some of these fishes. However, little is known about the distribution of such fluorescent body patterns in wrasses or the animals’ ability to perceive such colours.
Against this background, we (1) investigated long-wavelength emission autofluorescence in thirteen species of pseudocheilinid wrasses and (2) characterised the spectral absorbance of visual pigments in one of the examined species, the fairy wrasse Cirrhilabrus solorensis. Spectrophotometric analysis revealed that fluorescent body colouration is widespread and diverse within this clade, with considerable variation in both fluorescent pattern and maximum emission wavelength between species. Characterisation of visual pigments in retinal photoreceptors showed a single class of rod and three spectrally distinct cone photoreceptors, suggesting possible trichromacy.
Combining the emission characteristics of fluorescence body colouration and the spectral sensitivity data of retinal cells suggests that the visual system of C. solorensis is sensitive to pseudocheilinid fluorescence.
Wrasses (Labridae) represent the second largest marine fish family, containing more than 600 species within 82 genera . They are one of the most morphologically and ecologically diverse clades of marine teleosts [2–4] and are a dominant group in reef fish communities . Wrasses display a staggering diversity of complex colours virtually unique to this family [6, 7]. These colours have been linked to important ecological functions such as camouflage and aggressive mimicry , interspecific signalling  as well as courtship and male competition [10–12]. Yet, the range of colours that can bear such ecological functions is limited by two factors: the ability to generate colours under water and the visual capabilities of the fish.
Many wrasses live in the spectrally restricted part of the ocean – the ‘stenospectral zone’  – where reflective colours do not appear as they do at the surface . That is because with increasing depth, the long-wavelength (>600 nm) part of downwelling sunlight is quickly absorbed by sea water, which is most transparent to blue light of wavelengths at around 480 nm [15–17]. This lack of long-wavelength sunlight below about 10 to 20 m depth inhibits red and orange reflective colouration, which consequently appears grey or black under these conditions . In contrast, recently described red fluorescence in a wide variety of reef fishes – including wrasses – [19, 20] constitutes a fundamentally different mechanism, where fluorescent structures absorb ambient short-wavelength blue light and re-emit photons at longer wavelengths. This process can enable the display of red colour even at depths devoid of red sunlight. Hence, fluorescence can generate conspicuous colour contrasts, particularly in the near monochromatic light environment prevalent in most parts of the ocean . Yet for now, there is only limited data on both the perception and function of red fluorescence in fishes.
Research on the visual capabilities of reef fishes has advanced greatly with the use of microspectrophotometry (MSP) to measure the spectral absorbance of individual photoreceptors. This has led to a growing body of data with photoreceptor sensitivities of more than 80 reef fish species characterised to date [21–25]. However, despite the high number of species and the ecological importance of labrids, only few studies have analysed photoreceptor sensitivities in wrasses [7, 26] and therefore the visual capabilities of this family is mostly unknown.
This study investigates long-wavelength (>640 nm) fluorescence in 13 species of pseudocheilinid wrasses. Pseudocheilines are a monophyletic clade  of diurnal zooplanktivores (but see also ) and inhabit the base of tropical reefs at depths of 20 to 50 m, some venturing as deep as 200 m [4, 28–32], well within the stenospectral zone devoid of red sunlight. When first describing fluorescence in reef fishes, Michiels et al.  noted two autofluorescent pseudocheilinid species, Pseudocheilinus evanidus  and Paracheilinus octotaenia . Since then, fluorescence has been observed in more than 180 reef fish taxa, often in complex, clade-dependent patterns  and has been suggested to play a role in intraspecific communication . Indeed, recent behavioural experiments have shown that the pseudocheilinid fairy wrasse Cirrhilabrus solorensis  can perceive its own red fluorescent body colouration and that this fluorescent colour affects agonistic male-male interactions .
This work aims to characterise the visual system of the pseudocheilinid wrasse C. solorensis by reporting microspectrophotometric measurements of the spectral absorbances of each of the retinal photoreceptor types as well as the spectral transmittance data on the ocular media. Linking this information on the visual capabilities of this species with the deep red fluorescence featured in Pseudocheilines, enables a more complete analysis of colour perception in labrids in general and the role of long-wavelength fluorescence in particular.
Fluorescent body patterns varied greatly across species and, in the few cases examined, between sexes. Fluorescence was observed in the fins – especially in the dorsal and caudal fin rays – and in many cases formed blotches near the operculum or stripes in the dorsolateral region of the body. To illustrate different fluorescent patterns among species, both blue illuminated fluorescence images and broad-spectrum white light images are displayed in Fig. 1.
Peak fluorescence emission in all 13 species examined ranged from 641 nm in Cirrhilabrus rubrisquamis  to 669 nm in Paracheilinus carpenteri  and Pseudocheilinus hexataenia . Moreover, fluorescent brightness differed strongly across species. Fluorescence is characterised by wavelength of maximum emission and fluorescent brightness in Fig. 2.
Microspectrophotometric data for all photoreceptor classes found in the fairy wrasse Cirrhilabrus solorensis are summarised in Table 1 and displayed in Figs. 3 and 4. All visual pigment absorbance spectra are considered to represent vitamin A1-based visual pigments (i.e. rhodopsins), according to the fit of the data to A1 visual pigment templates . The retina of C. solorensis contains at least four spectrally distinct visual pigments in three classes of photoreceptors: one type of rod containing a visual pigment with a mean wavelength of maximum absorbance (λ max) of the pre-bleach spectra at 492.3 ± 1.0 nm; one type of single cone with λ max of 514.1 ± 6.6 nm and one type of twin cone.
The twin cones possess different visual pigments in their respective cone members with λ max at 497.7 ± 6.3 nm in one member and 532.3 ± 3.0 nm in the other member. Inspection of individual scans from single cone outer segments and also the mean spectrum constructed from all acceptable single cone records suggest the possibility that single cones express more than one visual pigment: the absorbance spectrum deviates markedly from the template on the short-wavelength limb, i.e. has a greater spectral bandwidth, and the running average of the peak of the spectrum (507 nm) is different to the estimate of λ max obtained by fitting a regression line to the long wavelength limb (516 nm). Based on the data for rods and twin cones, we assume that all pigments are A1-based. We modelled the fit to the mean spectra of a combination of two A1-based visual pigments (different opsins) following the methods described elsewhere , which gave predicted λ max values of 485 nm (41 %) and 527 nm (59 %) for the mean pre-bleach spectrum, and 489 nm (44 %) and 530 nm (56 %) for the mean difference spectrum. Both of the predicted λ max values are very close to the estimated λ max values of the pigments contained in the two members of the twin cone. The photoreceptor classes can be differentiated morphologically: rods are characterised by their long, cylindrical outer segments, while single cones feature shorter, conical outer segments. Twin cones comprise two members that resemble single cones in size and shape but have closely opposed inner and outer segments. For each receptor class, approximate sizes of the outer segments are given in Table 1.
Ocular media transmittance
The spectral transmittance of ocular media taken from two whole C. solorensis eyes is shown in Fig. 5. The wavelength of 0.5 transmittance (T 0.5) is 389 nm and no wavelengths shorter than approximately 360 nm can reach the retina.
The Pseudocheilines investigated here display a high diversity of deep red fluorescence: our data show variation in fluorescent peak emission and fluorescent brightness among species. In Cirrhilabrus cyanopleura , C. solorensis and C. tonozukai , both terminal-phase males and initial-phase females were analysed and distinct differences in relative fluorescence intensity and pattern, but not peak emission wavelength, were observed between sexes. These differences across species and sexes suggest that red fluorescence can potentially serve species recognition as well as mate choice and corroborate a potential signalling function [19, 20, 36, 44, 45].
Our microspectrophotometric data show that the fairy wrasse C. solorensis possesses three spectrally distinct cone visual pigments in one class of single cone and one class of twin cone. Although abundant in most teleost fish, birds, reptiles and marsupials, the exact function of twin- or double cones is not fully understood . While twin cones have long been associated with achromatic perception tasks such as luminance and polarisation detection [46–48], recent behavioural experiments have shown that one species reef fish can use twin cones for colour discrimination [49, 50]. It has thus been suggested that some fishes with one type of visual pigment in single cones and two different pigments in each member of twin cones are effectively trichromatic . The photoreceptor visual pigment λ max values of absorbance values of C. solorensis presented here are similar to existing data on other reef fish families  and generally match the blue dominated light environment, but lack a distinct UV cone receptor found in some shallow water species [26, 51]. This indicates that the visual system of fairy wrasses is well adapted to their stenospectral habitat, as predicted by the sensitivity hypothesis [21, 52].
The range of wavelengths an animal can perceive is not only dependent on the sensitivity of its visual pigments, but also on the wavelengths that can reach the retina  and so any interpretation of microspectrophotometric measurements must regard the ocular media spectral transmittance. Our data on whole eye samples in C. solorensis show a relatively high spectral transmittance across most of the spectrum with a short wavelength cut-off at approximately 360 nm. These results are consistent with previous work on ocular media in labrids, specifically data on Cirrhilabrus punctatus [54, 55].
Is the potentially trichromatic visual system of pseudocheilinid wrasses sensitive to their own long-wavelength fluorescence? When correcting the cone absorptance of C. solorensis for ocular media transmittance and combining the resulting spectral sensitivities with the fluorescence emission of the same species, there is a partial overlap at the long-wavelength sensitive twin cone member B (Fig. 6). While it is hard to predict how such an overlap is processed by the visual system, our physiological data indicate that the visual system of C. solorensis is sensitive to at least part of the fluorescence emitted by the Pseudocheilines characterised here. This notion is supported by our recent behavioural study in C. solorensis, where red fluorescent body colouration has been shown to affect male agonistic reactions . Microspectrophotometric measurements on the red fluorescent goby Eviota atriventris  indicate that this species, too, is capable of seeing its own fluorescence .
It has been argued that λ max values of photoreceptors are often shorter than expected due to physiological constraints of long-wavelength sensitive pigments, which are affected by thermal noise [17, 57]. However, it is important to note that colour vision is not the result of how much a certain receptor is stimulated in isolation, but how much it is stimulated in relation to other receptor types . By implication, even relatively weak long-wavelength absorbances can be sufficient to perceive a signal.
Our findings illustrate the presence and remarkable diversity of long-wavelength fluorescence in Pseudocheilines and provide descriptive data on their visual system, for the first time showing potential trichromacy in labrids. These physiological measurements lay the foundation for future experiments on the potential functions of red fluorescence in reef fish.
Fluorescence characterisation of 13 species of Pseudocheilines (Table 2) took place at the University of Tübingen, Germany, approved by local state authority under permit no. ZO 1/12. Microspectrophotometric (MSP) and spectrophotometric (ocular media transmittance) measurements of Cirrhilabrus solorensis were carried out at the University of Western Australia, following procedures approved by the UWA Animal Ethics Committee (RA/3/100/1220). All animals were obtained from ornamental fish traders (von Wussow Importe, Pinneberg, Germany and Oceanreef, Wangara, Australia).
For fluorescence characterisation, each fish was first sedated using cooled water and then placed onto its right flank in a water-filled petri dish lined with non-reflective black cloth. Spectrometric measurements were taken with a cooled, low-noise spectrophotometer (QE65000, Ocean Optics, Florida, USA), a bifurcated fibre optic cable (Ocean Optics QR400-7-VIS-BX) with a waterproof probe and SpectraSuite software (Ocean Optics, v. 2.0.132). A green light laser excitation source (CPS532 Thorlabs, New Jersey, USA) was combined with a short pass filter to clean up the excitation signal (BrightLine HC 533/SP, AHF Analysetechnik, Tübingen, Germany) at the incoming arm and a long-pass filter (EdgeBasic 532R-25, Semrock, New York, USA) in the outgoing arm that leads the emitted light from the sample into the spectrometer. Each measurement was taken with the probe tip submerged and held at an angle of 45° relative to the surface of the fish (see also ). Every animal was measured repeatedly on several predefined locations: the eye, dorsal part of the head, the operculum, both ventral and dorsal parts of the lateral body as well as each fin. Within all individuals, peak fluorescent emission was highly consistent across these body parts. Hence, for each species investigated, a single summarising measurement of peak fluorescence emission (λ max) and maximum fluorescent brightness was obtained .
Following spectrometry, each animal was transferred into a small, custom-built photo chamber featuring a scale bar. The fish was then photographed under broad spectrum white light and monochromatic blue light from two 450 nm LED torches (mini compact LCD, Hartenberger, Köln, Germany) each in combination with a short pass filter (Thorlabs FD2C) for a sharper excitation cut-off. A digital still camera (Canon EOS 7D) and an EF-S 60 mm f/2.8 macro lens was used in combination with an optical long-pass filter (LEE filter no. 105, Hampshire, UK) for fluorescence images. The latter attenuated the excitation light (<550 nm) and enhanced the visibility of long wavelength fluorescence . Pictures were used to graphically illustrate different fluorescent patterns and to assess standard length (L S, i.e. the distance from the snout to the caudal peduncle) in ImageJ v. 1.45 s .
Microspectrophotometry of visual pigments
Five male Cirrhilabrus solorensis (L S = 4.5–6.1 cm) were used for MSP analysis. Animals were dark-adapted for 1 h prior to being euthanised with an overdose of tricaine methanesulphonate salt (MS222). Retinal tissue samples were collected as described in detail elsewhere [23, 24]. In short, both eyes of each specimen were removed and dissected under infrared (IR) illumination using an IR image converter mounted on a dissecting microscope in order to avoid bleaching of photopigments. One eye was immersed in Hickman’s teleost ringer (420 mOsmol kg−1) for immediate dissection and MSP analysis, while the other eye was stored in a light-tight container at 4 °C for use at the following day. The eye was hemisected and both the lens and the vitreous humour removed. The retina was then extracted, dissected into several small pieces (approximately 1–3 mm2) and each piece transferred into a drop of teleost ringer solution containing 8 % dextran (MW 282,000; Sigma D-7265) sitting on a glass coverslip. A second coverslip was placed on top of the retinal sample and the edges sealed with nail varnish. Individual samples thus prepared were stored at 4 °C (see ) and analysed within the same day.
Absorbance spectra (330–800 nm) of visual pigments within photoreceptor outer segments were measured using a computer-controlled, single-beam, wavelength-scanning microspectrophotometer (for details, see ). For each photoreceptor cell examined, a sample and baseline scan was made from cellular and tissue-free regions of the preparation, respectively [60, 61]. The baseline transmittance was subtracted from the sample resulting in a pre-bleach spectrum. In order to ensure that the measured spectrum originated from a photolabile visual pigment, each outer segment was then bleached with full spectrum (‘white’) light for 2 min and subsequent sample and baseline scans were used to create a post-bleach spectrum. This post-bleach spectrum was subtracted from the pre-bleach spectrum to calculate a bleaching difference spectrum for each photoreceptor outer segment [23, 61]. Individual absorbance spectra were normalised and then analysed as described in  and . Briefly, peak and long-wavelength offset absorbances were determined by fitting a variable-point unweighted running average to the data . Following the methods of Govardovskii , a regression line was then fitted to the normalised absorbance spectrum between 30 and 70 % of the normalised maximum on the long-wavelength limb to predict the wavelength of maximum absorbance (λ max). Only spectral measurements that satisfied established selection criteria (e.g. free from distortion and confirmed as photolabile, see ) were included in the final analysis. Ten such difference spectra were averaged from separate cell outer segments to calculate mean λ max values of each photoreceptor type. For display purposes, averaged spectra were overlaid with a vitamin A1-based rhodopsin template .
Ocular media transmittance
Spectral transmittance measurements (330–800 nm) were collected from one male C. solorensis (L S = 6.8 cm) euthanised with an overdose of MS222 and both eyes were immediately enucleated to avoid tissue degradation . A small (approximately 2–3 mm2) piece of sclera was cut out of the back of each eye near the optic nerve and the underlying choroid, pigment epithelium and retina was removed to create an opening for the incident measuring beam. The light transmitted through the ocular media, lens and cornea was then measured in air [53, 54] with an Ocean Optics S2000 spectroradiometer and a xenon light source (Ocean Optics PX-2) using the setup described in detail by Theiss et al. . The integration time was set to 2.5 ms with 100 scans averaged for each measurement. Three of such averaged measurements were taken per eye, resulting in a total of six averaged ocular media transmittance spectra. Each spectrum was then normalised at 700 nm and the wavelength of 0.5 transmittance (T 0.5) was determined [53, 54].
Availability of data and materials
The data set supporting the results of this article is included within the article and its Additional file 1.
Westneat MW, Alfaro ME. Phylogenetic relationships and evolutionary history of the reef fish family Labridae. Mol Phylogenet Evol. 2005;36:370–90.
Westneat MW, Alfaro ME, Wainwright PC, Bellwood DR, Grubich JR, Fessler JL, Clements KD, Smith LL. Local phylogenetic divergence and global evolutionary convergence of skull function in reef fishes of the family Labridae. Proc R Soc B Biol Sci. 2005;272:993–1000.
Bellwood D, Wainwright P, Fulton C, Hoey A. Functional versatility supports coral reef biodiversity. Proc R Soc B Biol Sci. 2006;273:101–7.
Allen GR, Erdmann MV. Reef Fishes of the East Indies. Perth, Australia: Tropical Reef Research; 2012.
Wainwright PC, Bellwood DR, Westneat MW. Ecomorphology of locomotion in labrid fishes. Environ Biol Fish. 2002;65:47–62.
Marshall NJ. Communication and camouflage with the same ‘bright’colours in reef fishes. Philos Trans R Soc London, Ser B. 2000;355:1243–8.
Marshall N, Jennings K, McFarland W, Loew E, Losey G. Visual biology of Hawaiian coral reef fishes. II. Colors of Hawaiian coral reef fish. Copeia. 2003;455–66.
Randall JE. A review of mimicry in marine fishes. Zool Stud. 2005;44:299.
Cheney KL, Grutter AS, Blomberg SP, Marshall NJ. Blue and yellow signal cleaning behavior in coral reef fishes. Curr Biol. 2009;19:1283–7.
Robertson D. The social and mating systems of two labrid fishes, Halichoeres maculipinna and H. garnoti, off the Caribbean coast of Panama. Mar Biol. 1981;64:327–40.
Dawkins M, Guilford T. Colour and pattern in relation to sexual and aggressive behaviour in the bluehead wrasse Thalassoma bifasciatum. Behav Process. 1993;30:245–51.
Braun C, Michiels NK, Siebeck UE, Sprenger D. Signalling function of long wavelength colours during agonistic male-male interactions in the wrasse Coris julis. MEPS. 2014;504:277–86.
Meadows MG, Anthes N, Dangelmayer S, Alwany MA, Gerlach T, Schulte G, Sprenger D, Theobald J, Michiels NK. Red fluorescence increases with depth in reef fishes, supporting a visual function, not UV protection. Proc R Soc B Biol Sci. 2014;281:20141211.
Marshall N. The visual ecology of reef fish colours. In: Espmark Y, Trondheim TAGR, editors. Animal signals Adaptive significance of signalling and signal design in animal communication. Norway: Tapir Publishers; 2000.
McFarland WN. The visual world of coral reef fishes. In: The ecology of fishes on coral reefs, 1 edition. Sale PF, editor. San Diego: Academic Press; 1991: p. 16–38
Loew ER, Zhang H. Propagation of visual signals in the aquatic environment: An interactive windows-based model. In: Ladich SPC F, Moller P, Kapoor BG, editors. Communication in Fishes. Volume 2. Enfield, NH, USA: Science Publishers; 2006. p. 281–302.
Warrant EJ, Johnsen S. Vision and the light environment. Curr Biol. 2013;23:R990–4.
Johnsen S. Optics of Life: A Biologist's Guide to Light in Nature. Princeton: Princeton University Press; 2012.
Michiels N, Anthes N, Hart N, Herler J, Meixner A, Schleifenbaum F, Schulte G, Siebeck U, Sprenger D, Wucherer M. Red fluorescence in reef fish: A novel signalling mechanism? BMC Ecol. 2008;8:16.
Sparks JS, Schelly RC, Smith WL, Davis MP, Tchernov D, Pieribone VA, Gruber DF. The Covert World of Fish Biofluorescence: A Phylogenetically Widespread and Phenotypically Variable Phenomenon. PLoS One. 2014;9, e83259.
Marshall J, Vorobiev M, Siebeck U. What does a reef fish see when sees a reef fish? In: Ladich SPC F, Moller P, Kapoor BG, editors. Communication in Fishes. Volume 2. 2006. p. 393–422. F. Ladich SPC, P. Moller and B.G. Kapoor (Series Editor).
Mosk V, Thomas N, Hart NS, Partridge JC, Beazley LD, Shand J. Spectral sensitivities of the seahorses Hippocampus subelongatus and Hippocampus barbouri and the pipefish Stigmatopora argus. Vis Neurosci. 2007;24:345.
Theiss SM, Lisney TJ, Collin SP, Hart NS. Colour vision and visual ecology of the blue-spotted maskray, Dasyatis kuhlii Müller & Henle, 1814. J Comp Physiol A. 2007;193:67–79.
Hart NS, Theiss SM, Harahush BK, Collin SP. Microspectrophotometric evidence for cone monochromacy in sharks. Naturwissenschaften. 2011;98:193–201.
Cortesi F, Musilová Z, Stieb SM, Hart NS, Siebeck UE, Malmstrøm M, Tørresen OK, Jentoft S, Cheney KL, Marshall NJ. Ancestral duplications and highly dynamic opsin gene evolution in percomorph fishes. Proc Natl Acad Sci. 2014;201417803.
Losey G, McFarland W, Loew E, Zamzow J, Nelson P, Marshall N. Visual biology of Hawaiian coral reef fishes. I Ocular transmission and visual pigments. Copeia. 2003;2003:433–54.
Schmitz L, Wainwright P. Ecomorphology of the eyes and skull in zooplanktivorous labrid fishes. Coral Reefs. 2011;30:415–28.
Randall JE. A review of the labrid fishes of the genus Cirrhilabrus from Japan, Taiwan and the Mariana Islands with descriptions of two new species. Micronesica. 1992;25:99–121.
Lieske E, Myers R. Collins pocket guide. Coral reef fishes Indo-Pacific & Caribbean including the Red Sea. New York: HarperCollins Publishers; 1994. P. 400.
Baensch HA, Debelius H. Meerwasseratlas. Melle, Germany: Mergus Verlags GmbH; 1997.
Randall JE, Nagareda BH. Cirrhilabrus bathyphilus, a new deep-dwelling labrid fish from the Coral Sea. Cybium. 2002;26:123–7.
Brokovich E, Einbinder S, Shashar N, Kiflawi M, Kark S. Descending to the twilight-zone: Changes in coral reef fish assemblages along a depth gradient down to 65 m. Mar Ecol Prog Ser. 2008;371:253–62.
Jordan DS, Evermann BW. Descriptions of a New Genus and Two New Species of Fishes from the Hawaiian Islands. Washington, D.C.: US Government Printing Office; 1903.
Fourmanoir P. Poissons capturés par la mission de la" Calypso" en Mer Rouge. In: Résultats scientifiques des campagnes de la "Calypso" : 1 Campagne en Mer Rouge (1951–1952). Paris: Masson; 1955. p. 195–203.
Bleeker P. Bijdrage tot de kennis der ichthyologische fauna van Solor. 1853.
Gerlach T, Sprenger D, Michiels NK. Fairy wrasses perceive and respond to their deep red fluorescent coloration. Proc R Soc B Biol Sci. 2014;281:20140787.
Randall JE, Emery A. A new labrid fish of the genus Cirrhilabrus from the Chagos Archipelago, Indian Ocean. J Aquaric Aquat Sci. 1983;3:21–4.
Randall JE, Lubbock R. Labrid fishes of the genus Paracheilinus, with descriptions of three new species from the Philippines. Jpn J Ichthyol. 1981;28.
Bleeker P. Tiende Bijdrage tot de kennis der ichthyologische fauna van Borneo. Visschen van de rivieren Barito, Kahajan en Kapoeas, door Dr. P. Bleeker. Lange; 1857.
Govardovskii V, Fyhrquist N, Reuter T, Kuzmin D, Donner K. In search of the visual pigment template. Vis Neurosci. 2000;17:509–28.
Temple S, Hart NS, Marshall NJ, Collin SP. A spitting image: specializations in archerfish eyes for vision at the interface between air and water. Proc R Soc Lond B Biol Sci. 2010;277:2607–15.
Bleeker P. Bijdrage tot de kennis der ichthyologische fauna van Singapore. 1851.
Allen G, Kuiter R. Descriptions of two new wrasses of the genus Cirrhilabrus (Labridae) from Indonesia. Aqua J Ichthyol Aquat Biol. 1999;3:133–40.
Wucherer MF, Michiels NK. A Fluorescent Chromatophore Changes the Level of Fluorescence in a Reef Fish. PLoS One. 2012;7, e37913.
Wucherer MF, Michiels NK. Regulation of red fluorescent light emission in a cryptic marine fish. Front Zool. 2014;11:1–8.
Boehlert GW. Intraspecific evidence for the function of single and double cones in the teleost retina. Science. 1978;202:309–11.
Cameron DA, Pugh EN. Double cones as a basis for a new type of polarization vision in vertebrates. Nature. 1991;353:161–4.
Hawryshyn C, Moyer H, Allison W, Haimberger T, McFarland W. Multidimensional polarization sensitivity in damselfishes. J Comp Physiol A. 2003;189:213–20.
Pignatelli V, Champ C, Marshall J, Vorobyev M. Double cones are used for colour discrimination in the reef fish, Rhinecanthus aculeatus. Biol Lett. 2010;6:537–9.
Cheney K, Newport C, McClure E, Marshall J. Colour vision and response bias in a coral reef fish. J Exp Biol. 2013;216:2967–73.
Losey G, Cronin T, Goldsmith T, Hyde D, Marshall N, McFarland W. The UV visual world of fishes: a review. J Fish Biol. 1999;54:921–43.
Bayliss LE, Lythgoe R, Tansley K. Some new forms of visual purple found in sea fishes with a note on the visual cells of origin. Proc R Soc Lond Ser B Biol Sci. 1936;120:95–113.
Douglas R, McGuigan C. The spectral transmission of freshwater teleost ocular media—an interspecific comparison and a guide to potential ultraviolet sensitivity. Vis Res. 1989;29:871–9.
Siebeck UE, Marshall NJ. Ocular media transmission of coral reef fish—can coral reef fish see ultraviolet light? Vis Res. 2001;41:133–49.
Randall J, Kuiter R. Cirrhilabrus punctatus, a new species of labrid fish from the southwestern Pacific. Rev fr Aquariol. 1989;16:43–50.
Greenfield DW, Suzuki T. Eviota atriventris, a New Goby Previously Misidentified as Eviota pellucida Larson (Teleostei: Gobiidae). Zootaxa. 2012;3197:55–62.
Osorio D, Vorobyev M. A review of the evolution of animal colour vision and visual communication signals. Vis Res. 2008;48:2042–51.
Cuthill IC. Color perception. Bird coloration. 2006;1:3–40.
Rasband WS. ImageJ, US National Institutes of Health, Bethesda, Maryland, USA. 2012. http://imagej.nih.gov/ij/.
Hart NS. Microspectrophotometry of visual pigments and oil droplets in a marine bird, the wedge-tailed shearwater Puffinus pacificus: topographic variations in photoreceptor spectral characteristics. J Exp Biol. 2004;207:1229–40.
Hart NS. Vision in the peafowl (Aves: Pavo cristatus). J Exp Biol. 2002;205:3925–35.
Hart N, Partridge J, Cuthill I. Visual pigments, oil droplets and cone photoreceptor distribution in the European starling (Sturnus vulgaris). J Exp Biol. 1998;201:1433–46.
The authors would like to thank G. Schulte, C. Kerr and M. Archer for logistics and technical support, as well as C. Schmidt, O. Oelkrug and M. Hohloch for animal care. NSH and SPC were supported by The University of Western Australia and The State Government of Western Australia.
The authors declare that they have no competing interests,
TG and NKM designed the research. JT established the setup for fluorescence characterisation, collected emission measurements and processed fluorescence data. TG gathered data on microspectrophotometry, NSH provided microspectrophotometric setup, analysed and processed data on photoreceptor absorbance and collected spectra for ocular media transmittance. SPC and NKM provided lab space and valuable comments on the draft. TG wrote the manuscript. All authors read and approved the final manuscript.
About this article
Cite this article
Gerlach, T., Theobald, J., Hart, N.S. et al. Fluorescence characterisation and visual ecology of pseudocheilinid wrasses. Front Zool 13, 13 (2016) doi:10.1186/s12983-016-0145-1
- Red fluorescence
- Colour vision