Scotopic spectral sensitivity in a teleost fish (Scardinius erythrophthalmus) adapted to different daylengths

Vhioa Res. Vol. 13, pp. 245-252.

Persamon

Prew 1973. Printed in

GreatBritain

SCOTOPIC SPECTRAL SENSITIVITY IN A TELEOST FISH (SCARDINIUS ER YTHROPHTHALMUS) ADAPTED TO DIFFERENT DAYLENGTHS W. R. A. MUNTZand D. P. M. NORTHMORE Laboratory of

ExperimentalPsychology,Universityof Sussex (Receiued 29 June

1972)

RETINALextracts from many teleost fishes yield two visual pigments, one based on retinol (Al-based) and the other on 3dehy~oretinol (AZ-based) (DARTNALLand LYTHGOE,1965; SCHWANZARA,1967). The proportion of these two pigments has been found to vary with several factors, such as the salinity of the environment (e.g. WALD, 1957; BEATER,1966), the administration of thyroid hormone (BEATT~,1969 ; ALLEN,1971), the age of the fish (BRIDGES and YOSI-IKAMI,197Oa), the part of the retina from which the sample is taken (MUEITZand NORTHMORE,1971; REUTER, WHH-Eand WALD, 1971; DENTON, MUNTZ and NORTHMORE, 1971), and the lighting conditions (DARTHALL,LANDERand MUNZ, 1961; BRIDGES,1965; BEATER,1969). These various findings have led to considerable speculation on the visual role of these two pigment types. The problem can also be investigated by measuring the visual functions of suitable fish using either behavioural or physiological techniques. For example, MUNTZ and NORTHMORE(1970) made behavioural measurements of photopic spectral sensitivity on rudd (Scardiniuserythro~htha2~~)kept under different daylengths. Ibis species has two extractable visual pigments (VP5O71 and VP53Q whose proportion is affected by the lighting conditions (DARTNALLet al., 1961).Noeffect of daylengthonphotopic sensitivitywas found, however, even though the Al/AI ratio in retinal extracts from other fish kept under identical conditions had been markedly aflbcted. The simplest explanation of this finding is that daylength affects the seotopic receptors (rods) only, a suggestion that has also been made by BRIDGESand YOGHIKAMI(197Ob) on the basis of the different ways in which the outer segment discs of the rods and cones are formed (e.g. YOUNG,1971). It should be remembered however, that Murrrz and NORTHHORE’S (1970) experiment measured visual thresholds, and it is possible that when suprathreshold stimuli are used less sensitive photopic receptors come into play, which do show an effect of daylength. Measuring visual function using the el~~oretino~am, which requires much more intense stimuli, did in fact reveal an effect of daylength under photopic conditions, though this result could not be interpreted directly in terms of changes in the visual pigments (NORTHMORE and MUNTZ, 1970). In the present experiment, scotopic spectral sensitivity was measured behaviourally for rudd kept under different daylengths. A clear effect of daylength on scotopic visual function was found. METHODS The methodsused were basically similar to those of MCJWZand NORTIMW (1970), suitabty mod&d for

scotopic conditions. The subjects were 4 rudd (Scardinius erythrophthalmur), kept individually in tanks 245

W. R. A. MUNTZ ANDD. P. M. NORTHMORE

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26 x 46 cm by 26 cm deep. These tanks were separated from each other by black cardboard and kept in a room painted matt bfack. Three daylengths were used, 4, 12 and 18 hr. For the 4- and 12-hr daylengths iilumination was provided by a 60 W bulb 80 cm above the tanks; for the 18-hr daylength a 100 W bulb was used instead.

.TL

FIG. 1. Plan of apparatus. SL, stimulus light; L, achromatic lens; HG, heat glass; IF, interference filter; ND, neutral density filters; V, vane to select stimulus side; Sh, shutter; RF, response panel; RC, response chamber; CP, centre panel; TL, tank light.

The apparatus used is shown in Fig. 1. Each fish was trained and tested in its own tank. At the beginning of each training or testing session two panels were lowered into the tank. In one of them (the response panel, RP) there were two holes 4 cm in diameter, with their ccntres 65 cm apart and 7 cm above the floor of the tank. A Perspex box behind each hole formed a response chamber into which Tub&x worms were delivered for correct r&ponses. The end walls of the response chambers were of opal Pempex, on to which the stimuli 13 cm dia. circles of lb&t) were moiected. The second Dane1 (CP). which had a sin&e 10 x 7 cm rectaneular hole in it, was placed& the c&tre bf the tank. PassagA of the f&h through CP, a& entrances into the holes in RP, were monitored with gallium arsenide infra-red (900 run) sources and suitable photocells. A tank light (TL) was inserted into the end of the tank. This consisted of a 3 W 24 V bulb, underrun at 6.5 V to provide a dim orange light. Stimuli were provided by a 150 W 24 V tungsten-iodine bulb, underrun at 15 V from a stabilized power supply. The wavelength of the stimulus was controlled by interference f%ers (IF) and the intensity by neutral densitv filters (ND). The stimulus was turned on and off by a shutter (Sh). and the side to which it was p-&d was con&o&d by an eI~~oma~etic~ly driven v&e (V). .. During training and testing the stimulus was presented to one or other response chamber according to a GELXERMAN (1933) sequence. A trial started when the fish passed through the centre panel (CP) to the far end of the tank. This turned off the tank light (TL) and turned on the stimulus. The fish then returned through the centre panel to the response panel, and responded by entering one of the holes. If the fish responded to the side on which the stimulus was presented it was rewarded with Tubifex and the stimulus remained on for 3 set to help it see the reward. If it responded incorrectly, the stimulus was turned off immediately. In either case, as soon as the stimulus was turned off the tank light (TL) was turned on. The fish then swam towards the tank light, and in so doing passed through the centre panel (CP} and initiated another trial. A tank light was found necessary because the fish were very slow to return to the far end of the tank in total darkness. It is unlikeIy that the tank light seriously affected dark adaptation because it was very dim, and the experimental procedure also meant that the fish was never in the same end as the tank light when this was on. All manipulation of the apparatus at the beginning of a session was done using a deep red photographic safelight. Thresholds were determined by the same tracking procedure as was used by MUNTZ and NORTHMORE (1970). The animals received 150 trials each day. The apparatus was operated automatically by conventional solid state and el~~om~h~ical control circuitry. Stimulus calibration The wavelength of the stimulus light was controlled by seven interference filters (Balzars, Liechtenstein), for which spectral transmission curves were obtained with a Unicam SP800 spectrophotometer. The relative intensity available through the interference filters was measured with a HilgerSchwartz FT 17 thermopile. This thermopile was also used to measure the attenuation produced by the different neutrai density filters for the light coming through each interference fifter. The absolute energy of the stimulus was measured at 536 nm by using frog visual pigment as a chemical actinometer (DARTNALL,1958). A digitonin extract of pigment was prepared in the usual way, to which 10 per cent by volume of saturated sodium borate solution and the same amount of O-2 M hydroxylamine were added. The measurements were made by setting up the stimulus generating system and response panel in a dry tank. A l-ml cuvette of the visual pigment solution was placed in the tank 22 cm from the opal

247

Scotopic Spectral Sensitivity in a Teleost Fish

Perspex on which the stimulus was projected. The pigment solution was then exposed to the stimulus for a given time, after which it was removed and the amount of bleaching that had occurred was measured using a SPSOOspectrophotometer. This procedure was repeated several times, and the pigment finally bleached completely by tungsten light passed through a Wratten No. 15 filter. A photometric curve was then constructed from which the quanta/set cm’ entering the cuvette was estimated using the formulae given in DARTNALL (1968). The radiance of the stimulus, in quanta see-’ 0-l cmma, was then calculated in the usual way (e.g. BOYNTON, 1966). Experimental design The 6sh were placed on a 12-hr day, running from 2000 hr to 0800 hr, on 18/S/71, and testing began 5 weeks later, on 22/6/71. Smce testing never began before 0930 hr. the tish were always at least 1.5 hr dark adapted. Thresholds for the seven wavelengths tested had been obtained by 26/8/71, when the tish were placed on an 18-hr daylength (1400 hr to 0800 hr). Testing on this daylength began on 22/9/71 and continued until 17/11/71. The tish were then finally placed on a 4-hr daylength (1600 hr to 2000 hr) and thresholds obtained for this daylength between 7/l/72 and 20/3/72. The seven wavelengths were tested in the order given in Fig. 3 under each daylength condition. Testing was usually continued for 4 days (600 trials) for each thrphold determination, so that each fish gave between 12 and 13 thousand responses over the whole experiment.

RESULTS

Thresholds and fiducial limits were calculated from the data by transforming them to probits and fitting a regression line to them by the method of FINNJZY (1962). Details of the procedure may be found in MUNTZ and NORTHMORE (1970). The results and 95 per cent

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so0

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FIG. 2. Results for the four individual fish and the human subject. The plain circles and short

dashed line show the results for the IS-hr daylength. half filled circles and long dashed line for the 12-hr daylength, and filled circles and continuous line for the 4-hr daylength. The vertical bars show the 95 per cent fiducial limits of each threshold. The C.I.E. scotopic luminosity function is shown with the human data for comparison. Some of the points have been displaced slightly from their true spectral positions for clarity.

W. R. A. M~NTZANDD. P. M. NORTHMORE

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o----o--_.o.’

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500 WAVELENGTH

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(nm 1

FIG. 3. Mean thresholds for the four fish under different daylengths. Plain circles and short dashed line, 18-hr daylength; half filled circlesand long dashed line, 12-hr daylength; filledcircles and continuous line, 4-hr daylength. The heavy dashed line shows the spectral absorbance of a point on the retina of rudd C from DENTON et al. (1971).The figures in circles show the order

in which the different stimuli were used. limits for the individual fish are shown in Fig. 2, and the mean thresholds for all four fish in Fig. 3. It can be seen from Fig. 2 that there was considerable variation between the individual fish, especially in their relative sensitivity at short wavelengths. Thus, for example, fish 4 consistently showed a maximum at 443 nm, and in fact was more sensitive at this wavelength than any other under the 18-hr daylength condition. This fish may be contrasted with fish 3, where the sensitivity was relatively much lower at short wavelengths. If the results of the 4- and 18-hr daylengths are compared a clear effect is apparent for three of the fish (I,3 and 4). This shows itself as an increase in short wavelength sensitivity with the longer daylength while the sensitivity at long wavelengths remained relatively unaltered. There was also a slight increase in the relative sensitivity at short wavelengths with long daylengths in fish 2, but the difference in this case was very small. The size of the threshold change at each wavelength between the 4- and 18-hr conditions was ranked for each fish, and Kendall’s coefficient of concordance then calculated (SIEGAL,1956). This was found to be 0.733 which is highly significant (p c O*Ol),showing that there is a high degree of agreement between the animals on the relative effect of daylength on the thresholds at the different wavelengths. Results for the 12-hr daylength were in general intermediate between those obtained with the other two daylengths, although here again there was considerable individual variation. Thus fish 1 showed little difference between the 12- and 18-hr results, both of these being markedly different from the 4-hr results, while for fish 4 the results for the 12-hr daylength were similar to those for the 4-hr daylength, and very different from those for the 18-hr daylength. fiducial

Scotopic Spectral Sensitivity in a Teleost Fish

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Thresholds for three wavelengths were also obtained for a human subject. The apparatus was set up in a dry tank from which the rear wall had been removed. The subject sat behind the tank, and responded by putting a finger into one or another of the holes in the response chamber. The results agree well with the C.I.E. scotopic visibility function, and are about O-4 log units less sensitive than the absolute threshold values reported by HECHT, SCHLAER and PIRENNB(1942). The fish were as sensitive as the human subject, at any rate when adapted to the 18-hr daylength. DISCUSSION In order to relate the results to the spectral properties of the rudd’s visual pigments, it is necessary to know the absorption spectrum of the pigment at the density in which it occurs in the retina (DARTNALL,1953). The data of DENTONet al. (1971) show that this reaches a maximum of over O-6in the dorsal part of the eye. The absorption spectrum of a point on the intact retina of one of the fish (rudd C) used by Denton et al. is shown as the dashed curve in Fig. 3. The optical density at the wavelength of maximal absorption at this point was 064, and the retina of this fish contained little or no Al-based pigment. The mean of the 4-hr daylength results agrees well with this absorption spectrum over most of the spectrum. The curves for the 12- and 18-hr daylengths are relatively more sensitive at short wavelengths, presumably representing an increased contribution from the VP5071. Even with the 18-hr daylength, however, the contribution from the Al-based pigment is apparently small. Since the experimental room was painted matt black the light levels were low, which may have resulted in a comparatively low percentage of Al-based pigment even under long daylengths. Also, the Al-based pigment predominates in the dorsal part of the eye (M~JNTZand NORTHMORE,1971; DENTIN et al., 1971), while the fish probably used a more central part of the retina in the present experiment. The comparison of the results with the spectral absorbance of the visual pigments is less satisfactory for the two shortest wavelengths used, because of the considerable individual variation at these wavelengths. The presence and variability of substances absorbing at short wavelengths (cornea, lens, vitreous, etc.) will in general cause increased variability in this part of the spectrum, and is probably part of the reason for the variability found here. The short wavelength sensitivity appears in some cases to be surprisingly high, especially with fish 4. However, when the density of a visual pigment is as high as 064 the spectral absorbance curve is very broad, and at 440 nm, for example, the absorbance is only about 0.2 log units less than it is at its maximum (Fig. 3). Even under the 18-hr daylength, fish 4 was only 0.15 log units more sensitive at 443 nm than at 536 nm, a total deviation from expectation of about 0.35 log units, which may well be within experimental error. It has previously been reported that the scotopic spectral sensitivity of a related cyprinid, the goldfish (Carassius auratus) is too broad in comparison to the spectral absorption of that fish’s visual pigment, which suggests that cone mechanisms are contributing to scotopic visual function (BURKHARDT,1966; YAGER, 1968). The spectral sensitivity curves were, however, compared in each case to the extinction spectrum of the visual pigment, whereas they should have been compared to the absorption spectrum of the pigment appropriate to its retinal concentration. The optical density of the retinal pigment in situ is over O-6 for the rudd, and it is also high for several other species of fishes (DENTON,1959; DENTONet al., 1971). The breadth of the goldfish spectral sensitivity curves obtained by Burkhardt and Yager can be readily explained if it is assumed that the optical density of the retinal pigment of the goldfish is the same as in the rudd. Both Burkhardt and Yager’s results also show

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ANDD. P. M.

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irregularities which cannot be explained on the basis of the fish’s visual pigment, but which may well be within the range of experimental error. With short daylengths not only was the relative sensitivity at short wavelengths decreased, but the fish also showed a decrease in absolute senitivity. This may not be caused entirely by changes in the visual system, The animals’ food requirements and motivation appeared to decrease with the shorter daylengths, especially under the 4-hr lighting schedule, when they worked more slowly and sometimes failed to complete the full 150 trials in a day. Such a decline in motivation could have decreased the accuracy of performance, and hence the apparent sensitivity. A similar decrease in sensitivity with short daylengths was also found under photopic conditions (MUNTZ and NORTHMORE,1970). In that case the fish were on average O-36 log units less sensitive when kept under a 4-hr daylength than when kept under a 20-hr daylength, with no concurrent change in their spectral sensitivity. Acknou*!edgemen&--This research was supported by a grant from the Medical Research Council. Computer facilities used in analysing the results were made availabfe through a grant from the Scientific Research Council. REFERENCES ALLEN.

D. M. (1971). Photic control of the proportions of two visual pigments in a fish. Vision Res. 11,10771112. BEATIT, D. D. (1966). A study of the succession of visual pigments in the Pacific salmon (Oncorhynchlrs). Can. J. Zool.44,429-435. Bwrrv, D. D. (1969). Visual pigment changes in juvenile kokanee salmon in response to thyroid hormones. Vision Res. 9, 855-864. &XNTON, R. M. (1966). Vision. In ExperimentaI Methods andZn.strumentation in Psychology (edited by V. B. S~WSKI), McGraw-Hill, New York. BRUX;ES,C. D. B. (1965). Visual pigments in a fish exposed to different light-environments. Nature, Lortd. 206. I161-1162. BRIDGES,C. D. B. and YOSHIKAMI,S. (197Oa). The rhodopsin-porphyropsin system in freshwater fishes-l. Effects of age and photic environment. Vision Res. 10, 1315-1332. BRIDGES,C. D. B. and YOS~IIKAMI, S. (1970b). The rhodo~in-~~h~opsin system in freshwater fishes-2. Turnover and interconversion of visual pigment prosthetic groups in light and darkness: Role of the pigment epithelium. Vision Res. 10, 1333-1346. BURKHARDT,D. A. (1966). The goldfish electroretinogram: relation between photopic spectral sensitivity functions and cone absorption spectra. Vision Res. 6, 517-532. DARTNALL, H. J. A. (1953). The interpretation of spectral sensitivity curves. Br. med. Bull. 9, 24-30. DARTNALL,H. J. A. (1958). The spectral variation of the relative photosensitivities of some visual pigments. In Yjs~~~~rab~e~ ofcofour, National Physical Laboratory S~~siurn No. 8, pp. 121-148. H.M.S.O., London. DARTNALL, H. J. A. (1968). The photosensitivities of visual pigments in the presence of hydroxylamine. Vision Res. 8, 339-358. DARTNALL, H. J. A., LANDER, M. R. and Mmz, F. W. (1961). Periodic changes in the visual pigment of a fish. In Progress in Photobiology (edited by B. C. CHWTENSEN and B. BUCHMANN),Elsevier, Amsterdam. DAR~NALL,H. J. A. and Lrruoor:, J. N. (1965). The spectral clustering of visual pigments. Vision Res. 5, 81-100. DENTON, E. J. f 1959). The contributions of the orientated photosensitive and other molecules to the absorption of whole retina. Proc. R. Sot. B. 150, 78-94. DENTON, E. J., MUNTZ, W. R. A. and NORTHMORE, D. P. M. (1971). The distribution of visual pigment within the retina in two teleosts. J. mar. biol. Ass. U.K. 51, 905-915. FINNEY, D. J. (1962). Probit Analysis: a Statistical Treatment of the Sigmoid Response Curve. Cambridge University Press. GELLERMAN, L. W. (1933). Chance orders of alternating stimuli in visual discrimination experiments. J. getter. Psychot. 42, 207-208. HECHT, S.. SCHLAER, S. and PIRENNE, M. H. (1942). Energy, quanta and vision. J. gen. Physiol. 25,819-840. MUNTZ, W. R. A. and NORTHMORE,D. P. M. (1970). Vision and visual pigments in a tish, Scardinius erythrophthalmus (the rudd). Vision Res. 10,281-298. MUNTZ, W. R. A. and NORTHMORE,D. P. M. (1971). Visual pigments from different parts of the retina in rudd and trout. Vision Res. 11, 551-562.

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No~rrrhtoaa, D. P. M. and Mtnrrz, W. R. A. (1970). Electroretinogram determinations of spectral sensitivity in a tekost fish adapted to different daylengths. Vision Res. 10,799-816. Rstrmn, T. E., Wmrs, R. H. and WALD,G. (1971). Rhodopsin and porphyropsin fields in the adult bullfrog retina. J. gen. Physiol. 58,351-371. ScHwANzARA,S. A. (1967). The visual pigments of freshwater fishes. Vision Res. 7,121-148. SIEOAL,S. (1956). Nonparumetric Statistics@ the Behuuioruf Sciences. McGraw-Hill, New York. WAIT), G. (1957). The metamorphosis of visual systems in the sea lamprey. J. gen. Physiol. 40,901-914. YAOER,D. (1%8). Behavioral measures of the spectral sensitivity of the dark-adapted goldfish. Nature, Land. 220,1052-1053. YOUNG,R. W. (1971). An hypothesis to account for a basic distinction between rods and cones. Vision Res. 11,l-6.

Abstract-The efIect of daylength on scotopic spectral sensitivity was determined behaviourally for the rudd (Sccydinius erythrophthahnus), using a two choice discrimination situation. For every ii& three separate sensitivity curves were obtained, one for each of three daylengths (18, 12 and 4 hr). It was found that when the fish wem adapted to longer daylengths their absolute sensitivity increased, and they also became relatively more sensitive at short wavelengths. The absolute sensitivity of the ilsh under the long daylength condition was as good as that of a human subject. The rudd retina contains two visual pigments (VP507, and VP5351), and the behavioural results can be largely accounted for by the spectral absorbance of these pigments. Thus long daylengths are known to increase the proportion of VP5O71in the retina, which agree-swith the increased short wavelength sensitivity that was found when the daylength was increased. Also, the spectral sensitivity curve for the fish is broad compared, for example, to that of man, and the in situ density of the visual pigments is high (over O-6), which results in a corresponding broadening of the spectral absorbance curve.

RM d&ermine sur le rouget (Scardinius erythrophthulmus) l’effet de la longueur du jour sur la sensibilitt spectrale scotopique, par une methode de dressage a doubk choix. Pour chaque poissott on obtient trois courbes distinctes de sensibilite, respectivement pour les trois durees de jour (l&l2 et 4 hr). Quand l’animal est adapt6 aux longues d&es de jour. sa sensibilite absolve augmente et il devient aussi relativement plus sensible aux courtes longueurs d’onde. La sensibilite absolue du poisson dans la condition de longue dur& de jour est aussi bonne que pour un sujet humain. La &tine du rouget contient deux pigments visuels (VP5O71et VP535s). et ces r&sultats de comportement peuvent &t-e en grande partie expliques par les absorptions spectrales de ces pigments. Aiii on sait que le jour long augmente la proportion de VP507r dans la rCtine, a qui s’accorde avec I’augmentation de sensibilite aux courtes longueurs d’ondeconstateequand la longueur du jour croft. On constate aussi que la courbe de sensibilite spectrale du poisson est plw large que alle de l’homme par exemple, ce qui provient dune den&C tlev6e des pigmen visuels in situ (plus que 0,6) qui Clargit la courbe d’absorption spectrale correspondante.

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W. R. A. Mumz

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D. P. M. NORTHMORE

Zusammenfassung-Es wurde die Wirkung der Tageslange auf die skotopisch spektrale Empfindlichkeit fiir das Rotauge (Scar&&s erylrophthalmus) bestimmt. Von jedem Fisch wurden drei getrennte Empfmdlichkeit skurven erhalten, jeweils eine fiir drei verschiedene Tagesllngen (18, 12 und 4 Stunden). Es zeigte sich, daB bei Fischen, die an eine llngere Tagesllnge adaptiert waren, die absolute Empfindlichkeit zunahm und ebenso deren relative Emp6ndlichkeit fiir kiirzere Wellenlingen. Die absolute Empfindlichkeit des Fisches unter der langen Tagesltingenbedingung wurde als genauso gut gefunden wie bei Menschen. Die Rotaugenretina enthtiilt zwei Sehpigmente (VP 5071 und VP 5351), und die Ergebnisse kiinnen weitgehend der spektralen Absorption dieser Pigmente zugerechnet werden. So ist bekannt, dal3 bei langen Tageszeiten der Anteil von VP 507, in der Retina zunimmt. Das stimmt mit der Zunahme der Empfindlichkeit fiir kurze Wellenllngen, die man fand, wenn die Tageskinge zunahme iiberein. Ebenso ist die spektraleEmpfindlichkeitskurvedes Fischesweit vergleichbar, z.B. mit der des Menschen und die in situ-Dichte der Sehpigmente ist hoch (iiber 0,6). Das fiihrt zu einer entsprechenden Verbreiterung der spektralen Absorptionskurve.

Pe3IoMe-rloBeneIWecKaM MeTOHOM6bIJ-Ioonpe~eJIeHoBJIWWIieIIpO~OJDKHTeJIbHOCTH~Ha cKoTonu~ecKyIocneKrpanbHyIooyBcTBwTenbHocTbKpacHonepKE (Scardiniuserythrophtalmus); 6bIJI~cnonbsoBaHBbI6OpMe~y ABYMX pa3JIWIHbIMIicIiTyauIWM&i.~naKa~O~pbI6bI6bImf IIOJI)"IeHbI TpA OTaeJIL.HbIX KpIiBbIX'IyBCTBATeJIhHoCTH,nO OfIHOftJUDY KawrAO% W3 TpeX npo~onxuiren beocretiAHR (18 sac 12 pat R 4 nac). HatieHo, STO ecmi pbI6a 6bma anaIITxIposaHaK 6om.mefi npono~~~are~~bHOCTA ma, ee a6COmOTHaff SyBCTBHTWIbHOCTb yBenuvuBaeTcn II 0Ha cTaHoBATcn Tame 6onee ryecrBxTenbHot K K~~~TWM WHaHaM BOJ-IH. A6COJIIOTHaa 'IyBCTBATeJIbHOCTbpbI6bI B yCJIOBAIIXIIpOJJOJDKHTeJIbHOrO &IHR 6bIna TaKOti wte XOpOmek KaK II y 'WIOBeKa. &T'IaTKa KpaCHOnepKII COIIepm ABa 3pETeJIbHbIXmWMeHTa(VP 507, Ii VP 535*)X ~~~~JI~T~~I~~B~~~H%~KIIXOII~ITOBMO~~T~~IT~ nnipo~o HCnOnb30BaAbI npa OnpeneneHsu CneKTpaJIbHOrO IIOrJIOmeHAII3THX I1ATMeETOB. l-&KOJIbICy If3BeCTH0,'IT0 AJIIITeJIbHbIfi neHby~BaeTnponopua~~VP7,Bce~aTKe,mocornacyeTcxcysen~eHue~liyscrBweJIbHOCTH K CBeTy KOpOTKIIX LIJIKFI BOJIH,KOl-Aa yBWlWIliB%TCR IIpO~OJIWITeJIbHOCTb.qHR. TaKIiM o6pa3oM cneKTpa.rIbHaaYyBcTBHf'enbHOCTb pbI6bI MOxeT 6brrb CpaBHeHa, ~anpIiMep,CO CIIeKTpaJIbHOfiYyBCTBBTeJIbHOCTbIO YeJIOBeKa,KOTOpOft OAa IIIHpe,Hin Situ IIJIOTHOCTb 3pWTeJIbHbIXWrMeHTOB ee.BbICOKa (CBbIIIIe 0,6), 'IT0 Ii BbIpaZXaeTCR B COOTBeTcTByromeM pacunipeHHw ~p~~0li cneIcTpanpHor0 uornouleHwa.