occurs in coloration of many freshwater fish beening relatively constant throughout
the year and cryptic (in such, for example, bottom dwelling fish as wels, Silurus glanis). In this paper, we will consider those frequent cases
when chiefly males of freshwater fish acquire black coloration in the
reproductive period (nuptial melanization).
areas and rivers of the Ponto-Caspian basin, five species of gobiid fish with
nuptial melanization of body are most typical and abundant. Round goby, Neogobius melanostomus, monkey goby, N. fluviatilis, ratan goby, N. ratan, black goby, Gobius niger, and racer goby, Mesogobius gymnotrachelus, are among
them. Gobies are marine origin, but the foregoing species (as well as many
amelanistic species) inhabit desalinated areas and readily migrate into rivers
of the Ponto-Caspian basin where successfully breed (Pinchuk et al., 1985;
Romanesku, 2012). Some other euhaline gobies develop black nuptial coloration,
such as giant goby, Gobius cobitis),
but they avoid oligohaline bays and fresh waters.
reproductive period, gobies acquire conspicuous black coloration practically of
the whole body using such an appearance, on the one hand, to repel rivals (in
this case, black coloration is called threat, or antaposematic) and, on the
other hand, to attract females (Trifonov, 1955; Yankovsky, 1966). Some gobies
acquire color rims on the edge of both dorsal fins, pair pectoral and anal
fins: white in N. melanostomus,
yellow in M. gymnotrachelus and
orange in N. fluviatilis. In accordance with the accepted terminology (Trifonov, 1955; Yankovsky, 1966), these
conspicuous color signs are called gamosematic, bacause these signs appear in
males when they prepare the nests, indicating in this way on their readyness to
breed, and disappear in males when they begin to protect the nests with laying
and nest guarding in N. melanostomus are
well documented (Meunier et al., 2009).
round goby, N. melanostomus, and other gobies are rather visually guided
fish with the specialized chemoreceptory channel. N. melanostomus respond poorly to the odors of lake whitefish (Coregonus) tissues, crushed dreissenids
and fish eggs (Sreedharan
et al., 2009; Yavno & Corkum, 2011). At least Sreedharan et al. (2009) do
not recommend to use food-baited traps to control the spread of these fish.
According to Rollo et al. (2007), N. melanostomus have well developed vocalization and
are attracted by conspecific calls in both laboratory and field trials.
melanization is also found in such fish of the North American ichthyofauna as dirty
darter, Etheostoma olivaceum, Gila topminnow, Poeciliopsis
occidentalis, and Olympic mudminnow, Novumbra
1998). Coloration of males in brook stickleback, Culaea
inconstans (Ward & McLennan, 2006), mosquitofish, Gambusia holbrooki (Horth, 2004) and
Amur sleeper, Percottus glehni (Tsepkin, 1977), are other examples
of nuptial melanization.
in mosquitofish, G. holbrooki, black males have advantages and
disadvantages to more common silver rivals. On the one hand, largemouth bass, Micropterus salmoides, crayfish (Procambarus) and dragonfly larvae (Libellulidae) prefer, as natural predators, silver males (Horth, 2004), that is black
males are under less predation pressure. According to Taylor et al. (1996), on the
other hand, females of G. holbrooki prefer silver males and even can avoid
2004. Predation and the
persistence of melanic male mosquitofish (Gambusia
holbrooki). Journal of Evolutionary Biology 17,
A. 1998. Sexual
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Category: Coloration |
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Conspicuous coloration of males occurs
in many species of fish, birds and other animals being advantageous in
attracting potential mates. Although bright colors can entice females of the
same species, these colors may also attract predators. Female choice for bright
males and an enhanced risk of predation for bright males are both well
documented in numerous works (see Dill et al., 1999, and references therein).
fresh waters are optically turbid in comparison with pure sea waters, curves of
photopic spectral sensitivity in freshwater fish are strongly displaced to the
red part of the spectrum. For example, the maximum of spectral sensitivity in
threespined stickleback, Gasterosteus
aculeatus, is near 605 nm (Rowe et al., 2004). It means that for eyes of freshwater fish red and orange colors are brighter than
all other equipower monochromatic colors, and this feature occurs in nuptial signaling
allows males of freshwater fish to practice several strategies to find
trade-offs between conspicuousness for sexual mates and crypticity for
potential predators, including plasticity in nuptial color development (e.g., Endler,
1983; Candolin, 1998; Ruell et al., 2013). In this context, an ability to develop bright
red and orange colors in the under less illuminated parts of the fish’s body,
in conformity with the theory of color countershading in fresh waters, is the
and orange colors occur in breeding males just in the under parts of their
bodies such as breast, ventral part, belly and the lower fins. An important
role of this elements in nuptial coloration of males is documented in guppy, Poecilia reticulata (Endler, 1983;
Kodric-Brown, 1985), and other species of genus Poecilia, threespined stickleback, G. aculeatus (Rowe et al., 2004), European bitterling, Rhodeus sericeus (Candolin & Reynolds, 2001), and in other spesies of genus Rhodeus, as well as in males of other freshwater
fish. In some cases red and orange colors occur in the upper most illuminated
parts of the fish’s body, but patterns of this type will be considered
to Kodric-Brown (1998),
breeding males with red
fins occur in many families of North American freshwater fish, including
minnows (Cyprinidae), suckers (Catostomidae), killifish
(Fundulidae), sunfish (Centrarchidae), darters (Percidae) aa well as cichlids
bright red and orange colors are conspicuous at the shot distance for sexual
mates, but are cryptic in the countershading complex at the longer (that is optically
thick) distances for potential predators. According to Evans & Norris (1996),
red pigmentation of the fish’s body cannot be assessed accurately under green
light or hereof if viewed through the water column, as the natural green
al. (2001) demonstrate how fish can see other fish through the water column.
Candolin U. 1998. Reproduction under predation risk and the
trade-off between current and future reproduction in the threespine stickleback. Proceedings of the Royal Society, Biological Sciences 265, 1171-1175
Candolin U., Reynolds J.D. 2001. Sexual signaling in the European
bitterling: females learn the truth by direct inspection of the resource. Behavioral Ecology 12, 407-411
HedrickA.V., Fraser A. 1999. Male mating strategies under predation risk: do females call the shots? Behavioral Ecology 10, 452-461
Endler J.A. 1983. Natural and sexual
selection on color patterns in poeciliid fishes. Environmental Biology of Fishes 9, 173-190
Norris K. 1996.
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colored males of freshwater fish are forced to find trade-offs between
conspicuousness for sexual mates and cripticity for potential predators.
Divergence in spectral sensitivity of prey and predators is one of the possible
ways to solve this problem in its evolutionary development.
of spectral sensitivity in threespined stickleback, Gasterosteus aculeatus (605 nm: Rowe et al., 2004), as prey, and perch, Perca fluviatilis (635 nm: Protasov, 1968), as natural predators,
are strongly distanced. It means that for P.
fluviatilis, as specialized observers in the longwave part of the spectrum,
bright red breast and blue iris of G.
aculeatus (Rowe et al., 2004) must look darker (that is cryptic) than for
the owners of these colors. Similarly, the maximums of spectral sensitivity in
pumpkinseed sunfish, Lepomis gibbosus
(612 nm: Tamura & Niwa, 1967), as prey, and largemouth bass, Micropterus salmoides (673 nm: Kawamura
& Kishimoto, 2002), as natural predators, are distanced even more. So, for M. salmoides, with fine color vision in
the far red part of the spectrum,
conspicuous red iris and opercular flaps, all-important for breeding sunfish (Stacey & Chiszar, 1978), must be
dimmer than for the sunfish exploited these signals.
is the divergence of spectral sensitivity in the shortwave part of the
the ultraviolet (UV) part
of the spectrum (with the maximum of spectral sensitivity near 365 nm) affects female
mate choice in threespined sticklebacks, G.
aculeatus (Rick et. al., 2004; Boulcott et al., 2005; Rick et al., 2006). According to Leech & Johnsen
(2009), however, ability to see in the UV region (with the maximum near 385 nm)
occurs only in planktivorous individuals of Perca
flavescence (or P. fluviatilis)
disappearing in adult predatory fish.
Boulcott P.D., Walton K., Braithwaite V.A. 2005. The role of
ultraviolet wavelengths in the mate-choice decisions of female three-spined sticklebacks.
Journal of Experimental Biology 208,
G., Kishimoto T. 2002. Color vision, accomodation and visual acuity in the
largemouth bass. Fisheries Science
Leech D.M., Johnsen S.
2009. Light, Biological Receptors. Encyclopedia of Inland Waters. (Gene E.
Likens, Editor), Oxford,
Elsevier. Volume 2, 671-681
V.R., 1968. Vision and near orientation in fish. Israel
program for scientific translations, Jerusalem
Modarressie R., Bakker T.C.M. 2004. Male three-spined sticklebacks reflect in ultraviolet light. Behaviour 141, 1531-1541
Modarressie R., Bakker T.C.M. 2006. UV wavelengths affect female mate choice in
three-spined sticklebacks. Animal
Behaviour 71, 307–313
Baube C.L., Loew E.R., Phillips J.B. 2004. Optimal mechanisms fo finding and
selecting mates: how threespine sticklebac
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is an examplary pattern of animal coloration in which an animal’s pigmentation
is darker on the upper side and lighter on the under side of the body. When light
falls on any volume uniformly
colored object from
above, it makes the upper side appear lighter and the under side darker with
the gradual transition between them. Thanks to the counetrshading with the dark
upper side and the light under side, the same object appears flat and thus invisible on the surrounding background.
This basic pattern
is found in many species of mammals, reptiles, birds, fish and other animals.
countershading is determined by color vision of fish that is characterized by the different bell like curves of spectral
sensitivity. Spectral sensitivity
is an ability of the eye to perceive monochromatic light of equal power with the different wavelengths. Eyes of saltwater fish, and human, are most
sensitive to light with the wavelengths
of 550-560 nm (the green-yellow part
of the spectrum). Because fresh waters are optically turbid, eyes of freshwater
fish are more sensitive to light with the wavelengths of 600-680 nm (the orange-red
part of the spectrum). Due to bell like dependence of spectral sensitivity equipower
monochromatic light of different
wavelengths are not equally bright to
the eye. Green light is most bright for human and saltwter fish, red light is most
brigth for freshwater fish contrary to our perception.
For more information, please see post
Red displacement of spectral
sensitivity in freshwater fish
the terms of cryptic countershading, coloration of freshwater fish may be
conditionally divided into achromatic, or bright countershading patterns and
chromatic, or color countershading patterns. Greyish back, silver (mirrored)
sides and whitish belly are typical for fish with the achromatic
countershading. Green, yellow (goldish or golden), orange and red colors are
main components of the color countershading patterns. Darker colors lie on the top, brighter colors
lie on the bottom with the corresponding gradual transitions. The first sign of
the presence of color countershading in an appearance of freshwater fish is red
color of pectoral, pelvic, anal and caudal fins lied in the less illuminated parts or in
the shadow of the fish’s body.
In general, coloration of freshwater pelagic fish is ranged from
blank achromatic countershading patterns to color countershading patterns,
depending on the optical properties of the water.
idealized mixed countershading patterns, greenish back, silver sides, whitish
belly as well as yellowish, orange, reddish or red pectoral, pelvic, anal and caudal fins are typical. This
type of coloration is found in European asp, Aspius aspius, Aral redlip, A.a.
taeniatus, in many Amur fish (see Nikolski, 1956) like Amur redfin, Pseudaspius leptocephalus, skygazer, Erythroculter erythropteru
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to Walker & Hasler (1949), trained bluntnose minnow, Hyborhynchus notatus (Pimephales notatus) are able to discriminate
rinses of the following pairs of aquatic plants: Myriophyllum exalbescens and Ceratophyllum
demersum, Ranunculus trichophyllus
and Anacharis canadensis, Utricularia vulgaris and Vallisneria americana, Potamogeton zosteriformis and P.
cripus, P. amplifolius and P. vaginatus as well as Chara excelsa and P. pectinatus. Of 12 plant
species tested, only rinses with odors of C.
demersum and A. canadensis
resemble each other.
Figure 1. Bluntnose minnow, Pimephales notatus (powered by Joseph Tomelleri)
threshold of chemosensitivity to odors of aquatic plants is at the level of
1:10000 dilution (Walker & Hasler, 1949), plus additional dilution in the
test aquarium that demonstrates overall very high odor sensitivity.
Rinses of Cabomba
caroliniana, Sparganium sp., Utricularia vulgaris, Nuphar variegatum and Potamogeton epihydris are attractive for
migrating elvers of American eel, Anguilla rostrata
(Sorensen, 1986). However, the attractivity of these rinses is exceptionally determined
by epiphytic bacteria, fungi and algae that are abundant on the most species of
seaweeeds, Ascophyllum nodosum and Laminaria saccharina, repel elvers
rinses of decaying leaf detritus are highly attractive to elvers regardless of
where detritus is collected (Sorensen, 1986). In contrast, rinses of living and
fallen leaves collected from the forest floor are not attractive.
P.W. 1986. Origins of the freshwater attractant(s) of migrating elvers of the
American eel, Anguilla rostrata. Environmental Biology of Fishes 17,
Walker T.J., Hasler A.D. 1949. Detection
and discrimination of odors of aquatic plants by the bluntnose minnow (Hyborhynchus notatus). Physilological Zoology 22, 45-63
Category: Plants |
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