Freshwater percid (Percidae) fish can be divided into the two groups depending on type of their activity and sensory equipment. European perch, Perca fluviatilis, American yellow perch, Perca flavescens, and numerous American darters (Etheostoma) demonstrate the diurnal type of activity (first of all of the feeding activity), are visually guided fish and, thus, may be included in the first group.

In laboratory and natural conditions, both perches usually do not eat immobile as well as dead food and demonstrate relatively weak responses to food odors or their absence. According to Mirza et al. (2003), an aqueous brine shrimp (Artemia spp.) extract (5 g of frozen shrimp in 150 ml of distilled water for 1 hour) induces searching movements in P. flavescens. Both perches, however, do not go practically into the minnow traps baited with the animal lures (in contrast to cyprinid, cobitid and other fish).

In aquarium, blinded P. fluviatilis may find the pieces of earthworms using olfactory and gustatory systems (Wunder, 1927). But convergence of perch with brown trout, Salmo trutta, on sensory system utilization is incorrect.

Both species of euryhaline Percarina, Azov percarina, P. maeotica, and common percarina, P. demidoffi, use vision in day when hunting for zooplankton and lateral line system at night when hunting for preyfish (Kanaeva, 1956).

Roberts and Winn (1962) have tested utilization of the senses in feeding behavior of johnny darter, Etheostoma nigrum, using live worms (Tubifex), dead worms and crushed worm solutions. It is shown that darters prefer live worms and respond slightly to an olfactory stimulus. Daugherty et al. (1976) have studied responses of six species of darters (E. gracile, E. spectabile, E. whipplei, E. radiosum, E. collettei and E. punctulatum) to visual and olfactory cues of worms. It is revealed that olfactory cues (water from live Tubifex) alone are not sufficeint to stimulate complete feeding behaviour in darters, both in clear or muddy waters.

Fountain darter, Etheostoma fonticola, respond to live aquatic microinvertebrates and ignore immobile items (Shenck & Whiteside, 1977).

Darters or longperches of Percina genus are also diurnally active and feed on live macroinvertebrates (Greenberg, 1991). Percina are more mobile than Etheostoma and spent most time above the bottom.

Another group is formed by percids with the twilight or nocturnal type of feeding activity with the well developed chemosensory and lateral line systems. Three Europen zanders or pikeperches, Stizostedion lucioperca , S. volgensis and estuarine pikeperch S. marinus, both North American zanders, walleye S. vitreus and sauger S. canadensis, all species of Gymnocephalus genus (such as common ruffe Gymnocephalus cernuus, Donets ruffe G. acerina, striped ruffe G. schraetser and other), all species of Zingel genus (such as Z. zingel, Z. streber, Z. balcanicus and other) and sculpin-perch Romanichthys valsanicola (single species of Romanichthys genus) belong to this group. Three last genera are represented in temperate Europe, except common ruffes which occupy mainly boreal areas and are active intruders.

Responses of walleye S. vitreus to natural and artificial food odors are well documented (Rottiers & Lemm, 1985).

The olfactory sensitivity of ruffe G. cernuus to food odors (extracts of Chronomidae larvae) is about 10^-2 g l^-1 that is less than the olfactory sensitivity of cyprinid fish (Kasumyan et al., 2003).

Laboratory experiments in the dark using infrared video equipment show (Jassen, 1997) that ruffe G. cernuus detect Daphnia magna (Crustacea: Daphnidae) and mayfly Hexagenia limbata (Insecta: Ephemeridae) larvae at the greater distance than yellow perch P. flavescens moving also faster whilst searching for prey. Because of their sensory abilities, ruffe feed predominantly at night, reducing in parallel the competitive interference from perch P. fluviatilis (Schleuter & Eckmann, 2006).

Skin of percid fish contains alarm pheromone that is documented in yellow perch P. flevescens, common ruffe G. cernuus and other species. Realesing in the water, this pheromone induces in small (planktivorous) perch an avoidance behaviour, whereas large (piscivorous) perch display feeding behaviour (Mirza et al., 2003; Harvey & Brown, 2004).

Basic References

Daugherty C.H., Daugherty L.B., Blair A.P. 1976. Visual and olfactory stimuli in the feeding behavior of darters (Etheostoma) inhabiting clear and muddy water. Copeia 1976, 380-382

Greenberg L.A. 1991. Habitat use and feeding behavior of thirteen species of benthic stream fishes. Environmental Biology of Fishes 31, 389-401

Harvey M.C., Brown G.E. 2004. Dine or dash?: Ontogenetic shift in the response of yellow perch to conspecific alarm cues. Environmental Biology of Fishes 70, 345-352

Kanaeva I.P. 1956. Diurnal changes in the feeding of the Azov percarina. Journal of Ichthyology 7, 71-84

Kasumyan A.O., Marusov E.A., Sidorov S.S. 2003. Feeding behavior of the ruffe Gymnocephalus cernuus triggered by olfactory and gustatory stimulants. Journal of Ichthyology 43, S247-S254

Janssen J. 1997. Comparison of response distance to prey via the lateral line in the ruffe and yellow perch. Journal of Fish Biology 51, 921-930

Mirza R.S., Fisher S.A., Chivers D.P. 2003. Assessment of predation risk by juvenile yellow perch (Perca flavescens): responses to alarm cues from conspecifics and prey guild members. Environmental Biology of Fishes 66, 321–327.

Roberts N.J., Winn H.E. 1962. Utilization of the senses in feeding behavior of the johnny darter, Etheostoma nigrum. Copeia 1962, 567-570

Rottiers D.V., Lemm C.A. 1985. Movement of underyearling walleyes in response to odor and visual cues. The Progressive Fish-Culturist 47, 34-41

Schleuter D., Eckmann R. 2006. Competition between perch (Perca fluviatilis) and ruffe (Gymnocephalus cernuus): the advantage of turning night into day. Freshwater Biology 51, 287-297

Shenck J.R., Whiteside B.G. 1977. Food habits and feeding behavior of the fountain darter, Etheostoma fonticola (Osteichthyes: Percidae). The Southwest Naturalist 21, 487-492

Wunder W. 1927. Sinnesphysiologische Untersuchungen über die Nahrungsaufnahme bei verschiedenen Knochenfischarten. Zeitschrift für vergleichende Physiologie 6, 67-98