The food preferences of three-spined stickleback, Gasterosteus aculeatus L., downstream from a dam reservoir

Abstract

Submersed plants appeared in the impounded section of the Warta River as a consequence of low discharge in summer and were colonized by epiphytic fauna dominated by Hydra sp., Simuliidae, and Chironomidae. The three-spined stickleback consumed it voraciously, and their diet composition closely reflected the available food resources. In May their alimentary tracts were filled with Cladocera drifting from the reservoir, and then by the dominant taxa associated with macrophytes, especially chironomid periphyton scrapers. A comparison of dipteran head capsule width in the food resources and in the alimentary tract proved the three-spined stickleback preference for the largest larvae (optimal foraging strategy).

Effects of damming a large lowland river on chironomids and fish assessed with the (multiplicative partitioning of) true/Hill biodiversity measure

“…The effect of fish on chironomid community was stronger in site U because fish, mainly young, fed on benthic insects, while similar fish in site D foraged on microcrustaceans (mainly Cladocera, Copepoda, Ostracoda), which occurred both in spring and autumn, and were of reservoir origin (Marszał et al ., 1996). In site D, an additional food base in summer for mainly young fish (perch and ruffe) were epiphytic fauna, such as Chironomidae ( Cricotopus , Parachironomus and Tanytarsini) and Simuliidae (Dukowska et al ., 2009). The foraging of the dominant fish species on chironomids did not seem to limit their abundance owing to their very high P:B ratio (Dukowska, unpublished data).…”

Percid occupation of submersed riverine macrophytes: food resource partitioning between perch (Perca fluviatilis L.) and ruffe (Gymnocephalus cernuus L.)

“…Our earlier investigations showed the preferences of three-spined stickleback for the largest (oldest) larvae of the dominant epiphytic dipterans, both simuliids and chironomids (Dukowska et al 2009). In the present study we did not include this kind of data for perch and ruffe, but the same phenomenon was recorded in the case of these two percids.…”

“…However, in early autumn each year these hydrophytes have been mechanically damaged and uprooted by large volumes of water released from the reservoir. The trophic relationships within this rich but temporary biotic community have been partially investigated in terms of the primary and secondary invertebrate consumers (gathering collectors, scrapers and predators) and the tertiary consumer, the threespined stickleback, Gasterosteus aculeatus L. (Dukowska et al 1999(Dukowska et al , 2005(Dukowska et al , 2009.…”

“…In the Jeziorsko tailwater, two secondary or tertiary consumers forage among the submersed hydrophytes: perch and ruffe (Marszał et al 1996, Penczak et al 1998, Dukowska et al 2009, Głowacki et al 2011). Unlike lakes, for which abundant literature on percid foraging in the littoral and the pelagial zones exists (Diehl, Kornijów 1997;Jacobsen, Berg 1998;Perrow et al 1999;Okun, Mehner 2005;Borcherding, Magnhagen 2008), little is known about the percid diet in rivers.…”

Gyrodactylus gasterosteia difficult meal to swallow for the three-spined sticklebacks,Gasterosteus aculeatusL.

“…Furthermore, Dukowska et al . () demonstrated that the diet choices of sticklebacks were determined by the available food resources and readily switched from feeding on planktonic Daphnia to epiphytic species on macrophytes. Thus, sticklebacks appear to be somewhat generalist and opportunistic feeders.…”