Loss of larger cladoceran
species can reduce grazing pressure on lower trophic level phytoplankton which can induce algal blooms that may eventually disrupt the function of the ecosystem (Moss et al.
Diptera, Tricoptera, and unidentified) were the most common food items, present in 98% of fish, followed by formulated feed (55%), cladocerans
(53%), diatoms (45%), rotifers (34%), filamentous algae (28%), and bryozoan statoblasts (28%).
Copepods have a very different lifestyle from the cladocerans
and rotifers in that they reproduce sexually.
In 1997-2005, the abundance and biomass of copepods decreased up to two times, the abundance and biomass of cladocerans
almost two times (Fig.
Since spine development in cladocerans
often is triggered by the presence of both invertebrate and vertebrate predators, a lack of predatory cues in laboratory conditions often results in underdeveloped cyclomorphic features (Dzialowski et al 2003, Kappes and Sinsch 2002, Lysebo 1995, Work and Gophen 1995).
For example, competition for food resources is more important than predator avoidance in the vertical habitat segregation of cladocerans
Further, the idea of a cosmopolitinism in the geographical distribution of cladocerans
(Frey, 1987) and the use of taxonomical keys without detailed descriptions and illustrations has generated confusion about identification of many taxa.
In the Rio de la Plata estuary, where Limnoperna first invaded around 1990, from spring to fall golden mussel larvae are 8-9 times more abundant than the combined densities of copepods and cladocerans
Pteropods, larvaceans, cladocerans
and fish eggs were present in approximately 10% of capelin stomachs and represented ~1-3% of prey by numbers (Table 2).
Macrozooplankton communities typical of these reservoirs include small-bodied cladocerans
, calanoid and cyclopoid copepods, with copepod nauplii abundant in all seasons.
composed approximately 33% (by number and by weight) of the stomach contents during October for yellow perch <130 mm.
This does not differ greatly from the pelagic formation of Lake Michigan, which includes copepods, cladocerans
, roundworms, planarians, and leeches.