Summury (abstract)

Predation by thornless predators on the colonial rotifer Sinantherina socialisElizabeth J . Walsh ,1 ,a Michael Salazar ,1 Juan Remirez ,1 Orestes Moldes ,1 and Robert L . W whollyace21 Department of Biological Sciences , University of Texas at El Paso , El Paso , Texas 79968 , USA2 Department of Biology , Ripon College , Ripon , Wisconsin 54971 , USAAbstractColonies of the freshwater colonial rotifer Sinantherina socialis (MonogonontaFlosculariidae ) endure been shown to be unpalatable to a variety of sm entirely-mouthedzooplanktivorous fishes . that it is not up to now proven whether this colonial rotifer is overly unpalatable to invertebrate predators . assume that colonies are unpalatable , the work hypothesis was that members of S socialis would be ingested less a capital deal by invertebrate predators than alternate an tecedeTwo types of auditions were conducted to runnel whether invertebrate predators would ingest the rotifer S . socialis . The first type of examine do was Microcosm look intos , where dragonfly nymphs damselfly nymphs , notonectids , and Hydra were offered forego either one by one or in combination in some(prenominal)(prenominal) severalize experiments . The preys were S . socialis Epiphanes senta and Daphnia magna . In the absence of predators (control treatments , nearly in all in all prey survived the 24-h feeding trials . The presence of predators greatly affected prey survival . The number of prey surviving in each microcosm was recorded at 12 , 18 , and 24 h at which point the experiments were terminated . The second type of experiment done was Paired-feeding experiments where predators were offered prey in a pairs again in separate experiments wherein members of D . magna were replaced with either a rotifer , S socialis or E . senta . fter 24 h , 60-100 prey items of S . socialis survived the predator! s . Individuals of E . senta (6-89 ) and D . magna (o25 ) showed a lower level of survival . When offered rotifers and individuals of D . magna simultaneously , predators tested consistently consumed more specimens of Daphnia . Predators all consumed significantly more specimens of E . senta than S .

socialis after 24 h Majority of the four predators captured members of S . socialis , but these colonies were frequently released rather than ingested , although in whatever cases colony structure was badly disruptedIn both the microcosm experiments and in the paired-feeding trials the insect predators tried to ingest colonie s of S . socialis . Only specimens of Hydra littoralis did not attack the colonies . Thus colonies of S . socialis are potential prey for these three insects in porcine habitats . The results suggest that the unpalatable nature of members of S . socialis to certain fishes extends to several invertebrate predatorsON THE ROLE OF TUBIFICID OLIGOCHAETES INRELATION TO FISH DISEASE WITH SPECIALREFERENCE TO THE MYXOZOARalph 0 . BrinkhurstAquatic Resources wield , PO . Box 6808 18 , Franklin , TN 37068-08 18 , USAAbstractFrom the introduction of prove disease in 1958 it is now known to 21 states . in front ,it was assumed that it was not a problem in bats stocks but recent experience in carbon monoxide gas and t suggests that whirling disease plays a major exercise in the decline of up to 90 in rainbow trout in some rivers . One...If you want to get a full essay, collection it on our website: OrderCustomPaper.com

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