Publications

prey selection by mosquitofish (gambusia affinis) in california rice fields: effect of vegetation and prey species.	mosquitofish are widely used for biological control of mosquito larvae in rice fields, but the presence of different types of vegetation or alternative arthropod prey affects the performance of the fish. feeding experiments were conducted in 4 rice field vegetation zones. overall, predation was maximal in young and mature rice, moderate in the submerged naiad vegetation, and minimal in areas of open water. a preference for fourth instar culex tarsalis mosquito larvae over daphnia pulex and the a ...	1990	2324716
demographic costs of chaoborus-induced phenotypic plasticity in daphnia pulex.	it has been proposed that morphological defenses against predation have demographic costs. we measured the cost of a predator-induced morphological defense, using predaceous phantom midge larvae chaoborus americanus (insecta, diptera) and the prey species daphnia pulex (crustacea, cladocera). the induced defense is a neck tooth (and other pleiotropic structures) developed in juvenile d. pulex in the presence of c. americanus. laboratory life table experiments, in the absence of predation, indica ...	1990	28313251
acute toxicity of triphenyltin hydroxide to three cladoceran species.	the toxicity of an organotin pesticide, triphenyltin hydroxide, was assessed with several freshwater cladoceran species. daphnia pulex, daphnia magna, and ceriodaphnia dubia were exposed for 48 h to triphenyltin hydroxide in static acute toxicity tests. values of the 48-h trimmed spearman-karber ec(50)s for the three species were found to be 14.5, 16.5, and 11.3 microg litre(-1), respectively. analysis of variance performed on ec(50) values of replicates revealed no significant differences betwe ...	1989	15092487
effects of four agricultural pesticides on daphnia pulex, lemna minor, and potamogeton pectinatus.		1985	4074929
effect of selenium deficiency on cuticle integrity in the cladocera (crustacea).	daphnia pulex de geer and daphnia magna straus populations cannot be maintained in defined (sensu stricto) media containing less than 0.1 part per billion (ppb) of selenium. a concentration of 1 ppb is sufficient to satisfy minimal needs in otherwise sufficient media. in the first generation with no selenium added to the medium or detected in it, media deficiency is shown by a premature cuticle deterioration visually similar to senescence, by progressive loss of distal segments of second antenna ...	1984	6587360
effects of red-headed in sawfly, neodiprion lecontei, nuclear polyhedrosis virus on rainbow trout, salmo gairdneri, and daphnia pulex.	the effects of a nuclear polyhedrosis virus (npv) of the red-headed pine sawfly, neodiprion lecontei, on rainbow trout, salmo gairdneri, were investigated. the fish were exposed to this virus by intubation and topical application and no ill-effects were observed. similarly, no ill-effects were detected in daphnia pulex when the same npv was added to their culture medium. the materials were lyophilized, npv-infected sawfly larvae (normally used for insect control), lyophilized, uninfected larvae ...	1981	7026655
chaoborus americanus predation on various zooplankters; functional response and behavioral observations.	predation rates for chaoborus americanus on different types of noncyclomorphic zooplankton prey were determined in the laboratory as a function of both prey species and density. the sequence of events leading to consumption of prey was also observed, and probabilities determined for the various components.predation rates generally reached an upper limit as the density of prey increased to high levels. larger prey were always less vulnerable to chaoborus predation. among the species of zooplankto ...	1980	28310942
acute toxicity studies of surfactants to daphnia magna and daphnia pulex.		1979	231941
interference with fasciola hepatica snail finding by various aquatic organisms.	previous studies using radioactive miracidia have shown that a number of non-host snails and bivalves, interposed as 'decoys' in linear test channels, may interfere with the capacity of fasciola hepatica miracidia to infect lymnaea truncatula. applying similar experimental principles, the role of several other potential interferents have been analysed in the present study. daphnia pulex (cladocera) and larvae of corethra sp. (diptera) exercised significant interfering effects by protecting 'targ ...	1977	876683
occurrence in monia rectirostris (cladocera: daphnidae) of a parasite morphologically similar to pasteuria ramosa (metchnikoff, 1888).	pasteuria ramosa, a bacterial parasite of the cladocerans daphnia pulex and d. magna, was described by metchnikoff in 1888. because the organism could not be cultured, it was subsequently lost. however, the original illustrations and descriptions of the life cycle of p. ramosa are similar to a bacterial spore parasite of nematodes (bspn) that was recently described in meloidogyne. as a result of these similarities, a search for p. ramosa was initiated. an organism resembling p. ramosa was found ...	1977	922608
the ecoresponsive genome of daphnia pulex.	we describe the draft genome of the microcrustacean daphnia pulex, which is only 200 megabases and contains at least 30,907 genes. the high gene count is a consequence of an elevated rate of gene duplication resulting in tandem gene clusters. more than a third of daphnia's genes have no detectable homologs in any other available proteome, and the most amplified gene families are specific to the daphnia lineage. the coexpansion of gene families interacting within metabolic pathways suggests that ...	0	21292972