Containment effects in copepod grazing experiments: A plea to end the black box approach1

Roman, Michael R.; Rublee, Parke A.

doi:10.4319/lo.1980.25.6.0982

Cited by 93 publications

(49 citation statements)

References 12 publications

(20 reference statements)

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“…In contrast, Phaeocystis was too small to be grazed by C. hyperboreus. Although grazer excretion can induce growth of small autotrophs leading to underestimates of their removal rates (Roman & Rublee 1980), grazing by C. hyperboreus in this case did not occur. Thus, C. finmarchicus apparently was able to feed on smaller particles than C. hyperboreus.…”

Section: Sizementioning

confidence: 95%

On the trophic coupling between protists and copepods in arctic marine ecosystems

Levinsen¹,

Turner²,

Nielsen³

et al. 2000

Mar. Ecol. Prog. Ser.

214

127

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Grazing experiments were conducted at different seasons with the large Calanus finmarchicus, C. glacialis and C. hyperboreus, and the small Acartia longiremis in Disko Bay, West Greenland and Young Sound, NE Greenland. Female copepods incubated in 200 µm screened natural water preferred large protists. Thus, particularly during the post-bloom period, the relatively large heterotrophic protists (ciliates and heterotrophic dinoflagellates) contributed substantially to the trophic coupling between protists and copepods. However, low grazing by C. glacialis and C. hyperboreus in mid-June suggests that large parts of the populations of these species had terminated feeding at this time, prior to overwintering. Clearance increased with ciliate and dinoflagellate size above 10 µm equivalent spherical diameter (ESD), equal to the size of the smallest heterotrophic protists. At a size of 30 to 40 µm ESD maximum clearance was observed. Grazing on Phaeocystis single cells of 5 µm by C. finmarchicus showed a lower size-limit for capture of this species < 5 µm which contrasts with C. glacialis and C. hyperboreus, which had a lower size-limit near 10 µm. In addition to size and relative concentrations of phytoplankton and heterotrophic protists, prey and/or predator behavior is suggested to play an important role for copepod feeding.

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Section: Sizementioning

confidence: 95%

On the trophic coupling between protists and copepods in arctic marine ecosystems

Levinsen¹,

Turner²,

Nielsen³

et al. 2000

Mar. Ecol. Prog. Ser.

214

127

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show abstract

“…While numerous authors have explored problems associated with this experimental approach (e.g. Roman & Rublee 1980), food removal incubation studies remain the most accurate and informative method currently available for investigating predation on nonphytoplankton taxa (Bamstedt et al 2000). Few studies of marine invertebrate predators, however, have used the same experimental system to compare temperature-dependent consumption on multiple prey types, using freshly field-captured predators and prey at naturally occurring temperatures and densities.…”

Section: Discussionmentioning

confidence: 99%

Functional response and potential predatory impact of Tortanus dextrilobatus, a carnivorous copepod recently introduced to the San Francisco Estuary

Hooff¹,

Bollens²

2004

Mar. Ecol. Prog. Ser.

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Despite a dramatic increase in the introduction of non-indigenous estuarine zooplankton in recent decades, the trophic implications of such introductions have rarely been quantified. Here we investigate predation rates of Tortanus dextrilobatus, a carnivorous copepod recently introduced to the San Francisco Estuary that achieves peak abundances in excess of 1000 ind. m . The functional response of T. dextrilobatus feeding upon 2 copepod prey types -the non-indigenous cyclopoid Oithona davisae, and the 'native' calanoid Acartia (Acartiura) sp. -was described by a type II functional response (Ivlev function) at 2 experimental temperatures. In 3 of these 4 treatments, 90% I max was achieved within a naturally occurring range of prey densities. Taxon-specific seasonal size variation was identified, and carbon-based consumption values were used to determine temperature-dependent rates of predation on both prey types. These empirically derived consumption rates and temperature dependence values were then applied to broadscale surveys (1997 to 1999) of zooplankton community composition in order to estimate the predatory impact of T. dextrilobatus upon prey populations in the San Francisco Estuary. Predatory impact estimates (% population consumed d -1 ) greater than 1% occurred on a regular basis when T. dextrilobatus was abundant, with maxima exceeding 20, 65, and 25% for O. davisae, Acartia (Acartiiura) sp. and all Copepoda, respectively. These observations support the hypothesis that non-indigenous invertebrate zooplanktivores can play a significant role, at least seasonally or episodically, in the secondary production dynamics of aquatic ecosystems.KEY WORDS: Zooplankton ecology · Feeding · Predation · Copepods · Tortanus dextrilobatus · Non-indigenous · Invasion · San Francisco Estuary Resale or republication not permitted without written consent of the publisherMar Ecol Prog Ser 277: [167][168][169][170][171][172][173][174][175][176][177][178][179] 2004 A rapid increase in biological invasions of estuarine habitats in recent decades has increased the prospect of potential deleterious effects on community and ecosystem level dynamics (Carlton & Geller 1991, Ruiz et al. 1997, Parker et al. 1999). Yet, a recent literature review by Bollens et al. (2002) revealed a scarcity of studies exploring such impacts in zooplankton communities, despite widespread documentation of invasion occurrence and mechanisms. Determining the impacts of human mediated introductions has been a challenge for natural resource managers and ecologists alike, and while they may represent unfortunate cases of often inadvertent biomanipulation, they provide a unique opportunity for investigating fundamental questions in plankton community ecology and invasion biology. One such question is the degree to which predation pressures may be important in regulating population dynamics of secondary producers.The San Francisco Estuary has been identified as one of the most highly invaded aquatic ecosystems (Cohen & Carlton 1998), and the zoop...

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“…These animals ingest food rapidly at first, decreasing this rate as they become sated (Beukema 1968;Runge 1980). Roman and Rublee (1980) have shown experimentally that measured filtering rates of Calanoid copepods decline in long experiments. The shape of their curves suggest that the rate declines exponentially with time and the slope (-0.0009) seems of the same order of magnitude as, but somewhat larger than, those reported in Eq.…”

Section: Methodological Artifacts-several Factorsmentioning

confidence: 99%

Empirical analysis of zooplankton filtering and feeding rates1

Peters

Downing

1984

Limnology & Oceanography

343

203

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Multiple regression analysis of published zooplankton filtering and feeding rates yielded separate regression equations for cladocerans, marine Calanoid copepods, and all zooplankton. Ingestion rate was found to increase significantly with animal size, food concentration, and temperature. Filtering rate also increased with animal size and temperature, but declined as food concentration increased. The analysis suggests a difference in particle size preference between cladocerans and copepods. Experimental conditions such as crowding and duration also significantly affected filtering and feeding rates. The regression models allow examination of differences and similarities among zooplankton taxa, functional response, particle size selection, energy allocation, and threshold food concentration. The statistical models describe suspension feeding more precisely than either average literature values or verbal descriptions of trend. The results also suggest possible mechanisms of feeding limitation and provide a heuristic framework for the design of experimental analyses of zooplankton feeding in marine and freshwater systems.

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Containment effects in copepod grazing experiments: A plea to end the black box approach1

Cited by 93 publications

References 12 publications

On the trophic coupling between protists and copepods in arctic marine ecosystems

On the trophic coupling between protists and copepods in arctic marine ecosystems

Functional response and potential predatory impact of Tortanus dextrilobatus, a carnivorous copepod recently introduced to the San Francisco Estuary

Empirical analysis of zooplankton filtering and feeding rates1

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