Importance of ciliates as prey of the euphausiid Euphausia pacifica in the NW North Pacific

Nakagawa, Yoshizumi; Ota, Takashi; Endo, Yuki; Taki, Kenji; Sugisaki, Hiroya

doi:10.3354/meps271261

Cited by 29 publications

(14 citation statements)

References 17 publications

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“…The juvenile euphausiids did shift their TP significantly, consistent with our view of E. pacifica as an omnivorous zooplankter. These euphausiids are known to consume a variety a food items, including ciliates (Nakagawa et al 2004), copepod carcasses (Park et al 2011), and marine snow (Dilling et al 1998). However, the magnitude of the LME interaction parameter was smaller than the trophic parameter, implying a TP change of , 1 full trophic level (Table 3).…”

Section: Discussionmentioning

confidence: 99%

Environmental perturbation effects on baseline δ¹⁵N values and zooplankton trophic flexibility in the southern California Current Ecosystem

Décima

Landry

Popp

2013

Limnology & Oceanography

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Nitrogen isotopic compositions of zooplankton in the California Current Ecosystem (CCE) are known to vary over inter-annual scales of climate variability, but the extent to which those changes are driven by variations in baseline phytoplankton d 15 N values vs. zooplankton trophic position (TP) is poorly resolved. We use field samples collected during a large natural environmental perturbation, the 1998-1999 alternation between El Niñ o and La Niñ a states, to test the ability of large dominant CCE zooplankton Euphausia pacifica and Calanus pacificus to alter their TPs in response to environmental variability. To distinguish trophic changes from variations of d 15 N values at the base of the food web, the zooplankton were assayed by Compound Specific Isotope Analysis of Amino Acids (CSIA-AA). Linear mixed-effect models were developed to utilize data from all amino acids (AAs), providing greater statistical power than the typical CSIA-AA approach of using only phenylalanine and glutamic acid. We confirm a significant 15 N enrichment of , 2% at the base of the food web for all AAs and all zooplankton groups during the 1998 El Niñ o. This baseline enrichment in 15 N has been speculated to occur during El Niñ o events but never conclusively shown. We also demonstrate a significantly elevated TP, implying increased carnivory during 1998, for E. pacifica while C. pacificus did not alter their TP between years. Lastly, TPs calculated from the standard CSIA-AA equation with laboratory-derived constants gave unrealistically low estimates, suggesting an assessment of these variables in situ is needed for an accurate application in natural systems.

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Section: Discussionmentioning

confidence: 99%

Environmental perturbation effects on baseline δ¹⁵N values and zooplankton trophic flexibility in the southern California Current Ecosystem

Décima

Landry

Popp

2013

Limnology & Oceanography

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“…In addition, by feeding on small ciliates and harboring larger ones, appendicularians could modify the size spectra of ciliate populations. Then by supporting higher growth rates for ciliates and larger ciliates, appendicularians might also indirectly support other organisms, such as copepods and euphausiids, that feed preferentially on ciliates (Wiadnyana and Rassoulzadegan 1989;Jonsson and Tiselius 1990;Nakagawa et al 2004). Finally, when the house is discarded, ciliates remain trapped inside until its degradation, which could last 6 d (Davoll and Silver 1986).…”

Section: Discussionmentioning

confidence: 99%

Experimental and modeling evidence of appendicularian‐ciliate interactions

Lombard

Eloire

Gobet

et al. 2009

Limnology & Oceanography

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Interactions between appendicularians and ciliates were observed over the life span of Oikopleura dioica in laboratory cultures and clarified with the use of mathematical modeling and microscopic observations. Complex interactions including competition, parasitism, predation, and histophagy occurred simultaneously, resulting in apparent mutualism. The large ciliate Strombidium sp. entered the inlet filters of appendicularian houses (larger than 500 mm body size) by distorting the mesh. Once inside, Strombidium fed on particles concentrated on the filters. When appendicularians were larger than 900 mm, both the high flow rate in the buccal tube and their esophagus width allowed the ''host'' appendicularian to capture and ingest ciliates. Thus, ciliates seem to be sequentially competitors, then parasites or commensal in appendicularian houses, and finally prey for appendicularians. Appendicularian rates of somatic growth and reproduction were enhanced when ciliates were ingested. This additional food supply could be essential in oligotrophic environments. Reciprocally, appendicularians support higher ciliate growth rates, allowing ciliates to survive and grow in food-limited environments. Appendicularians thus modify the size spectrum of the microbial food web both by removing small organisms (0.2-30 mm) and enhancing the growth of mid-sized and large ciliates.

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“…Ciliates have also been evaluated as preferred food sources for copepods [9], euphausiids [10], and other mesozooplankton and macrozooplankton [1,11].…”

Section: Introductionmentioning

confidence: 99%

Microzooplankton as a food source for the Pacific oyster Crassostrea gigas: seasonal variation in gut contents and food availability

Kamiyama

2011

Fish Sci

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In this study I investigated the seasonal occurrence of microzooplankton in the gut of the Pacific oyster Crassostrea gigas. Gut contents consisted of various microzooplankton, including tintinnid ciliates, dinoflagellates (Dinophysis spp.), copepods, copepod nauplii, bivalve larvae, and rotifers. Monthly variations in the abundance of protists (tintinnids and Dinophysis spp.) in the gut contents were significantly correlated with the variation in their abundances in the surrounding seawater, whereas this relationship was not significant with metazoans (copepods, copepod nauplii, and bivalve larvae). In laboratory experiments, oysters actively fed on ciliates. When oysters fed on ciliates labeled with a stable nitrogen isotope ( 15 N), the 15 N:total N ratio of the oyster tissues was significantly higher than that for oysters under a no-food condition, suggesting that oysters assimilate nitrogen of the ciliates into their body tissues. Based on these results, I conclude that microzooplankton forms an important food source for oysters, especially when other food sources such as phytoplankton are not abundant.

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Importance of ciliates as prey of the euphausiid Euphausia pacifica in the NW North Pacific

Cited by 29 publications

References 17 publications

Environmental perturbation effects on baseline δ¹⁵N values and zooplankton trophic flexibility in the southern California Current Ecosystem

Environmental perturbation effects on baseline δ¹⁵N values and zooplankton trophic flexibility in the southern California Current Ecosystem

Experimental and modeling evidence of appendicularian‐ciliate interactions

Microzooplankton as a food source for the Pacific oyster Crassostrea gigas: seasonal variation in gut contents and food availability

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Importance of ciliates as prey of the euphausiid Euphausia pacifica in the NW North Pacific

Cited by 29 publications

References 17 publications

Environmental perturbation effects on baseline δ15N values and zooplankton trophic flexibility in the southern California Current Ecosystem

Environmental perturbation effects on baseline δ15N values and zooplankton trophic flexibility in the southern California Current Ecosystem

Experimental and modeling evidence of appendicularian‐ciliate interactions

Microzooplankton as a food source for the Pacific oyster Crassostrea gigas: seasonal variation in gut contents and food availability

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Product

Resources

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Environmental perturbation effects on baseline δ¹⁵N values and zooplankton trophic flexibility in the southern California Current Ecosystem

Environmental perturbation effects on baseline δ¹⁵N values and zooplankton trophic flexibility in the southern California Current Ecosystem