Ammonium excretion by gelationous zooplankton and their contribution to the ammonium requirements of microplankton in Chesapeake Bay

Nemazie, D. A.; Purcell, Jennifer E.; Glibert, Patricia M.

doi:10.1007/bf00350062

Cited by 52 publications

(38 citation statements)

References 30 publications

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“…Nitrogen from zooplankton ingested was calculated as in Purcell (1992), and averaged 331 1-19 N medusa-' d -' Therefore, ichthyoplankton contributed 18% of the nitrogen from zooplankton and ichthyoplankton in the diet (402 pg N medusa-' d-'1, which exceeds the daily minimum nitrogen demand, as estimated by ammonium excretion, for medusae up to about 60 mm in diameter (Purcell 1992). Ctenophores also are consumed by the medusae, and are another source of nitrogen that could exceed these other sources in the diet (one 70 mm ctenophore = 3150 pg N; Nemazie et al 1993). However, medusa ingestion rates of ctenophores could not be determined from gut content analyses.…”

Section: Date In July 1991mentioning

confidence: 97%

Predation mortality of bay anchovy Anchoa mitchilli eggs and larvae due to scyphomedusae and ctenophores in Chesapeake Bay

Purcell¹,

Nemazie²,

Dorsey³

et al. 1994

Mar. Ecol. Prog. Ser.

148

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We measured predation on bay anchovy Anchoa mitchilli eggs and larvae by abundant scyphomedusae Chrysaora quinquecirrha and ctenophores Mnemiopsis leidyi from gut contents, digestion rates, and densities of predators and prey during 9 d in July 1991 at 4 stations in Chesapeake Bay, USA. These predation rates were compared to egg and larval mortality rates measured concurrently in ichthyoplankton surveys. Daily predation by medusae and ctenophores was 19 * 13":) (mean + SD) of the eggs over the 20 h stage duration, with medusae responsible for 26 to 100% of the predation. These gelatinous predators accounted for 21 i 17 ":, of the total estimated daily egg-stage rnortality. On average, medusae consumed 29 + 14 O/u d -' of the larval bay anchovy, which was 41 35% of total estimated larval mortality. Predation on larvae by ctenophores was not detected. These predation effects are compared with those measured concurrently in free-drifting 3 2 m3 mesocosms. We conclude that medusae, which had high feeding rates but low abundances, and ctenophores, which had lour feeding rates but high abundances, were important predators of bay anchovy eggs and larvae in the mesohaline region of Chesapeake Bay

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Section: Date In July 1991mentioning

confidence: 97%

Predation mortality of bay anchovy Anchoa mitchilli eggs and larvae due to scyphomedusae and ctenophores in Chesapeake Bay

Purcell¹,

Nemazie²,

Dorsey³

et al. 1994

Mar. Ecol. Prog. Ser.

148

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“…No RRs were found for cubozoan medusae. In two studies (Nemazie et al, 1993;Pitt et al, 2005), metabolism was measured as excretion rates, which we converted to RRs by the O:N atomic ratio of 11.6 (Purcell & Kremer, 1983). RRs were standardized to ml O 2 medusa -1 d -1 by the conversions 1 ml O 2 = 1.42 mg O 2 = 44.88 lmol O 2 = 89.76 lg atoms O 2 .…”

Section: Regression Analyses Of Scyphomedusa Respiration Ratesmentioning

confidence: 99%

Use of respiration rates of scyphozoan jellyfish to estimate their effects on the food web

et al. 2010

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One of the main objectives of research on jellyfish is to determine their effects on the food web. They are voracious consumers that have similar diets to those of zooplanktivorous fish, as well as eating microplankton and ichthyoplankton. Respiration rates (RRs) can be used to estimate the amount of food needed to balance metabolism, and thereby estimate minimum ingestion. We compiled RRs for scyphozoan medusae in three suborders (Semeaostomeae, Rhizostomeae, and Coronatae) to determine if a single regression could relate RRs to mass for diverse scyphomedusan species. Temperature (7-30°C) was not a significant factor. RRs versus wet weight (WW) regressions differed significantly for semeaostome and rhizostome medusae; however, RRs versus carbon mass over five-orders of magnitude did not differ significantly among suborders. RRs were isometric against medusa carbon mass, with data for all species scaling to the power 0.94. The scyphomedusa respiration rate (SRR) regression enables estimation of RR for any scyphomedusa from its carbon mass. The error of the SRR regression was ±72%, which is small in comparison with the 1,000-fold variation in field sampling. This predictive equation (RR in ml O 2 d -1 = 83.37 * g C 0.940 ) can be used to estimate minimum ingestion by scyphomedusae without exhaustive collection of feeding data. In addition, effects of confinement on RRs during incubation of medusae were tested. Large medusae incubated in small container volumes (CV) relative to their size (ratios of CV:WW \ 50) had RRs *one-tenth those of medusae in relatively larger containers. Depleted oxygen during incubation did not depress RRs of the medusae; however, swimming may have been restricted and respiration reduced in consequence. We briefly review other problems with RR experiments and suggest protocols and limitations for estimating ingestion rates of jellyfish from metabolic rates.

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“…Consumption of zooplankton and ichthyoplankton in July 1991 (Purcell et al 1994a) would meet daily nitrogen demands (5 400 pg N d-') for medusae 160 mm diameter (Purcell 1992). However, just 1 ctenophore 23.8 mm in length (3.5 m1 volume) contains 400 1-19 nitrogen (calculated from equations in Nemazie et al 1993). Therefore, ctenophores could contribute more nitrogen than other planktonic foods combined.…”

Section: Clearance Rates Of Medusae Feeding On Ctenophoresmentioning

confidence: 99%

Predation by the scyphomedusan Chrysaora quinquecirrha on Mnemiopsis leidyi ctenophores

Purcell¹,

Cowan²

1995

Mar. Ecol. Prog. Ser.

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Numerous species of gelatinous zooplankton are known to eat ctenophores, but their predation interactions have seldom been studied. Laboratory experiments showed that Chrysaora quinquecirrha medusae ( 3 to 20 mm diameter) usually consumed entire ctenophores (Mnerniopsis leidyi) that were equal in diameter or smaller. Although ctenophores larger in diameter than medusae were sometimes consumed completely, often only the lobes of the ctenophores were eaten. These damaged ctenophores healed in the laboratory. Short-lobed ctenophores had reduced fecundity, and probably lowered feeding rates as well. Short-lobed ctenophores were abundant (24 to 76% of the population) in situ during 1990. Large medusae (40 to 120 mm diameter) in 3.2 m3 in situ mesocosms cleared ctenophores at high rates (up to 6180 1 d-'). Clearance rates of medusae decreased with increasing ctenophore density and s u e , and increased with medusa size. The laboratory-determined clearance rate equation, in combination with medusa sizes and densities in situ, predicted that medusae could eliminate ctenophores from a tributary, but not at 2 stations in the main-stem Chesapeake Bay (USA), which was in agreement with in situ population data. The multlple negative effects of C. quinquecirrha on M. leidyi populations may lead to complex community-level changes that actually may reduce mortality of zooplankton and ichthyoplankton.

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Ammonium excretion by gelationous zooplankton and their contribution to the ammonium requirements of microplankton in Chesapeake Bay

Cited by 52 publications

References 30 publications

Predation mortality of bay anchovy Anchoa mitchilli eggs and larvae due to scyphomedusae and ctenophores in Chesapeake Bay

Predation mortality of bay anchovy Anchoa mitchilli eggs and larvae due to scyphomedusae and ctenophores in Chesapeake Bay

Use of respiration rates of scyphozoan jellyfish to estimate their effects on the food web

Predation by the scyphomedusan Chrysaora quinquecirrha on Mnemiopsis leidyi ctenophores

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