Comparative experimental studies on the feeding of chaetognaths and ctenophores

Reeve, M. R.

doi:10.1093/plankt/2.4.381

Cited by 94 publications

(53 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Type of prey is probably also important, but we used the same DT irrespective of number and type of prey due to lack of published data. Reeve (1980) found that DT was proportional to the number of prey in the gut of S. hispida. Multiple prey were found in 3 to 10% of the S. setosa that contained prey in this study, so the error of using a single DT at each date is small.…”

Section: A La N U S F In M a R C H Ic U S P S E U D O C A La N U S mentioning

confidence: 98%

See 1 more Smart Citation

Diet of the chaetognaths Sagitta setosa and S. elegans in relation to prey abundance and vertical distribution

Tönnesson¹,

Tiselius²

2005

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

The chaetognaths Sagitta setosa and S. elegans and their potential prey organisms were collected from 6 different depth strata on 6 day and night occasions in the Gullmar fjord, west Sweden. The chaetognaths were analysed for gut contents and predation impact estimated. Number of prey per chaetognath (NPC) ranged from 0.2 to 1.0 for S. setosa and 0.4 to 0.9 for S. elegans, with significantly higher values at night. For S. setosa, small copepods dominated gut contents, with the addition of the appendicularian Oikopleura dioica and chaetognaths later in the season. For S. elegans, the great majority of prey were Calanus copepodites. Predation impact was strong on single copepod species, increasing from 0.4 to a maximum of 48% of the individuals removed daily by S. setosa at the end of October. S. elegans consumed 5 to 18% of the deeper dwelling Calanus community daily. Cannibalism was pronounced in S. setosa; in October, 74 to 84% of the population could potentially be removed each day. Selective feeding was observed in S. setosa by estimating clearance rates for different prey. Pseudocalanus sp. was over-represented in the guts (clearance 120 ml ind. ). S. setosa was able to maintain a daily ration of 11 to 17% of body weight despite a rapid decline in copepod prey abundance, and this was possible through cannibalism and intense predation on O. dioica. KEY WORDS: Predator-prey interactions · Predation impact · Cannibalism · Population dynamicsResale or republication not permitted without written consent of the publisher Mar Ecol Prog Ser 289: 177-190, 2005 chaetognath abundance in the autumn, copepod populations decline rapidly and chaetognath predation impact might be high. Finally, the strong cannibalism displayed in several chaetognaths has been suggested to be an important factor for the rapid population decline of S. setosa in late autumn (Øresland 1987), but this effect has not been quantified.In the present study, the diets of the 2 chaetognaths were determined on 6 day/night sampling occasions during the autumn. Simultaneously, prey composition and vertical distribution were determined and used to estimate predation pressure and selective feeding. MATERIALS AND METHODSStudy area. The study was conducted in the Gullmar fjord, a relatively shallow fjord (120 m, entrance sill = 45 m) on the west coast of Sweden. The water column is permanently stratified with a surface layer (0 to 20 m) of variable salinity (15 to 27 ‰), an intermediate layer (20 to 50 m; 27 to 32 ‰) and a stagnant deep layer (50 to 120 m; 32 to 34 ‰). The conditions in the upper 50 m of the fjord resemble the surrounding coastal waters. For a more detailed description of the fjord, see Øresland (1985). Sampling was conducted in the central and deepest part of the fjord (58°19.2' N, 11°32.8' E) on 6 occasions from 6 August to 15 December 1998. Sampling scheme. Temperature and salinity were measured on each sampling occasion by CTD casts (Type ME OTS 1500). Zooplankton were sampled by sequential duplicate vertical hauls with 90 µ...

show abstract

Section: A La N U S F In M a R C H Ic U S P S E U D O C A La N U S mentioning

confidence: 98%

“…Chaetognaths are important zooplankton predators in the sea (Reeve 1980, Feigenbaum & Maris 1984, Baier & Purcell 1997b. Most are ambush feeders and detect prey by sensing hydrodynamic signals (Feigenbaum & Reeve 1977).…”

Section: Introductionmentioning

confidence: 99%

Diet of the chaetognaths Sagitta setosa and S. elegans in relation to prey abundance and vertical distribution

Tönnesson¹,

Tiselius²

2005

Mar. Ecol. Prog. Ser.

View full text Add to dashboard Cite

show abstract

“…In this study, in average, less than 10% was found with food in their gut. Some factors that affect the frequency of individuals containing preys are the capture of chaetognaths at depths and times where feeding does not occur (Nagasawa & Marumo, 1972;Oresland, 1987), evacuation of gut content due to stress provoked by sampling (Baier & Purcell, 1997) and inhibition of ingestion due to high concentration of preys (Sullivan, 1980;Reeve, 1980).…”

Section: Feeding Habitsmentioning

confidence: 99%

Distribution, abundance and biomass of Chaetognaths off São Sebastião region, Brazil in February 1994

Liang

Vega-Pérez

2002

Rev. Bras. Oceanogr.

View full text Add to dashboard Cite

(Praça do Oceanográfico, SP, Brasil) lavega@usp.br• Abstract: The distribution, abundance, biomass, population structure and feeding habits of chaetognaths collected off São Sebastião region, Brazil, in February 1994 are described. Bongo nets were hauled obliquely to collect zooplankton samples. Forty-three samples obtained with the 333 urn mesh were analysed. In this study, 7 chaetognath species belonging to two genera were identified. Sagitta friderici, S. tenuis and S. bipunctata were grouped into the neritic category, and Sagitta enflata, S. hispida, S. minima and Krohnita pacifica into the semi-neritic group. The analysis of the community structure distinguished 3 zones: 1) a nearshore zone evidenced by low richness; 2) an offshore zone evidenced by higher number of species and 3) another offshore zone, located south and south-westward of São Sebastião Island, characterised by higher richness but with dominance of one species. The nearshore zone was dominated by the neritic species S. friderici and S. tenuis, whereas the offshore zone was dominated by S. enflata. Abundance and biomass increase from nearshore toward offshore zones by about two orders of magnitude. Gut content analysis revealed over 90% of empty guts. The chaetognath population was composed mainly of juveniles. The diets among the different chaetognath species was very similar, composed mostly of small copepods and appendicularians.• Resumo: No presente trabalho foram estudados a distribuição, abundância, biomassa, estrutura da população e hábito alimentar dos quetógnatos coletados na região de São Sebastião, Brasil, em fevereiro de 1994. As 43 amostras de zooplâncton utilizadas na elaboração deste trabalho foram obtidas através de arrastos oblíquos usando uma rede Bongô (333 um), providas de fluxômetro. Foram identificadas sete espécies de Chaetognatha pertencentes a dois gêneros. Sagitta friderici, S. tenuis e S. bipunctata foram agrupadas como espécies neríticas, enquanto que Sagitta enflata, S. hispida, S. minima e Krohnita pacifica semi-neriticas. A análise da estrutura da comunidade, mostrou a existência de 3 zonas: 1) zona costeira caracterizada por poucas espécies; 2) zona oceânica com muitas espécies e 3) zona oceânica, ao sul e sudoeste da Ilha de São Sebastião, com muitas espécies, mas predominância de uma espécie. A zona nerítica foi dominada pelas espécies S. friderici e S. tenuis, e a zona oceânica por S.enflata. Abundância e biomassa do grupo aumentou da região costeira para a oceânica. A população foi composta principalmente de jovens. A análise do conteúdo intestinal revelou mais de 90% de indivíduos com o trato digestivo vazio. A dieta das diferentes espécies foi bastante similar, sendo composta principalmente de pequenos copépodos e apendiculários.

show abstract

“…This simplification, combined with sparse experimental data on gelatinous zooplankton, renders estimation of a typical carnivore parameter set exceptionally difficult. For example, we have chosen a basal respiration rate for carnivores of 7 5% of body C d-I, based on the work of Reeve et al (1978) on the ctenophore I? pileus.…”

Section: Parameter Estimationmentioning

confidence: 99%

“…We differ from these workers in using a C to dry weight conversion factor of 0.1 (rather than 0.2) for gelatinous zooplankton. We obtain this value from the mean of Reeve's (1980) data on conversion factors for a number of species, including P. pileus (0.025), the species reported by Rodhouse and Roden as comprising 37% by dry weight of all gelatinous zooplankton in Killary Harbor.…”

Section: Validation Against Killary Harbor Datamentioning

confidence: 99%

A strategic simulation model of a fjord ecosystem

Ross

Gurney

Health

et al. 1993

Limnology & Oceanography

View full text Add to dashboard Cite

We formulate a strategic simulation model of a fjordic ecosystem, paying careful attention to consistency of spatial and temporal scales. Our model incorporates all the major physical and biological elements of the system but is simple enough to allow unambiguous identification of the mechanisms underlying its behavior. Despite this simplicity the model is capable of semiquantitative agreement with the observed behavior of the Killary Harbor ecosystem over the 198 1 season.The key conclusion from our analysis of the model is that because of the very high rates of tidal and freshwater flushing in Scottish sea-lochs, the persistence of such systems is ultimately determined by the balance of nutrient import and export in a manner analogous to a laboratory chemostat. Except at the peak of the spring bloom, inorganic nitrogen supply exceeds biological demand, so that primary production is controlled by physical factors (temperature and irradiance) and the activities of higher trophic levels.

show abstract

Comparative experimental studies on the feeding of chaetognaths and ctenophores

Cited by 94 publications

References 0 publications

Diet of the chaetognaths Sagitta setosa and S. elegans in relation to prey abundance and vertical distribution

Diet of the chaetognaths Sagitta setosa and S. elegans in relation to prey abundance and vertical distribution

Distribution, abundance and biomass of Chaetognaths off São Sebastião region, Brazil in February 1994

A strategic simulation model of a fjord ecosystem

Contact Info

Product

Resources

About