Carnivorous Suspension Feeding by the Subarctic Calanoid Copepod Neocalanus cristatus

1988 ◽  
Vol 45 (6) ◽  
pp. 1069-1074 ◽  
Author(s):  
Charles H. Greene ◽  
Michael R. Landry
Keyword(s):  
Calanoid Copepod ◽  
Prey Size ◽  
Prey Selection ◽  
Suspension Feeding ◽  
Calanoid Copepods ◽  
Pelagic Ecosystem ◽  
Foraging Mode ◽  
Feeding Experiments ◽  
Feeding Modes

Carnivorous suspension feeding is described for the large subarctic calanoid copepod Neocalanus cristatus. This foraging mode relies on the use of a feeding current to entrain potential prey items and transport them into the copepod's capture area. The extensive use of a feeding current to entrain and transport prey into the capture area distinguishes carnivorous suspension feeding from the predatory modes typically described for other calanoid copepods. The consequences of carnivorous suspension feeding on N. cristatus' prey-selection patterns are significant. Feeding experiments reveal that the vulnerability of naupliar prey declines with increasing prey size, just the opposite result observed for other marine calanoids exhibiting more typical predatory feeding modes. The role of omnivorous feeding by N. cristatus within the pelagic ecosystem of the subarctic Pacific is also discussed. In contrast with earlier hypotheses, the results reported here are consistent with the emerging view that this large suspension-feeding copepod may be having at least as great an impact on the microzooplankton as on the phytoplankton of the region.

Frequency-dependent prey selection by larvae of Toxorhynchites splendens (Diptera: Culicidae)

1996 ◽  
Vol 86 (6) ◽  
pp. 633-639 ◽  
Author(s):  
D. Dominic Amalraj ◽  
P. K. Das
Keyword(s):  
Aedes Aegypti ◽  
Foraging Behaviour ◽  
Anopheles Stephensi ◽  
Prey Size ◽  
Prey Selection ◽  
Fourth Instar ◽  
Frequency Dependent ◽  
Size Selection ◽  
The Stability

AbstractThe foraging behaviour of frequency-dependent prey selection by larval instars of Toxorhynchites splendens (Wiedemann) was studied in the laboratory. Prey size selection (second vs fourth instars of Aedes aegypti Linnaeus or Anopheles stephensi Liston) by third and fourth instar predators was frequency-dependent. However, in the case of second instar predators, prey size selection was not frequency-dependent and the predator preferred second instar to fourth instar prey. When offered second instars of Aedes aegypti and Anopheles stephensi the preference for one species over the other was frequency-dependent in all the three predator instars. The role of frequency-dependent prey selection in the stability of prey—predator interaction at low equilibrium levels is discussed.

Tooth morphology and food processing in Ophiothrix fragilis (Abildgaard, in O.F. Müller, 1789) and Ophiura albida Forbes, 1839 (Echinodermata: Ophiuroidea)

Zoosymposia ◽  
2012 ◽  
Vol 7 (1) ◽  
pp. 111-119 ◽  
Author(s):  
KARIN BOOS
Keyword(s):  
Food Processing ◽  
Structural Quality ◽  
Suspension Feeding ◽  
Tooth Morphology ◽  
Food Items ◽  
Feeding Experiments ◽  
Feeding Modes ◽  
Prey Organism ◽  
Benthic Prey ◽  
Broad Scale

Based on the main feeding modes of two common European brittlestars, Ophiothrix fragilis and Ophiura albida, the pre­sent study relates the species’ tooth morphology to their function in processing food items of different structural quality. Clusters of grinding dental papillae in the suspension feeding O. fragilis seem most appropriate for loosening compound food items, i.e., food boli, or potentially for grazing. Large triangular teeth are considered to be used as crushing and cut­ting instruments, most likely for processing loosened or broken up food masses into smaller digestible portions. In the mostly predating and scavenging O. albida, sharp and pointy or broad scale-like oral papillae may serve in gripping and fixing live benthic prey organisms or carrion, while the larger spine-like teeth may be applied as carnassial instruments thrusting into the flesh of a prey organism and tearing off pieces. Designating the two species either as grinders and cutters processing compound and hard structured food or as grippers and tearers handling softer textures, still awaits confirmation through feeding experiments and observational documentation.

Differential Predation by Chaoborus americanus on Males and Females of Two Species of Diaptomus

1993 ◽  
Vol 50 (2) ◽  
pp. 410-415 ◽  
Author(s):  
Jules M. Blais ◽  
Edward J. Maly
Keyword(s):  
Prey Species ◽  
Calanoid Copepod ◽  
Prey Size ◽  
Handling Time ◽  
Prey Type ◽  
Feeding Rates ◽  
Feeding Experiments ◽  
Chaoborus Americanus ◽  
Differential Predation ◽  
Males And Females

Feeding experiments were performed to determine relative feeding rates of fourth-instar Chaoborus americanus larvae (Diptera) on both sexes of two calanoid copepod species, Diaptomus leptopus and D. minutus. Feeding rates, using a single prey type, showed that predation rates by Chaoborus on female D. minutus were highest, followed by male D. minutus, male D. leptopus, and female D. leptopus, respectively, when exposed to Chaoborus individually. Selectivity experiments with the four prey types made available simultaneously confirmed this pattern. Prey sizes and swimming speeds were determined, and both strike efficiency and handling time of Chaoborus were measured. Data suggested that selection between prey species was determined primarily by prey size whereas selection between sexes was determined primarily by differential swimming speed.

Methyl mercury in zooplankton—the role of size, habitat, and food quality

2002 ◽  
Vol 59 (10) ◽  
pp. 1606-1615 ◽  
Author(s):  
Martin Kainz ◽  
Marc Lucotte ◽  
Christopher C Parrish
Keyword(s):  
Organic Matter ◽  
Fatty Acid ◽  
Body Size ◽  
Methyl Mercury ◽  
Size Fraction ◽  
Food Sources ◽  
Calanoid Copepods ◽  
Bacterial Food

Pathways of methyl mercury (MeHg) accumulation in zooplankton include ingestion of organic matter (OM). We analyzed fatty acid (FA) biomarkers in zooplankton to (i) investigate the effect of allochthonous and autochthonous OM ingestion on MeHg concentrations ([MeHg]) in zooplankton and (ii) examine how algal and bacterial food sources affect MeHg bioaccumulation. We partitioned bulk zooplankton samples (i.e., >500, 202, 100, and 53 μm) from Lake Lusignan (Québec) and measured [MeHg] and [FA] in each fraction. [MeHg] increased with increasing body size and was significantly higher in pelagic than in littoral macrozooplankton (>500 μm). The amount of the ingested terrestrial FA biomarker 24:0 indicated that less than 1% of the total FA in zooplankton was derived from allochthonous sources. More than 60% of the ingested FA originated from algal biomarkers and <10% from bacterial biomarkers. Relative amounts of algal-derived essential FA and bacterial FA were not associated with [MeHg] in any size fraction. In pelagic zones, the amount of MeHg in zooplankton related positively to the number of large organisms such as Calanoid copepods and Daphnia. We propose that the accumulation of MeHg in lacustrine zooplankton depends on the zooplankton habitat rather than on the quality of ingested food.

scholarly journals Changes in foraging mode caused by a decline in prey size have major bioenergetic consequences for a small pelagic fish

2021 ◽  
Author(s):  
Elisa Thoral ◽  
Quentin Queiros ◽  
Damien Roussel ◽  
Gilbert Dutto ◽  
Eric Gasset ◽  
...  
Keyword(s):  
Prey Size ◽  
Pelagic Fish ◽  
Small Pelagic Fish ◽  
Foraging Mode

As the prey thickens: rainbow trout select prey based upon width not length

2021 ◽  
pp. 1-11
Author(s):  
Michael J. Dodrill ◽  
Charles B. Yackulic ◽  
Theodore A. Kennedy ◽  
Michael D. Yard ◽  
Josh Korman
Keyword(s):  
Rainbow Trout ◽  
Prey Size ◽  
Choice Model ◽  
Prey Selection ◽  
Invertebrate Drift ◽  
Fish Length ◽  
Larval Stages ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Selective Foraging ◽  
Length Width

Drift-feeding fish are typically considered size-selective predators. Yet, few studies have explicitly tested which aspect of prey “size” best explains size selection by drift-foraging fish. Here, we develop a Bayesian discrete choice model to evaluate how attributes of both prey and predator simultaneously influence size-selective foraging. We apply the model to a large dataset of paired invertebrate drift (n = 784) and rainbow trout (Oncorhynchus mykiss) diets (n = 1028). We characterized prey “size” using six metrics (length, width, area, hemispherical area, volume, mass) and used pseudo-R2 to determine which metric best explained observed prey selection across seven taxa. We found that rainbow trout are positively size-selective, they are selecting prey based upon differences in prey width, and size-selectivity increases with fish length. Rainbow trout demonstrated strong selection for the adult and pupae stages of aquatic insects relative to their larval stages. Our study provides strong empirical evidence for size-selective foraging in rainbow trout and demonstrates prey selection is based primarily upon width, not length or area as has been widely reported.

Abundance of Boeckella gracilis (Daday, 1902) (Copepoda, Calanoida) in seasonal coastal pools in the Araucania region (38°S, Chile)

Crustaceana ◽  
2018 ◽  
Vol 91 (10) ◽  
pp. 1211-1217
Author(s):  
Patricio De los Ríos
Keyword(s):  
Correlation Analysis ◽  
Environmental Stress ◽  
Relative Abundance ◽  
Calanoid Copepod ◽  
Inverse Correlation ◽  
Inland Waters ◽  
Absolute Abundance ◽  
Significant Inverse Correlation

Abstract The presence of the calanoid copepod Boeckella gracilis (Daday, 1902) in Chilean seasonal pools has been only poorly studied as yet. The aim of the present study thus is to investigate the role of conductivity and temperature on the relative and absolute abundance of B. gracilis in seasonal coastal pools in the Araucania region (38°S, Chile). The results of correlation analysis revealed the presence of a significant inverse correlation between conductivity and relative abundance, whereas no significant correlations were found between conductivity and absolute abundance, between temperature and absolute abundance, and between temperature and relative abundance. These results agree partially with similar observations for mountain pools in the same region, but they would not agree with observations for calanoids of saline and subsaline inland waters in the northern and southern extremes of Chile. Considering this scenario, the species would show different populational responses to environmental stress in different situations, which phenomenon deserves to be studied more extensively and in more detail.

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