Diets of calanoid copepods on the West Florida continental shelf: Relationships between food concentration, food composition and feeding activity

Kleppel, G. S.; Burkart, C. A.; Carter, K.; Tomas, Carmelo R.

doi:10.1007/bf00942105

Cited by 58 publications

(36 citation statements)

References 43 publications

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“…d 15 N base was calculated for each stratum using the mean isotope value of copepods collected in light traps. The trophic position of copepods was estimated as 2.5 based on the enriched d 15 N of light trap collections compared to smaller copepods from net tows at the SS stratum (see Results) and the omnivorous diet of many copepods (Kleppel et al 1996). A D n value of 3.5 was used for trophic enrichment (Post 2002).…”

Section: Stable Isotopesmentioning

confidence: 99%

Fitness consequences of habitat variability, trophic position, and energy allocation across the depth distribution of a coral-reef fish

2017

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Environmental clines such as latitude and depth that limit species' distributions may be associated with gradients in habitat suitability that can affect the fitness of an organism. With the global loss of shallow-water photosynthetic coral reefs, mesophotic coral ecosystems (*30-150 m) may be buffered from some environmental stressors, thereby serving as refuges for a range of organisms including mobile obligate reef dwellers. Yet habitat suitability may be diminished at the depth boundary of photosynthetic coral reefs. We assessed the suitability of coral-reef habitats across the majority of the depth distribution of a common demersal reef fish (Stegastes partitus) ranging from shallow shelf (SS, \10 m) and deep shelf (DS, 20-30 m) habitats in the Florida Keys to mesophotic depths (MP, 60-70 m) at Pulley Ridge on the west Florida Shelf. Diet, behavior, and potential energetic trade-offs differed across study sites, but did not always have a monotonic relationship with depth, suggesting that some drivers of habitat suitability are decoupled from depth and may be linked with geographic location or the local environment. Feeding and diet composition differed among depths with the highest consumption of annelids, lowest ingestion of appendicularians, and the lowest gut fullness in DS habitats where predator densities were highest and fish exhibited riskaverse behavior that may restrict foraging. Fish in MP environments had a broader diet niche, higher trophic position, and higher muscle C:N ratios compared to shallower environments. High C:N ratios suggest increased tissue lipid content in fish in MP habitats that coincided with higher investment in reproduction based on gonado-somatic index. These results suggest that peripheral MP reefs are suitable habitats for demersal reef fish and may be important refuges for organisms common on declining shallow coral reefs.

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Section: Stable Isotopesmentioning

confidence: 99%

Fitness consequences of habitat variability, trophic position, and energy allocation across the depth distribution of a coral-reef fish

2017

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“…Small calanoid copepods ingested approximately their body carbon daily, while in large copepods the IR as %BC ranged from 27 % (January 1998) to 46% (January 1997) ( Table 4). Daily rations for copepods (genera Eucalanus, Undinula, Centropages and Temora) from the Florida continental shelf varied from 1 to 14 % BC d-' (Kleppel et al 1996), 7 to 18 % BC d-' for largesized copepods from the Barents Sea (BAmstedt et al 1992) and between 0.9 and 2.8% BC d-' for Calanus chilensis, Eucalanus inermis and Centropages brachiatus from the Peru upwelling system (Dagg et al 1980). …”

Section: Biological Conditionsmentioning

confidence: 99%

Composition, biomass and potential grazing impact of the crustacean and pelagic tunicates in the northern Humboldt Current area off Chile:differences between El Niño and non-El Niño years

González¹,

Sobarzo²,

Figueroa³

et al. 2000

Mar. Ecol. Prog. Ser.

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A multi-disciplinary research program was conducted in the northern Humboldt Current System in a 80 X 80 nautical n7ile area off Antofagasta, northern Chile (23" S) on 3 occasions: before the 1997/98 El Nirio event (January 1997), and dunng the onset and maximum penods of the event (July 1997 and January 1998, respectively). As a part of this program, the trophodynamic role of p e l a g~c tunlcates (salps and appendiculanans), as well as the crustacean zooplankton, divided into 3 size classes (large-[euphauslids], medium-[large calanoid copepods] and small-size animals [small calanoid and cyclopoid copepods]) were assessed One of the most conspicuous physical processes was the deepenlng of the thermocline during the El Nirio event, which in turn led to suppression of nutrient enrichment by upwelling events and low chlorophyll a (chl a ) concentrations in the study area. Chl a and particulate organlc carbon (POC) values were hlgher near the coast, and coastaWoceanic gradients were greater m the case of chl a. High chl a (100 to 160 mg m-') and POC ( l 1 to 17 g m-2) concentrations were usually found associated with bays and/or capes w~thin 40 nautical miles of the coast. In contrast, oceanic areas showed low concentrations throughout the study. Small calanoid and cyclopoid copepods represented only a minor fraction of the total crustacean zooplankton carbon (4 to 20%), although they often accounted for a relatively large portion of the total ingestion (26 to 68%) of the crustacean zooplankton community. Euphausiids represented a large fraction of total crustacean zooplankton carbon (28 to 73 %), and accounted for between 5 and 61 % of total crustacean zooplankton grazing. Ingestion rate as a percentage of body carbon was negatively correlated with animal size, varying between 4 % in euphausiids (17 mm) and 123% in small calanoid copepods (0.8 to 1.7 mm). A companson of estimated daily respiration rates and daily carbon ingestion rates indicated that ingestion of phytoplankton would have exceeded respiratory demands for both large and small calanoid copepods during all 3 sampling periods. In contrast, ingestion of phytoplankton failed to account for the respiratory needs of the euphausiids. This, together with microscopical observations, led to the conclusion that euphausiids utilised other sources of carbon such as detritus, micro-and mesozooplankton in addition to phytoplankton. Crustacean zooplankton showed a s~gnificant grazing impact, removing from 10 to 34 % of primary production (PP). Salps of the species Salpa fuslformis were present in dense aggregates that could have removed up to 60% of PP during January 1997. On average, the grazing impact of this specles was approximately one-half (16%) that of the whole crustacean zooplankton community combined (34 % ) . We did not find any significant difference in zooplankton biomass between January 1997 (nonEl Nino) and January 1998 (El Nino), with average biomasses of 24.6 and 21.4 mg dry wt m-" respectively. There was, however, a shift in the size spec...

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“…However, gut and fecal pellet studies seem not to be a reliable way to determine the composition of copepod food since digestion can be very rapid and many food sources have no skeletal remains that could be retrieved. Bottle incubations in situ have traditionally been used to characterize diets of calanoid copepods and to quantify temporal ratios of consumption (Kleppel et al 1996).…”

Section: Introductionmentioning

confidence: 99%

Copepod feeding study in the upper layer of the tropical South China Sea

et al. 2009

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The South China Sea (SCS) is the world's largest marginal sea being notable for vertical mixing at various scales resulting in a sequence of chemical and biological dynamics in surface waters. We investigated the ingestion, gut content, evacuation and clearance rates of copepods collected from six stations (including a South East Asia Time Series station) along a transect line in the tropical of a SCS cruise during September 27, 1999 to October 2, 1999. The goal of the present study was to understand the feeding ecology of copepods in the upper water layers (0-5 m) of the northern SCS during autumn. We measured the gut pigment contents of 33 copepod species by the gut fluorescence method. The gut chlorophyll a values of most small size copepods (\1 mm) were lower than 1.00 ng Chl a individual -1 . The highest gut pigment content was recorded in Scolecithrix danae (7.07 ng Chl a individual -1 ). The gut pigment contents of 33 copepod species (including 70 samples and 1,290 individuals) estimated is negatively correlated with seawater temperature (Pearson correlation r = -0.292, P = 0.014) and is positively correlated with the chlorophyll a concentration of ambient waters (Pearson correlation r = 0.243, P = 0.043). Mean gut pigment content, ingestion and clearance rates (from 80 samples and 1,468 individuals) show that larger copepods ([2 mm) had significantly higher values than medium sized copepods (1-2 mm) and smaller sized copepods. The present study shows that the performance of feeding on phytoplankton was variable in different sized copepod groups, suggesting that copepods obtained in the tropical area of the southeastern Taiwan Strait might be opportunistic feeders.

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Diets of calanoid copepods on the West Florida continental shelf: Relationships between food concentration, food composition and feeding activity

Cited by 58 publications

References 43 publications

Fitness consequences of habitat variability, trophic position, and energy allocation across the depth distribution of a coral-reef fish

Fitness consequences of habitat variability, trophic position, and energy allocation across the depth distribution of a coral-reef fish

Composition, biomass and potential grazing impact of the crustacean and pelagic tunicates in the northern Humboldt Current area off Chile:differences between El Niño and non-El Niño years

Copepod feeding study in the upper layer of the tropical South China Sea

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