Gut pigment destruction by the copepod Acartia clausi

1998 ◽  
Vol 20 (10) ◽  
pp. 1953-1961 ◽  
Author(s):  
V. Tirelli ◽  
P. Mayzaud
Keyword(s):  
Acartia Clausi ◽  
Gut Pigment

The ecological state of the Elefsis Bay prior to the operation of the athens sea outfall

1994 ◽  
Vol 30 (10) ◽  
pp. 161-171 ◽  
Author(s):  
A. J. Theodorou
Keyword(s):  
River Discharge ◽  
Thermal Stratification ◽  
Lower Layer ◽  
Ecological State ◽  
Annual Cycles ◽  
Untreated Wastewater ◽  
Resistant Species ◽  
Acartia Clausi ◽  
Gyrodinium Aureolum ◽  
Agricultural Areas

Nutrient pollution in Elefsis Bay arises mainly from the disposal of Athens untreated wastewater at the eastern entrance of the Bay. The absence of river discharge, lack of cultivated agricultural areas providing runoff and the Bay's limited circulation provide the conditions for the Bay's eutrophication by the discharge of untreated wastewater. In the spring of 1993 this discharge was replaced by a new deep outfall system. To monitor any future changes an assessment of the present ecological state of the Bay is required. Analysis of appropriate data showed that Elefsis Bay accumulates nutrients. In summer a strong thermal stratification causes anoxic conditions to occur in the lower layer. The ecosystem exhibits reduced species diversity and strong oscillations of plankton annual cycles. Flagellates (Cryptomonas sp.) dominate the phytoplankton, followed by dinoflagellates (Gyrodinium aureolum, Prorocentum dentatum) and only in the spring diatoms (Nitzschia) predominate. The zooplankton was dominated by copepods (Acartia clausi) and cladoceran (Podon polyphemoides). Macrobenthos consists of a small number of pollution-resistant species of Polychaeta (Capitela capitata), whilst in summer only one species of Molluscs (Corbula gibba) survives.

scholarly journals The Respiration of some Planktonic copepods II. The Effect Of Temperature

1953 ◽  
Vol 31 (3) ◽  
pp. 447-460 ◽  
Author(s):  
D. T. Gauld ◽  
J. E. G. Raymont
Keyword(s):  
Respiratory Rate ◽  
The Body ◽  
The Other ◽  
Effect Of Temperature ◽  
Acartia Clausi ◽  
Temora Longicornis ◽  
Different Temperatures ◽  
Planktonic Copepods ◽  
The Difference ◽  
The Relationship

The respiratory rates of three species of planktonic copepods, Acartia clausi, Centropages hamatus and Temora longicornis, were measured at four different temperatures.The relationship between respiratory rate and temperature was found to be similar to that previously found for Calanus, although the slope of the curves differed in the different species.The observations on Centropages at 13 and 170 C. can be divided into two groups and it is suggested that the differences are due to the use of copepods from two different generations.The relationship between the respiratory rates and lengths of Acartia and Centropages agreed very well with that previously found for other species. That for Temora was rather different: the difference is probably due to the distinct difference in the shape of the body of Temora from those of the other species.The application of these measurements to estimates of the food requirements of the copepods is discussed.

scholarly journals Short-term changes in the mesozooplankton community and copepod gut pigment in the Chukchi Sea in autumn: reflections of a strong wind event

2015 ◽  
Vol 12 (13) ◽  
pp. 4005-4015 ◽  
Author(s):  
K. Matsuno ◽  
A. Yamaguchi ◽  
S. Nishino ◽  
J. Inoue ◽  
T. Kikuchi
Keyword(s):  
Atmospheric Turbulence ◽  
Chukchi Sea ◽  
Strong Wind ◽  
Calanoid Copepods ◽  
Mesozooplankton Community ◽  
Chl A ◽  
Wind Event ◽  
Food Requirement ◽  
Copepodid Stage ◽  
Gut Pigment

Abstract. To evaluate the effect of atmospheric turbulence on a marine ecosystem, high-frequency samplings (two to four times per day) of a mesozooplankton community and the gut pigment of dominant copepods were performed at a fixed station in the Chukchi Sea from 10 to 25 September 2013. During the study period, a strong wind event (SWE) was observed on 18 September. After the SWE, the biomass of chlorophyll a (Chl a) increased, especially for micro-size (> 10 μm) fractions. The zooplankton abundance ranged from 23 610 to 56 809 ind. m−2 and exhibited no clear changes as a result of the SWE. In terms of abundance, calanoid copepods constituted the dominant taxa (mean: 57 %), followed by barnacle larvae (31 %). Within the calanoid copepods, small-sized Pseudocalanus spp. (65 %) and large-sized C. glacialis (30 %) dominated. In the population structure of C. glacialis, copepodid stage 5 (C5) dominated, and the mean copepodid stage did not vary with the SWE. The dominance of accumulated lipids in C5 and C6 females with immature gonads indicated that they were preparing for seasonal diapause. The gut pigment of C. glacialis C5 was higher at night and was correlated with ambient Chl a (Chl a, and a significant increase was observed after the SWE (2.6 vs. 4.5 ng pigment ind.−1). The grazing impact by C. glacialis C5 was estimated to be 4.14 mg C m−2 day−1, which corresponded to 0.5−4.6 % of the biomass of the micro-size phytoplankton. Compared with the metabolic food requirement, C. glacialis feeding on phytoplankton accounted for 12.6 % of their total food requirement. These facts suggest that C. glacialis could not maintain their population by feeding solely on phytoplankton and that other food sources (i.e., microzooplankton) must be important in autumn. As observed by the increase in gut pigment, the temporal phytoplankton bloom, which is enhanced by the atmospheric turbulence (SWE) in autumn, may have a positive effect on copepod nutrition.

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