摘要:

AbstractThe respiratorion rates of Crustacea from temperate and tropical waters of the Atlantic Ocean were measured directly at habitat temperatures of 19, 25 and 29 °C. The results were analysed together with data obtained from similar investigations in previous years (Ivleva, 1977) on Crustacea from moderately cold and polar latitudes at 10, 6 and 0 °C. Variations of the values forAandkin generalized regressions(R = AWκ)for Crustacea within the temperature limits of the physiological range were shown to have quite a clear‐cut and regular character. The coefficientkvaried from 0.60 to 0.79 and revealed a tendency to increase as temperatures decreased. The value ofAincreased with rising temperature within all intervals from 0 to 30 °C. The quantitative relationship between respiration rate and temperature was evaluated by the Arrhenius equation. Statistical processing of resultant data indicated a rather close association between logAand the habitat temperature of the Crustacea but only slight deviations from the theory of empirically found values. The accelerating effect of temperature (μ) was 13 ± 0.13 keal/mol. This value was used to calculateQ10, which was more convenient for practical p

ISSN:0020-9309    

DOI:10.1002/iroh.19800650102

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19800650103

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

摘要:

AbstractThe Lough Erne System (Northwest Ireland) consists of two linked eutrophic lakes. Phosphorus input budgets suggested mean catchment exports of 30–62 kg total P km−2a−1, resulting in a heavy P loading to the small upper lake. The export of soluble P is related to the human population density in the catchment. Although complex in outline, the upper lake has similar phytoplankton populations throughout, but the populations in the simpler shaped lower lake differ quantitatively and qualitatively from place to place. This is probably due to differences in mixed depth. A chlorophyllamap of the surface water of the lower lake, obtained by fluorometry, showed the relationship between algal biomass and depth of

ISSN:0020-9309    

DOI:10.1002/iroh.19800650104

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

摘要:

AbstractBased on the study of over 500 zooplankton samples collected in Sri Lanka (Ceylon) during 1965–1974, the species composition from different habitats is analysed. The zooplankton assemblage is typically tropical with relatively few species of Cladocera and Copepoda. The Rotifera include a large number of species of the genusBrachionus.The limnetic zooplankton resembles the pond zooplankton closely in that all the eurytopic species found in the different types of habitats, including ponds, also occur in the limnetic zooplankton. The large Cladocera belonging to the genusDaphniaare very rare. In general, large zooplankters are absent. The size composition of the zooplankton has a smaller range than in temperate regions. This is due to the absence of large‐sized zooplankton species.The reasons for the differences in species variety and size composition between zooplankton of temperate and tropical regions is perhaps due to a number of factors. These include the effects of high and uniform temperatures, food availability and predation by fish and invertebra

ISSN:0020-9309    

DOI:10.1002/iroh.19800650105

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19800650107

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

摘要:

AbstractRotifers encountered from a poor (mesotrophic) fen, Avalon Peninsula of Newfoundland, are listed. Sixty‐four species and varieties, including 25 Bdelloidea and 39 Monogononta, were recorded. All but 4 of the reported species and varieties are new records for the Province of Newfoundland, while 27 are new records for Canada; of these, 13 are new for North America.A seasonal quantitative study of rotifer communities in the hummock‐hollow formations on the fen was carried out from August 1973 to October 1974. An average of 354 rotifers/cm2(17 species) was found per formation. Monogononta almost totally disappeared during winter, while the Bdelloidea decreased somewhat in numbers. The tops of hummocks contained mainly bdelloid species. The number of monogononts increased both in species and individuals on the slopes of hummocks and was greatest in the hollows, although the total number of rotifers was less in these areas than in the hummock tops.Some physical and biological factors affecting the rotifer communities were examined. Rotifers in these sites are not subjected to dessication. Predation was not an important factor.A quantitative sampling method was devised for procuring relatively accurate samples from livingSphagnum, and for extracting rotifers from these samp

ISSN:0020-9309    

DOI:10.1002/iroh.19800650108

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19800650109

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

摘要:

AbstractPlankton biomass in size segregated (i.e. 0.45–10 μm, 10–64 μm, 64–165 μm, and>165 μm) samples was measured using ATP assays for two years in H. H. Moss Reservoir. The presence of variable numbers of microcrustacean zooplankton in the>165 μ size class introduced significant, and perhaps inaccurate, variance into temporal dynamics of total ATP concentrations. As many as six physiochemical parameters, measured during 1975–76, were required to produce a significant multiple regression against ATP concentrations; a significant correlation between total ATP measured in the photic zone and surface temperature was observed. A large standing crop of nannoplankton (i.e. 0.45–10 μm) existed in the anaerobic and aphotic hypolimnion during summer stratification both years. This suggested that microbial heterotrophy was an especially important primary trophic event in the reservoir. Particulate (POC) and dissolved (DOC) organic carbon were measured in 1976–77. Organic carbon (POC + DOC) regressed significantly against ATP concentration in the 0.45–10 μm size class and microbial biomass (i.e. 0.45–165 μm) averaged 32 per cent of POC. When biomass was monitored over 24‐hour periods in the photic zone, significant changes were documented in various size classes, especially nannoplankton; but total microbial biomass rem

ISSN:0020-9309    

DOI:10.1002/iroh.19800650110

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19800650112

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY

ISSN:0020-9309    

DOI:10.1002/iroh.19800650113

出版商:Akademie Verlag, Berlin    

年代:1980

数据来源: WILEY