Population and Production Dynamics of an Enchytraeid Worm in a Subtropical Blackwater River

1987 ◽  
Vol 44 (8) ◽  
pp. 1469-1474 ◽  
Author(s):  
David L. Stites
Keyword(s):  
Aquatic Insect ◽  
Dry Mass ◽  
Coarse Sand ◽  
Annual Production ◽  
Total Density ◽  
Frequency Method ◽  
Blackwater River ◽  
Size Frequency ◽  
Center Channel ◽  
Production Dynamics

Population and production dynamics of Barbidrilus paucisetus Loden and Locy (Oligochaeta: Enchytraeidae) in a sixth-order blackwater river are described. This worm was the dominant member of the meiofauna of the sand habitat, accounting for 50–90% of the total density. Population density varied seasonally, increasing from < 20 000/m2 in the winter to 60–120 000/m2 in the summer. Biomass averaged 145 mg dry mass/m2 with a range of 8–326 mg/m2. Density peaked in the clean coarse sand of the center channel areas and was lower where the sand was finer and where more organic matter was present. Size frequency histograms indicated that there were three recruitment peaks during the sampling year, with mature and new individuals present in all seasons. Annual production (2.12 g dry mass/m2, SE = 0.15 g/m2), was estimated using the size frequency method and a cohort production interval correction of 3. Annual production was low compared with that of terrestrial Enchytraeidae and comparable with that of many aquatic insect species. Annual production/biomass ratio (14.3) was higher than terrestrial Enchytraeidae, due to the comparatively short generation time of this species.

Life history, secondary production and population dynamics of Gammarus fossarum (Koch, 1836) in a constant temperature stream

Biologia ◽  
2012 ◽  
Vol 67 (1) ◽  
Author(s):  
Pavel Beracko ◽  
Anna Sýkorová ◽  
Andrej Štangler
Keyword(s):  
Life Cycle ◽  
Constant Temperature ◽  
Growth Function ◽  
Dry Mass ◽  
Frequency Method ◽  
Daily Growth ◽  
Gammarus Fossarum ◽  
Frequency Distributions ◽  
Size Frequency ◽  
The Mean

AbstractPopulation of the freshwater amphipod Gammarus fossarum was investigated in a calcareous stream with almost constant temperature (7–8°C) in the Chočské Vrchy Mts (West Carpathians, Slovakia). Quantitative samples of G. fossarum taken during 2005 showed population densities varying from 100 m−2 in August to 585 m−2 in late November. The population was split into juveniles, mature males, mature females without eggs and females with eggs. The percentage of juveniles (40–64%) was always the highest of any of the categories. Ovigerous females occurred throughout the year. The mean sex ratio was 1: 2.4 (male: female), although its values varied considerably with the time of year. Breeding was continuous, although juvenile recruitment peaked in early spring, summer and early winter. Three discrete cohorts were distinguished from the size frequency distributions. The life span was 6–7 months and the individuals matured approximately in the half of life cycle. The mean fecundity was 9.6 embryos per brood. Variation in fecundity was mostly explained by size of the incubating females. The absolute growth of this species was best described by the Gompertz growth function. Relative growth rates (% body DM day−1) fluctuated in a nonlinear manner with size and age. The highest values of daily growth (2–4% of dry mass per day) were noted approximately in the half of life cycle. Annual production, estimated by the size-frequency method, was 1618.9 g dry mass m−2 and P/B ratio was 5.15.

Life spans of two species of tropical mayfly nymph (Ephemeroptera) from Magela Creek, Northern Territory

1982 ◽  
Vol 33 (1) ◽  
pp. 173 ◽  
Author(s):  
R Marchant
Keyword(s):  
Life Cycle ◽  
Life Span ◽  
Northern Territory ◽  
Annual Production ◽  
Length Frequency ◽  
Frequency Method ◽  
B Values ◽  
Size Frequency ◽  
Mayfly Nymph ◽  
Growth And Reproduction

The nymphs of Cloeon fuviatile and a species of Tasmanocoenis were common in the shallows (< 1 m) of two billabongs in Magela Creek, Northern Territory. Monthly estimates of abundance and length frequency showed that growth and reproduction occurred continuously. Estimates of the ratio of annual production to mean biomass (PIB) were calculated with the size-frequency method, using different values for nymphal life span; these estimates, when compared with P/B values predicted from the literature, suggested that the nymphs had a life span of about 1 month. Such a rapid life cycle is at least in part the result of the high mean temperature (30°C) in the shallows.

Estimates of annual production for some aquatic insects from the La Trobe River, Victoria

1986 ◽  
Vol 37 (2) ◽  
pp. 113 ◽  
Author(s):  
R Marchant
Keyword(s):  
Aquatic Insects ◽  
Temperate Zone ◽  
Annual Production ◽  
Frequency Method ◽  
Habitat Temperature ◽  
Size Frequency ◽  
Total Annual Production ◽  
Annual Turnover

Annual production was estimated by the size-frequency method for Ephemeroptera (Tasmanocoenis tonnoiri, two species of Baetis, Atalonella spp., Atulophlebioides sp.), Plecoptera (Leptoperla spp.) and Trichoptera (Ecnomus sp.) at four sites on the lowland section of the La Trobe River. Annual production (P) of individual ephemeropteran species (or genera) varied from 0.02 to 0.7 g m-2 while total annual production of this order at two sites was 0.7-1 . 5 g m-. Annual production of Leptoperla spp. was 0.03 g m-2 at one site while Ecnomus sp, averaged 2 g m-2 at two sites. Estimates of annual production were subject to an error of at least t 50%. Annual turnover ratios (P/B; B is mean biomass) varied from 9 to 19 and were three to four times higher than published values for similar-sized macroinvertebrates in the temperate zone (generally < 15°C mean annual habitat temperature). This probably resulted from the higher average temperatures (17-18°C) at most sites.

Production of the amphipod Hyalella azteca (Saussure) in a northern Ontario lake

1983 ◽  
Vol 61 (9) ◽  
pp. 2051-2059 ◽  
Author(s):  
Dorothy H. Lindeman ◽  
Walter T. Momot
Keyword(s):  
Littoral Zone ◽  
Lake Ontario ◽  
Hyalella Azteca ◽  
Dry Weight ◽  
Annual Production ◽  
Frequency Method ◽  
Northern Ontario ◽  
Habitat Temperature ◽  
Size Frequency ◽  
Annual Biomass

Annual production of the amphipod, Hyalella azteca, was estimated in three habitats of the upper littoral zone of Dock Lake, Ontario, over a 2-year period (1980–1981). Cohort production (P) by the size frequency method was 1.39 g/m2 (dry weight), mean annual biomass (B) was 0.36 g/m2, and the P/B ratio was 3.9 for the 1980 year class. Five other methods for estimating production were applied to this cohort, providing comparable estimates ranging from 1.21 (instantaneous growth) to 1.65 (cohort G) g/m2. Size frequency estimates of annual production for 1980 and 1981 were 1.24 and 1.40 g/m2, respectively. The annual P/[Formula: see text] ratios of 3.9 and 4.0 for these 2 years agree with the cohort value. A comparison of production estimates for Hyalella azteca in the literature shows a gradient of production which correlates with the habitat temperature regime.

Use of the Size–Frequency (Hynes) Method to Estimate Annual Production of a Stream Fish Population

1983 ◽  
Vol 40 (11) ◽  
pp. 2030-2034 ◽  
Author(s):  
Greg C. Garman ◽  
Thomas F. Waters
Keyword(s):  
Salmo Trutta ◽  
Fish Population ◽  
Annual Production ◽  
Salmo Gairdneri ◽  
Frequency Method ◽  
Reliable Determination ◽  
Size Frequency ◽  
Production Values ◽  
Significant Difference

Previously developed and accepted methods of fish production estimation, such as instantaneous growth (G method), require aging of sampled individuals. Hynes' size–frequency method, however, does not require cohort separation. Annual production and approximate 95% confidence intervals are presented and compared for populations of brook, brown, and rainbow trout (Salvelinus fontinalis, Salmo trutta, and Salmo gairdneri) in Valley Creek, Minnesota, 1977–78, using the size–frequency and G methods. No significant difference was found between production values calculated by the two methods. It is proposed that the size–frequency method provides a reliable determination of annual production of fish populations and will be especially useful where accurate aging of individuals is not possible or where aging represents excessive labor.

Annual Production by Caddisflies and Mayflies in a Western Minnesota Plains Stream

1982 ◽  
Vol 39 (12) ◽  
pp. 1628-1635 ◽  
Author(s):  
M. B. MacFarlane ◽  
T. F. Waters
Keyword(s):  
Standing Stock ◽  
Annual Production ◽  
Insect Community ◽  
Downstream Site ◽  
Frequency Method ◽  
Third Order ◽  
Upstream Site ◽  
Size Frequency ◽  
Total Annual Production ◽  
Wet Weight

Annual production was estimated for five species of caddisflies and mayflies, comprising major components of the insect community, in the Redwood River, a second- to third-order plains stream in western Minnesota. Estmates were made at two sites, one above and one below an impoundment. At the upstream site, annual production (g∙m−2, wet weight) and annual P/B ratios (in parentheses) were Hydropsyche bifida, 8.3 (6.9); Cheumatopsyche pettiti, 5.5 (7.0); Stenonema nepotellum, 3.4 (5.7); Stenacron interpunctatum canadense, 0.8 (7.0); and Caenis simulans, 4.7 (4.2); with total annual production of 22.7 g∙m−2. At the downstream site, annual production and P/B ratios were H. bifida, 34.3 (4.4); C. pettiti, 68.5 (4.4); S. interpunctatum canadense, 24.1 (6.1); and C. simulans, 2.8 (4.4); with total annual production of 129.7 g∙m−2. These species comprised 27.5% of the total insect standing stock at the upstream site and 75.9% downstream. The hydropsychid production at the downstream site was apparently sustained by the drift of zooplankton from the impoundment, resulting in considerably higher production by hydropsychids than reported in woodland streams.Key words: production, Trichoptera, Ephemeroptera, plains stream, benthos, size–frequency method

Production and Biomass of Pokea Clam (Batissa violacea var. celebensis von Martens, 1897) in the Langkumbe River Waters North Buton Southeast Sulawesi

2021 ◽  
Vol 5 (1) ◽  
pp. 14-24
Author(s):  
Tri Abdul Rahman ◽  
Bahtiar Bahtiar ◽  
Pramono Hery Santoso
Keyword(s):  
Sampling Method ◽  
Total Sample ◽  
Dry Mass ◽  
Annual Production ◽  
Fishing Gear ◽  
River Waters ◽  
The People ◽  
Length Width ◽  
Traditional Fishing ◽  
Swept Area

Langkumbe River is located in West Kulisusu District and has long been used by the community for various daily activities. One of the resources often used by the people around Langkumbe River is pokea clams. The aim of this study was to determine the production and biomass of pokea clams (B. violacea) in Langkumbe River Waters of North Buton Regency from August to October 2017. The sampling method used was swept area method using a traditional fishing gear "Tangge" (fishing gear). The samples were measured for the length, width and thickness.  The total weight was measured with the clam/total mass (MT) and the weight of the meat. The samples were dried using an oven for 24 hours at 70 °C to obtain the shell-free dry mass (SFDW). Data were analyzed using standard formulas. The total sample obtained was 1.307 individuals. The highest density of pokea clam was found in August at 596.8 ind/m². Annual production of pokea clam (B. violacea) in Langkumbe River with a total annual production of 1,107.33 gSFDW/m2/year. The highest and lowest production are 297.09 gSFDW/m²/year at size 2.19-2.54cm and -0.16 gSFDW /m²/year at size 4.70-5.05cm, respectively. The total population biomass was 528.03 gSFDW/m2 with the highest biomass 171.72 gSFDW/m²/year at size 2.55-2.90 cm and the lowest was 1.40 gSFDW /m²/year at size 4.70-5.05 cm, so that the recovery rate (P/B ratio) was 2.1 gSFDW/m2/year.

scholarly journals Competitiveness of alexandergrass or Bengal dayflower with soybean

2010 ◽  
Vol 28 (3) ◽  
pp. 515-522 ◽  
Author(s):  
A.C.R. Dias ◽  
S.J.P. Carvalho ◽  
L.W. Marcolini ◽  
M.S.C. Melo ◽  
P.J. Christoffoleti
Keyword(s):  
Competitive Ability ◽  
Dry Mass ◽  
Total Density ◽  
Weed Species ◽  
Replacement Series ◽  
Commelina Benghalensis ◽  
Randomized Design ◽  
Full Flowering ◽  
Completely Randomized Design ◽  
Soybean Plants

Weeds compete with field crops mainly for water, light and nutrients, and the degree of competition is affected by the weed density and the intrinsic competitive ability of each plant species in coexistence. The objective of this research was to compare the competitiveness of alexandergrass (Brachiaria plantaginea) or Bengal dayflower (Commelina benghalensis) in coexistence with soybean, cv. M-Soy 8045. A factorial experiment (2 x 5) with two weed species and five competition proportions was carried out in a completely randomized design with four replicates. Proportions were based on a replacement series competition design, always maintaining the total density of four plants per 10 L plastic pots, which corresponded to 60 plants m ². The weed-crop proportions were: 0:4; 1:3; 2:2; 3:1; 4:0; that corresponded to the proportion of 100, 75, 50, 25 and 0% of soybean plants and the opposite for weeds, B. plantaginea or C. benghalensis plants. Leaf area, shoot dry mass of the weeds and soybean and number of soybean trifoliate leaves were evaluated when the soybean reached the phenologic stage of full flowering. B. plantaginea was a better competitor than soybean plants. Otherwise, C. benghalensis revealed a similar competitive ability that of the soybean. In both cases, there were evidences that intraspecific competition was more important.

Life history and production of Ephoron album (Say) (Ephemeroptera: Polymitarcidae) in the Valley River, Manitoba

1985 ◽  
Vol 63 (7) ◽  
pp. 1668-1674 ◽  
Author(s):  
D. J. Giberson ◽  
T. D. Galloway
Keyword(s):  
Dry Weight ◽  
Exposure Period ◽  
Summation Method ◽  
Instantaneous Growth Rate ◽  
Frequency Method ◽  
Instantaneous Growth ◽  
Size Frequency ◽  
Curve Method ◽  
Rate Method ◽  
Valley River

Ephoron album was the dominant summer mayfly in shallow riffles in the agricultural zone of the Valley River, Manitoba, in 1982 and 1983. There was one generation per year; eggs deposited in August hatched in late May of the following year and nymphs developed rapidly during the summer months. The eggs required a cold period to promote hatching and hatching success of eggs treated in the laboratory at −2 °C for varying periods of time was positively correlated to the length of the exposure period. No eggs hatched following exposure to 4 or 10 °C. Production for 1982 was estimated by four methods for the production interval of only 72 days: the instantaneous growth rate method (1.32 ± 0.44 g fresh dry weight∙m−2∙year−1), the Allen curve method (1.32 g∙m−2∙year−1), the removal – summation method (1.43 ± 0.41 g∙m−2∙year−1), and the size–frequency method (1.48 ± 0.51 g∙m−2∙year−1). Confidence intervals (95%) were calculated using the method of C. C. Krueger and F. B. Martin for the size–frequency estimate of production and by bootstrapping for the removal–summation and instantaneous growth estimates.

The fire pulse: wildfire stimulates flux of aquatic prey to terrestrial habitats driving increases in riparian consumers

2010 ◽  
Vol 67 (3) ◽  
pp. 570-579 ◽  
Author(s):  
Rachel L. Malison ◽  
Colden V. Baxter
Keyword(s):  
Benthic Invertebrates ◽  
Aquatic Insects ◽  
Riparian Vegetation ◽  
Aquatic Insect ◽  
Dry Mass ◽  
High Severity ◽  
Aquatic Insect Emergence ◽  
Terrestrial Habitats ◽  
Aquatic Productivity ◽  
Adult Aquatic Insects

We investigated the midterm effects of wildfire (in this case, five years after the fire) of varying severity on periphyton, benthic invertebrates, emerging adult aquatic insects, spiders, and bats by comparing unburned sites with those exposed to low severity (riparian vegetation burned but canopy intact) and high severity (canopy completely removed) wildfire. We observed no difference in periphyton chlorophyll a or ash-free dry mass among different burn categories but did observe significantly greater biomass of benthic invertebrates in both high severity burned and unburned reaches versus low severity burned reaches. Moreover, a significantly greater flux of adult aquatic insect emergence occurred at sites that experienced high severity fire versus low severity burned and unburned sites. The greatest number of spiders and bat echolocation calls were also observed at sites of high severity fire. Our results suggest that fires of different severity may have very different affects on stream-riparian food webs and that high severity wildfire may lead to an extended “fire pulse” that stimulates aquatic productivity and flux of prey to terrestrial habitats, driving local increases in riparian consumers.

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