Population Dynamics of Daphnia galeata mendotae as Modified by Chronic Cadmium Stress

1978 ◽  
Vol 35 (4) ◽  
pp. 461-469 ◽  
Author(s):  
J. S. Marshall
Keyword(s):  
Population Dynamics ◽  
Carrying Capacity ◽  
Brood Size ◽  
Lake Michigan ◽  
Cadmium Stress ◽  
Whole Body ◽  
Average Weight ◽  
Daphnia Galeata ◽  
Female Ratio ◽  
Daphnia Galeata Mendotae

Forty populations of Daphnia galeata mendotae were maintained for 22 wk (or until they became extinct) in a medium consisting of filtered Lake Michigan water to which Chlamydomonas reinhardi and different concentrations of a mixture of labelled (109Cd) plus stable CdCl2 were added 24 h before use. The medium was changed daily Monday through Fridays. Weekly determinations were made of total numbers, average individual dry weight, mean brood size, egg–female ratio, aborted eggs and embryos, and average whole-body 109Cd content. Chronic cadmium stress reduced the populations' average numbers and biomass, while it increased the populations' turnover rates, temporal variability, probability of extinction, and proportion of ovigerous females. For individuals there was increased prenatal mortality, reduced life expectancy, increased average weight, and increased brood size. Due to compensatory increases in the proportion of ovigerous females and mean brood size, the cadmium sensitivity of population attributes was considerably less than that of the most sensitive individual attribute, prenatal mortality. A linear relationship between population carrying capacity (relative mean numbers) and added cadmium concentration indicated that the effective concentration for a 50% reduction of carrying capacity (EC50) is 7.7 μg Cd/L and that for a 1% reduction (EC1) is 0.15 μg Cd/L. An increase of 0.15 μg Cd/L in Lake Michigan itself, barring synergistic interaction with other factors in the lake, would probably not have a detectable effect on the population dynamics of D. galeata mendotae. Key words: zooplankton dynamics, stress ecology, Daphnia galeata mendotae, cadmium, heavy metals, toxic substances, Laurentian Great Lakes

Acid and Aluminum Effects on Sodium Homeostasis and Survival of Acid-Sensitive and Acid-Tolerant Cladocera

1992 ◽  
Vol 49 (11) ◽  
pp. 2392-2398 ◽  
Author(s):  
Karl E. Havens
Keyword(s):  
Acid Stress ◽  
Relative Increase ◽  
Al Toxicity ◽  
Whole Body ◽  
Population Declines ◽  
Daphnia Galeata ◽  
Sodium Homeostasis ◽  
Bosmina Longirostris ◽  
Acid Tolerant ◽  
Daphnia Galeata Mendotae

Acid-sensitive (Daphnia galeata mendotae) and acid-tolerant (Bosmina longirostris) cladocerans were exposed to 0, 100, or 200 μg Al/L at pH 4.5, 6.0, or 7.5. Whole-body Na content and survivals were determined after 12- and 24-h exposures to the nine treatments. Daphnia galeata mendotae experienced significant decreases in body Na content and survival at pH 4.5. Aluminum effects were pH dependent. At pH 7.5 and 6.0, Na content and survival declined with increasing Al; at pH 4.5, the highest Al concentration enhanced Na content and prolonged survival. Bosmina longirostris Na content and survival were only slightly reduced at pH 4.5, and there were no significant Al or pH × Al interaction effects. The results support the view that (1) the extinction of D. galeata mendotae and the relative increase of B. longirostris during lake acidification are largely due to differential impacts of acid stress on osmoregulation and (2) Al toxicity might also be a factor responsible for D. galeata mendotae population declines, which are most pronounced near pH 6.0.

First observations of tumor-like abnormalities (exophytic lesions) on Lake Michigan zooplankton

1999 ◽  
Vol 56 (10) ◽  
pp. 1711-1715 ◽  
Author(s):  
M Omair ◽  
Henry A Vanderploeg ◽  
David J Jude ◽  
Gary L Fahnenstiel
Keyword(s):  
North America ◽  
Lake Michigan ◽  
Calanoid Copepods ◽  
Daphnia Galeata ◽  
Common Cause ◽  
Depth Contour ◽  
Herbivorous Species ◽  
Limnocalanus Macrurus ◽  
Daphnia Galeata Mendotae ◽  
Animal Size

Tumor-like abnormalities (exophytic lesions) were found on a variety of planktonic calanoid copepods and cladocerans (Diaptomus spp., Epischura lacustris, Limnocalanus macrurus, Polyphemus pediculus, Diaphanosoma sp., and Daphnia galeata mendotae) collected from inshore (3-m depth contour) and offshore (100- to 110-m depth contours) stations of eastern Lake Michigan. The abnormalities, which were quite large relative to animal size and variable in shape, are documented in photographs. Abnormality incidences among species ranged between 0 and 72%. Predatory species of calanoids and cladocerans had higher incidences of tumors than herbivorous species. The abnormalities on some copepods were very similar to cysts described for calanoid copepods in Lago Maggiore, Italy, which like Lake Michigan is undergoing oligotrophication. The recent appearance of the lesions in Europe and North America may indicate an emerging global phenomenon that has a common cause.

Dynamics of Cadmium-Stressed Plankton Communities

1980 ◽  
Vol 37 (3) ◽  
pp. 403-414 ◽  
Author(s):  
J. S. Marshall ◽  
D. L. Mellinger
Keyword(s):  
Dissolved Oxygen ◽  
Lake Michigan ◽  
Zooplankton Community ◽  
Cadmium Stress ◽  
Crustacean Zooplankton ◽  
Functional Responses ◽  
Experimental Lakes Area ◽  
Individual Values ◽  
Zooplankton Density ◽  
Plankton Communities

Structural and functional responses of plankton communities to cadmium stress were studied during 1977 in Lake Michigan using small-volume (8 L) completely sealed enclosures, and in Canada's Experimental Lakes Area (ELA) Lake 223 using large-volume (1.5 × 105 L) open-surface enclosures. In Lake Michigan, reductions of the average abundance of micro-crustaceans by cadmium were significantly greater in "light" or shallow epilimnetic incubations than they were in "dark" or deep epilimnetic incubations. Measurements of dissolved oxygen indicated that this interaction with light (depth) was an indirect effect due to a reduction of photosynthesis and primary production. Zooplankton density and species diversity were not significantly affected within 21 d by cadmium concentrations [Formula: see text] and [Formula: see text] Cd/L, respectively, whereas final dissolved oxygen concentration and percentage similarity (PS) of the crustacean zooplankton community were significantly reduced by [Formula: see text] Cd/L. In the ELA Lake 223 experiment, the reducing effect of cadmium on zooplankton density increased up to 31 d after Cd enrichment and then decreased, probably due to decreasing Cd concentrations in the water. Values of PS on day 24 for the ELA enclosures enriched with 1 and 3 μg Cd/L were within the 95% confidence limits for individual values predicted from a regression of PS on cadmium for the 21-d Lake Michigan experiments.Key words: plankton communities, zooplankton, phytoplankton, cadmium stress, Lake Michigan, Canadian Shield lakes

Population dynamics of Stenothoe valida Dana, 1852 (Amphipoda, Stenothoidae) at Cheongsapo beach of Busan, Republic of Korea

Crustaceana ◽  
2021 ◽  
Vol 94 (4) ◽  
pp. 413-429
Author(s):  
Ye Ji Lee ◽  
Won Gyu Park
Keyword(s):  
Population Dynamics ◽  
Life History ◽  
Sex Ratio ◽  
Brood Size ◽  
Ovigerous Female ◽  
Seasonal Pattern ◽  
Recruitment Rate ◽  
Republic Of Korea ◽  
Female Size ◽  
History Of

Abstract The population dynamics of Stenothoe valida Dana, 1852 were studied at Cheongsapo beach of Busan, Republic of Korea, from March 2019 to March 2020. Sampling was conducted once a month at low tide during spring tides. Specimens were grouped by the cephalic length at 0.025 mm intervals, and classified into four categories: females, ovigerous females, males and juveniles. The sex ratio, defined as females : total males + females, exceeded 0.5 during most of the study period. Brood size was significantly coupled with ovigerous female size. Two to four cohorts appeared at each study period. New cohorts occurred at almost every sampling except in the samples Jun-2, and Nov-2. Life span was estimated at 1-2 months. The juvenile ratio, the ratio of ovigerous females, and the recruitment rate estimated by FiSAT were commonly high in summer and winter. The life history of S. valida was not coupled with water temperature, but had a strong seasonal pattern.

Lake Trout Population Dynamics in the Northern Refuge of Lake Michigan: Implications for Future Rehabilitation

2010 ◽  
Vol 30 (3) ◽  
pp. 629-641 ◽  
Author(s):  
Charles P. Madenjian ◽  
Timothy J. Desorcie
Keyword(s):  
Population Dynamics ◽  
Lake Michigan ◽  
Lake Trout ◽  
Trout Population

scholarly journals Lipid requirement of bay snook (Petenia splendida Günther, 1862) juveniles

2020 ◽  
Vol 48 (4) ◽  
pp. 674-685
Author(s):  
Uriel Rodríguez-Estrada ◽  
Otilio Méndez-Marín ◽  
Alfredo Pérez-Morales ◽  
Rafael Martínez-García ◽  
Emyr Peña-Marín ◽  
...  
Keyword(s):  
Polynomial Regression ◽  
Lipid Level ◽  
Control Diet ◽  
Optimal Growth ◽  
Whole Body ◽  
Average Weight ◽  
Lipid Levels ◽  
Commercial Diet ◽  
Highest Weight ◽  
Lipid Requirement

This research study is focused on the lipid requirements of Petenia splendida (0.65 ± 0.19 g) juveniles. Fish were fed with trout commercial diet (Silver Cup™ - 45% protein and 16% lipids), as control diet - CD (which is usually used to feed this species at commercial scale), and four isoproteic (45% crude protein) diet formulated with different lipid levels (5, 10, 15 and 20%). Diets were administered for 60 days by triplicate per treatment. Our results showed that fish fed with 10, 15 and 20% lipid levels were significantly higher (P < 0.05) in average weight and total length. Same treatments were significantly lower (P < 0.05) in terms of FCR compared to those shown in 5% and CD. However, fish fed 20% lipid level, showed a significant decrease in WG and a significant (P < 0.05) increase in FCR compared to those shown in 15% lipid level. Fish fed with 15% showed the highest weight gain and the lowest FCR compared with the rest of the treatments. Lipid efficiency ratio (LER) showed significant (P < 0.05) differences among experimental groups. Compared to other diets containing lipid levels (5, 10, and 20%) fish fed 15% diet recorded the lowest protein and lipid content in whole body. Additionally, based on second order polynomial regression analysis of WG, it was demonstrated that 16.2% lipid provides an optimal growth for P. splendida.

scholarly journals A seven year experience in patients undergoing total thyroidectomy for benign diseases in a single unit of tertiary care centre: a retrospective case study

2019 ◽  
Vol 7 (9) ◽  
pp. 3317
Author(s):  
Dheer S. Kalwaniya ◽  
Jaspreet S. Bajwa ◽  
Gowtham K. Gowda ◽  
Akshay Narayan ◽  
Rohit Choudhary
Keyword(s):  
Total Thyroidectomy ◽  
Single Unit ◽  
Tertiary Care ◽  
Average Weight ◽  
New Delhi ◽  
Safe Procedure ◽  
Tertiary Care Centre ◽  
Retrospective Case ◽  
Benign Diseases ◽  
Female Ratio

Background: Thyroidectomy is a common surgical procedure performed worldwide by surgeons with varied training. It is the experience and the skills by which a surgeon performs, the indication of surgery and the extent of surgery which determines the outcome and the complication rates.Method: This study is a retrospective study performed from January 2012 to December 2018 when a total of 170 patients underwent total thyroidectomy via kocher’s incision for benign diseases with clinically in hypothyroid state at Safdarjung Hospital, New Delhi in a single unit of a tertiary care hospital.Results: The male: female ratio was 1:7.09 with average age of patients being 40years. The overall complication rate was 18.82% (32 patients). Postoperative transient hypocalcaemia being the most common complication. There was no case of permanent hypocalcaemia. There was no injury to any nerve (recurrent or superior laryngeal). Transient recurrent laryngeal paresis was noted in 4(2.35%) which resolved with conservative management. Complications like wound infection, sympathetic chain injury were not noted. The characteristic feature of this study was five cases of giant secondary retrosternal goitre which had average weight of greater than 500 grams which were operated using kocher’s incision. The average weight of other 165 patients was 70grams +/- 12 grams. There were no major post-operative complications except for post-operative recurrent laryngeal nerve paresis and seroma formation which was evacuated after 3 weeks of surgery.Conclusion: Hence, from this it is concluded that it is the surgical experience and skills of the surgeon which make total thyroidectomy a safe procedure providing permanent cure with a low post-operative morbidity risk even with large sized retrosternal thyroid glands which can be operated via neck incision.

scholarly journals Breeding biology of coppersmith barbet, Megalaima haemacephala (Müller, 1776)

2013 ◽  
Vol 31 ◽  
pp. 31-34
Author(s):  
Noor Jahan Sarker ◽  
M Firoj Jaman ◽  
Shariar Mustafa ◽  
Md Saidur Rahman
Keyword(s):  
Incubation Period ◽  
Breeding Season ◽  
Breeding Success ◽  
Brood Size ◽  
Botanical Garden ◽  
Egg Laying ◽  
Breeding Biology ◽  
Average Weight ◽  
Average Height ◽  
Average Depth

Breeding biology of the Coppersmith barbet, Megalaima haemacephala (Müller, 1776) was carried out between February, 2006 and January, 2007 at Sharawardy Uddyan, Ramna Park, Curzon Hall and National Botanical Garden. The breeding season started from December and ended in June. In total 20 nests were observed, of which 10 nests were studied in details in four study areas. The coppersmith barbet mostly preferred to make holes on the branches of koroi (Albizzia procera) for nesting. Egg laying started on 15th February in the study areas. Average height of nests from the ground was 9.7m and average depth and diameter of the holes was 29.20cm and 4.46cm respectively. New holes were constructed yearly or the old one was reused. Both the sexes took part in incubation of eggs, brooding and feeding to the nestlings. A total of 30 eggs were laid in 10 nests. Clutch size varied from 2 – 4 eggs (average: 3 eggs). Among them, 20 (66.67%) eggs were hatched and the rest 10 (33.33%) were unhatched and lost. Average incubation period was 14 days. The male and the female incubated the eggs for an average of 27.44 minutes/ hours and 32.56 minutes/ hours, respectively. Average number of nestlings (brood size) per nest was 2. Out of 20 nestlings, 16 left their nests successively. The breeding success was 53.33% in relation to the number of eggs laid and 80% in relation to nestlings hatched. The average weight of eggs and nestlings was 3.59g and 9.33g, respectively. The main causes of loss of the eggs and nestlings were human interference, predation and ectoparasitic infections. Insects and fruits were fed to the nestlings by their parents.DOI: http://dx.doi.org/10.3329/ujzru.v31i0.15397Univ. j. zool. Rajshahi Univ. Vol. 31, 2012 pp. 31-34 

Experimental and Mathematical Simulation of Population Dynamics of Rhizospheric Bacteria under Conditions of Cadmium Stress

Microbiology ◽  
2005 ◽  
Vol 74 (6) ◽  
pp. 735-740 ◽  
Author(s):  
V. N. Pishchik ◽  
N. I. Vorob'ev ◽  
N. A. Provorov
Keyword(s):  
Population Dynamics ◽  
Mathematical Simulation ◽  
Cadmium Stress ◽  
Rhizospheric Bacteria
Sign in / Sign up

Export Citation Format

Share Document