Long-term effects of high CO2 on growth and survival of juveniles of the striped venus clam Chamelea gallina: implications of seawater carbonate chemistry

2021 ◽  
Vol 168 (8) ◽  
Author(s):  
Laura Sordo ◽  
Catarina Duarte ◽  
Sandra Joaquim ◽  
Miguel B. Gaspar ◽  
Domitília Matias
Keyword(s):  
Long Term Effects ◽  
Carbonate Chemistry ◽  
Growth And Survival ◽  
High Co2 ◽  
Chamelea Gallina ◽  
Seawater Carbonate Chemistry

scholarly journals Evaluation of a semi-automatic system for long-term seawater carbonate chemistry manipulation

2013 ◽  
Vol 86 (4) ◽  
pp. 443-451 ◽  
Author(s):  
RODRIGO TORRES ◽  
PATRICIO H MANRIQUEZ ◽  
CRISTIAN DUARTE ◽  
JORGE M NAVARRO ◽  
NELSON A LAGOS ◽  
...  
Keyword(s):  
Automatic System ◽  
Carbonate Chemistry ◽  
Seawater Carbonate Chemistry

scholarly journals The 1912 Douglas-Fir Heredity Study: Long-Term Effects of Climatic Transfer Distance on Growth and Survival

2019 ◽  
Vol 118 (1) ◽  
pp. 1-13 ◽  
Author(s):  
J Bradley St. Clair ◽  
Glenn T Howe ◽  
Jennifer G Kling
Keyword(s):  
Pacific Northwest ◽  
Douglas Fir ◽  
Future Climate Change ◽  
Long Term Effects ◽  
Term Survival ◽  
Growth And Survival ◽  
Seed Sources ◽  
The Pacific ◽  
Near Term

Abstract The 1912 Douglas-Fir Heredity Study is one of the first studies undertaken by the US Forest Service, and one of the first forest genetics studies in North America. The study considers provenance variation of 120 parent trees from 13 seed sources planted at five test sites in the Pacific Northwest. The unique, long-term nature of the study makes it valuable to revisit and consider its biological and historical significance. This analysis considers how far climatically Douglas-fir populations may be moved without incurring unacceptable declines in growth and survival. Results indicate that Douglas-fir seed sources may be moved at least 2° C cooler or warmer and still retain good long-term survival and productivity. However, projected future climate change beyond 2° C may lead to lower survival and productivity. One option to address these concerns is assisted migration; however, if seed sources are moved beyond 2–3° C to a cooler climate in anticipation of warming, or from a more continental to a maritime climate, we are likely to see increased mortality and associated losses in productivity in the near-term. Lessons from this study include: (1) pay attention to good experimental design; we were able to overcome limitations from the design by using new statistical approaches; (2) maladaptation may take time to develop; poorer survival was not evident until more than two decades after planting; and (3) long-term studies may have value for addressing new, unforeseen issues in the future.

scholarly journals Prey selectivity and the effect of diet on growth and development of a dragonfly, Sympetrum sanguineum

2019 ◽  
Author(s):  
Pavla Dudová ◽  
David S Boukal ◽  
Jan Klecka
Keyword(s):  
Handling Time ◽  
Optimal Foraging Theory ◽  
Mixed Diet ◽  
Prey Selectivity ◽  
Long Term Effects ◽  
Short Term ◽  
Growth And Survival ◽  
Prefer Prey ◽  
Predatory Insects

Despite a long tradition of research, our understanding of mechanisms driving prey selectivity in predatory insects is limited. According to optimal foraging theory, predators should prefer prey which provides the highest amount of energy per unit time. However, prey selectivity may also depend on previous experience and nutritional demands driven by stoichiometry. From the long-term perspective, diet composition affects predator fitness. An open question is whether short-term selectivity of predators provides a diet which is optimal in the long-term. To shed more light on these issues, we conducted laboratory experiments on prey selectivity and its long-term consequences in larvae of the dragonfly Sympetrum sanguineum. We conditioned the larvae to one of two prey types, the cladoceran Daphnia magna and Chironomus larvae, and then exposed them to various combinations of the two prey types. We found that dragonfly larvae conditioned to Chironomus larvae consumed the same amount of D. magna, but significantly less Chironomus larvae compared to dragonfly larvae conditioned to D. magna. However, there was no effect of experience on their success of capture and handling time, suggesting a limited role of learning in their ability to process prey. We then tested the long-term effects of diets with different proportions of both prey for survival and growth of the dragonfly larvae. Individuals fed Chironomus-only diet performed significantly worse than dragonflies fed D. magna, while larvae fed a mixed diet performed the best in terms of growth and survival until adulthood. In conclusion, we show that dragonfly larvae fed by Chironomus larvae performed poorly and compensated by preferring D. magna when both prey types were available. The superiority of the mixed diet suggests that a diverse diet may be needed to satisfy nutritional demands in S. sanguineum larvae. We demonstrate that merging short-term predation experiments with relevant data on predator fitness may provide better understanding of predator-prey interactions and conclude that detailed information on the (mis)matches between prey stoichiometry and predator nutritional demands is needed for further progress.

Lack of Long-term Effects of the Administration of Heptachlor to Suckling Rats

1972 ◽  
Vol 58 (1) ◽  
pp. 49-53 ◽  
Author(s):  
José R. Cabral ◽  
Maria Cristina Testa ◽  
Benedetto Terracini
Keyword(s):  
Corn Oil ◽  
Survival Rates ◽  
Pituitary Tumors ◽  
Long Term Effects ◽  
Stomach Tube ◽  
Experimental Conditions ◽  
Growth And Survival ◽  
And Control ◽  
Lipomatous Tumors

95 Wistar rats were given 5 administrations of 10 mg/kg heptachlor in corn oil each by stomach tube, every second day starting at 10 days of age. Seven animals died before weaning. No early deaths were recorded among 36 controls given corn oil only. 29 experimental animals were killed at 60 weeks of age to detect early changes which were nevertheless absent. Growth and survival rates were similar in experimental and control animals. The incidence of tumors at different sites in males and that of adrenal, thyroid and pituitary tumors in females were comparable in both groups. 9 of 28 treated females developed a total of 12 tumors in various organs (including 5 mammary tumors and 2 renal lipomatous tumors) whereas 4 of 27 control females developed a total of 4 tumors (2 of which were located in the breast). In view of the different locations of the tumors and the lack of the reproducibility of the finding among males the results are not considered as evidence of carcinogenicity of heptachlor under the present experimental conditions.

scholarly journals Prey selectivity and the effect of diet on growth and development of a dragonfly, Sympetrum sanguineum

2019 ◽  
Author(s):  
Pavla Dudová ◽  
David S Boukal ◽  
Jan Klecka
Keyword(s):  
Handling Time ◽  
Optimal Foraging Theory ◽  
Mixed Diet ◽  
Prey Selectivity ◽  
Long Term Effects ◽  
Short Term ◽  
Growth And Survival ◽  
Prefer Prey ◽  
Predatory Insects

Despite a long tradition of research, our understanding of mechanisms driving prey selectivity in predatory insects is limited. According to optimal foraging theory, predators should prefer prey which provides the highest amount of energy per unit time. However, prey selectivity may also depend on previous experience and nutritional demands driven by stoichiometry. From the long-term perspective, diet composition affects predator fitness. An open question is whether short-term selectivity of predators provides a diet which is optimal in the long-term. To shed more light on these issues, we conducted laboratory experiments on prey selectivity and its long-term consequences in larvae of the dragonfly Sympetrum sanguineum. We conditioned the larvae to one of two prey types, the cladoceran Daphnia magna and Chironomus larvae, and then exposed them to various combinations of the two prey types. We found that dragonfly larvae conditioned to Chironomus larvae consumed the same amount of D. magna, but significantly less Chironomus larvae compared to dragonfly larvae conditioned to D. magna. However, there was no effect of experience on their success of capture and handling time, suggesting a limited role of learning in their ability to process prey. We then tested the long-term effects of diets with different proportions of both prey for survival and growth of the dragonfly larvae. Individuals fed Chironomus-only diet performed significantly worse than dragonflies fed D. magna, while larvae fed a mixed diet performed the best in terms of growth and survival until adulthood. In conclusion, we show that dragonfly larvae fed by Chironomus larvae performed poorly and compensated by preferring D. magna when both prey types were available. The superiority of the mixed diet suggests that a diverse diet may be needed to satisfy nutritional demands in S. sanguineum larvae. We demonstrate that merging short-term predation experiments with relevant data on predator fitness may provide better understanding of predator-prey interactions and conclude that detailed information on the (mis)matches between prey stoichiometry and predator nutritional demands is needed for further progress.

Ovarian Dysfunction in Fetally Irradiated Beagles

1977 ◽  
Vol 35 ◽  
pp. 658-659
Author(s):  
T. M. Seed ◽  
M. H. Sanderson ◽  
D. L. Gutzeit ◽  
T. E. Fritz ◽  
D. V. Tolle ◽  
...  
Keyword(s):  
Gamma Rays ◽  
Low Dose ◽  
Long Term Effects ◽  
Ovarian Dysfunction ◽  
Dose Rates ◽  
Highly Sensitive ◽  
Microscopic Evaluation ◽  
Ovarian Pathology ◽  
Normal Offspring

The developing mammalian fetus is thought to be highly sensitive to ionizing radiation. However, dose, dose-rate relationships are not well established, especially the long term effects of protracted, low-dose exposure. A previous report (1) has indicated that bred beagle bitches exposed to daily doses of 5 to 35 R 60Co gamma rays throughout gestation can produce viable, seemingly normal offspring. Puppies irradiated in utero are distinguishable from controls only by their smaller size, dental abnormalities, and, in adulthood, by their inability to bear young.We report here our preliminary microscopic evaluation of ovarian pathology in young pups continuously irradiated throughout gestation at daily (22 h/day) dose rates of either 0.4, 1.0, 2.5, or 5.0 R/day of gamma rays from an attenuated 60Co source. Pups from non-irradiated bitches served as controls. Experimental animals were evaluated clinically and hematologically (control + 5.0 R/day pups) at regular intervals.

Ultrastructural investigations of MDL 19,660-induced effects on the canine platelet and megakaryocyte

1990 ◽  
Vol 48 (3) ◽  
pp. 374-375
Author(s):  
D.E. Loudy ◽  
J. Sprinkle-Cavallo ◽  
J.T. Yarrington ◽  
F.Y. Thompson ◽  
J.P. Gibson
Keyword(s):  
Antidepressant Drug ◽  
Beagle Dogs ◽  
Long Term Effects ◽  
Short Term ◽  
Platelet Counts ◽  
Toxicological Studies ◽  
Induced Aggregation ◽  
Internal Architecture

Previous short term toxicological studies of one to two weeks duration have demonstrated that MDL 19,660 (5-(4-chlorophenyl)-2,4-dihydro-2,4-dimethyl-3Hl, 2,4-triazole-3-thione), an antidepressant drug, causes a dose-related thrombocytopenia in dogs. Platelet counts started to decline after two days of dosing with 30 mg/kg/day and continued to decrease to their lowest levels by 5-7 days. The loss in platelets was primarily of the small discoid subpopulation. In vitro studies have also indicated that MDL 19,660: does not spontaneously aggregate canine platelets and has moderate antiaggregating properties by inhibiting ADP-induced aggregation. The objectives of the present investigation of MDL 19,660 were to evaluate ultrastructurally long term effects on platelet internal architecture and changes in subpopulations of platelets and megakaryocytes.Nine male and nine female beagle dogs were divided equally into three groups and were administered orally 0, 15, or 30 mg/kg/day of MDL 19,660 for three months. Compared to a control platelet range of 353,000- 452,000/μl, a doserelated thrombocytopenia reached a maximum severity of an average of 135,000/μl for the 15 mg/kg/day dogs after two weeks and 81,000/μl for the 30 mg/kg/day dogs after one week.

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