scholarly journals Effects of temperature and desiccation on survival rate of Haemonchus contortus infective larval stage

2018 ◽  
Vol 16 (1) ◽  
pp. 17-21
Author(s):  
P. Iliev ◽  
A. Ivanov ◽  
P. Prelezov
Keyword(s):  
Survival Rate ◽  
Larval Stage ◽  
Haemonchus Contortus ◽  
Effects Of Temperature

Observations on the free-living stages of the stomach worm Haemonchus contortus

Parasitology ◽  
1963 ◽  
Vol 53 (3-4) ◽  
pp. 469-481 ◽  
Author(s):  
J. H. Rose
Keyword(s):  
Haemonchus Contortus ◽  
Free Living ◽  
Rate Of Development ◽  
Temperature And Humidity ◽  
Survival And Development ◽  
Effects Of Temperature ◽  
Eggs And Larvae ◽  
Heavy Mortality

Outdoor observations were made on the rate of development of the free-living stages of H. contortus at different times of the year, and on the migratory activities and longevity of the larvae in faeces, on herbage and in soil.The effects of temperature and humidity on the survival and development of eggs and larvae, both in faeces and when separated from the faeces, were studied in the laboratory.The results of these observations are discussed in relation to the heavy mortality of the free-living stages of H. contortus and to the transmission of infection in the field.

scholarly journals STUDY ON SURVIVABILITY OF NEWLY HATCHED LARVAE OF TWO SPECIES OF PEPPERMINT SHRIMP FED WITH DIFFERENT COMBINATIONS AND DENSITIES OF LIVE FOODS

2019 ◽  
Vol 14 (1) ◽  
pp. 15
Author(s):  
Indra Pratama ◽  
Hatim Albasri
Keyword(s):  
Survival Rate ◽  
Larval Stage ◽  
Survival Rates ◽  
The Third ◽  
Randomized Design ◽  
Average Survival ◽  
Peppermint Shrimp ◽  
Trial Treatment ◽  
Newly Hatched Larvae ◽  
Average Survival Rate

This study was aimed to evaluate different types and combinations of live foods in relation to the survivability of newly hatched Lysmata vittata and Lysmata intermedia larvae. The experiment consisted of three trials (different species, combinations, and densities of live foods) arranged in a completely randomized design. The first and second trials were subjected to L. vittata with three treatments for each trial (1A, 1B, 1C for trial-1; 1D, 1E, 1F for trial-2). The third trial consisted of two treatments (2A and 2B) tested on L. intermedia. Each treatment had three replicates. The results showed that the survival rates were low in all treatments. However, each treatment showed a significant effect (P<0.05) on the average survival rate of L. vittata and L. intermedia larvae. In the first trial, treatment 1C was the only one that had survived larvae after day 35 with 4.44% of final average survival rate (FASR). Four of the larvae reached the post-larval stage. In the second trial, treatment 1F showed a better condition than the other treatments with 5.56% FASR. Nevertheless, no larvae in the second trial had transformed to post-larval stage before the experiment ended at day 46. In the third trial, no larvae survived to reach the post-larval stage. In spite of this, treatment 2B had better daily average survival rate (DASR) than treatment 2A. This research concludes that the use of copepods as live food at an early larval stage and Artemia at a later stage is relatively more effective to improve the survival rate of peppermint shrimp larvae.

Effects of temperatures on survival of Aphelenchoides besseyi in prolonged storage of rice grains

Nematology ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1169-1177
Author(s):  
Shigeru Hoshino ◽  
Katsumi Togashi
Keyword(s):  
Survival Rate ◽  
Storage Period ◽  
Seed Storage ◽  
Middle Part ◽  
Prolonged Storage ◽  
Instantaneous Rate ◽  
Aphelenchoides Besseyi ◽  
Different Temperatures ◽  
Effects Of Temperature ◽  
Rice Seeds

Summary The white-tip nematode, Aphelenchoides besseyi, is a seed-borne ectoparasite of the rice plant Oryza sativa. Nematodes in dried rice seeds are in dehydrated quiescence or anhydrobiosis and are reactivated by rehydration. To understand the persistent parasitism better, the effects of temperature on nematode survival were examined during prolonged periods of seed storage. There was a marked difference in the survival rate among different temperatures; survival was lower at 20 and 25°C than at −5 to 10°C after storage for 190 days. No nematodes survived a storage period of 1313 days at 20 and 25°C. When rice seeds were held at 5°C, the survival rate of nematodes decreased during a period of 7315 days. The estimated instantaneous rate of mortality per month was higher in the early and late parts of the period than in the middle part. Another nematode population also showed a reduction in the survival rate during 6553 days storage at 5°C. In storage at −30°C, survival was not affected during a period of 6485 days. After storage at −30°C for 6546 days, 96% of rice seeds germinated, whereas 60-96% of seeds of two groups germinated after storage at 5°C for 6610-7373 days. Therefore, prolonged storage of rice seeds at 5 or −30°C was unlikely to disrupt the connection between rice plants and A. besseyi.

scholarly journals Developmental stages of a mottled emigrant butterfly, catopsilia pyranthe

1970 ◽  
Vol 19 (2) ◽  
pp. 171-179 ◽  
Author(s):  
MH Arju ◽  
MA Bashar ◽  
G Moula
Keyword(s):  
Life Cycle ◽  
Survival Rate ◽  
Key Words ◽  
Laboratory Condition ◽  
Food Consumption ◽  
Larval Stage ◽  
Developmental Stages ◽  
Average Duration ◽  
Cycle Duration ◽  
Life Cycle Duration

The overall life cycle, duration and survival rate of different developmental stages (egg, larva and pupa) of Catopsilia pyranthe conducted at 27 ± 3°C and RH 75% ± 2. showed that within 6.4 days 68% eggs hatched. The average duration from egg to adult, larval stage and pupal were 23.87, 10.93 and 6.8 days, respectively. Fifty six out of 68 larvae successfully completed their whole 5 instars. There were positive correlation among the larval instars, amount of food consumption and excretion of faeces. About 52% pupa were emerged as adult at laboratory condition. Key words: Life cycle; Catopsilia pyranthe; Developmental stages; Rearing DOI: http://dx.doi.org/10.3329/dujbs.v19i2.8961 DUJBS 2010; 19(2): 171-179

scholarly journals The combined effects of temperature and aromatase inhibitor on metamorphosis, growth, locomotion, and sex ratio of tiger frog (Hoplobatrachus rugulosus) tadpoles

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e8834
Author(s):  
Yun Tang ◽  
Zhi-Qiang Chen ◽  
You-Fu Lin ◽  
Jing-Yi Chen ◽  
Guo-Hua Ding ◽  
...  
Keyword(s):  
Body Size ◽  
Survival Rate ◽  
Sex Ratio ◽  
Aromatase Inhibitor ◽  
Condition Factor ◽  
Sex Ratios ◽  
Control Group ◽  
Treatment Groups ◽  
Effects Of Temperature ◽  
Steroid Hormone Level

Background The tiger frog (Hoplobatrachus rugulosus) is widely raised by many farms in southern region of China as an economically edible frog. The growth, development, and sexual differentiation of amphibians are influenced by temperature and steroid hormone level. However, the problem of hormone residues is caused by the addition of exogenous hormones in frog breeding, it is worth considering whether non-sterol aromatase inhibitors can be used instead of hormones. Methods In our study, H. rugulosus tadpoles were subjected to two water temperatures (29 °C and 34 °C) and three letrozole concentrations in the feed (0, 0.1 and 1 mg/g) to examine the effects of temperature, aromatase inhibitor and their interaction on metamorphosis, locomotion, and sex ratios. A G-test and contingency table were used to analyze the metamorphosis rate of tadpoles and the survival rate of froglets after feeding for 90 days. A G-test was also used to analyze sex ratios in different treatment groups. Results Metamorphosis time and body size (snout–vent length, body mass and condition factor) were significantly different between the two temperature treatments. Metamorphosis time was longer and body size was increased at 29 °C compared to those at 34 °C. Letrozole concentration and the temperature × letrozole interaction did not affect these variables. The jumping distance of froglets following metamorphosis was positively associated with the condition factor; when controlling for condition factor, jumping distance was not affected by temperature, letrozole concentration and their interaction. Temperature and letrozole concentration also did not affect metamorphosis and survival rate. Sex ratio of the control group (0 mg/g letrozole) was 1:1 at 29 °C, but there were more males at 34 °C. The sex ratios of H. rugulosus treated with letrozole at 29 °C and 34 °C were significantly biased toward males, and male ratio increased as letrozole concentration increased. Furthermore, more males were produced at 34 °C than at 29 °C at each letrozole concentration.

Development of a culture tank to improve the survival rate in the early larval stage

Impact ◽  
2020 ◽  
Vol 2020 (6) ◽  
pp. 58-59
Author(s):  
Yuki Takahashi
Keyword(s):  
Survival Rate ◽  
Endangered Species ◽  
Graduate School ◽  
Aquatic Plants ◽  
Larval Stage ◽  
Marine Species ◽  
Assistant Professor ◽  
Early Larval Stage ◽  
Collaborative Team ◽  
Global Population

Aquaculture is a method of producing fish, crustaceans, molluscs, aquatic plants, algae and other organisms in a sustainable manner. As the global population continues to grow, so too has demand and, as a result, many marine species have become severely depleted. Aquaculture is a means of sustainably addressing this demand, replenishing wild stocks and rebuilding populations of endangered species. Assistant Professor Yuki Takahashi, from the Graduate School of Fisheries Sciences at Hokkaido University in Japan, is working as part of a collaborative team of researchers from across academia and industry in Japan to adress this issue of sustainability of demand, by developing an aquaculture tank designed to improve the survival rate in the early larval stage.

LYSOGENY IN ENTEROPATHOGENIC ESCHERICHIA COLI: III. THE EFFECTS OF TEMPERATURE AND CHLORAMPHENICOL ON THE LYSOGENY OF D-1 PHAGE-INFECTED CELLS

1961 ◽  
Vol 7 (6) ◽  
pp. 915-920 ◽  
Author(s):  
John P. Glynn ◽  
W. Robert Bailey
Keyword(s):  
Escherichia Coli ◽  
Survival Rate ◽  
Enteropathogenic Escherichia Coli ◽  
E Coli ◽  
Appropriate Treatment ◽  
Infected Cells ◽  
Effects Of Temperature

Evidence is presented to show that cells of Escherichia coli O26:B6 infected with E. coli O111 phage D-1 exhibited a greater lysogenic response if the temperature, shortly after infection, was lowered from 37 °C. Under the same conditions, lysogeny among survivors was reduced markedly at 45 °C. Cooling the system to 20 °C prior to infection increased both the survival rate and lysogenic response among phage-infected survivors. Appropriate treatment with chloramphenicol increased both survival rate and lysogenic frequency.

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