Postembryonic growth and development of Caridina nilotica aruensis Roux (Decapoda: Atyidae) reared in the laboratory

1976 ◽  
Vol 27 (2) ◽  
pp. 263 ◽  
Author(s):  
JP Glaister
Keyword(s):  
Growth Rate ◽  
Growth And Development ◽  
Egg Size ◽  
Larval Growth ◽  
Egg Mass ◽  
Larval Life ◽  
Freshwater Shrimps ◽  
The Mean ◽  
Standard Deviations

The larval growth and development of C. n. aruensis reared in the laboratory is described and illustrated. Four zoeal and one post-zoeal stages were found to occur with an approximate time between hatching and metamorphosis of 14 days. The mean egg size was 0.64 by 0.40 mm with standard deviations of 0.042 and 0.028 respectively, whilst the mean number of eggs per egg mass was 74 (s.d. 15.2). The large egg size of C. n. aruensis is correlated with an abbreviated larval life and is a feature of many freshwater shrimps. Zoeal locomotion was thoracic whilst that of the post-zoea was abdominal. The growth rate of C. n. aruensis is described.

scholarly journals Effect of generator (exhaust) fumes on the growth and development of Lycopersicum esculentus (tomato)

2016 ◽  
Vol 20 (2) ◽  
pp. 335-340
Author(s):  
M.N. Chukwu ◽  
E.A. Adams
Keyword(s):  
Growth Rate ◽  
Correlation Coefficient ◽  
Analysis Of Variance ◽  
Air Pollutants ◽  
Growth And Development ◽  
Exhaust Fumes ◽  
The Mean ◽  
The Government ◽  
Level Of Significance ◽  
Source Of Pollution

The effects of generator (Exhaust) Fumes on the growth and development of Lycopersicum esculentus were evaluated in this study. It involved sowing ten seeds of L. esculentus in plastic pots. These were allowed to germinate and stabilize for two weeks after which they were exposed to 0.75KVA generator fumes 8 hours a day at the distance of 3 m, 6 m, and 9 m respectively from the source while the control was retained at the planting site. Results were analyzed using analysis of variance (ANOVA) and Pearson’s correlation coefficient at 5% level of significance. Although the mean dry weights of the plants increased as the distance of the plants from the source of pollution increased, only the 3 m treatment led to significant reduction of the growth rate of the seedlings (p < 0.05). The heights of  the plants were adversely affected by the fume emission especially at the distance of 3 m away from the source (p < 0.05). The leaf number per plant increased as the distance of the plants from the source of pollution increased with significant effects on plant from distance of 3 m and 6 m at the later stage of their growth (p < 0.05). Significant differences (p < 0.05) were observed among the plants in the different treatments for the different parameters measured.. Farmers should locate their farmlands at a distance of at least 50 km away from the factories to minimize effect of air pollutants and the government should also place a ban on importation of old generators.Keywords: generator fume, emission, Lycopersicum esculentus, growth, germination

scholarly journals The growth rate of the Long Rough Dab Hippoglossoides platessoides (Fabr.)

1955 ◽  
Vol 34 (2) ◽  
pp. 297-311 ◽  
Author(s):  
T. B. Bagenal
Keyword(s):  
Growth Rate ◽  
Age Group ◽  
Population Means ◽  
Rate Of Growth ◽  
The Mean ◽  
Standard Deviations ◽  
Hippoglossoides Platessoides

SUMMARYThe ages of 1426 female, and 135 male Long Rough Dabs have been determined from otolith readings. The females were found to live into their seventh year and reach 30.5 cm, compared with males that live to their fifth year and reach 19.0 cm in length. However, the mean increase in length per year for a given length, has been found to be the same. The growth of the females has been shown to fit the equation lt=26.437 (I—0.574t) and of the males lt=17.754 (I —0.585t). In the case of the females the observed and calculated values agree quite closely, but with the males there is a greater difference, and it is believed that the discrepancy is due to net selection. The suggestion is made that the calculated mean lengths for each age group are better estimates of those of the population than are the observed sample means. The two standard deviations limits can be estimated about the population means and the sample values are found to be within these limits.Comparison with previous studies shows that the Clyde fish are smaller and shorter-lived than more northern specimens, though broadly speaking the rate of growth for comparable ages is not so dissimilar.

Influence of Cotton Plant Structures on Heliothine Larval Development and the Production and Infectivity of Occlusion Bodies of Nucleopolyhedrovirus in Larvae

2003 ◽  
Vol 38 (3) ◽  
pp. 368-376
Author(s):  
M. Ibrahim Ali ◽  
S. Y. Young ◽  
G. W. Felton ◽  
D. A. Streett
Keyword(s):  
Growth And Development ◽  
Helicoverpa Zea ◽  
Larval Growth ◽  
Developmental Period ◽  
Pupal Weight ◽  
Plant Structure ◽  
Larval Weight ◽  
Highest Weight ◽  
Occlusion Bodies ◽  
The Mean

Helicoverpa zea (Boddie) and Heliothis virescens (F.), reared on different cotton structures, were studied for larval growth and development, susceptibility to H. zea nucleopolyhedrovirus (HzNPV), and production of occluded virus (OBs). Larval weight of both species after 10 d of rearing differed with larvae on artificial diet having the highest weight and those on square bracts the lowest weight. In both species, pupal weight and length of pupal developmental period were positively correlated with the larval weight, but length of the larval developmental period was negatively correlated with larval weight. Mortality from virus infection of H. zea and H. virescens larvae on squares, square bracts or flowers did not differ significantly among the structures. In both species, the number of viral OBs produced was greater in larvae fed flowers than those fed other structures and was positively correlated with the weight gained by a healthy larva on that plant structure. The mean LC50 for OBs produced in H. zea or H. virescens larvae on square, square bract or flower did not differ significantly. These results indicate that dietary difference in fruiting structures of cotton plants directly affects H. zea and H. virescens larval growth and development and indirectly affects the production of virus by HzNPV-infected larvae.

scholarly journals Growth and development of shoot apex in barley II. Distribution of growth rates during vegetative phase

2014 ◽  
Vol 49 (1-2) ◽  
pp. 33-48 ◽  
Author(s):  
Zygmunt Hejnowicz ◽  
Wiesław Włoch
Keyword(s):  
Growth Rate ◽  
Shoot Apex ◽  
Growth And Development ◽  
Distal Part ◽  
Relative Rate ◽  
Volume Growth ◽  
Leaf Primordia ◽  
Relative Growth ◽  
Apical Dome ◽  
The Mean

The changes in the volume of the apical dome and of the frusta indicate that the mean relative rate of volume growth of the whole apical dome is much higher than in the first frustum which, in turn, grows much faster than the next one. It was found in studies of the distribution of mitoses and of cell arrangement that the volume relative growth rate of the distal part of the apical dome is at least 5-10 times slower than that at the level of new leaf primordia initiation.

scholarly journals Mean daily growth of herring larvae in relation to temperature over a range of 5–20°C, based on weekly repeated cruises in the Greifswalder Bodden

2009 ◽  
Vol 66 (8) ◽  
pp. 1696-1701 ◽  
Author(s):  
Rainer Oeberst ◽  
Mark Dickey-Collas ◽  
Richard D. M. Nash
Keyword(s):  
Growth Rate ◽  
Significant Influence ◽  
Temperature Increase ◽  
Size Range ◽  
Larval Growth ◽  
Growth Period ◽  
Large Temperature ◽  
Daily Growth ◽  
Temperature Range ◽  
The Mean

Abstract Oeberst, R., Dickey-Collas, M., and Nash, R. D. M. 2009. Mean daily growth of herring larvae in relation to temperature over a range of 5–20°C, based on weekly repeated cruises in the Greifswalder Bodden. – ICES Journal of Marine Science, 66: 1696–1701. Reported estimates of mean daily growth of herring larvae generally cover the temperature range 1–12°C and few estimates are available for temperatures >15°C. We use larval surveys on Rügen spring-spawning herring in the Strelasund and the Greifswalder Bodden to estimate larval growth over a wider temperature range because the water temperature in that area normally increases from 5 to 20°C during the larval growth period (i.e. from spring to summer). This large temperature increase has a significant influence on the mean daily growth of herring larvae. Growth estimates were based on the modes of length frequencies observed at individual stations or accumulated over strata from consecutive surveys. Mean daily growth (G; mm d−1) of larvae was primarily determined by the ambient temperature (T) during the growth interval (5–7 d), resulting in the following relationship: G = 0.011 + 0.037 T. A non-linear function is also described. Growth rate was not length-dependent over the size range studied (5–20 mm). The study also showed that herring larvae were growing and surviving in temperatures up to 17.5°C.

Variability in Head Circumference Growth Rate During the First 2 Years of Life

PEDIATRICS ◽  
1992 ◽  
Vol 90 (2) ◽  
pp. 190-192
Author(s):  
M. Jaffe ◽  
Y. Tal ◽  
B. Hadad ◽  
E. Tirosh ◽  
A. Tamir
Keyword(s):  
Growth Rate ◽  
Body Weight ◽  
Body Length ◽  
Head Circumference ◽  
Full Term ◽  
Study Group ◽  
Clinical Interpretation ◽  
Total Cohort ◽  
The Mean ◽  
Standard Deviations

The head circumference (HC) curves were plotted for a group of 415 healthy full-term babies over the first 2 years of life. Two hundred ten (51%) of the cohort demonstrated HC variability, defined as an HC acceleration or deceleration of at least 1 centile curve for at least 2 months. Of these, the deceleration pattern was predominant (80.9%), and also frequently permanent (87%). The HCs of 3 (1.42%) of 210 infants with HC variability ended up with a deviation of 2 standard deviations or more from the mean. The onset of HC transition occurred from the mean age of 1.3 months, and the new curve had stabilized by age 13 months In 95% of the study group. Parallel changes occurred In body weight and body length In approximately 48% of the total cohort, but more frequently in the variable-HC group. The clinical interpretation of these findings is discussed.

The incidence of central serous chorioretinopathy in the population of Kazan: Results of a retrospective epidemiological analysis for 2009–2018

2020 ◽  
pp. 30-33
Author(s):  
D. R. Аgliullin ◽  
G. R. Khasanova ◽  
E. A. Abdulaeva ◽  
S. T. Agliullina ◽  
A. N. Amirov ◽  
...  
Keyword(s):  
Growth Rate ◽  
Central Serous Chorioretinopathy ◽  
Morbidity Rate ◽  
Seasonal Prevalence ◽  
Upward Trend ◽  
Epidemiological Analysis ◽  
Significant Upward Trend ◽  
Track Record ◽  
Minimum Age ◽  
The Mean

Objective: To assess the incidence of central serous chorioretinopathy (CSC) through the example of a large industrial Russian city.Methods: A retrospective analysis of CSC of Kazan population for 2009–2018 has been done.Results: From 2019 to 2018, 831 new cases of CSC were registered in Kazan. A statistically significant upward trend with growth rate 105.2% and accession rate 5.2% was typical for the annual track record. The mean age of patients was 50 years, the minimum age was 14 years, the maximum age was 87 years. A statistically significant upward trend was detected in track record of incidence in groups of 30–39-year-old and 40–49-year-old. Seasonal increase of the incidence was recorded in February, March, April, October, and November.Conclusions: The upward trend and seasonal prevalence are typical for longterm morbidity of CSC in Kazan. The highest morbidity rate of CSC and statistically significant upward trend of its incidence in track record were recorded in the age of 30–39. 

Continuous Precipitation of Lead Iodide

1994 ◽  
Vol 59 (7) ◽  
pp. 1503-1510
Author(s):  
Stanislav Žáček ◽  
Jaroslav Nývlt
Keyword(s):  
Growth Rate ◽  
Particle Size ◽  
Crystal Size ◽  
Crystal Growth Rate ◽  
Laboratory Model ◽  
Lead Iodide ◽  
Secondary Nucleation ◽  
Equimolar Ratio ◽  
Continuous Precipitation ◽  
The Mean

Lead iodide was precipitated from aqueous solutions of 0.015 - 0.1 M Pb(NO3)2 and 0.03 - 0.2 M KI in the equimolar ratio using a laboratory model of a stirred continuous crystallizer at 22 °C. After reaching the steady state, the PbI2 crystal size distribution was measured sedimentometrically and the crystallization kinetics was evaluated based on the mean particle size. Both the linear crystal growth rate and the nucleation rate depend on the specific output of the crystallizer. The system crystallization constant either points to a significant effect of secondary nucleation by the mechanism of contact of the crystals with the stirrer blade, or depends on the concentrations of the components added due to the micromixing mechanism.

Physiology of Larval Feeding

2018 ◽  
Keyword(s):  
Growth And Development ◽  
Marine Invertebrate ◽  
Larval Growth ◽  
Circulatory System ◽  
Future Research ◽  
Larval Feeding ◽  
Digestive Physiology ◽  
Larval Body ◽  
The Individual ◽  
Invertebrate Larvae

The functional properties of marine invertebrate larvae represent the sum of the physiological activities of the individual, the interdependence among cells making up the whole, and the correct positioning of cells within the larval body. This chapter examines physiological aspects of nutrient acquisition, digestion, assimilation, and distribution within invertebrate larvae from an organismic and comparative perspective. Growth and development of larvae obviously require the acquisition of “food.” Yet the mechanisms where particulate or dissolved organic materials are converted into biomass and promote development of larvae differ and are variably known among groups. Differences in the physiology of the digestive system (secreted enzymes, gut transit time, and assimilation) within and among feeding larvae suggest the possibility of an underappreciated plasticity of digestive physiology. How the ingestion of seawater by and the existence of a circulatory system within larvae contribute to larval growth and development represent important topics for future research.

The missing links: larval and post-larval development of the ascoglossan opisthobranch Elysia viridis

2000 ◽  
Vol 80 (6) ◽  
pp. 1087-1094 ◽  
Author(s):  
Cynthia D. Trowbridge
Keyword(s):  
Larval Development ◽  
Growth Rates ◽  
Shell Length ◽  
Larval Growth ◽  
Model Organism ◽  
Larval Life ◽  
Codium Fragile ◽  
Planktotrophic Larvae ◽  
Algal Diet ◽  
Better Than

The stenophagous ascoglossan (=sacoglossan) opisthobranch Elysia viridis has long been a model organism for the study of endosymbiosis or kleptoplasty as well as one of the few herbivores to consume the introduced green macroalga Codium fragile on European shores. Larval and post-larval dynamics of the ascoglossan were investigated. Planktotrophic larvae of E. viridis grew at 5–10 μm d−1 (shell length) at 15°C on a unicellular algal diet (the cryptophyte Rhodomonas baltica); larvae became competent one month post-hatching. Effective feeding and chloroplast acquisition typically started within 2–3 d of metamorphosis. Slugs grew about 8 mm in the first month of post-larval life. During this period, juveniles held in the light did not grow faster or survive better than conspecifics held in the dark; thus, functional kleptoplasty did not occur during first three weeks of benthic life. While larval growth rates and the nature of metamorphic cues are consistent with those of many other opisthobranch species with planktotrophic larvae, measures of post-larval growth—particularly as it pertains to kleptoplasty—is a new contribution to opisthobranch biology.

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