On the Growth at Moulting of Lobsters (Homarus Vulgaris) in Cornwall and Yorkshire

1967 ◽  
Vol 47 (3) ◽  
pp. 629-643 ◽  
Author(s):  
B. T. Hepper
Keyword(s):  
Growth Rate ◽  
Population Study ◽  
Growth Pattern ◽  
Carapace Length ◽  
Field Experiments ◽  
Size Range ◽  
Probability Paper ◽  
Significant Difference ◽  
Two Factors ◽  
Mean Size

In experiments in Cornwall and Yorkshire 214 marked lobsters (Homarus vulgarisM. Edw.) were returned after moulting. Of these a number had moulted more than once, and the separation into once-, twice- and three-times-moulted lobsters was achieved using probability paper.There was no significant difference in growth of lobsters from the two areas. It is concluded that the best method of plotting growth in lobsters is to plot carapace length before moulting against carapace length after moulting.It is concluded that male lobsters show arithmetic growth over the size range 68–123 mm carapace length, adding a constant mean increment of 9.8 mm carapace length at each moult.It is concluded that arithmetic growth, with a mean increment of 8.4 mm, adequately describes the growth of female lobsters over a small size range centred on a mean size of about 85 mm, but would lead to inaccuracies over a wider size range.The concept of arithmetic growth in relation to the general growth pattern is briefly discussed.IntroductionIn a population study a knowledge of the growth rate is essential. In crustaceans estimation of the growth rate is complicated by two factors: first, it is usually not possible to age the animals, and second, the growth rate is made up of two components, the increase in size at moulting and the frequency with which moults occur.The present paper presents data on the growth of lobsters at a moult, obtained from field experiments conducted in Cornwall in 1957–59, and in Yorkshire in 1958 and 1960.

scholarly journals RESPONSE OF SOME WHEAT GROWTH TRAITS FOR FOR FOLIAR SPRAYING WITH HUMIC AND GLUTAMIC ACID

2019 ◽  
Vol 50 (6) ◽  
Author(s):  
Baqir & Zeboon
Keyword(s):  
Growth Rate ◽  
Humic Acid ◽  
Glutamic Acid ◽  
Growth Traits ◽  
Flag Leaf ◽  
Block Design ◽  
Dry Weight ◽  
Engineering Sciences ◽  
Significant Difference ◽  
Two Factors

A field experiment was conducted at the Agricultural Experiment Unit, College of Agriculture Engineering Sciences, University of Baghdad, during two winter seasons 2016-2017 and 2017-2018 to study the response of some growth traits for wheat Cv. Al forat to foliar spraying using with humic glutamic acid and acid. A factorial experiment was with in Randomized Complete Block Design applied three replications, it involved two factor ,first factor was glutamic acid with three concentrations (0,250,500) mg L-1, second factor was humic acid with three concentrations (0,1,2) ml L-1, have been sprayed at tillering and flowering stages. The results showed that all the studed growth traits (plant height, ,number of tillers, flag leaf area dry weight for plant , crop growth rate ,relative growth rate and biological yield) were affected  by spraying with humic acid and glutamic acid for two season concentration , 2ml -1 from humic acid was superior on most of studies traits , as for glutamic acid ,plants treated with concentrations 250 and 500 mg L-1 were produced the highest mean for studies traits but without significant difference between them in some traits .The interaction between two factors was significant on most studies growth traits .

The growth, ecology and population structure of giant tortoises on Aldabra

1971 ◽  
Vol 260 (836) ◽  
pp. 327-372 ◽  
Keyword(s):  
Growth Rate ◽  
Carapace Length ◽  
Size Range ◽  
Habitat Preferences ◽  
Local Variation ◽  
Island Population ◽  
Island Growth ◽  
Age Classes ◽  
Mean Values ◽  
Differential Movement

The giant tortoise of Aldabra, Geochelone gigantea , shows quite marked changes in proportions with age, although during growth the relations between the length of the carapace and various measurements of the plastron and scutes involve not only strong but also weak allometry. Certain scutes show a predisposition to split during growth. Accidental damage to the carapace is frequent. Males reach over 100 cm in carapace length but females are smaller, up to 80 cm. There is no segregation between the sexes in any single measurement investigated, except among the very largest animals. A general appraisal of carapace and tail shape is sufficient to sex only animals above 60 cm in carapace length. The number of annuli on each scute corresponds to the number of years of age at least up to the formation of the tenth to fifteenth annulus. A general assessment of the pattern of growth is made by plotting body measurements against number of annuli. Growth curves of individual tortoises are reconstructed by relating measurements of successively formed annuli to age. Growth rate is recorded by plotting the difference between successive pairs of annulus measurements against age. The growth rate of ageable tortoises varies between local populations on South Island and between populations of South and Middle Island. Growth rate declines with age, reaching asymptotes at mean values of between 20 and 30 years. Some individuals exhibit sudden increases in growth rate after several years of very slow growth. There is a well-marked daily cycle of activity, feeding being limited to the early morning and late evening. Agonistic behaviour is virtually absent. Breeding is seasonal and the males select partners from within a limited size range of tortoises. Most mating attempts are unsuccessful. On Aldabra, tortoises occur in a wide variety of habitats, in each of which they depend on a different plant species or vegetational association for food. On coastal plains the chief source of food is Sporobolus virginicus . A variety of small herbs is consumed on the barren stretches of coastal champignon. Distribution in these areas is profoundly affected by the availability of shade. Further inland, the tortoises browse heavily on Guettarda speciosa in woods dom inated by this tree. They take advantage of seasonal successions in the vegetation associated with freshwater pools, feeding on each community as it develops. Most of the woody plants near the pools are ignored. On the platin, browsing is selective and the regeneration of some trees is held in check. A very im portant food source here is the `tortoise turf’ (a sward in which Panicum sp. is often dominant) developed under conditions of heavy grazing and susceptible to erosion by wind and the tortoises themselves. On Middle Island, where the population is small, the tortoises exert very little effect on the vegetation. Associations with other animals are mostly casual, but along the south coast dunes Coenobita rugosus is dependent on tortoise faeces for food. Fossilized tortoise bones have been discovered at many points on Aldabra, deposited in brown limestone. They probably date from before the interstadial of about 30 000 years ago. Some adult tortoises range over 7 km or more, across a variety of habitats, but many individuals appear to be sedentary. The population of South Island is enormous of the order of 100 000 animals with a density of about 30 hm -2 on the platin. Higher densities are reached in Guellarda woodland. Local variation in numbers, size range and age structure depend on habitat preferences, differential movement of age classes and regional differences in growth rate. Attempts at assessing age class distribution are affected particularly by undersampling of the younger age classes, and the difficulty of counting the worn growth rings in animals with more than about 14. In the census sample, which may itself be an imperfect sample of the whole South Island population, at least 35 % of the animals are below 20 years of age and only about 20 % can have reached sexual maturity. More than 50 age classes may be present, but this and similar deductions are still speculative.

scholarly journals OF SOME FIELD TRAITS OF WHEAT TO ABA UNDER EFFECT OF WATER STRESS RESPONSE

2017 ◽  
Vol 48 (4) ◽  
Author(s):  
Hashim & Ahmed
Keyword(s):  
Growth Rate ◽  
Water Stress ◽  
Plant Height ◽  
Field Experiments ◽  
Crop Growth ◽  
Control Treatment ◽  
Research Station ◽  
Crop Growth Rate ◽  
Effect Of Water ◽  
Significant Difference

Two field experiments were carried out at the field crop research station- Abu-Ghraib of agricultural researches office during 2014-2015 and 2015-2016 to investigate effect of water irrigation quantities and ABA concentrations soaking and spraying on some morphological traits of wheat cultivar bahooth 10. Split plot arrangement by RCBD with three replicates for each experiment. First trial included for water irrigation volumes which control treatment (irrigation 50% of the water available), 70% and 40% from control treatment as well as rainy treatment (germination irrigation + rainfed) which occupied main plots while ABA soaking concentration (0, 1, 2, and 3) micromoles which occupied sub plots. Second experiment included same irrigation treatments which occupied main plots while ABA spraying concentration (0, 30, 60 and 90) micromoles occupied sub plots. Irrigation treatment 70% of first experiment produced plant height was 97.08 cm and flag leaf area 46.35 cm-2 and dry weight at 100% anthesis 1144.57 gm m-2.  For second experiment control treatment gave highest values for duration from planting to 100% anthesis 113.41 and 111.50 day, number of tillers 388.95 and 403.18 tiller m-2 , the crop growth rate 10.61 and 11.31 g m-2 day for both season respectively with no significant difference with 70% of control treatment for both seasons. Soaking concentration 3 micromoles attained the highest value of number of tillers 338.58 and 354.20 tiller m-2, dry matter at 100% anthesis 970.10 and 1102.43 gm m-2, day the crop growth rate 8.85 and 10.16 gm-2 . day for both seasons respectively .While spraying 90 micromoles concentration gave the lowest values for plant height 82.63 and 88.22 cm, but the highest value for number of tillers 336.67 and 384.92 tiller m-2 , for both season , day the crop growth rate 9.13 and 9.05 g m-2 day for first season with did not differ significantly from 60 micromoles . Therefore could be conclude to capability of irrigation with 70% from full irrigation without signification effect in growth traits, as well as can be treat plant wheat with ABA concentration 3 and 60 micromoles soaking and spraying respectively to improve their ability to tolerance water stress .

scholarly journals RESPONSE OF CILANTRO (CORIANDRUM SATIVUM) TO COMBINATIONS OF GIBBERELLIC ACID, FOLCYSTEINE, AND NITROGEN

HortScience ◽  
1996 ◽  
Vol 31 (5) ◽  
pp. 760c-760
Author(s):  
Jose Pablo Morales-Payan ◽  
Bielinski M. Santos
Keyword(s):  
Gibberellic Acid ◽  
Field Experiments ◽  
Block Design ◽  
Foliar Spray ◽  
Coriandrum Sativum ◽  
Fresh Weight ◽  
Nitrogen Levels ◽  
Significant Difference ◽  
Randomized Complete Block Design ◽  
Two Factors

Field experiments were conducted in the Dominican Republic to determine the effect of combinations of N with folcysteine and gibberellic acid 3 on cilantro (Coriandrum sativum) yield. Nitrogen levels (0, 36, 55, 73, 91 kg·ha–1) in soil application at sowing were combined with foliar spray of the biostimulant folcysteine or gibberellic acid (0, 100, 200, 300, and 400 ppm) 15 days after emergence. Treatments were applied in a factorial arrangement on a randomized complete block design with three replications. Fresh weight of the aerial part of the plants was determined 40 days after emergence. No significant difference was found due to folcysteine treatment. Nitrogen had a significant effect, with optimal yield at 55 kg·ha–1. Significant interaction was detected for the combinations of gibberellic acid and N, with yield increasing as the rate of the two factors increased.

scholarly journals Growth in the northern stone crab Lithodes maja Linnaeus, 1758 (Decapoda: Anomura: Lithodidae), a potential fishery target, in the laboratory

2019 ◽  
Vol 39 (5) ◽  
pp. 582-585
Author(s):  
Alastair Brown ◽  
Sven Thatje
Keyword(s):  
Growth Rate ◽  
Carapace Length ◽  
Size Range ◽  
Age At Maturity ◽  
Early Juvenile ◽  
Stone Crab ◽  
Size Growth ◽  
Size At Age ◽  
Juvenile Males

Abstract Data are presented on growth in early juvenile (N = 36; 2.05–3.95 mm carapace length) Lithodes maja Linnaeus, 1758 reared at 6 °C in the laboratory, and on growth in males (N = 24; 45.9–113.3 mm carapace length) and females (N = 9; 61.0–81.3 mm carapace length) maintained at 6 °C in the laboratory. Growth rate did not differ significantly among early juvenile, males, or females, and therefore appeared linear across the size range examined. Intermoult period increased with increasing size. Growth and intermoult period models were combined to estimate size at age. Age at maturity appears greater in L. maja than in other species of Lithodes, suggesting that L. maja may be more vulnerable to fisheries overexploitation.

scholarly journals Relative growth and sexual maturity of the freshwater shrimp Palaemon pandaliformis (Crustacea, Palaemonidae) in northeastern of Brazil (Canavieiras, Bahia)

2013 ◽  
Vol 103 (1) ◽  
pp. 31-36 ◽  
Author(s):  
Lucas R. P. Paschoal ◽  
Fernanda J. Guimarães ◽  
Erminda C. G. Couto
Keyword(s):  
Growth Pattern ◽  
Sexual Maturity ◽  
Carapace Length ◽  
Ovigerous Female ◽  
Global Scale ◽  
Northeastern Brazil ◽  
Species Comparison ◽  
Relative Growth ◽  
Significant Difference ◽  
Freshwater Environments

This study comprises the description of relative growth and sexual maturity of a population of Palaemon pandaliformis Stimpson, 1871 in Salsa River (Northeastern Brazil). Samples were collected monthly between September 2009 and August 2010. Females were larger, heavier, and showed a greater allometric coefficient (b) than male specimens. Only carapace length vs. pleura length in females presented a significant difference in the relative growth pattern, indicating a puberty moult. This relationship is strictly correlated to reproduction and its success rate in female shrimps. Estimated carapace length in 50% of mature females (CL50) was 4.53 mm. It was not possible to compare obtained CL50 results due to a lack of studies on this species. Comparison was based on the size of the smallest captured ovigerous female (3.81 CL mm), which is within the scope of recorded size for estuaries located in higher latitudes. This study reveals the lack of research on this genre in freshwater environments on a national and global scale.

Electron Microscopy of the Shape of Small Metal Particles

1977 ◽  
Vol 35 ◽  
pp. 300-301
Author(s):  
M. Jose Yacaman
Keyword(s):  
Electron Microscopy ◽  
Metal Particle ◽  
Field Experiments ◽  
Size Range ◽  
Dark Field ◽  
Metal Particles ◽  
Bragg Condition ◽  
Crystal Particle ◽  
Small Metal Particle ◽  
Small Metal Particles

In the Study of small metal particles the shape is a very Important parameter. Using electron microscopy Ino and Owaga(l) have studied the shape of twinned particles of gold. In that work electron diffraction and contrast (dark field) experiments were used to produce models of a crystal particle. In this work we report a method which can give direct information about the shape of an small metal particle in the amstrong- size range with high resolution. The diffraction pattern of a sample containing small metal particles contains in general several systematic and non- systematic reflections and a two-beam condition can not be used in practice. However a N-beam condition produces a reduced extinction distance. On the other hand if a beam is out of the bragg condition the effective extinction distance is even more reduced.

scholarly journals Assessment of the Growth and Reproductive Performance of Cloned Pietrain Boars

Animals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2053
Author(s):  
Junsong Shi ◽  
Baohua Tan ◽  
Lvhua Luo ◽  
Zicong Li ◽  
Linjun Hong ◽  
...  
Keyword(s):  
Growth Rate ◽  
Body Size ◽  
Growth Performance ◽  
Reproductive Performance ◽  
Semen Quality ◽  
Small Body ◽  
Economic Benefits ◽  
Large Animal ◽  
Significant Difference ◽  
F1 Progeny

How to maximize the use of the genetic merits of the high-ranking boars (also called superior ones) is a considerable question in the pig breeding industry, considering the money and time spent on selection. Somatic cell nuclear transfer (SCNT) is one of the potential ways to answer the question, which can be applied to produce clones with genetic resources of superior boar for the production of commercial pigs. For practical application, it is essential to investigate whether the clones and their progeny keep behaving better than the “normal boars”, considering that in vitro culture and transfer manipulation would cause a series of harmful effects to the development of clones. In this study, 59,061 cloned embryos were transferred into 250 recipient sows to produce the clones of superior Pietrain boars. The growth performance of 12 clones and 36 non-clones and the semen quality of 19 clones and 28 non-clones were compared. The reproductive performance of 21 clones and 25 non-clones were also tested. Furthermore, we made a comparison in the growth performance between 466 progeny of the clones and 822 progeny of the non-clones. Our results showed that no significant difference in semen quality and reproductive performance was observed between the clones and the non-clones, although the clones grew slower and exhibited smaller body size than the non-clones. The F1 progeny of the clones showed a greater growth rate than the non-clones. Our results demonstrated through the large animal population showed that SCNT manipulation resulted in a low growth rate and small body size, but the clones could normally produce F1 progeny with excellent growth traits to bring more economic benefits. Therefore, SCNT could be effective in enlarging the merit genetics of the superior boars and increasing the economic benefits in pig reproduction and breeding.

scholarly journals Morphological variation of the deciduous second molars in the Baka Pygmies

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Petra G. Šimková ◽  
Gerhard W. Weber ◽  
Fernando V. Ramirez Rozzi ◽  
Lotfi Slimani ◽  
Jérémy Sadoine ◽  
...  
Keyword(s):  
Growth Rate ◽  
Morphological Variation ◽  
Growth Pattern ◽  
Distal Region ◽  
Dental Morphology ◽  
Human Sample ◽  
Different Populations ◽  
Dental Traits ◽  
South Americans ◽  
Range Of Variation

AbstractThe Baka Pygmies are known for their short stature resulting from a reduced growth rate during infancy. They are peculiar also for their teeth erupt earlier than in any other African population, and their posterior dentition is larger than in non-Pygmy populations. However, the Baka’s dental morphology, like several other aspects of their biology, is still understudied. Here, we explore the variation of the Baka’s deciduous upper and lower second molars (dm2s) in comparison to a geographically heterogeneous human sample by means of 3D geometric morphometrics and analysis of dental traits. Our results show that the different populations largely overlap based on the shape of their dm2s, especially the lower ones. Their distal region and the height of the dentinal crown differ the most, with the Baka showing the most extreme range of variation. Upper and lower dm2s covary to a great extent (RV = 0.82). The Baka’s and South Americans’ dm2s were confirmed among the largest in our sample. Despite the Baka’s unique growth pattern, long-lasting isolation, and extreme dental variation, it is not possible to distinguish them from other populations based on their dm2s’ morphology only.

scholarly journals Effect of genotype, age of hens and K/k allele on eggshell quality

2011 ◽  
Vol 56 (No. 5) ◽  
pp. 242-249 ◽  
Author(s):  
Z. Ledvinka ◽  
L. Zita ◽  
M. Hubený ◽  
E. Tůmová ◽  
M. Tyller ◽  
...  
Keyword(s):  
Growth Rate ◽  
Egg Production ◽  
Statistical Significance ◽  
Live Weight ◽  
Shape Index ◽  
Feed Mixture ◽  
Eggshell Quality ◽  
Feather Growth ◽  
Two Factors ◽  
The Relationship

We assessed the influence of the particular genotype, age of layers, feather growth-rate gene, and their mutual interactions on selected indicators of eggshell quality in six groups of hens of the laying type Dominant. The following genotypes were examined in the experiment: Barred Plymouth Rock, Dominant BPR 951 (K) strain, slow-feathering; Barred Plymouth Rock, Dominant BPR 901 (k) strain, fast-feathering; Blue Plymouth Rock, Dominant BLPR 954 (K) strain, slow-feathering; Blue Plymouth Rock, Dominant BLPR 894 (k) strain, fast-feathering; crossbreds of the above strains in the F<sub>1</sub> generation Dominant D 107 blue (K), slow-feathering and Dominant D 107 blue (k), fast-feathering. The layers were fed a feed mixture NP1 (16.64 % CP) from the 20<sup>th</sup> week of age and a feed mixture NP2 (15.02% CP) from the 42<sup>nd</sup> week. Husbandry conditions met the regular requirements of laying hens. Egg production and live weight of hens were monitored for the duration of the experiment (12 months). Eggshell quality was examined at the layers' age of 27, 35 and 56 weeks. The average hen-day egg production for the duration of the experiment (12 months) was not significantly influenced by the particular genotype or the feather growth-rate gene. The varying representation of the feather growth-rate gene significantly (P &le; 0.001) influenced the live weight; similarly, the relationship between the genotype and the representation of K/k alleles was significant. The average egg weight was influenced statistically significantly (P &le; 0.001) by the age of hens, their genotype (P &le; 0.05), feather growth-rate gene (P &le; 0.001), and the relationship between the age and genotype (P &le; 0.001). The age of hens, genotype, and the interaction of these two factors affected the egg shape index, as did the incidence of the feather growth-rate gene within the population (with a statistical significance of P &le; 0.001). The age, genotype and the feather growth-rate gene incidence within the population also significantly affected the eggshell quality indicators. In the eggshell to egg ratio, eggshell thickness and strength, an interaction was determined between the age of hens and their particular genotype. The eggshell colour was also significantly (P &le; 0.001) affected by hens' age, genotype (P &le; 0.001), as well as by the feather growth-rate gene (P &le; 0.001). No significant interaction between the age and the genotype was found for this indicator.

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