The Reproductive Capacity of the Larch Sawfly and Some Factors of Concern in its Measurement

1966 ◽  
Vol 98 (6) ◽  
pp. 561-578 ◽  
Author(s):  
R. J. Heron

AbstractOvarian development and egg production in the larch sawfly, Pristiphora erichsonii (Hartig), were studied in the development of a method for measuring reproductive capacity for population studies. Most of the oöcytes are mature at the time of adult emergence but some mature in the following few days. Quantitative differences in foliage consumption during the larval stages have an appreciable effect on egg production but normal environmental temperature differences and exposure to flooding during the spring development period influence ovarian development only to a limited extent.Reproductive capacity can be determined by oöcyte counts of dissected adults of uniform age. The sample size necessary for estimates of various degrees of precision was calculated.Several size measurements have a significant correlation with the numbers of oöcytes produced. The regression of numbers of oöcytes on adult weight is of limited usefulness in the estimation of reproductive capacity. This is largely due to the individual variability in the extent to which fat body tissue is utilized in ovarian development particularly in the case of the larger adults.

Author(s):  
O.V. Mareev ◽  
◽  
G.O. Mareev ◽  
M.E. Gutynina ◽  
D.A. Maksimova ◽  
...  

2008 ◽  
Vol 43 (2-3) ◽  
pp. 161-171 ◽  
Author(s):  
Pierre Martel ◽  
Tibor Kovacs ◽  
Virginie Bérubé

Abstract Pulp and paper mill effluents have been reported to cause changes in reproductive indicators of fish in laboratory and field studies. These changes include reduced egg production and gonad size, and altered hormone levels and expression of secondary sex characteristics. We examined the performance of biotreatment plants for their potential in abating effects of pulp and paper mill effluents on fish reproduction under laboratory conditions. A bleached kraft mill effluent (BKME) treated in an aerated lagoon and a thermomechanical pulp mill effluent (TMPE) treated by aerobic sludge in a sequential batch reactor were selected for study. Mature fathead minnows (Pimephales promelas) were exposed to effluents before and after biotreatment under continuous renewal conditions for 21 days. Egg production was monitored daily, while morphometric parameters (length, weight, gonad size), secondary sexual characteristics, and steroid hormone and vitellogenin levels were measured at the end of the effluent exposure. The effluent from both mills before biotreatment impaired the reproductive capacity of minnows (egg production) at concentrations of 10 and 20% vol/vol, but not at 2% vol/vol. Exposure to biotreated effluents from both mills at concentrations of 2, 10, 20, and 40% vol/vol caused no significant differences in overall reproductive capacity of minnows as compared with controls. These results indicate that biotreatment can significantly improve the quality of a BKME and an effluent from a TMP mill with respect to the reproductive capacity of fish as determined in laboratory tests.


Author(s):  
E. Rehleckaya ◽  
A. Dymkov ◽  
L. Lazarets ◽  
A. Maltsev

Purpose: Install the influence of the «small diameter of the egg» on the living mass and the reproductive qualities of chickens of meat crosses and the quail of meat breeds.Materials and methods. The selection was carried out along egg production and mass of eggs and additionally on the average small diameter of 5 eggs by value of ≥0.5σ from the average for the herd, while the evaluation on the basis of the «small diameter of the egg» was carried out in chickens aged 238 days of life, quails — 70 days of life. Calculated the average for each female and the average for the herd. For further reproduction, chickens carrying eggs with a small egg diameter ≥0.5σ from the average for the herd. Studies were held in SibNIP on quail and on the courses.Results. In the initial period of the egg laying, the individual variability of the small diameter of the egg — more than 10% (in the future, the figure decreased). The close correlation rate of the small egg diameter in the first half of the egg laying with such at the end of the bird's operation period was revealed. It has been established that the large diameter of the egg has a positive reliable connection with a lively mass, but negative with egg production. The reliable correlation rate of the small diameter of the egg with a live weight at a 42-day age, as well as with the derivation of eggs. The inheritance coefficients of the small diameter of the egg are comparable to the inheritance coefficients of the mass of eggs and significantly exceed those for a large diameter of the egg. The selection according to the small diameter of the eggs by ≥0.5σ from the average for the herd led to the fact that the chickens of the experimental groups reliably exceeded the live weight in the SB level of 1.57%, in the line G8 — by 1.35%. The superiority of a lively mass of quail of experienced groups was more pronounced than that of the chickens: the Pharaoh breed — by 4.15%, the Texas white breed is 4.22%. In relation to the derivation of eggs, a similar trend was traced. The derivation of eggs in quails of experienced groups was more than 4.59–4.98%; Country, respectively, 4.57–5.22%. Egg production of females of comparable groups of both chickens and quail was almost on the same level, and the difference was unreliable.Conclusion. It was established that a new method of breeding the poultry of the meat direction of productivity allows without decreasing egg production to increase the living mass of chickens of meat crosses by 1.5%, rewinds of meat breeds — by 4%, the derivation of eggs, respectively, by 4–5%. The method is intended for early prediction of females productivity during breeding selection.


Author(s):  
Julie M. Fives ◽  
F. I. O'Brien

The Galway Bay area was sampled quantitatively for plankton during 1972–3. The larvae and/or post-larvae of 67 species of fish were identified from the plankton. The recorded occurrence per m3 and the percentage occurrence of the individual species is presented and discussed, and reference is made to the concurrent occurrence of various chaetognath species and copepod species. The results of previous investigations of the plankton of the Galway Bay area are mentioned.


1979 ◽  
Vol 27 (3) ◽  
pp. 349 ◽  
Author(s):  
GAC Beattie

Inhibition of ovarian development in L. cuprina by two aziridinyl chemosterilants, N,N'-hexamethylenebis(1-aziridinecarboxamide) and N. N'bisaziridinyl-N"-cyclohexylphosphine sulphide, was due to the direct effect of the sterilants on the ovary. The sterilants caused infecundity by interfering with mitosis in the follicle cells. Contrary to the accepted view, no evidence was obtained to suggest that infecundity resulted from inhibition of endomitosis in the nurse cell nuclei. Neither sterilant prevented the digestion of protein by the midgut, nor did they prevent the endocrine system and fat body from functioning.


2019 ◽  
Author(s):  
Vera Weisbecker ◽  
Thomas Guillerme ◽  
Cruise Speck ◽  
Emma Sherratt ◽  
Hyab Mehari Abraha ◽  
...  

AbstractBackgroundWithin-species skull shape variation of marsupial mammals is widely considered low and strongly size-dependent (allometric), possibly due to developmental constraints arising from the altricial birth of marsupials. However, species whose skulls are impacted by strong muscular stresses – particularly those produced through mastication of tough food items – may not display such intrinsic patterns very clearly because of the known plastic response of bone to muscle activity of the individual. In such cases, shape variation should not be dominated by allometry; ordination of shape in a geometric morphometric context through principal component analysis (PCA) should reveal main variation in areas under masticatory stress (incisor region/zygomatic arches/mandibular ramus); but this main variation should emerge from high individual variability and thus have low eigenvalues.ResultsWe assessed the evidence for high individual variation through 3D geometric morphometric shape analysis of crania and mandibles of thre species of grazing-specialized wombats, whose diet of tough grasses puts considerable strain on their masticatory system. As expected, we found little allometry and low Principal Component 1 (PC1) eigenvalues within crania and mandibles of all three species. Also as expected, the main variation was in the muzzle, zygomatic arches, and masticatory muscle attachments of the mandibular ramus. We then implemented a new test to ask if the landmark variation reflected on PC1 was reflected in individuals with opposite PC1 scores and with opposite shapes in Procrustes space. This showed that correspondence between individual and ordinated shape variation was limited, indicating high levels of individual variability in the masticatory apparatus.DiscussionOur results are inconsistent with hypotheses that skull shape variation within marsupial species reflects a constraint pattern. Rather, they support suggestions that individual plasticity can be an important determinant of within-species shape variation in marsupials (and possibly other mammals) with high masticatory stresses, making it difficult to understand the degree to which intrinsic constraint act on shape variation at the within-species level. We conclude that studies that link micro- and macroevolutionary patterns of shape variation might benefit from a focus on species with low-impact mastication, such as carnivorous or frugivorous species.


2017 ◽  
Vol 48 (2) ◽  
Author(s):  
Al-Zubaidy & Al-Shammari

The results of numerical response showed to increasing rates of egg production for the predator female with prey density increases, noting of a positive correlation between the number of eggs lying by the female predator and prey density, Being 7, 13.1, 17 and 30 eggs/female during her life when making egg densities of prey 10, 20, 40 and 60 eggs/day during the period of development of Larval ages respectively.  Statistical analysis results have pointed to the moral differences between those rates at 0.05 probability level. Food conversion efficiency was marked by ECI also increases with increasing density of prey . Food conversion efficiency to  eggs by female predator increased  in high densities of prey compared with low  densities as well as reduced food efficiency with increasing density of prey  where when lying densities and decreased when high densities prey. It also shortened the duration of phases three predator when prey density increases amounting to (2.74, 3.37, 9.15) and(1.62, 4.32, 5.04), (1.86, 2.82, 4.07) and (1.16 , 2.89, 3.42) consecutive days so that the total duration of Larval stage 15.26, 10.98, 8.75 and 7.47 days respectively with high significance deference. As well as high rates of predation 80, 74.24, 96.52 and 116.91 egg respectively and moral difference in egg consumption rates between larval stages as well as during the period of Larval stages  at probability 0.05.  survival rates also increased  for the  larval, pupal  and   adults stages  when the density of the prey increased  with high  significance  difference.


2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Satinath Paul ◽  
Bela Keshan

The present study observed the effect of heat stress on ovarian development, fecundity, and vitellogenin gene expression in silkworm,Bombyx mori. The result showed that the heat shock treatment to spinning larvae and pupae at 39°C (1 h and 2 h) did not cause any adverse effect on the reproductive performance ofB. mori.However, the heat shock treatment at 42°C or above caused a decrease in the fecundity. The heat shock treatment to day 2 pupae for 2 h at 45°C caused a drastic effect on the development of ovary as measured by gonadosomatic index. The study thus showed that a brief exposure ofBombyxlarvae and pupae to a temperature of 42°C or higher, much prevalent in tropical countries like India, greatly affects the ovarian development and reproductive performance of this commercially important insect. The study further showed a developmental- and tissue-specific expression of vitellogenin mRNA in fat body and ovary upon heat shock. When heat shock treatment was done at 39°C and 42°C to spinning larvae, ovary showed an upregulation in the expression of vitellogenin mRNA, whereas fat body failed to do so. However, at 45°C, both fat body and ovary showed a downregulation. The heat shock treatment to day 2 pupae showed an upregulation in the vitellogenin mRNA expression in both fat body and ovary, even at 45°C. The upregulation in the expression of vitellogenin upon heat shock indicates its role in thermal protection ofBombyxlarvae and pupae.


2020 ◽  
Vol 19 (4) ◽  
pp. 10-14
Author(s):  
Z. Masna

The individual face shape, the ratio of its proportions, the articulation capabilities of each person to a significant extent depend on the characteristics of occlusion and occlusion, in turn, are determined by the size, shape and ratio of dental, alveolar and basal arches. Two of them - alveolar and basal - pass at the corresponding levels of the alveolar areas of the jaws, which means that it is almost impossible to correct them, therefore they play the role of landmarks for setting the dental arch during dental prosthetics. A full-fledged aesthetic and functional restoration of the maxillofacial region after prosthetics largely depends on the dentist taking into account the individual morphological characteristics of the jaws, their cellular areas and specifically the morphometric parameters of the collar and basal arches. In order to determine the possible variants of the shape of the alveolar and basal arches of the upper jaw and the patterns of their ratio during the routine dental examination, 55 people (27 men and 28 women) aged 21-60 years with preserved maxillary dentition were examined. It has been established that the alveolar and basal arches of the upper jaw can have the shape of five geometric shapes: an oval, a semicircle, an ellipse, a trapezoid or a square. In this case, the shape of the collar and basal arches can coincide or be combined in various combinations. The analysis of the obtained results showed that in men the alveolar arch most often had the shape of an oval (70%), in women - an oval or semicircle (43%, respectively). With the aim of possible variants of the alveolar and basal arches form determination and peculiarities of their correlation 55 individuals (27 men and 28 women) in age of 21-60 years with the preserved teeth row were examined during planned dental examination. All examined were patients of the “Dental clinic of dr. Dakhno” (Kyiv). Computer tomographic investigation was made to these patients according to medical indications, scanning was made parallely to the occlusal plane. Image reconstruction was conducted with the use of highly dimentional bone algorithm. Alveolar and basal arch form of the upper jaw were determined on the images. It was established that alveolar and basal arches of the upper jaw can have a form of five geometrical figures: oval, semicircle, ellipse, trapeze or square. Form of the alveolar and basal arches can match or can combine in different combinations. Received results analysis testified that alveolar arch has a form of the oval in men and oval or semicircle – in women. Basal arch in men also most frequently has a form of oval, less often – semicircle, square and trapeze. In women basal arch more often has a form of trapeze or semicircle, less often – oval or square. In men alveolar and basal arches form matched in 41% of cases, in women – only in 31% of cases among total amount of all examined individuals. Most often alveolar and basal arches matched in the form of oval and semicircle, only in one case arches of the trapeze form matched in man, in woman – square form. Maxillary alveolar and basal arches form variants analysis let to determine areas, where distance between alveolar crests was maximal. Most variable this index was in individuals with the oval form of the alveolar arch on the level of 16-26, 17-27 or 18-28 teeth. Peculiarities of the alveolar and basal arches form of the alveolar process of the upper jaw in male and female individuals are characterized with expressed individual variability. These peculiarities consideration during dental prosthesis let avoid series of complications connected with the pressure redistribution on the osseous tissue of the jaws during articulation. 


1965 ◽  
Vol 43 (3) ◽  
pp. 425-431
Author(s):  
G. C. COLES

1. There are two adult-specific proteins in the haemolymph of Rhodnius. They appear to be formed in the fat body. 2. The two proteins are absorbed by the oocytes and form the bulk of the soluble egg proteins. 3. The changes in the concentration of total protein in the haemolymph and of four protein fractions, as separated on cellulose acetate, do not reflect egg production. This may be a consequence of the hormonal control of reproduction.


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