SOME POPULATION FEATURES OF REPRODUCTIVE CAPACITY IN NEODIPRION SWAINEI (HYMENOPTERA: DIPRIONIDAE)

1970 ◽  
Vol 102 (1) ◽  
pp. 68-84 ◽  
Author(s):  
L. A. Lyons
Keyword(s):  
Egg Production ◽  
Egg Size ◽  
Regression Line ◽  
Reproductive Potential ◽  
Reproductive Capacity ◽  
Single Population ◽  
Males And Females ◽  
Prolonged Diapause ◽  
Single Regression ◽  
Production Characteristics

AbstractEgg production in Neodiprion swainei may be severely reduced by food quality and quantity, tachinid parasitism, and prolonged diapause. Since these and other agents may affect the sawfly both lethally and sublethally and may operate differentially against males and females, population losses are not adequately expressed in terms of numbers of individuals. However, reduction of the potential number of eggs the population could produce provides an integrated measure of these effects. One example, from an experiment in which larvae were fed various quantities and types of foliage, demonstrates that loss of reproductive potential is several times as great as the loss of individuals and indicates that the latter seriously underestimates the importance of food in population events.Cocoon diameter and fecundity are closely related. In a Saguenay Valley population, fecundity, cocoon diameter, and deviations from the regression line were bimodally distributed, indicating a mixture of two types of individuals differing in egg production characteristics. Families within a single population differed from each other by as much as 14 eggs in the elevation of the regression line; this was more than the observed difference in elevation between populations. A single regression equation satisfactorily predicted fecundity in one Quebec and a Wisconsin population, but was unsuitable for two other Quebec populations, each of which required its own equation. Among insects of common size, mean egg length varied inversely with fecundity, but it is uncertain whether differences in egg size were responsible for variation in the fecundity-cocoon diameter relationship.

scholarly journals Fishery-induced changes in Norwegian red king crab (Paralithodes camtschaticus) reproductive potential

2013 ◽  
Vol 71 (2) ◽  
pp. 365-373 ◽  
Author(s):  
Ann Merete Hjelset
Keyword(s):  
Egg Production ◽  
Barents Sea ◽  
Reproductive Potential ◽  
Size Composition ◽  
Red King Crab ◽  
Paralithodes Camtschaticus ◽  
King Crab ◽  
Males And Females ◽  
Induced Changes ◽  
Individual Fecundity

Abstract Hjelset, A. M. 2014. Fishery-induced changes in Norwegian red king crab (Paralithodes camtschaticus) reproductive potential. – ICES Journal of Marine Science, 71: 365–373. The introduced red king crab (Paralithodes camtschaticus) in the Barents Sea supports a valuable fishery in northern Norway. In this paper, I examine the effect of the increased harvest rate and the recently added female quota on the potential egg production of the stock. The size ranges of males and females in the period 1995–2011 were recorded, and estimated stock abundance of ovigerous females and established individual fecundity parameters from 2000–2007 were used to assess the reproductive potential of the stock from 1995–2011. The upper size ranges of males and females decreased throughout the period studied, presumably mainly due to fishing. The change in size composition among ovigerous females and functional mature males, and the reduced mean individual fecundity in the stock seem to have had a negative effect on the potential egg production of the stock.

The Benefits of Biotreatment for Reducing the Effects of Pulp and Paper Mill Effluents on Fish Reproduction in Laboratory Tests

2008 ◽  
Vol 43 (2-3) ◽  
pp. 161-171 ◽  
Author(s):  
Pierre Martel ◽  
Tibor Kovacs ◽  
Virginie Bérubé
Keyword(s):  
Laboratory Tests ◽  
Egg Production ◽  
Pimephales Promelas ◽  
Paper Mill ◽  
Pulp And Paper ◽  
Reproductive Capacity ◽  
Fish Reproduction ◽  
Pulp And Paper Mill ◽  
Paper Mill Effluents ◽  
Gonad Size

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.

Bénéfices à court terme des mouvements anadromes saisonniers pour une population d'omble de fontaine (Salvelinus fontinalis) du Nouveau Québec

1991 ◽  
Vol 48 (11) ◽  
pp. 2212-2222 ◽  
Author(s):  
Jean-François Doyon ◽  
Christiane Hudon ◽  
Roderick Morin ◽  
F. G. Whoriskey Jr.
Keyword(s):  
Water Level ◽  
Egg Size ◽  
Salvelinus Fontinalis ◽  
Condition Factor ◽  
Size At Maturity ◽  
Brook Charr ◽  
Tissue Water Content ◽  
Tissue Water ◽  
Single Population ◽  
Energetic Reserves

This study characterizes the seasonal anadromous movements of a brook charr population and compares its biological and energetic characteristics with charr spending summer in freshwaters. Downstream movements monitored at a counting fence over 3 yr were most intense in spring but occurred until fall and were positively correlated with rapid increases of water level. The timing of movements varied from year to year. Smaller charr were most subject to being swept downstream compared with freshwater residents, and most trout were concentrated near the mouth of the river. These patterns suggest that the downstream movements of charr in this system are passive. Upstream migrants had a higher condition factor and a lower tissue water content than freshwater residents, indicating that downstream movements result in a faster accumulation of energetic reserves during summer. However, the fortuitous character of anadromous migrations as well as the absence of differences in the biological characteristics (growth, size at maturity, fecundity, egg size) suggests that anadromous and resident fish belong to a single population whose yearly migrant component could be randomly determined.

Effects of constant and fluctuating temperatures on egg production in the threespine stickleback (Gasterosteus aculeatus)

1989 ◽  
Vol 67 (6) ◽  
pp. 1599-1602 ◽  
Author(s):  
Vital Boulé ◽  
Gerard J. Fitzgerald
Keyword(s):  
Reproductive Performance ◽  
Egg Production ◽  
Egg Size ◽  
Laboratory Experiments ◽  
Gasterosteus Aculeatus ◽  
Reproduction Number ◽  
Temperature Fluctuations ◽  
Spawning Grounds ◽  
Threespine Sticklebacks ◽  
Fluctuating Temperatures

Female threespine sticklebacks (Gasterosteus aculeatus) spend only 9–15 days on the spawning grounds, an intertidal salt marsh at Isle Verte, Quebec, during a 2-month breeding season. Individuals average only one spawning. However, in the laboratory they lay clutches of several hundred eggs every 3–5 days for several months. We designed laboratory experiments to determine (i) whether daily temperature fluctuations similar to those encountered in the marsh affect reproduction (number of clutches, number of eggs per clutch, and size of eggs) and (ii) whether the amplitude of the fluctuations encountered by the fish affects reproduction. We compared the reproduction of females held in fluctuating temperatures with that of females kept at 20 °C. Fish kept under fluctuating conditions produced more eggs per clutch but had longer interspawning intervals than those at 20 °C. Total seasonal egg production and egg size did not differ between the two groups. Fish in fluctuating temperatures survived longer and were in better condition than those at 20 °C. We conclude that the amplitude of the fluctuations is less important than mean temperature in determining reproductive performance. Fluctuating temperatures on the spawning grounds are not responsible for the short residency there.

VARIATION, SEXUAL DIMORPHISM, AND MATURITY IN A QUEBEC POPULATION OF THE COMMON SNAPPING TURTLE, CHELYDRA SERPENTINA

1960 ◽  
Vol 38 (1) ◽  
pp. 19-38 ◽  
Author(s):  
James E. Mosimann ◽  
J. Roger Bider
Keyword(s):  
Carapace Length ◽  
Relative Rate ◽  
Analysis Of Covariance ◽  
Head Width ◽  
Posterior Lobe ◽  
Chelydra Serpentina ◽  
Single Population ◽  
Species Analysis ◽  
The Common ◽  
Males And Females

An analysis was made of a sample of 55 snapping turtles, Chelydra serpentina, from a single locality in southern Quebec. The variation studied is regarded as being representative of that of a single population of the species. Analysis of covariance was used in studying dimorphism in various measurements. Conclusions reached are: (a) the sex ratio is one; (b) males grow to a larger size than females; (c) males and females become mature at a carapace length of about 200 millimeters; (d) the ratio precloacal distance over posterior lobe of the plastron gives a practical index for sex determination in adults; (e) there is a set of small but interrelated changes correlated with a greater precloacal distance in the male: These are that males have the plastron shifted forward slightly, have the bridge slightly longer relative to plastron length, and have the posterior lobe of the plastron slightly shorter relative to plastron length; (f) the precloacal length of the male (which area accommodates the penis) grows relatively faster than carapace length; the precloacal length of the female grows at the same relative rate as carapace length; (g) there is virtually no dimorphism in shell dimensions nor in head width.

Growth of the edible crab (Cancer pagurusL.) off south-west England

1974 ◽  
Vol 54 (4) ◽  
pp. 803-823 ◽  
Author(s):  
D. B. Bennett
Keyword(s):  
Egg Production ◽  
Carapace Width ◽  
Large Male ◽  
Annual Growth ◽  
Published Data ◽  
North East ◽  
South West ◽  
Males And Females ◽  
Moulting Cycle ◽  
South West England

Moult increments, annual moult frequency and hence annual growth were determined from suture-tagged edible crabs (Cancer pagurusL.) released and recaptured off Devon, Cornwall, and Dorset.The average moult increments of males and females at a premoult carapace width of 100 mm were similar; at larger sizes the average moult increment of females was considerably less than that of males. Annual moult frequency ofC. pagurusin south-west England decreased with increase in size, females more so than males.As a result of the smaller moult increments and lower moult frequency of females, their annual growth is considerably less than that of males. This appears to be the result of three aspects of sex and reproduction: (1) reduction in moult increments, probably as a result of competition for nutritive resources between egg production and body growth; (2) the interruption of the moulting cycle by successive annual spawnings from a single impregnation at the previous moult; and (3) accentuation of the larger increments in weight at moulting of male crabs due to the allometric growth of their chelae. A consequence of the higher growth rate of males is the presence of very large male crabs – a distinctive feature of the population structure of the stock off south-west England.The growth of C.pagurusin south-west England was compared with published data for stocks off the east and north-east coast. Moult increments were similar for both areas, but there were considerable differences in the moult frequencies. In the south-west, males moult more frequently than females; the opposite is the case for the east and north-east crab stocks. A valid reason for this difference has not yet been established.

scholarly journals Does increased information about reproductive potential result in better prediction of recruitment?

2011 ◽  
Vol 68 (8) ◽  
pp. 1361-1368 ◽  
Author(s):  
M. Joanne Morgan ◽  
Alfonso Perez-Rodriguez ◽  
Fran Saborido-Rey
Keyword(s):  
Reproductive Biology ◽  
Egg Production ◽  
Gadus Morhua ◽  
Reproductive Potential ◽  
Essential Element ◽  
Greenland Halibut ◽  
Greenland Halibut Reinhardtius Hippoglossoides ◽  
Difficult Challenge ◽  
The Relationship ◽  
Hippoglossoides Platessoides

The relationship between stock size and recruitment is an essential element in the understanding of the productivity of a population. However, predicting the number of recruits produced by a population has proven to be a difficult challenge. This may in part be a result of poor estimation of reproductive potential (RP). We determined if including increased information on reproductive biology in indices of RP results in better predictions of recruitment. We investigated some of the conditions that lead to better (or worse) recruitment prediction when more biologically complex indices of RP are used. Data from four populations in the Northwest Atlantic were examined: southern Grand Bank (NAFO Division 3NO) cod ( Gadus morhua ), Flemish Cap (NAFO Division 3M) cod, Newfoundland (NAFO Division 3LNO) American plaice ( Hippoglossoides platessoides ), and Greenland halibut ( Reinhardtius hippoglossoides ) (NAFO Subarea 2 + Division 3KLMNO). Stock–recruit models paired with complex indices of RP gave a better estimate of recruitment in slightly more than half of the tests conducted. When there were larger trends in the reproductive biology (maturity at age, sex ratio and egg production), more complex indices of RP were more likely to provide a better estimate of recruitment.

BIOCHEMICAL VALUES OF METABOLISM IN DAIRY GOATS WITH DIFFERENT REPRODUCTIVE POTENTIAL

2020 ◽  
Author(s):  
В.Б. ЛЕЙБОВА ◽  
М.В. ПОЗОВНИКОВА
Keyword(s):  
Alkaline Phosphatase ◽  
Reproductive Cycle ◽  
Reproductive Potential ◽  
Low Fertility ◽  
Reproductive Capacity ◽  
Total Protein Content ◽  
Breeding Period ◽  
Biochemical Profile ◽  
Dairy Goats ◽  
Blood Samples

Проведена оценка биохимического профиля клинически здоровых коз за 2 мес до начала периода размножения в связи с их последующей репродуктивной способностью. Объектом исследования были козы зааненской породы в 1-ю лактацию. Возраст первого окота у животных составлял 400—460 сут. Отбор проб крови осуществляли в июне, через 2,5—3 мес после окота. По окончании случного сезона и сезона окотов коз разделили на 2 группы: I (n=14) — особи с завершенным репродуктивным циклом, II (n=6) — животные, не принесшие потомства. Концентрация общего холестерина в крови за 2 мес до начала периода размножения была в 1,2 раза выше (P<0,05) у коз с завершенным впоследствии репродуктивным циклом по сравнению с животными, оставшимися бесплодными. Корреляционный анализ показал, что некоторые метаболические связи, указывающие на особенности белково-углеводного обмена, имели различия по силе и направленности у особей сравниваемых групп. У животных с низкой фертильностью обнаружена положительная корреляционная связь между содержанием в крови общего белка и активностью аланинаминотрансферазы (P<0,05), а также концентрацией глюкозы и активностью щелочной фосфатазы (P<0,05). У особей, принесших потомство, подобных взаимосвязей не обнаружено. В предыдущем репродуктивном цикле показатели воспроизводительной способности у коз двух групп были сходными. Удой за первые 100 суток текущей лактации, содержание белка и жира в молоке также не имели достоверных различий. Концентрация холестерина в крови молочных коз до наступления периода размножения может служить одним из маркеров их последующей способности к воспроизводству. The biochemical profile of clinically healthy goats was assessed 2 months before the beginning of the breeding period in connection with their subsequent reproductive capacity. The object of the study were goats of the Saanen breed in the first lactation. The age of the first lambing in animals was 400—460 days. Blood samples were taken in June, 2.5—3 months after lambing. At the end of the breeding and lambing season, the goats were divided into 2 groups: I (n = 14) — individuals with a complete reproductive cycle, II (n = 6) — animals that did not bear offspring. The concentration of total cholesterol in the blood for 2 months of the pre-breeding season was 1.2 times higher (P<0.05) in goats with a subsequently completed reproductive cycle compared with animals that remained infertile. Correlation analysis showed that some metabolic links, indicating the peculiarities of protein-carbohydrate metabolism, had differences in strength and direction in individuals of the compared groups. In animals with low fertility, a positive correlation was found between the total protein content in the blood and the activity of alanine aminotransferase (P<0.05), as well as the concentration of glucose and the activity of alkaline phosphatase (P<0.05). In individuals that brought offspring, such relationships were not found. In the previous reproductive cycle, the indicators of reproductive capacity in goats of the two groups were similar. Milk yield for the first 100 days of the current lactation, protein and fat content in milk also did not have significant differences. The concentration of cholesterol in the blood of dairy goats before the onset of the breeding period can serve as one of the markers of their subsequent ability to reproduce.

RESPONSE OF LAYING HENS TO GRADED LEVELS OF DIETARY NUTRAFOS 3 IN A HUMID TROPICAL ENVIRONMENT

2021 ◽  
Vol 15 ◽  
pp. 185-196
Author(s):  
M. MONSI ◽  
A. O. AMAKIRI
Keyword(s):  
Treatment Effect ◽  
Feed Efficiency ◽  
Egg Production ◽  
Egg Size ◽  
Laying Hens ◽  
Gallus Domesticus ◽  
Feed Consumption ◽  
Tropical Conditions ◽  
Overall Performance ◽  
Haugh Unit

Four groups of 48 laying hens (Gallus domesticus), midway in their laying cycle were fed diets containing graded levels (0.00%, 1.5%, 2.5% and 3.5%) of dietary Nutrafos 3 for 56 days. The completely randomized experimental arrangement was designed to evaluate the responses of the caged layers to the inclusive levels of the additive under humid tropical conditions. The dietary additive produced statistically significant (P< 0.01) improvements in the rate of egg production of the hens. Significant increases (P< 0.01) in feed consumption and improvements in feed efficiency (P < 0.01) were also observed. Haugh unit was significantly (P < 0.05) depressed by dietary Nutrafos 3, especially at the highest level of inclusion. There was no treatment effect on egg size as well as some major anatomical characteristics. The best overall performance was achieved at the 3.5% level of dietary inclusion in contrast to the proprietary recommendation of 2.5%.

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