scholarly journals When Do Mountain Whitefish (Prosopium williamsoni) Spawn? A Comparison of Estimates Based on Gonadosomatic Indices and Spawner and Egg Counts

2017 ◽  
Vol 10 (1) ◽  
pp. 12-22
Author(s):  
Robyn L. Irvine ◽  
Joseph L. Thorley ◽  
Louise Porto
Keyword(s):  
Gonadosomatic Index ◽  
Reproductive Potential ◽  
Area Under The Curve ◽  
Relative Mass ◽  
Statistical Estimates ◽  
Curve Model ◽  
Prosopium Williamsoni ◽  
Potential Impact ◽  
Fish Spawn ◽  
High Effort

Determining when fish spawn has major implications for effective fisheries management, particularly in dam-controlled rivers where reproductive potential may be affected by an altered hydrograph. Three methods for estimating spawn timing in riverine broadcast spawners were compared for their precision, effort and potential impact on a population of Mountain Whitefish in the regulated Lower Duncan River, Canada. The first method is based on the Gonadosomatic Index (GSI), which is a measure of the relative mass of an individual’s gonads. The second method is based on counts of aggregating adults, while the third method is based on passive egg collection using egg mats. Analysis of the GSI data provided the most precise estimates. It estimated that spawning occurred between October 30th and November 26th in 2010 and between November 8th and November 27th in 2011. Collection of GSI data required moderate effort and had some impact due to the need for lethal harvest. Analysis of the spawner counts using a simple Bayesian Area-Under-the-Curve model provided less precise estimates of spawn timing but the method likely had negligible impact on the population and required only moderate effort. Deployment of egg mats required high effort and collected insufficient information to derive statistical estimates of spawn timing. We discuss how information from different methods could be combined together into a single integrated model to maximize the precision while minimizing the effort and impact.

Eels at the Edge: Science, Status, and Conservation Concerns

2009 ◽  
Keyword(s):  
Gonadosomatic Index ◽  
Reproductive Potential ◽  
Anguilla Rostrata ◽  
Spawning Ground ◽  
Silver Eel ◽  
Migration Distance ◽  
American Eel ◽  
Individual Fitness ◽  
Silver Eels ◽  
Somatic Tissues

<em>Abstract.—</em>The American eel <em>Anguilla rostrata </em>is declining in the St. Lawrence River watershed, where sex ratio is highly unbalanced in favor of females. Since the American eel is a panmictic species, this demographic dominance is implicated in reproductive potential of the species. The major objective of this study was to evaluate the reproductive strategies of five subpopulations of female eels. It was assumed that fecundity varies among subpopulations according to their migration distance because of the tradeoff between energy allocated to gonads and to somatic tissues. Thirty female silver eels were collected from each of five locations in the St. Lawrence watershed 2,850–4,300 km from the spawning area. Among subpopulations, mean length ranged from 67.9 to 104.3 cm, weight from 595 to 2,366 g, fecundity from 6.5 to 14.5 million oocytes, age from 20 to 23 years, gonadosomatic index from 2.9 to 4.1%, and somatic lipid content from 17.5 to 21.7%. Because of panmixia, no genetic influence on intersite variability is expected. Environmental differences in growth habitats and individual fitness might determine acquisition and allocation of resources, as well as subsequent variability in traits that would affect reproduction. In contrast to previous hypotheses, variations in such traits were attributed to eel size rather than migration distance. The number of oocytes per silver eel was positively correlated with length rather than negatively correlated with migration distance. In the St. Lawrence watershed, large eels are highly fecund regardless of their distance from the spawning ground.

Chylomicron and apoB48 metabolism in the JCR:LA corpulent rat, a model for the metabolic syndrome

2007 ◽  
Vol 35 (3) ◽  
pp. 477-481 ◽  
Author(s):  
R. Mangat ◽  
J. Su ◽  
P.G. Scott ◽  
J.C. Russell ◽  
D.F. Vine ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Area Under The Curve ◽  
Mechanistic Studies ◽  
Vascular Remodelling ◽  
Cvd Risk ◽  
Core Content ◽  
The Metabolic Syndrome ◽  
Apolipoprotein B48 ◽  
Potential Impact ◽  
Chylomicron Metabolism

Postprandial (PP) lipaemia is a significant contributor to the development of dyslipidaemia and cardiovascular disease (CVD). It is also evident that PP lipaemia is prevalent during conditions of obesity and insulin resistance (IR) and may contribute to increased progression of CVD. Our group has assessed the potential of the obese JCR:LA-cp rat as a model of PP lipaemia in order to explore CM (chylomicron) metabolism during the onset and development of IR in the metabolic syndrome. Studies confirm that both fasting plasma and PP apoB48 (apolipoprotein B48) area under the curve are significantly elevated in the obese JCR:LA-cp phenotype as compared with lean controls. Mechanistic studies have also shown that the concentration of lymphatic CM apoB48 and CM size are significantly increased in this model. Furthermore, PP dyslipidaemia in the obese rat can be improved acutely with supplementation of n−3 polyunsaturated fatty acids. Using a different approach, we have subsequently hypothesized that the vascular remodelling that accompanies IR may explain accelerated entrapment of apoB48-containing particles. Small leucine-rich proteoglycans (including biglycan and decorin) have been observed to co-localize with apoB in human tissue. However, the potential impact of IR on vascular remodelling, particularly in the presence of obesity, remains unclear. Preliminary observations from the JCR:LA-cp model indicate that biglycan protein core content increases with age and is exacerbated by IR, suggestive of pro-atherogenic remodelling. The focus of this review is to contribute to the perspective of PP lipaemia in CVD risk associated with the metabolic syndrome through the use of animal models.

Parasite effects on the survival, growth, and reproductive potential of yellow perch (Perca flavescens Mitchill) in Canadian Shield lakes

2001 ◽  
Vol 79 (11) ◽  
pp. 1980-1992 ◽  
Author(s):  
M W Johnson ◽  
Terry A Dick
Keyword(s):  
Visceral Fat ◽  
Yellow Perch ◽  
Perca Flavescens ◽  
Reproductive Potential ◽  
Fish Host ◽  
Canadian Shield ◽  
Relative Mass ◽  
Parasitic Infections ◽  
Host Sex ◽  
Shield Lakes

Three parasites of yellow perch, Perca flavescens, in four Canadian Shield lakes were studied for their effects on perch growth and mortality. Glugea sp. xenomas in cells of the intestinal wall and in visceral fat and Apophallus brevis metacercariae infecting the musculature reduced the growth of perch, causing mortality in younger and smaller fish. High numbers of Raphidascaris acus encysted in the liver of yellow perch correlated significantly with a reduction in visceral-fat mass in age 1+ females and age 0+ and 1+ males. A significant correlation in these subsamples indicates that host sex, size, trophic status, and relative mass of the liver are linked to R. acus density. Our data suggest that interactions among parasitic infections and age, size, and sex of the fish host can affect growth and survival of the host, especially during periods of low energy inputs and reproductive stress.

scholarly journals Water hardness influenced reproductive potential in two freshwater fish species; Poecilia reticulata and Betta splendens

2020 ◽  
Author(s):  
Abarna Krishnakumar ◽  
Anton Patrick ◽  
Uthpala Jayawardena
Keyword(s):  
Fish Species ◽  
Natural Waters ◽  
Poecilia Reticulata ◽  
Gonadosomatic Index ◽  
Larval Growth ◽  
Reproductive Potential ◽  
Water Hardness ◽  
Larval Survival ◽  
Betta Splendens ◽  
Test Species

Abstract Objective: Hardness of water in the form of CaCO3 affect reproductive potential in various fish species, differently. The study evaluates the effect of water hardness on growth and reproduction of two aquarium fishes, Poecilia reticulata (Ovo-viviparous sp.) and Betta splendens (Oviparous sp.) by growing them under 150 (control), 320, 540 and 900 ppm CaCO3 levels in semi natural aquaria. Results: Growth increased with increasing water hardness, reporting a significant growth of P. reticulata (p=0.005) at 900ppm. Similarly, the reproductive potential of P. reticulata was improved significantly, recording the highest fecundity (16.22 ± 3.90) and Gonadosomatic Index (GSI-2.48 ± 0.597) at 900ppm. However, in B. splendens water hardness adversely affected the reproduction by reporting a significantly low hatchability and disturbed bubble nests at 900ppm, compared to the largest bubble nest formed at the control (108.58 ± 16.19 cm2). Thus, study revealed differential effects of water hardness on reproductive potential of the test species, by increasing the potential of P. reticulata while decreasing that of B. splendens. Though larval survival was affected in both species, larval growth was improved significantly in P. reticulata at 900ppm level. Understanding reproductive potential of aquarium fishes in natural waters is crucial for their propagation purposes. .

scholarly journals Hard time to be parents? Sea urchin fishery shifts potential reproductive contribution of population onto the shoulders of the youngest

2016 ◽  
Author(s):  
Barbara Loi ◽  
Ivan Guala ◽  
Rodrigo Pires da Silva ◽  
Gianni Brundu ◽  
Maura Baroli ◽  
...  
Keyword(s):  
Sea Urchin ◽  
Sea Urchins ◽  
Gonadosomatic Index ◽  
Reproductive Potential ◽  
Size Class ◽  
High Density ◽  
Similar Amount ◽  
Potential Contribution ◽  
Total Density ◽  
Commercial Size

Background. In Sardinia, as in other regions of the Mediterranean Sea, sustainable fisheries of the sea urchin Paracentrotus lividus have become a necessity. At harvesting sites, the systematic removal of large individuals (diameter ≥ 50 mm) seriously compromises the biological and ecological functions of sea urchin populations. Specifically, in this study, we compared the reproductive potential of the populations from two Mediterranean coastal sites which have different levels of protection. The sites were Su Pallosu, where fishing pressure is high (take zone) and at Tavolara-Punta Coda Cavallo Marine Protected Area (no-take zone) where the pressure is negligible. Methods. Reproductive potential was estimated by calculating Gonadosomatic Index (GSI) from June 2013 to May 2014 both for individuals of commercial size (diameter without spines, TD ≥ 50 mm) and the undersized ones with gonads (30 ≤ TD < 40 mm and 40 ≤ TD < 50 mm). Gamete Output was calculated for the commercial-size class and the undersized individuals with fertile gonads (40 ≤ TD < 50 mm) in relation to their natural density (Gamete Output per m2). Results. The reproductive potential of populations was slightly different at the beginning of the sampling period but it progressed at different rates with an early spring spawning event in the take zone and two gamete depositions in early and late spring in the no-take zone. For each fertile size class, GSI values changed significantly during the year of our study and between the two levels of protection. Although the multiple spawning events determined a two-fold higher total Gamete Output of population (popTGO) in the no-take zone, the population Mean Gamete Output (popMGO) was similar in the two zones. In the take zone, the commercial-sized individuals represented approximatively 5% of the population, with almost all the individuals smaller than 60 mm producing an amount of gametes nearly three times lower than the undersized ones. Conversely, the high density of the undersized individuals released a similar amount of gametes to the commercial-size class in the no-take zone. Discussion. Overall, the lack of the commercial-size class in the take zone does not seem to be very alarming for the self-supporting capacity of the population, and the reproductive potential contribution seems to depend more on the total density of fertile sea urchins than on their size. However, since population survival in the take zone is supported by the high density of undersized sea urchins between 30 and 50 mm, management measures should be addressed to maintain this size and to shed light on the source of the larval supply.

scholarly journals Water hardness influenced reproductive dynamics in two freshwater fish species; Poecilia reticulata and Betta splendens

2020 ◽  
Author(s):  
Abarna Krishnakumar ◽  
Anton Patrick ◽  
Uthpala Jayawardena
Keyword(s):  
Fish Species ◽  
Natural Waters ◽  
Poecilia Reticulata ◽  
Gonadosomatic Index ◽  
Larval Growth ◽  
Reproductive Potential ◽  
Water Hardness ◽  
Larval Survival ◽  
Betta Splendens ◽  
Test Species

Abstract Objective: Hardness of water in the form of CaCO3 affect reproductive potential in various fish species, differently. The study evaluates the effect of water hardness on growth and reproduction of two aquarium fishes, Poecilia reticulata (Ovo-viviparous sp.) and Betta splendens (Oviparous sp.) by growing them under 150 (control), 320, 540 and 900 ppm CaCO3 levels in semi natural aquaria. Results: Growth increased with increasing water hardness, reporting a significant growth of P. reticulata (p = 0.005) at 900 ppm. Similarly, the reproductive potential of P. reticulata was improved significantly, recording the highest fecundity (16.22 ± 3.90) and Gonadosomatic Index (GSI-2.48 ± 0.597) at 900 ppm. However, in B. splendens water hardness adversely affected the reproduction by reporting a significantly low hatchability and disturbed bubble nests at 900 ppm, compared to the largest bubble nest formed at the control (108.58 ± 16.19 cm2). Thus, study revealed differential effects of water hardness on reproductive potential of the test species, by increasing the potential of P. reticulata while decreasing that of B. splendens. Though larval survival was affected in both species, larval growth was improvement significantly in P. reticulata at 900 ppm level. Understanding reproductive dynamics in natural waters are crucial for propagation and conservation perspectives of freshwater fishes.

Influences of female body condition on recruitment success of walleye (Sander vitreus) in Wisconsin lakes

2019 ◽  
Vol 76 (11) ◽  
pp. 2131-2144 ◽  
Author(s):  
Zachary S. Feiner ◽  
Stephanie L. Shaw ◽  
Greg G. Sass
Keyword(s):  
Body Condition ◽  
Gonadosomatic Index ◽  
Reproductive Potential ◽  
Relative Weight ◽  
Reproductive Traits ◽  
Large Female ◽  
Female Size ◽  
Sander Vitreus ◽  
Small Female ◽  
Using Data

Stock reproductive potential informs population dynamics and response to harvest. Indices of body condition, like relative weight (Wr), may indicate individual energetic state and provide a mechanistic link between spawning stock traits and recruitment. We tested for relationships among Wr of three female size classes (381–456, 457–557, and ≥558 mm total length), reproductive traits, and age-0 recruitment using data from 92 walleye (Sander vitreus) populations in the Ceded Territory of Wisconsin during 1989–2015 and a lake-specific time series from Escanaba Lake, Wisconsin, during 1958–2014. In Escanaba Lake, Wr was positively related to maturation in small females and was positively related to fecundity and gonadosomatic index in intermediate fish. Among and within populations, Wr demonstrated compensatory density dependence and positive relationships with growing degree-days. Recruitment was positively related to large female Wr variation across lakes and negatively related to small female Wr variation in Escanaba Lake. Improving the condition of large female walleye may promote recruitment, and Wr may serve as an accessible metric of reproductive potential in walleye stock–recruit analyses.

scholarly journals Pathogens with potential impact on reproduction in captive and free-ranging European bison (Bison bonasus) in Poland - a serological survey

2021 ◽  
Vol 17 (1) ◽  
Author(s):  
Anna Didkowska ◽  
Daniel Klich ◽  
Anna Hapanowicz ◽  
Blanka Orłowska ◽  
Marta Gałązka ◽  
...  
Keyword(s):  
Animal Species ◽  
Neospora Caninum ◽  
Reproductive Potential ◽  
European Bison ◽  
Bison Bonasus ◽  
Serum Samples ◽  
Similar Frequency ◽  
Current Prevalence ◽  
Potential Impact ◽  
Free Ranging

Abstract Background The European bison is an endangered species, and as such it is extremely important to monitor herds for pathogens which can lead to reproductive failure. The aim of the present study was to determine the current prevalence of antibodies to pathogens known to potentially influence reproduction in European bison. Serum samples from 183 bison, originating from different parts of Poland, were tested using commercial ELISA tests for antibodies to Chlamydia spp., Coxiella burnetti, Leptospira interrogans, Neospora caninum and Toxoplasma gondii; the findings were compared between captive and main free-ranging herds, and with regard to the influence of demographic factors such as age and sex. The prevalence of seropositivity was also checked with regard to location and the animal species sharing it. Results Chlamydia spp. antibodies were present in 48 out of 130 (36.9%) tested samples. Coxiella burnetii was found in one sample out of 178 (0.58%). N. caninum in 36 out of 172 (20.9%) and T. gondii in 23 out of 172 (13.4%). No sample was positive for leptospirosis. Neither sex nor age appeared to have a significant effect on the occurrence of antibodies to the identified species. The prevalence of Chlamydia spp. in the samples varied significantly according to location; however, similar frequency ranges were observed between free ranging and captive herds. In contrast, antibodies to N. caninum were more common in free-ranging herds than captive herds, with the highest frequency observed in the Bieszczady Mountains. Conclusions Chlamydia spp., N. caninum and T. gondii might have a similar impact on the reproductive potential of European bison as they have on cattle. The high occurrence of antibodies to N. caninum in bison from the Bieszczady Mountains may be associated with the relatively high density of the wolf population in the area.

scholarly journals Reproduction aspect of green swordtail, Xiphophorus hellerii Heckel 1848 in Tamblingan Lake, Bali

2020 ◽  
Vol 20 (1) ◽  
pp. 81
Author(s):  
I Nyoman Yoga Parawangsa ◽  
M. Fadjar Rahardjo ◽  
Charles P. H. Simanjuntak
Keyword(s):  
Body Weight ◽  
Gonadosomatic Index ◽  
Reproductive Potential ◽  
Mesh Size ◽  
Biological Information ◽  
Total Length ◽  
Xiphophorus Hellerii ◽  
Fish Samples ◽  
Spawning Time ◽  
Observation Times

Eco-biological information of green swordtail in Tamblingan Lake is unknown. This research aimed to reveal sex ratio, gonadosomatic index, viviparity, spawning time and location of green swordtail in Tamblingan Lake. Fish was collected by gill nets with a mesh size of 0.5 and 1.0 cm in five sampling stations  from January to June 2019. Total length and body weight of all fish samples were measured then dissected to observe the level of gonad maturity and viviparity in female fish. A total of 373 green swordtail with total length ranged and body weight ranged from 30.4-69.2 mm and 0.7935 – 7.6612 g, respectively. The results showed that males outnumberd of females in all sampling periods. Gonadosomatic index of male and female ranged from 0.159-1.239 and 0.204-13.592, respectively. The mature individuals were captured in all sampling stations and observation times. This species has a good reproductive potential with viviparity ranges between 6-54 juveniles.

scholarly journals Water hardness influenced variations in reproductive potential of two freshwater fish species; Poecilia reticulata and Betta splendens

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Abarna Krishnakumar ◽  
E. S. Patrick Anton ◽  
Uthpala A. Jayawardena
Keyword(s):  
Fish Species ◽  
Natural Waters ◽  
Poecilia Reticulata ◽  
Gonadosomatic Index ◽  
Larval Growth ◽  
Reproductive Potential ◽  
Water Hardness ◽  
Larval Survival ◽  
Betta Splendens ◽  
Test Species

Abstract Objective Hardness of water in the form of CaCO3 affects reproductive potential in various fish species, differently. This study evaluates the effect of water hardness on growth and reproduction of two aquarium fishes, Poecilia reticulata (Ovo-viviparous sp.) and Betta splendens (Oviparous sp.) by growing them under 150 (control), 320, 540 and 900 ppm CaCO3 levels in semi natural aquaria. Results Growth increased with increasing water hardness, reporting a significant progress of P. reticulata (p = 0.005) at 900 ppm. Similarly, the reproductive potential of P. reticulata was improved significantly, recording the highest fecundity (16.22 ± 3.90) and Gonadosomatic Index (GSI-2.48 ± 0.6) at 900 ppm. However, in B. splendens water hardness adversely affected the reproduction by resulting a significantly low hatchability and disturbed bubble nests at 900 ppm, compared to the largest bubble nest formed at the control condition (108.58 ± 16.19 cm2). Thus, the study revealed differential effects of water hardness on reproductive potential of the test species, by increasing the potential of P. reticulata while decreasing that of B. splendens. Though larval survival was affected in both species, larval growth was improved significantly in P. reticulata at 900 ppm level. Understanding reproductive potential of aquarium fishes in natural waters is crucial for their management purposes.

Sign in / Sign up

Export Citation Format

Share Document