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Rodrigo Wiff - One of the best experts on this subject based on the ideXlab platform.

  • accuracy of Gonadosomatic Index in maturity classification and estimation of maturity ogive
    2019
    Co-Authors: Andres Flores, Rodrigo Wiff, Konstantinos Ganias, Tara C Marshall
    Abstract:

    Abstract Determination of the stage of sexual maturation of an individual fish is commonly assessed using either microscopic or macroscopic staging. Microscopic staging examines either the internal cellular structure (histology) or the external appearance of the whole-oocyte (whole mount). Macroscopic staging is the visual evaluation of the external gonad development according to a standardised reference scale. Histology is the most widely used microscopic method and highly accurate but expensive and time consuming because it requires specialised equipment. Macroscopic staging is cheaper and faster but is associated with higher degree of error and bias. This study describe a methodological approach to assessing maturity stages of individual fish that is both inexpensive, rapid and more accurate than macroscopic staging. We have named it the gonometric method because it is based on direct measurements of the gonodasomatic Index (GSI), which expresses gonad weight as a proportion of total or somatic weight. Immature, mature-active, and mature-inactive fish were classified using a logistic multinomial model giving a threshold value of GSI named here as GSIcut-off. The gonometric method was applied to four fish species that had different reproductive strategies, including demersal and pelagic species. For all four species the gonometric method estimated the maturity ogives with comparable precision to microscopic methods (p > 0.05). Across species, GSIcut-off values correlate with growth parameter of the von Bertalanffy growth function and length at 50% maturity, suggesting that the scaling of the GSIcut-off value is underpinned by fundamental allometric principles. Further testing of the gonometric method is required, but our results suggest that it has considerable potential for providing a faster and more accurate alternative to maturity staging without the need for extensive training requirements to ensure consistency across individual observers.

  • Original Article Using the Gonadosomatic Index to estimate the maturity ogive: application to Chilean hake (Merluccius gayi gayi)
    2016
    Co-Authors: Rodrigo Wiff
    Abstract:

    The proportion of mature fish at age or length is one of the most important population attributes in assessing reproductive potential. This pro-portion is usually named the maturity ogive. The most crucial step in estimating this proportion deals with maturity staging assessed by macro-scopic or histology analysis. Macroscopic analysis is relatively inexpensive but usually introduces large amount of error. Histology is the most accuratemethod formaturity staging but is expensive and time consuming.Here,wepropose using the Gonadosomatic Index (GSI) as an alternative way to estimate thematurityogives. A logisticmultinomialmodelwas implemented to separate immature,mature-active, andmature-inactive fish, based only on their value of GSI. We evaluated the performance of the GSI-based method by comparing the results with ogives estimated from macroscopic andhistological stagingusing the extensivedatabaseavailable forChileanhake (Merluccius gayi gayi).Maturityogives fromGSI analysis were evaluatedat the start and endof the reproductive season. Results showed that, in all cases analysed,maturity ogives fromGSIwere closer to the ogives based on histology than those from macroscopic staging. Comparing across periods, those maturity ogives computed at the start of the reproductive season give estimates very similar to those from histological staging. To have unbiased estimates of maturity ogives fromGSI analysis

  • Using the Gonadosomatic Index to estimate the maturity ogive: application to Chilean hake (Merluccius gayi gayi)
    2016
    Co-Authors: Rodrigo Wiff
    Abstract:

    The proportion of mature fish at age or length is one of the most important population attributes in assessing reproductive potential. This pro-portion is usually named the maturity ogive. The most crucial step in estimating this proportion deals with maturity staging assessed by macro-scopic or histology analysis. Macroscopic analysis is relatively inexpensive but usually introduces large amount of error. Histology is the most accuratemethod formaturity staging but is expensive and time consuming.Here,wepropose using the Gonadosomatic Index (GSI) as an alternative way to estimate thematurityogives. A logisticmultinomialmodelwas implemented to separate immature,mature-active, andmature-inactive fish, based only on their value of GSI. We evaluated the performance of the GSI-based method by comparing the results with ogives estimated from macroscopic andhistological stagingusing the extensivedatabaseavailable forChileanhake (Merluccius gayi gayi).Maturityogives fromGSI analysis were evaluatedat the start and endof the reproductive season. Results showed that, in all cases analysed,maturity ogives fromGSIwere closer to the ogives based on histology than those from macroscopic staging. Comparing across periods, those maturity ogives computed at the start of the reproductive season give estimates very similar to those from histological staging. To have unbiased estimates of maturity ogives fromGSI analysis, we recommend using data from the start of the reproductive season to minimise the frequency of spent fish. In addition, the assumption of th

M Y Hossain - One of the best experts on this subject based on the ideXlab platform.

  • length weight relationships condition factor Gonadosomatic Index based size at first sexual maturity spawning season and fecundity of aspidoparia morar cyprinidae in the jamuna river brahmaputra river distributary northern bangladesh
    2013
    Co-Authors: M Y Hossain, Zoarder Faruque Ahmed, Mas Jewel, M S Arefin, M S Mohmud, Md Imam Hossain, M M Rahman, Ferdous Ahamed, Jun Ohtomi
    Abstract:

    Summary The present study describes the length-weight relationships (LWRs), length-length relationships (LLRs), Fulton's condition factor (KF), size at first sexual maturity, spawning season, sex ratio and fecundity of the Morari Aspidoparia morar (Hamilton, 1822) (Cyprinidae). Sampling was done using traditional fishing gear jhaki jal (cast net) from July 2010 to June 2011. Total length (TL), fork length (FL) and standard length (SL) were measured with digital slide calipers. Individual body weight (BW) and gonad weight (GW) were determined to an accuracy of 0.01 g for all specimens. The Gonadosomatic Index (GSI) was calculated and size at first maturity for males and females estimated using GSI and TL as indicators. Female ≥ size at first maturity was used to determine fecundity. A total of 1200 specimens (males = 552, females = 648) ranging from 4.06–12.84 cm TL and 0.53–16.75 g BW were analyzed. The overall coefficient b for the LWR indicated positive allometric growth (>3.00) in males and isometric growth in females (~ 3.00). ancova (analysis of covariance) revealed significant differences between males and females (P   0.973, P < 0.001). Sizes at first sexual maturity for males and females were 6.0 and 7.0 cm TL, respectively. KF changed little throughout the year and GSI peaked in November to April, indicating the spawning season (GSImax = 15.0 in females, 2.0 in males). Mature females were dominant during the entire spawning season except in April. Mean total fecundity was 6700 ± 3500, ranging from 1860 to 19680. In addition, relative fecundity ranged from 190 to 1200 (mean 560 ± 235) in the Jamuna River. To ensure sustainable management of this species, the protection of mature individuals during the peak spawning season is highly recommended.

  • Gonadosomatic Index based size at first sexual maturity of the catfish eutropiichthys vacha hamilton 1822 in the ganges river nw bangladesh
    2012
    Co-Authors: M Y Hossain, Mas Jewel, Luthfun Nahar, Mosaddequr Rahman, A Naif, Jun Ohtomi
    Abstract:

    Summary This study describes the size at first sexual maturity, length–weight relationships (LWR) in relation to size at first sexual maturity, and Fulton’s condition factor (KF) of Eutropiichthys vacha in the Ganges River, northwestern Bangladesh. Sampling was done using traditional fishing gear including cast nets, square lift nets and conical traps during January and April, and July to December 2010. For each individual, total length (TL) was measured to the nearest 0.01 cm, and total weight (BW) was determined to the nearest 0.01 g. The Gonadosomatic Index (GSI) was calculated by the equation, GSI (%) = (Gonad weight in g/BW) × 100. The size at first sexual maturity of males and females was estimated by the relationship between Gonadosomatic Index and total length. A total of 583 specimens (289 males; 294 females) ranging from 8.30 to 27.00 cm TL and 3.16 to 159.50 g BW were analyzed. Sizes at first sexual maturity for male and female E. vacha were 13.15 and 14.00 cm TL, respectively. The analysis of covariance (ancova) revealed significant differences in slope and intercept between early and late phases for males (F = 4.532, P < 0.001) and females (F = 21.984, P < 0.001). The KF was not significantly correlated with TL for males (rs = 0.052; P = 0.378), but was highly correlated for females (rs = −0.165; P = 0.005). This study establishes a strong base for monitoring changes in length at first sexual maturity attributable to high fishing pressures or other reasons within the Ganges and associated river ecosystems.

  • Gonadosomatic Index based size at first sexual maturity and fecundity indices of the indian river shad gudusia chapra clupeidae in the ganges river nw bangladesh
    2010
    Co-Authors: M Y Hossain, Zoarder Faruque Ahmed, Akms Islam, Saleha Jasmine, Jun Ohtomi
    Abstract:

    Summary The present study aims to estimate the size at first sexual maturity and fecundity for female Gudusia chapra from the lower Ganges River, northwestern Bangladesh. A total of 250 female specimens, 3.60–13.70 cm in standard length (SL) and 1.00–43.60 g in body weight (BW), were collected during March–August 2006. The Gonadosomatic Index (GSI) for females was calculated by the equation, GSI (%) = (GW/BW) × 100. The size at first sexual maturity of females was estimated by the relationship between their Gonadosomatic Index and standard length. The specimen larger (≥8.00 cm in SL) than first size at sexual maturity was used for the estimation of fecundity. The size at first sexual maturity for female G. chapra was considered to be 8.00 cm SL in the Ganges River. The mean total fecundity was 20200 ± 6500 and ranged from 10800 to 36200. This study should be useful for fisheries biologists/managers to impose adequate regulations for sustainable-fishery management in the Ganges River and elsewhere in Bangladesh.

Mardiati, Siti Muflichatun - One of the best experts on this subject based on the ideXlab platform.

  • EFEK EKSTRAK ETHANOL DAUN MIMBA TERHADAP Gonadosomatic Index (GSI), JUMLAH DAN UKURAN FOLIKEL ATRESIA PADA MENCIT (Mus musculus L.) BETINA
    2018
    Co-Authors: Hidayah Nurul, Sitasiwi, Agung Janika, Mardiati, Siti Muflichatun
    Abstract:

    Neem leaves contain flavonoid, triterpenoid and saponin compounds that have antifertility potential to suppress of reproduction rate of rodentia pests. The purpose of this study was to examine the effect of neem leaf ethanol extract on Gonadosomatic Index (GSI), number and size of atresia follicles in female mice. This study used a Completely Randomized Design Method consist of 5 treatments and 4 replications namely K + (Contraceptive Pills); K- (Aqua); P1, P2 and P3 (Treatment of neem leaf ethanol extract at dosage of 8.4 mg / kgBW, 11.2 mg / kgBW and 14 mg / kgBW). The treatment was administered orally at a volume of 0.2 ml / animal every morning for 21 days. Measurement of body weight was conducted at the beginning of treatment and every 7 days. The ovaries were isolated, weighed and histologically  processed using paraffin method and H & E staining. the number and diameter of  atresia follicles were counted on ovaries. The data was analyzed using ANOVA test and DMRT test at 95% confidence level. The results showed that neem leaf ethanol extract had no significant effect GSI and diameter of atresia follicle but had significant effect on the number of  atresia follicle. It can be concluded that neem leaf ethanol extract can increase the number of atresia follicle in mice by suppressing the synthesis and action of reproductive hormone.   Keywords: mimba leaf, atresia follicle, GSI, mic

Siti Muflichatun Mardiati - One of the best experts on this subject based on the ideXlab platform.

  • efek ekstrak ethanol daun mimba terhadap Gonadosomatic Index gsi jumlah dan ukuran folikel atresia pada mencit mus musculus l betina
    2018
    Co-Authors: Nurul Hidayah, Agung Janika Sitasiwi, Siti Muflichatun Mardiati
    Abstract:

    Neem leaves contain flavonoid, triterpenoid and saponin compounds that have antifertility potential to suppress of reproduction rate of rodentia pests. The purpose of this study was to examine the effect of neem leaf ethanol extract on Gonadosomatic Index (GSI), number and size of atresia follicles in female mice. This study used a Completely Randomized Design Method consist of 5 treatments and 4 replications namely K + (Contraceptive Pills); K- (Aqua); P1, P2 and P3 (Treatment of neem leaf ethanol extract at dosage of 8.4 mg / kgBW, 11.2 mg / kgBW and 14 mg / kgBW). The treatment was administered orally at a volume of 0.2 ml / animal every morning for 21 days. Measurement of body weight was conducted at the beginning of treatment and every 7 days. The ovaries were isolated, weighed and histologically  processed using paraffin method and H & E staining. the number and diameter of  atresia follicles were counted on ovaries. The data was analyzed using ANOVA test and DMRT test at 95% confidence level. The results showed that neem leaf ethanol extract had no significant effect GSI and diameter of atresia follicle but had significant effect on the number of  atresia follicle. It can be concluded that neem leaf ethanol extract can increase the number of atresia follicle in mice by suppressing the synthesis and action of reproductive hormone. Keywords: mimba leaf, atresia follicle, GSI, mice

Maria Gabriella Marin - One of the best experts on this subject based on the ideXlab platform.

  • Do males and females respond differently to ocean acidification? An experimental study with the sea urchin Paracentrotus lividus
    2020
    Co-Authors: Tihana Marčeta, Valerio Matozzo, Silvia Alban, Denis Badocco, Paolo Pastore, Maria Gabriella Marin
    Abstract:

    Seawater pH lowering, known as ocean acidification, is considered among the major threats to marine environment. In this study, post-spawning adults of the sea urchin Paracentrotus lividus were maintained at three pH values (8.0, 7.7, 7.4) for 60 days. Physiological, biochemical, cellular, behavioural and reproductive responses were evaluated in males and females. Significant differences between sexes were observed, with higher ammonia excretion and lower catalase activity in males. Respiration rate (after 21 days), catalase activity in gonads and total coelomocyte count showed the same increasing trend in males and females under low pH. Ammonia excretion, Gonadosomatic Index and lysozyme activity exhibited opposite responses to low pH, with an increasing trend in males and decreasing in females. Results demonstrated that exposure to low pH could result in different response strategies of male and female sea urchins at a physiological, biochemical and immunological level. Reduced female Gonadosomatic Index under low pH suggested decreased energy investment in reproduction.