scholarly journals Mackerel (Scomber australasicus) Reproduction in Northeastern Taiwan

2021 ◽  
Vol 9 (12) ◽  
pp. 1341
Author(s):  
Sunarti Sinaga ◽  
Hsueh-Jung Lu ◽  
Jia-Rong Lin
Keyword(s):  
Management Strategy ◽  
Gonadosomatic Index ◽  
Spawning Season ◽  
Batch Fecundity ◽  
Target Species ◽  
Female Fish ◽  
Coastal Fisheries ◽  
Spawning Frequency ◽  
Free Weight ◽  
Total Fecundity

Blue mackerel (Scomber australasicus) is a crucial target species for coastal fisheries in Taiwan, and additionally it has maintained its status as the highest-produced species. The timely measurement of spawning status is crucial for determining the correct management strategy for this species. The objective of this study was to determine size at maturity, fecundity, batch fecundity, and spawning frequency on the basis of samples collected from Nan-Fang-Ao fishing port in Yilan, during the spawning season from 2017 to 2019. Histological sections indicated that the blue mackerel were multiple spawners; a higher percentage of female fish spawned at the peak of the gonadosomatic index. The 50% sizes at maturity were 32.02, 32.13, and 29.64 cm. Mean total fecundity (batch fecundity) was 165 (103), 229 (96), and 210 (68) oocytes per ovary-free weight (g) for 2017, 2018, and 2019, respectively; fecundity was determined through observation of postovulatory follicles (POFs). The spawning frequencies (spawning fraction) in 2017, 2018, and 2019 were 3–10 days (0.13), 4–14 days (0.08), and 4–12 days (0.09), respectively. The spawning frequencies determined through the three estimated methods, namely the sums of (a) hydrated and Day 0 POFs; (b) Day 1+ POFs, and (c) all data combined, were 1 spawning event per 8, 10, and 9 days, respectively. The reproduction of the blue mackerel was greater in 2017 than it was in 2018 or 2019, as indicated by the higher batch fecundity and shorter spawning seasons. Environmental factors should also be considered as a major factor influencing successful reproduction and spawning season

scholarly journals Fecundity regulation in horse mackerel

2013 ◽  
Vol 71 (3) ◽  
pp. 546-558 ◽  
Author(s):  
Cindy J. G. van Damme ◽  
Anders Thorsen ◽  
Merete Fonn ◽  
Paula Alvarez ◽  
Dolores Garabana ◽  
...  
Keyword(s):  
Lipid Content ◽  
Egg Production ◽  
Gonadosomatic Index ◽  
Production Method ◽  
Spawning Season ◽  
Horse Mackerel ◽  
Hepatosomatic Index ◽  
Batch Fecundity ◽  
Production Methods ◽  
Unbiased Estimates

Abstract Egg production methods have been used successfully in the provision of advice for fisheries management. These methods need accurate and unbiased estimates of fecundity. We explore the reproductive strategy of horse mackerel and estimation of fecundity. Fecundity and fecundity regulation in relation to condition was investigated over a number of years. Fulton's K, lipid content, and hepatosomatic index increased after the start of spawning, though decreased again at the end of spawning. The increase in the gonadosomatic index, fecundity, and body condition after the onset of spawning suggests that horse mackerel utilizes food resources during the spawning season and might be an income breeder. However, the decline in K and lipid before the spawning season suggests that the first batch of oocytes is developed on stored energy. Fecundity varied between years and within a spawning season. Over latitude, variations in fecundity were small. K and lipid content are not reliable indices as proxy for fecundity. Batch fecundity appears to be heterogeneous across the spawning season but homogeneous across latitude. The homogeneity of batch fecundity over latitude could indicate that the daily egg production method is an appropriate approach for estimating the abundance of a wide ranging species, as horse mackerel.

scholarly journals Fecundity and Gonadosomatic Index of Sucker Throat Catfish, Pseudecheneis sulcata (McClelland, 1842) from the Snow-fed Tamor River in Eastern Nepal

2021 ◽  
Vol 11 (2) ◽  
pp. 1-9
Author(s):  
Jash Hang Limbu ◽  
Dipak Rajbanshi ◽  
Prakash Kumar ◽  
Bharat Raj Subba
Keyword(s):  
Body Weight ◽  
Reproductive Biology ◽  
Gonadosomatic Index ◽  
Spawning Season ◽  
Stream Fish ◽  
Female Fish ◽  
Ovary Weight ◽  
Relative Fecundity ◽  
Absolute Fecundity ◽  
Total Length

In comparison to other nations, the Nepalese information on the reproductive biology of hill-stream fish is limited. So, the purpose of the present study was to provide information related to reproductive biology of a hill-stream sucker throat catfish Pseudecheneis sulcata from the snow-fed Tamor River, Nepal. The study was carried out from June 2018 to May 2019.  A total of 57 female fish was collected. The fecundity of 22 females was assessed, while the gonadosomatic index was determined using all the collected samples. The absolute fecundity ranged from 2,316 to 7,597 eggs, with an average of 3,660 ± 210. This range of absolute fecundity indicates that Pseudecheneis sulcata is a moderately fecund fish when compared to certain low fecund species and some exceptionally fecund fish with tens of thousands of eggs. Relative fecundity ranged from 65.47 to 129.11 with a mean of 88.98 ± 4.35. The present study demonstrated that absolute fecundity was moderately correlated with total length (r = 0.45) and strongly linked with body weight (r = 0.78), and ovary weight (r = 0.80). Mean gonadosomatic index (GSI) was recorded the highest in January (15.7 ± 1.22%), and showed a decrease in the subsequent month of February (10.3 ± 0.75%), March (6.25 ± 0.28%) and April (1.66 ± 0.40%). The trends of GSI might have indicated that the sucker throat catfish was a batch spawner, with spawning season occuring between January and March.

scholarly journals Analysis of reproductive biology and spawning season of the pink ear emperor Lethrinus lentjan, from marine ecosystem

2020 ◽  
Vol 37 ◽  
pp. 1-10
Author(s):  
Elsayed M. Younis ◽  
Nasser A. Al-Asgah ◽  
Abdel-Wahab A. Abdel-Warith ◽  
Mohamed H. Gabr ◽  
Fozi S. Shamlol
Keyword(s):  
Fish Species ◽  
Gonadosomatic Index ◽  
Marine Ecosystem ◽  
Local Population ◽  
Spawning Season ◽  
Monthly Basis ◽  
Population Sampling ◽  
Maturation Rate ◽  
Maturation Index ◽  
One Year

A total of 593 samples of Lethrinus lentjan (Lacepede, 1802) were collected from the Red Sea, Jeddah, Saudi Arabia, to study their productive biology and spawning season of the local population. Sampling was carried out on a monthly basis for a period of one year. The monthly sex ratios indicated that females were dominant throughout the study period, with an overall male:female sex ratio of 1:7.98, although males were larger than females. The highest monthly performance maturation index (PMI), as well as the male and female gonadosomatic index (GSI) and ovarian maturation rate (OMR) were observed in February and March. Histological examination of the gonads confirmed the process of sexual transformation in this fish species, wherein individuals mature first as female, and then change sex to male (protogynous hermaphroditism). Histological sections also showed that the sexual maturation of males of L. lenjtan comprised three main stages, while the sexual development of females could be classified into four main stages. Extended spawning in the form of batches released during different months throughout the year were recorded for this fish species, with the main spawning season in February and March, and an additional, shorter spawning season in September.

scholarly journals Seasonal variations in the population biology of Salmostoma bacaila (Cyprinidae) from a tributary of the Payra River, Bangladesh

2019 ◽  
pp. 113-119
Author(s):  
Ahamed Ahamed ◽  
Faruque Ahmed Zoarder ◽  
Jun Ohtomi
Keyword(s):  
Sex Ratio ◽  
Seasonal Variations ◽  
Population Biology ◽  
Sexual Maturity ◽  
Condition Factor ◽  
Gonadosomatic Index ◽  
Spawning Season ◽  
Frequency Distributions ◽  
Size At Sexual Maturity ◽  
Management And Conservation

Some biological parameters of Salmostoma bacaila – including sex ratio, length-frequency distributions (LFDs), size at sexual maturity, spawning season, length-weight relationships (LWRs) and condition factor – were studied. Samples were collected seasonally during June 2017 to May 2018 from a tributary of the Payra River. The overall sex ratio was significantly different from the expected value of 1:1 (p < 0.001), in favour of male specimens. Females were significantly larger than males. Size at sexual maturity was estimated at 7.6~7.7 cm total length. Seasonal variations in the gonadosomatic index (GSI) indicate that the main spawning season is from spring to summer. The LWRs showed negative allometric growth in both sexes, but with clear seasonal variation. Fulton’s condition factor varied in both sexes and was attributed to variations in GSI with maturity. The fin¬dings of this study will be helpful for management and conservation of S. bacaila populations.

Spawning and fecundity of the western king prawn, Penaeus latisulcatus Kishinouye, in Western Australian Waters

1980 ◽  
Vol 31 (1) ◽  
pp. 21 ◽  
Author(s):  
JW Penn
Keyword(s):  
Spawning Season ◽  
Ovary Development ◽  
Southern Population ◽  
Spawning Frequency ◽  
Total Length ◽  
Australian Coastline ◽  
The Individual ◽  
Western Australian

The microscopic and macroscopic changes which occur during ovary development to spawning have been investigated for P. larisulcatus. The latter stages (3 and 4) of development and the act of spawning have been found to be confined to single intermoult periods, with spawning being possible during each of a series of consecutive intermoult periods. Fecundity was found to vary significantly with the size of the individual, with the number of eggs ranging from approximately 105000 (123 mm total length female) to 650000 (217 mm total length female) at each spawning. The use of an index of population fecundity in combination with estimates of spawning frequency to document spawning seasons is discussed. Using the population fecundity method the two northern populations have been shown to have a year round spawning season, with maximum spawning occurring from autumn to spring. while the southern population was shown to have shorter seasons over summer. A relationship between ovary development and temperatures in excess of 17�C is suggested as the probable cause of the differences in duration of spawning seasons along the Western Australian coastline.

Ligula intestinalis infection as a potential source of bias in the bioindication of endocrine disruption in the European chub Leuciscus cephalus

2005 ◽  
Vol 79 (1) ◽  
pp. 91-94 ◽  
Author(s):  
M. Schabuss ◽  
M. Gemeiner ◽  
A. Gleiß ◽  
J.W. Lewis ◽  
I Miller ◽  
...  
Keyword(s):  
Developmental Stages ◽  
Gonadosomatic Index ◽  
Endocrine Disrupting Chemicals ◽  
Infected Fish ◽  
Female Fish ◽  
Male Fish ◽  
Ligula Intestinalis ◽  
European Chub ◽  
Endocrine Disrupting ◽  
Leuciscus Cephalus

AbstractEuropean chub Leuciscus cephalus collected from five localities in the lowland and subalpine regions of Austria were analysed for oestrogenic effects of endocrine-disrupting chemicals and the presence of the plerocercoid of the tapeworm Ligula intestinalis. Of 1494 chub analysed, only seven (six males, one female) were found to be infected with single, but large plerocercoids up to 15 cm in length. Ligula-infected fish showed comparatively immature gonads, as demonstrated by the gonadosomatic index and gamete developmental stages. Plasma levels of the egg precursor protein vitellogenin also showed concentrations ranging below the detection limit. The present results indicate that chub infected with L. intestinalis and exposed to exogenous oestrogenic compounds can result in reduced gonadal maturation and produce false oestrogen-positive diagnoses in male fish. For plasma vitellogenin levels, L. intestinalis infections can result in false oestrogen-negative diagnoses in male and female fish.

Gonadal Maturation and Histological observations of S. curvifrons in River Jhelum Kashmir

2018 ◽  
Author(s):  
Sauliheen Qadri ◽  
Tasaduq H Shah ◽  
M. H. Balkhi ◽  
Bilal A. Bhat ◽  
F. A. Bhat ◽  
...  
Keyword(s):  
Gonadosomatic Index ◽  
Gonadal Development ◽  
Spawning Season ◽  
Gonadal Maturation ◽  
Maturity Stages ◽  
Preparatory Phase

The objective of the present study is to describe the phases of gonadal development and determine the spawning season of Schizothorax curvifrons in River Jhelum Kashmir. A total of 298 fish specimen were studied to analyse the gonadosomatic index and maturity stages of S. curvifrons. Five maturity stages namely Immature phase, Preparatory phase, Maturing phase, Ripe/spawning phase and Spent phase were observed in the gonads. Based on GSI values and gonadal conditions, April to June appears to be the spawning season for S. curvifrons

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