scholarly journals A note on the breeding season, sex ratio and embryonic development of the dogfish Scyliorhinus canicula (L.)

1952 ◽  
Vol 31 (2) ◽  
pp. 269-275 ◽  
Author(s):  
John E. Harris
Keyword(s):  
Sex Ratio ◽  
Embryonic Development ◽  
Breeding Season ◽  
Temperature Characteristic ◽  
Spawning Season ◽  
Spawning Ground ◽  
Teleost Species ◽  
Scyliorhinus Canicula ◽  
Different Temperatures

Records of nearly 2000 dogfish collected from the Ilfracombe region suggest that the spawning season of this fish starts in November and continues at least until July. This area probably represents a spawning ground into which the females migrate during the spawning season; the males follow them much later in April and May.Figures are given to show the time taken at different temperatures for the embryo to develop to a series of definite morphological stages; these suggest that the temperature characteristic of the development (µ = 20,000) is substantially the same as for several teleost species.

scholarly journals Study of Some Biological Aspects of the Nile Carp, Labeo niloticus (Pisces, Cyprinidae) from Khashm El-Girba Reservoir and Atbara River, Sudan: I Abundance; Sex Ratio; Gonado-somatic Index and Breeding Season

2020 ◽  
pp. 21-28
Author(s):  
Mutasim Yousif Mohamed Abdalla ◽  
Abuelgasim Ibrahim Abdelhalim ◽  
Ahmed El Bedawi Adam
Keyword(s):  
Sex Ratio ◽  
Breeding Season ◽  
Spawning Season ◽  
Beach Seine ◽  
Sudan I ◽  
Biological Aspects ◽  
Two Peaks ◽  
Somatic Index

The aim of this study is to investigate some biological aspects of the Nile carp, Labeo niloticus, in Khashm El-Girba reservoir and Atbara River, Sudan. The study was conducted during December 2015 to November 2016. Samples were collected bi-monthly from three localities, namely; Um Aswad (Atbara River), El-Remila and El-Monaba (Khashm El-Girba reservoir), using beach seine nets of 1.2 cm 4.0 cm and 7.0 cm stretched mesh. A total number of 1,190 specimens of L. niloticus were collected from the three sampling sites. Two peaks of abundance were observed for L. niloticus at all sampling sites (February- March and September- October). Sex ratio was 1:1, except in downstream areas, where females were more dominant than males. Gonado-somatic index showed one peak of increase, and ranged from 1.28 - 1.79 and 0.50 – 1.701 for females and males respectively, indicating one spawning season.

Biology of the Feral Cat, Felis Catus (L.), On Macquarie Island.

1985 ◽  
Vol 12 (3) ◽  
pp. 425 ◽  
Author(s):  
NP Brothers ◽  
IJ Skira ◽  
GR Copson
Keyword(s):  
Sex Ratio ◽  
Breeding Season ◽  
Felis Catus ◽  
Feral Cat ◽  
Feral Cats ◽  
Macquarie Island ◽  
Pregnant Females

246 feral cats were shot on Macquarie Island, Australia, between Dec. 1976 and Feb. 1981. The sex ratio ( males : females ) was 1:0.8. The percentages of animals with tabby, orange and black coats were 74, 26 and 2 resp. [sic]. Of the 64 orange cats, 56 were males . The breeding season was Oct.-Mar., with a peak in Nov.-Dec. The number of embryos in the 14 pregnant females averaged 4.7 (range = 1-9). The size of the 23 litters that were observed averaged 3 (range = 1-8). Kitten survival to 6 months of age was estimated to be <43%.

The effect of melatonin treatment during the seasonal anoestrus on the superovulatory response and embryo production of high-prolificacy Rasa Aragonesa ewes before culling

2003 ◽  
Vol 2003 ◽  
pp. 82-82
Author(s):  
F. Forcada ◽  
J.A. Abecia ◽  
J.A. Valares
Keyword(s):  
Embryonic Development ◽  
Breeding Season ◽  
Litter Size ◽  
Direct Effect ◽  
Ovulation Rate ◽  
Corpora Lutea ◽  
Melatonin Treatment ◽  
Embryo Production ◽  
Spring Equinox

The efficacy of melatonin implants inserted around the spring equinox to improve fertility and ovulation rate or litter size in Mediterranean ewes has been previously reported (Chemineau et al., 1996; Forcada et al., 2002a.), indicating the ability of the hormone to regulate the hypothalamic activity (Viguié et al., 1995). Moreover, a direct effect of melatonin on corpora lutea and embryonic development has been also reported (Wallace et al., 1988; Abecia et al., 2002). The use of prolific Rasa Aragonesa (RA) ewes (a Mediterranean breed) before culling as embryo donors has been previously tested in the breeding season (Forcada et al., 2002b.). The aim of this experiment was to improve embryo production during the seasonal anoestrus period in selected superovulated RA ewes at the end of their reproductive lives through the use of melatonin.

scholarly journals Sex Ratio, Fecundity and Morphometry of the Eggs of Freshwater Prawn Macrobrachium Americanum (Bate, 1868) in the Petatlán River, Sinaloa, Mexico

2021 ◽  
Vol 79 (1) ◽  
pp. 1-14
Author(s):  
Genaro Diarte-Plata ◽  
Ruth Escamilla-Montes ◽  
Salvador Granados-Alcantar ◽  
Antonio Luna-González
Keyword(s):  
Sex Ratio ◽  
Embryonic Development ◽  
Linear Model ◽  
Potential Model ◽  
Total Weight ◽  
Stage Ii ◽  
Freshwater Prawn ◽  
Spherical Form ◽  
Relative Fecundity ◽  
Egg Diameter

Abstract Macrobrachium americanum has a high commercial value with good fishing and cultivation possibilities in Mexico. Currently there is little information on reproductive aspects so the present work analyzed the sex ratio, fecundity and morphometry of the eggs of M. americanum in the Petatlán River, Sinaloa, Mexico. A total of 31 ovigerous females were captured. The sex ratio was 0.39 F: 1 M. The partial fecundity (Pf) varied from 34, 554 to 342, 372 eggs (128, 246 ± 12, 306 eggs, average Pf). The relationships between body and length-fecundity (R2= 0.5546), cephalothorax and length-fecundity (R2= 0.4995) were adjusted to a linear model, and the total weight-fecundity to a potential model (R2= 0.5013). The average relative fecundity was 37, 132 ± 5, 162 eggs/g. A total of 7 stages of embryonic development were observed. In the first stages, the egg presents a spherical form and in the latter an ovoid shape. Maximum egg diameter values are presented in stages VII, VI and VIII. Stage II provided the largest number of eggs (1, 013, 073 eggs). It is essential to optimize the exploitation of the population of M. americanum present in the Petatlán River through the creation of scientific bases for the sustainability of the fishery.

scholarly journals REPRODUCTIVE ASPECTS OF SCALLOPED PERCHLET, Ambassis nalua (HAMILTON, 1822) IN PABEAN BAY INDRAMAYU, WEST JAVA

2017 ◽  
Vol 9 (1) ◽  
pp. 113
Author(s):  
Nisha Desfi Arianti ◽  
M.F. Rahardjo ◽  
Ahmad Zahid
Keyword(s):  
Sex Ratio ◽  
Sampling Period ◽  
Spawning Season ◽  
West Java ◽  
Fish Samples ◽  
Length Range ◽  
Males And Females ◽  
Mature Fish ◽  
First Maturity ◽  
Somatic Index

<p align="center"><strong><em>ABSTRACT</em></strong></p><p><em>Scalloped perchle</em><em>t</em><em>, </em><em>Ambassis nalua</em><em>, </em><em> is one of fishes in Pabean Bay</em><em>, </em><em>Indramayu. This research aims to determine the reproductive </em><em>aspects </em><em>of Ambassis nalua in Pabean Bay Indramayu includ</em><em>ing</em><em> sex ratio, spawning season, first maturity, fecundity and spawning pattern. Fish samples were collected by trap net and trammel net at three site</em><em>s</em><em> in Pabean Bay</em><em> </em><em>from April to October 2015. A total of 424 of A. nalua were caught, consist of 114 males and 310 females; with total length range</em><em>d</em><em> from 38</em><em>.</em><em>04 to 112</em><em>.</em><em>63 mm and </em><em>total </em><em>weight </em><em>ranged from </em><em>0.37 </em><em>to </em><em>25.44 g. Sex ratio</em><em> of mature fish </em><em> </em><em>was 1:1.9</em><em>. The </em><em>mature </em><em>males and females were found </em><em>in </em><em>every month</em><em> of sampling period</em><em>. </em><em>The </em><em>gonado-somatic index (GSI) ranged from 0</em><em>.</em><em>40 to 0</em><em>.</em><em>83 </em><em>and 2.</em><em>36 to 4.54 for </em><em>male and </em><em>female</em><em>, respectively</em><em>. </em><em>The p</em><em>eak of spawning season</em><em> </em><em>was </em><em>found </em><em>in </em><em>September. The first maturity (Lm<sub>50</sub>)</em><em> </em><em>for male</em><em> and female were </em><em>79.17 mm</em><em> and </em><em>91.25 mm</em><em>, </em><em>respectively. The fecundity varied from 3</em><em>,</em><em>451–32</em><em>,</em><em>465</em><em> eggs.</em><em> </em><em>E</em><em>gg diameter </em><em>distribution </em><em>shows </em><em>that </em><em>spawning pattern of A. nalua was batch spawner.</em><strong><em></em></strong></p><p><em> </em></p><strong><em>Keywords</em></strong><em>: Ambassis nalua, spawning season, sex ratio, reproduction</em>

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.

Thermal influence on the embryonic development and hatching rate of the flameback pygmy angelfish Centropyge aurantonotus eggs

Zygote ◽  
2019 ◽  
Vol 28 (1) ◽  
pp. 80-82
Author(s):  
Raoani Cruz Mendonça ◽  
Sarah Pittigliani Ikebata ◽  
Sérgio Leandro Araújo-Silva ◽  
João Vitor Azevedo Manhães ◽  
Mônica Yumi Tsuzuki
Keyword(s):  
Embryonic Development ◽  
Incubation Temperature ◽  
Abiotic Factors ◽  
Environmental Parameters ◽  
Hatching Rate ◽  
Influence Of Temperature ◽  
Different Temperatures ◽  
Influence Of Temperature On ◽  
Thermal Influence ◽  
Hatching Rates

SummaryThe flameback pygmy angelfish Centropyge aurantonotus, highly appreciated and valued by the aquarium market, is heavily harvested and traded. Temperature is one of the abiotic factors that has the most influence on fish development, especially in the early stages of life. For captive production, it is essential to know the appropriate environmental parameters for each species. In this sense, this study aimed to evaluate the influence of temperature on the embryonic development and hatching rates of C. aurantonotus incubated at six different temperatures (20, 22, 24, 26, 28, 30°C). Embryonic development events were very similar in terms of morphological and chronological characteristics compared with other species of the genus Centropyge. Incubation time was inversely proportional to temperature. The treatment at 22°C required twice the time of that required by 30°C treatment for hatching to occur. The best incubation temperature range was 24–28°C. Values below 22°C and at 30°C showed lower hatching rates compared with other treatments. Based on these results, the recommended temperature at which to incubate C. aurantonotus eggs is between 24–28°C.

Biology of lake sturgeon (Acipenser fulvescens) spawning below a dam on the Richelieu River, Quebec: behaviour, egg deposition, and endocrinology

2013 ◽  
Vol 91 (3) ◽  
pp. 175-186 ◽  
Author(s):  
J.D. Thiem ◽  
D. Hatin ◽  
P. Dumont ◽  
G. Van Der Kraak ◽  
S.J. Cooke
Keyword(s):  
Sex Ratio ◽  
Reproductive Biology ◽  
Residence Time ◽  
Lake Sturgeon ◽  
Blood Sampling ◽  
Acipenser Fulvescens ◽  
Spawning Ground ◽  
Egg Deposition ◽  
Daily Spawning ◽  
Gill Netting

Knowledge of the reproductive biology of wild sturgeon populations is critical to ensure the survival of this unique group of animals. We combined gill-netting surveys, nonlethal blood sampling, radiotelemetry, and egg collection to examine the reproductive biology of lake sturgeon (Acipenser fulvescens Rafinesque, 1817) at a suspected spawning ground below a dam on the Richelieu River, Quebec. Lake sturgeon were present at the beginning of sampling in early May, and spawning took place from 26 May to 5 June when water temperature averaged 13.4 ± 0.1 °C (range 11.5–15.5 °C). Daily spawning population estimates ranged from 285 to 1282 individuals and the sex ratio of spawners was estimated at 2.1 males per female. The presence of radio-tagged individuals on the spawning grounds peaked from 20 to 28 May, corresponding with known spawning bouts. Residence time of spawners on the spawning ground ranged from 1 to 27 days (median = 5 days) and there were no differences in residence time between sexes. Nonlethal blood sampling enabled the quantification of steroid levels to determine the spawning population sex ratio, and steroid levels were highest before spawning was known to occur and decreased concurrently with, and after, known spawning events.

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