scholarly journals Sex ratio and fecundity of Chrysichthys nigrodigitatus (Family - Claroteidae) from Asejire Lake, Nigeria

2021 ◽  
Vol 31 (1) ◽  
pp. 135-143
Author(s):  
I. O. Taiwo ◽  
O. Odunaiya
Keyword(s):  
Body Weight ◽  
Sex Ratio ◽  
Standard Length ◽  
Egg Production ◽  
Line Graph ◽  
Male Specimen ◽  
Female Ratio ◽  
Straight Line ◽  
Male Female Ratio ◽  
Average Size

Sex ratio and fecundity of Chrysichthys nigrodigitatus from Asejire Lake were examined. The length-weight relationship showed that weight was curvilinearly related to standard length. The logarithm transformation of weight against standard length gave a straight-line graph represented by the following equation: Log W = -0.66 + 2.13 Log sl r2= 0.854; (p<0.001) n = 209 Males were generally more with a male : female ratio of 1:0.18. The average fish weight was 88.97g (16.28 cm standard length). Sexual maturity was attained at an average size of 45.0g (14.0 cm standard length). Relative fecundity was dependent on body weight and standard length (P< 0.05 and P < 0.01 respectively). Chrysichthys nigrodigitatus expended between 0.75% - 27.30% of body weight in egg production. The condition factor values showed that a female specimen of equal length with a male specimen is heavier. Six gonad maturity stages were identified, ovary and gonad weights increased with stage of maturity.

scholarly journals On the fecundity and sex-ratio of Botia Dario (Hamilton) (Cypriniformes : Cobitidae)

1970 ◽  
Vol 26 ◽  
pp. 27-29 ◽  
Author(s):  
M Afzal Hussain ◽  
Mst Rehana Khatun ◽  
M Altaf Hossain
Keyword(s):  
Body Weight ◽  
Sex Ratio ◽  
Standard Length ◽  
Female Ratio ◽  
Ovary Weight ◽  
Total Length ◽  
Length Standard ◽  
The Mean ◽  
The Relationship ◽  
Male To Female

A total of 1183 Botia Dario (Hamilton) samples were collected from Rajshahi (Shaheb Bazar, Binodpur Bazar, Talaimari Bazar, Kazla Bazar and Godagari) during the period from January, 2002 to August, 2003 to study the fecundity, sex-ratio, relationship between fecundity and total length, standard length, body weight, ovary length as well as ovary weight. The mean fecundity was calculated as 31833.50±10313.42 with a range of 5245 to 53754 in fishes ranging in total length from 96 mm to 135 mm (mean 115.50±12.11 mm) and in body weight from 14.51 g to 43.29 g (mean 29.71±6.91 g). The relationship between the fecundity (F) and total length (TL), standard length (SL), body weight (BW), ovary length (OL) and ovary weight (OW) were found to be linear with the ‘r’ values 0.94, 0.94, 0.95, 0.92 and 0.98, respectively. The ovum diameter ranged from 0.3 to 0.72 mm and the mean diameter was calculated as 0.518±0.06 mm. The male to female ratio was 1:0.61. Key words: Botia dario, fecundity, sex-ratio. Univ. j. zool. Rajshahi Univ. Vol. 26, 2007. pp. 27-29

Reproductive behaviour of female rosy bitterling Rhodeus ocellatus in response to a female-biased operational sex ratio

Behaviour ◽  
2014 ◽  
Vol 151 (6) ◽  
pp. 755-768 ◽  
Author(s):  
Caiping Liao ◽  
Dan Yu ◽  
Yiyu Chen ◽  
Martin Reichard ◽  
Huanzhang Liu
Keyword(s):  
Sex Ratio ◽  
Active Role ◽  
Reproductive Behaviour ◽  
Operational Sex Ratio ◽  
Reproductive Tactics ◽  
Female Ratio ◽  
Dominant Female ◽  
Male Female Ratio ◽  
Shaped Pattern ◽  
Rhodeus Ocellatus

While the effect of Operational Sex Ratio (OSR) on reproductive behaviour of males has been studied extensively, little is known of the response of females facing a female-biased OSR. We investigated the effect of different OSRs on female reproductive behaviour using the rosy bitterling, Rhodeus ocellatus, a freshwater fish that lays its eggs inside the gills of living freshwater mussels. Three levels of OSR (male/female ratio 1:1, 1:3 and 1:5) were tested. We demonstrated that inspection of the mussel (spawning substrate) by individual females increased with increasingly female-biased OSR, but that the rate of following territorial male decreased. Aggression towards other females was not affected by the OSR. Interestingly, when a male bitterling led a non-dominant female towards the mussel, the dominant female would become aggressive to the male and chase the non-dominant female away. Aggression towards male followed a bell-shaped pattern and was highest at an OSR of 1:3. In both the female-biased OSRs examined, almost 50% of dominant females tended to chase away other females and defend the mussel, showing territoriality in a similar manner to males. These observations suggest that female reproductive behaviour is strongly affected by the OSR, and their reproductive tactics during courtship change from a passive role in courtship (following a male) to an active role in courtship (approaching a male), with presence of female territorial behaviour as the OSR becomes increasingly female-biased. This study provides strong evidence that a female-biased OSR has an important effect on female reproductive behaviour.

Studies on the sex ratio of worms in schistosome infections

Parasitology ◽  
1990 ◽  
Vol 101 (1) ◽  
pp. 27-34 ◽  
Author(s):  
G. F. Mitchell ◽  
E. G. Garcia ◽  
S. M. Wood ◽  
R. Diasanta ◽  
R. Almonte ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Endemic Area ◽  
The Philippines ◽  
Mammalian Host ◽  
Late Time ◽  
Laboratory Mice ◽  
Female Ratio ◽  
Male Female Ratio ◽  
Duration Of Infection ◽  
Wild Rats

SUMMARYSex ratios of adult schistosomes in mice are almost invariably different from 1·0 and are biased towards males. The bias applies to wild rats infected with Schistosoma japonicum and trapped in an endemic area of the Philippines (male: female ratio = 1·7). It also applies to cercariae of snails collected in such areas and assessed by infection of laboratory mice using cercariae from individual snails (male: female ratio may approach 6·0). Experiments were designed to determine if duration of infection in the mammalian host was a factor that influenced the sex ratio of miracidia used for infecting snails and subsequently mice. BALB/c and C57BL/6 mice were infected with 100 cercariae of S. mansoni, and liver eggs harvested at early and late time points for infection of snails and production of cercariae. Two phenomena were demonstrated: firstly, a more pronounced male bias when eggs were harvested late compared with early in infection; secondly, a reduced apparent hatchability of eggs in BALB/c compared with C57BL/6 livers. The possibility is raised by the data that female miracidia within eggs of chronically infected individuals may be more prone to immune damage than male miracidia with important epidemiological consequences.

The Sex Ratio and Rate of Reoperation for Dupuytren’s Contracture in Men and Women

1999 ◽  
Vol 24 (4) ◽  
pp. 456-459 ◽  
Author(s):  
S. WILBRAND ◽  
A. EKBOM ◽  
B. GERDIN
Keyword(s):  
Sex Ratio ◽  
Recurrent Disease ◽  
Hand Surgery ◽  
University Hospital ◽  
Early Age ◽  
Dupuytren’S Contracture ◽  
Female Ratio ◽  
Men And Women ◽  
Male Female Ratio ◽  
Repeated Surgery

We identified all patients treated by local fasciectomy at the Department of Hand Surgery, Uppsala University Hospital between 1965 and 1996. A total of 2375 operations were performed on 1600 patients. We found a male: female ratio of 5.9:1. Women had a higher mean age at first operation (62.4 years) than men (59.8 years). One-third of the men required repeated surgery and one-quarter of the women. Early age at first operation was associated with recurrent disease.

scholarly journals Reproductive biology of the orangefin ponyfish Photopectoralis bindus (Valenciennes, 1835) off Mangaluru coast, Karnataka

2019 ◽  
Vol 66 (2) ◽  
Author(s):  
Shobha Rawat ◽  
Jitendra Kumar ◽  
S. Benakappa ◽  
Mahesh Chand Sonwal ◽  
Kumar A.S. Naik
Keyword(s):  
Body Weight ◽  
Reproductive Biology ◽  
Monsoon Season ◽  
Female Ratio ◽  
Fish Size ◽  
Male Female Ratio ◽  
Post Monsoon Season ◽  
Spawning Periodicity ◽  
Somatic Index ◽  
Peak Value

The spawning periodicity of Photopectoralis bindus (Valenciennes, 1835) was studied off Mangaluru coast from September 2015 to April 2016 using 490 specimens with total length 6.8-12.3 cm (9.6±0.9 cm) and body weight 4.6 -30.28 g (14.20±3.59 g). Results indicated that the average sizes at maturity were 9.3 cm (males) and 9.5 cm (females). The male-female ratio was 1:0.72. Absolute fecundity estimated was 9349±853 eggs that increased with fish size (R2 = 0.92). Higher gonado-somatic index (GSI) was observed in post-monsoon season with peak value in December (female: 3.39±1.00%; male: 2.84±0.796%) indicating seasonal spawning of the fish.

INEQUALITY OF GENDER RATIO AMONG RELIGIOUS AND SOCIAL GROUPS IN INDIA

2016 ◽  
Vol 4 (2) ◽  
pp. 68 ◽  
Author(s):  
Sandipan R. Gavhale
Keyword(s):  
Sex Ratio ◽  
Gender Gap ◽  
Social Groups ◽  
Social Condition ◽  
Gender Ratio ◽  
Problematic Situation ◽  
Female Ratio ◽  
Economic Progress ◽  
The Social ◽  
Male Female Ratio

India was a mother-dominant country. But today, the atrocities event ratio and the gender gap in India have increased, which is serious and considerable matter. The male-female ratio in society is an indicator of the socio-economic progress of the country, considering this point, the social condition of India, is not improved by satisfactory.There are many social groups and various distinct cultures their effects become on unequal sex ratio this inequality exists into the upper caste. So this article focuses on class wise gender ratio in India as comparative gender ratio of SC, ST to another social group like upper caste. So this matter should be examined in thought level. Consequently, the social problems are increasing day after day, which should be studied by the thinkers to be improved from this problematic situation. 

Influence of sex ratio and sexual lability on seed production in the dioecious perennial shrub Atriplex amnicola (Chenopodiaceae)

1997 ◽  
Vol 37 (6) ◽  
pp. 661 ◽  
Author(s):  
M. Strawbridge ◽  
R. W. Bell ◽  
J. A. McComb ◽  
E. G. Barrett-Lennard
Keyword(s):  
Sex Ratio ◽  
Seed Production ◽  
Seed Quality ◽  
Seed Set ◽  
Dioecious Species ◽  
Female Ratio ◽  
Male Female Ratio ◽  
Perennial Shrub ◽  
Set Up ◽  
Field Plots

Summary. Pollen supply can limit seed set in dioecious species such as Atriplex amnicola Paul G. Wilson (river saltbush). Clonal populations, with 4 different male : female ratios (0 : 1, 1 : 8, 1 : 1 and 5 : 1), were set up in widely spaced field plots at Tammin, Western Australia. After 1 season, plants were examined for fruit fill and fruit germination. The optimal male : female ratio for Atriplex amnicola seed production was between 1 : 8 (11% males) and 1 : 1 (50% males). These ratios resulted in mean fruit fills of 24 and 36%, respectively. Genotype had a significant effect on fruit fill. The 3 clones tested had fruit fills of 40, 36 and 31%. These differences in fruit fill were as significant as those obtained from reducing the percentage of males from 50 to 11%. A population of 700 seedlings of A. amnicola examined over 5 years was shown to be sexually labile, with a slight decrease over time in males and an increase in females and monoecious plants. Sexual lability appeared to be linked to plant aging rather than to environmental stimuli. It was concluded that plantations of river saltbush set up for seed production should be planted with selected genotypes at a male : female ratio of between 1 : 8 and 1 : 1 and that plantations need to be monitored for change in sex ratio with time, to ratios suboptimal for seed quality and production.

A contribution to the biology of the burrowing mud shrimp, Callianassa subterranea (Decapoda: Thalassinidea)

1994 ◽  
Vol 74 (3) ◽  
pp. 623-635 ◽  
Author(s):  
A.A. Rowden ◽  
M.B. Jones
Keyword(s):  
Sex Ratio ◽  
Carapace Length ◽  
Sampling Period ◽  
Bimodal Distribution ◽  
Allometric Growth ◽  
Female Ratio ◽  
The North ◽  
Male Female Ratio ◽  
Mud Shrimp ◽  
Callianassa Subterranea

Samples of the mud shrimp Callianassa subterranea (Montagu) were taken at irregular intervals (September and October 1989, April and July 1990, August 1991) from a depth of 47 m at a fixed station in the North Sea (54°35′N 04°50′E). At this site, mud shrimps appear to have a contagious distribution, the mean density varied between 38 and 59 individuals m-2 and the sex ratio was biased significantly to males (mean male: female ratio, 1·9), except for shrimps of ≥8 mm carapace length (CL) which had an equal sex ratio. The combined samples for the full sampling period showed a bimodal distribution for males and females, with a possible third mode for males, suggesting a life cycle of between 2 and 3 years. Only females ≥7 mm CL carried eggs. Lack of samples over winter prevent any conclusive description of seasonal population patterns; however, reproduction (based on the presence of ovigerous females) extended from April to September with a peak in July and post-larval shrimps (<3 mm CL) were present each month. The allometric growth of the primary chela identified male (6·5 mm CL) and female (7·5 mm CL) size at maturity. Differences in allometric growth after maturity result in males having larger and more massive primary chelae than females of equal carapace length. The parasitic isopod Ione thoracica (Montagu) infected between 20% (October) and 10–8% (August) of mud shrimps, with males having a significantly higher level of infestation than females.

On the Sex Ratio in Glossina

1952 ◽  
Vol 43 (2) ◽  
pp. 231-235 ◽  
Author(s):  
F. A. Squire
Keyword(s):  
Sex Ratio ◽  
Good Deal ◽  
Tsetse Fly ◽  
Reproductive Capacity ◽  
Female Ratio ◽  
The Past ◽  
Factors Influencing ◽  
Early Appearance ◽  
Age Factor ◽  
Male Female Ratio

The preponderance of males in tsetse-fly catches is an interesting fact that has not been understood in the past. Attention is drawn to the importance of the agefactor. Teneral flies are nearly always taken in equal numbers whereas non-teneral A.G.I flies and A.G.2 flies have the highest male/female ratio. In A.G.3, the ratio drops, indicating a decline in reproductive capacity. Females become fugitive about seven days after emergence, at the time when the first egg is almost due to descend into the uterus, i.e., at the end of the teneral stage. This is the mating phase par excellence. Mating is prolonged, vigorous, and frequent, and this accounts for the early appearance of the mating scars. As the uterus lies under and between the mating cushions, it is unsafe for females with eggs in the uterus or young larvae to mate. Third-instar larvae are safer as the highly chitinized polypneustic lobes take the brunt of the pummelling from the claspers. Safe periods also occur during the hiatus between larvipositions when the uterus is empty. There are, of course, other factors influencing the ratio, but the age factor is considered paramount, and failure to recognize this in the past has resulted in a good deal of confusion.

Suicide in Nógrád County, Hungary, 1970-1994

Crisis ◽  
1999 ◽  
Vol 20 (2) ◽  
pp. 64-70 ◽  
Author(s):  
Tamás Zonda
Keyword(s):  
High Risk ◽  
Psychiatric Disorders ◽  
Suicide Rate ◽  
Risk Groups ◽  
The Elderly ◽  
Female Ratio ◽  
Suicide Notes ◽  
Suicidal Intention ◽  
Male Female Ratio

The author examined completed suicides occurring over a period of 25 years in a county of Hungary with a traditionally low (relatively speaking) suicide rate of 25.8. The rates are clearly higher in villages than in the towns. The male/female ratio was close to 4:1, among elderly though only 1.5:1. The high risk groups are the elderly, divorced, and widowed. Violent methods are chosen in 66.4% of the cases. The rates are particularly high in the period April-July. Prior communication of suicidal intention was revealed in 16.3% of all cases. Previous attempts had been undertaken by 17%, which in turn means that 83% of suicides were first attempts. In our material 10% the victims left suicide notes. Psychiatric disorders were present in 60.1% of the cases, and severe, multiple somatic illnesses (including malignomas) were present in 8.8%. The majority of the data resemble those found in the literature.

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