Nestling sex ratio is associated with both male and female attractiveness in rock sparrows

2018 ◽  
Vol 49 (8) ◽  
pp. e01666
Author(s):  
Alejandro Cantarero ◽  
A. Pilastro ◽  
M. Griggio
Keyword(s):  
Sex Ratio ◽  
Male And Female ◽  
Female Attractiveness

The DEVELOPMENT OF Elaeidobius kamerunicus FAUST POPULATION AFTER INTRODUCTION AND THE IMPROVEMENT OF OIL PALM FRUIT SET IN SERAM ISLAND, MOLLUCAS, INDONESIA

2016 ◽  
Vol 24 (1) ◽  
pp. 47-55
Author(s):  
Agus Eko Prasetyo ◽  
Agus Susanto
Keyword(s):  
Sex Ratio ◽  
Oil Palm ◽  
Fruit Set ◽  
Average Risk ◽  
Palm Fruit ◽  
Male And Female ◽  
Risk Of Death ◽  
North Sumatra ◽  
Female Flowers ◽  
Elaeidobius Kamerunicus

Elaeidobius kamerunicus is the main pollinating agent in oil palm plantations in Indonesia today. The development of oil palm plantations in new areas requires introduction of these insects, moreover the new areas are located on different islands. First introduction of Elaeidobius kamerunicus Faust had been done from North Sumatra to Seram Island on 23 September 2013. The introduction was performed on larva and pupa stadium in 4-5 days post anthesising of male inflorescences. The introduction of E. kamerunicus using plywood boxes has an average risk of death by 7.89% at 6 days delivery period. Observation before releasing of the weevils showed that this insect was not detected in both of oil palm male and female flowers and the oil palm fruit set was very low approximately 11.27%. For about 500 weevils/ha were released in Marnuhu estate and could be developed into 362,401 weevils/ha in 5 months with 97.86% of oil palm sex ratio. The oil palm fruit sets were increased after 1 and 2 months introduction, 53.70% and 75.56 %, respectively. The lower sex ratio of oil palm or the more availability of male inflorescences make growth of E. kamerunicus population became faster and the greater number of weevils that visiting anthesising of female flowers make the higher value of oil palm fruit set.

The DEVELOPMENT OF Elaeidobius kamerunicus FAUST POPULATION AFTER INTRODUCTION AND THE IMPROVEMENT OF OIL PALM FRUIT SET IN SERAM ISLAND, MOLLUCAS, INDONESIA

2018 ◽  
Vol 24 (1) ◽  
pp. 47-55
Author(s):  
Agus Eko Prasetyo ◽  
Agus Susanto
Keyword(s):  
Sex Ratio ◽  
Oil Palm ◽  
Fruit Set ◽  
Average Risk ◽  
Palm Fruit ◽  
Male And Female ◽  
Risk Of Death ◽  
North Sumatra ◽  
Female Flowers ◽  
Elaeidobius Kamerunicus

Elaeidobius kamerunicus is the main pollinating agent in oil palm plantations in Indonesia today. The development of oil palm plantations in new areas requires introduction of these insects, moreover the new areas are located on different islands. First introduction of Elaeidobius kamerunicus Faust had been done from North Sumatra to Seram Island on 23 September 2013. The introduction was performed on larva and pupa stadium in 4-5 days post anthesising of male inflorescences. The introduction of E. kamerunicus using plywood boxes has an average risk of death by 7.89% at 6 days delivery period. Observation before releasing of the weevils showed that this insect was not detected in both of oil palm male and female flowers and the oil palm fruit set was very low approximately 11.27%. For about 500 weevils/ha were released in Marnuhu estate and could be developed into 362,401 weevils/ha in 5 months with 97.86% of oil palm sex ratio. The oil palm fruit sets were increased after 1 and 2 months introduction, 53.70% and 75.56 %, respectively. The lower sex ratio of oil palm or the more availability of male inflorescences make growth of E. kamerunicus population became faster and the greater number of weevils that visiting anthesising of female flowers make the higher value of oil palm fruit set.

Sperm Competition and the Dynamics of X Chromosome Drive: Stability and Extinction

Genetics ◽  
2002 ◽  
Vol 160 (4) ◽  
pp. 1721-1731 ◽  
Author(s):  
Jesse E Taylor ◽  
John Jaenike
Keyword(s):  
Sex Ratio ◽  
Sperm Competition ◽  
X Chromosome ◽  
Sex Chromosome ◽  
Basin Of Attraction ◽  
Male Mating ◽  
Male And Female ◽  
Mating Rate ◽  
Female Mating ◽  
Balanced Polymorphism

AbstractSeveral empirical studies of sperm competition in populations polymorphic for a driving X chromosome have revealed that Sex-ratio males (those carrying a driving X) are at a disadvantage relative to Standard males. Because the frequency of the driving X chromosome determines the population-level sex ratio and thus alters male and female mating rates, the evolutionary consequences of sperm competition for sex chromosome meiotic drive are subtle. As the SR allele increases in frequency, the ratio of females to males also increases, causing an increase in the male mating rate and a decrease in the female mating rate. While the former change may exacerbate the disadvantage of Sex-ratio males during sperm competition, the latter change decreases the incidence of sperm competition within the population. We analyze a model of the effects of sperm competition on a driving X chromosome and show that these opposing trends in male and female mating rates can result in two coexisting locally stable equilibria, one corresponding to a balanced polymorphism of the SR and ST alleles and the second to fixation of the ST allele. Stochastic fluctuations of either the population sex ratio or the SR frequency can then drive the population away from the balanced polymorphism and into the basin of attraction for the second equilibrium, resulting in fixation of the SR allele and extinction of the population.

scholarly journals KOMPOSISI UKURAN, PERBANDINGAN JENIS KELAMIN, DAN TINGKAT KEMATANGAN GONAD IKAN TODAK BERPARUH PENDEK (Tetrapturus angustirostris) DI SAMUDERAHINDIA

2017 ◽  
Vol 3 (2) ◽  
pp. 123
Author(s):  
Dian Novianto ◽  
Budi Nugraha ◽  
Andi Bahtiar
Keyword(s):  
Indian Ocean ◽  
Sex Ratio ◽  
Size Composition ◽  
Maturity Stage ◽  
Chi Square ◽  
Male And Female ◽  
Level Ii ◽  
Chi Square Test ◽  
The Indian Ocean ◽  
Tuna Longline

Ikan todak berparuh pendek atau ikan tumbuk atau shortbill spearfish (Tetrapturus angustirostris) merupakan salah satu hasil tangkapan sampingan rawai tuna. Informasi mengenai ikan todak berparuh pendek seperti komposisi ukuran, perbandingan kelamin, dan tingkat kematangan gonadsangat terbatas. Tulisan ini bertujuan untuk menyajikan data dan informasi mengenai aspek biologi ikan todak berparuh pendek yang merupakan hasil tangkapan sampingan dari rawai tuna yang beroperasi di Samudera Hindia. Penelitian ini dilakukan pada bulan September sampai Desember 2008 di perairan Samudera Hindia. Hasil penelitian menunjukan bahwa ikan todak berparuh pendek memiliki kisaran panjang tubuh 135-175 cmLJFL dan modus pada kisaran 155-165 cmLJFL.Perbandingan jenis kelamin ikan jantan dan betina 1:13,5, berdasarkan atas hasil uji chi-square menunjukan bahwa rasio ikan jantan dan betina pada periode penelitian ini tidak seimbang. Pada bulan September ikan todak berparuh pendek betina didominansi oleh tingkat kematangan gonad IIsebesar 66,7%, bulan Oktober oleh tingkat kematangan gonad V sebesar 46,2%, bulan Nopember oleh tingkat kematangan gonad II sebesar 53,3%, sedangkan pada bulan Desember oleh tingkat kematangan gonad III sebesar 42,9%. Pada bulan Nopember sampai Desember terlihat bahwa tingkat kematangan gonad V mulai berkurang, hal ini menunjukan bahwa pada bulan Nopember sampai Desember diduga banyak ikan todak berparuh pendek betina yang sudah memijah. Shortbill Spearfish (Tetrapturus angustirostris) is one of bycatch of tuna longline. Information about shortbill spearfish on the size composition, sex ratio, and maturity stage is still very limited. The objective this paper is to present the data and information about shortbill spearfish which is a bycatch of tuna longline that operated in the Indian Ocean. Research was conducted during September until December 2008 in Indian Ocean. The results showed that the shortbill spearfish have body length about 135-175 cmLJFL and modes in 155-165 cmLJFL. Sex ratio of the male and female was 1:13.5. Based on chi-square test showed that the ratio of male and female in the period of the study was not balanced. In September, the female stage maturity was dominated by level II of 66.7%, October by level V of 46.2%, November by level II of 53.3%, and December by level III of 42.9%. During November until December showed that the maturity stage of level V was decreased, this shows that in this time the female of shortbill spearfish was spawned.

scholarly journals Hubungan panjang bobot dan faktor kondisi ikan wader bintik dua Barbodes binotatus (Valenciennes, 1842) di Sungai Barambai Samarinda Kalimantan

2019 ◽  
Vol 18 (2) ◽  
pp. 87 ◽  
Author(s):  
. Jusmaldi ◽  
Nova Hariani
Keyword(s):  
Sex Ratio ◽  
Condition Factor ◽  
Mean Value ◽  
Male And Female ◽  
Weight Relationship ◽  
Total Length ◽  
East Kalimantan ◽  
Fish Samples

Biology of the spotted barb Barbodes binotatus (Valenciennes, 1842) in Barambai River, east Kalimantan is unknown. This study aimed to analyses sizes of fish, sex ratio, length-weight relationship and condition factor of the spotted barb. A total of 347 fish samples were collected by several gears in Barambai River from August to October 2017. The results of this research showed that the total length of the fish ranged from 45.67 to 146.01 mm and weight ranged from 1.27-43.34 g. The sex ratio of male and female were 1:1.12. The length-weight equations for males was W = 1x10-5 L3.063, W = 8x10-6L3.108 for females, and W = 9 x 10-6 L3.091 for both sexes. The condition factor (K) for the spotted barb was ranged between 0.826 – 2.214 with mean value of 1.163.  AbstrakBiologi ikan wader bintik dua Barbodes binotatus (Valenciennes, 1842) di Sungai Barambai, Kalimantan Timur belum diketahui. Penelitian ini bertujuan menganalisis ukuran ikan, nisbah kelamin, hubungan panjang bobot, dan faktor kon-disi. Total 347 sampel ikan dikumpulkan dengan menggunakan berbagai alat tangkap di Sungai Barambai dari bulan Agustus sampai Oktober 2017. Hasil penelitian menunjukkan bahwa panjang total ikan berkisar dari 45,67 sampai 146,01 mm dan bobot tubuh berkisar 1,27- 43,34 gram. Nisbah kelamin jantan dan betina 1: 1,12. Model hubungan panjang bobot ikan jantan W = 1x10-5 L3,063, ikan betina W = 8x10-6L3,108,dan keseluruhan jenis ikan W =  9 x 10-6  L3,091. Faktor kondisi (K) ikanwader bintik dua berkisar antara 0,826 - 2,214 dan rata-rata 1,163. 

scholarly journals Length-Weight Relationship and Sex Ratio of Amblypharyngodon Mola in Dekar Haor of Sunamganj, Bangladesh

2018 ◽  
Vol 44 (2) ◽  
pp. 185-193
Author(s):  
PR Das ◽  
MS Uddin ◽  
MS Islam ◽  
M Biswas ◽  
MR Mia
Keyword(s):  
Sex Ratio ◽  
Freshwater Fish ◽  
Condition Factor ◽  
Correlation Coefficients ◽  
Male And Female ◽  
Positive Correlation ◽  
Average Ratio ◽  
Weight Relationship ◽  
R Value ◽  
Relationship Of

The study was carried out to determine length-weight relationship and sex ratio of a freshwater fish Amblypharyngodon mola (Hamilton 1822) collected from Dekar haor of Sunamganj district during the period of January to August 2017. A total of 2000 fishes were collected for the study and categorized these fishes into three groups namely males, females and combined sexes. Among 2000 mola 777 were male and 1223 were female. Length-weight equations and the correlation coefficients obtained for males, females and combined ones were: males Y = –1.97 + 3.00X, r = 0.883; females Y = –2.30 + 3.41X, r = 0.914 and combined Y = –2.11 + 3.16X, r = 0.904. Female’s A. mola attained more weight with the increases in length. Value of correlation coefficient ‘r’ was 0.883 for male and exhibited highly positive correlation between length and weight. On the contrary, ‘r’ value for female was 0.914 and it had also strongly positive correlation between length and weight relationships. Length-weight relationship of A. mola for male, female and combined sexes showed allometric pattern of growth. Condition factor ‘K’ for male, female and combined sexes was 1.09, 1.05 and 1.06, respectively and indicated better condition of fishes. The highest sex ratio (1 : 2.05) was found in May and the lowest (1 : 1.33) was in February. Dominance of females over males throughout the year was observed with an average ratio of male and female 1 : 1.57. Therefore, results of the study indicate that the existing hydrobiological conditions of the haor are conducive for food availability, free movement, feeding and better growth of the fish. Asiat. Soc. Bangladesh, Sci. 44(2): 185-193, December 2018

scholarly journals Assamese Monkeys in Nagarjun Forest of Shivapuri Nagarjun National Park, Nepal

2013 ◽  
Vol 28 (1-2) ◽  
pp. 181-190 ◽  
Author(s):  
Mukesh K Chalise ◽  
Hideshi Ogawa ◽  
Bishnu Pandey
Keyword(s):  
Sex Ratio ◽  
National Park ◽  
Temperate Forest ◽  
Sampling Methods ◽  
Population Distribution ◽  
Age Groups ◽  
Male And Female ◽  
Ring Road ◽  
Troop Size ◽  
Macaca Assamensis

The population distribution of Assamese monkey Macaca  assamensis were studied in Nagarjun forest of Shivapuri Nagarjun National Park, Nepal and data collected during Dec. 2013 and January 2014, by scan sampling methods along with transect walk through forest trails and ring-road of forest. Sevenbi sexual troops were observed in subtropical/lower temperate forest of Nagarjun forest especially around Raniban forest area. The observed smallest troop was with 9 individuals while the largest troop had 37 (41) individuals of different age. The average troop size is 20.57. Out of three broad age groups adults were 56.31% and immature 43.06% while infant alone were 18.06%. The sex ratio between male and female was 1:1.34. Plant usage for feeding and resting were also enumerated. Nagarjun forest troops use mostly tall trees for the night halts and resting in day time.

SIZE DIFFERENCES, SEX RATIO, AND SPATIAL DISTRIBUTION OF MALE AND FEMALE WATER TUPELO, NYSSA AQUATIC A (NYSSACEAE)

1993 ◽  
Vol 80 (1) ◽  
pp. 26-30 ◽  
Author(s):  
Margaret M. Shea ◽  
Philip M. Dixon ◽  
Rebecca R. Sharitz
Keyword(s):  
Spatial Distribution ◽  
Sex Ratio ◽  
Male And Female ◽  
Water Tupelo
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