scholarly journals Notes on the Reproductive Traits of Holothuria fuscogilva Cherbonnier, 1980 from Laguindingan, Misamis Oriental, Philippines

2021 ◽  
Vol 6 ◽  
Author(s):  
Venus Leopardas ◽  
◽  
Mariefe Quiñones ◽  
Lovella Calala ◽  
Sandra Manulat ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Significant Variation ◽  
Sea Cucumber ◽  
Gonad Index ◽  
Reproductive Traits ◽  
Gonad Maturation ◽  
Gonad Maturity ◽  
Breeding Technology ◽  
Output Information ◽  
Male To Female

Reproductive traits of white teatfish Holothuria fuscogilva from Laguindingan, Misamis Oriental were investigated from February to July 2020. Gonad samples from 62 adult individuals weighing 1,240g to 5,800g were collected and examined macroscopically and microscopically to determine gonad morphology, sex ratio, gonad maturity, and gonad index. Gonads were composed of numerous branched tubules of varying lengths and frequency of bifurcations arising from the gonad basis. There was no significant variation in the ratio of male to female white teatfish (x2=2.32, α=0.05) and were mostly mature in May (weighing 1,750g–4,000g in males and 2,600g-3,900g in females) with relatively high gonad output. Information on gonad maturation is useful in the development of a successful breeding technology for this economically important sea cucumber species.

scholarly journals Population structure and reproductive cycle of the commercial sea cucumber Holothuria mexicana in Belize

2018 ◽  
Vol 66 (4) ◽  
Author(s):  
Arlenie Rogers ◽  
Jean-François Hamel ◽  
Annie Mercier
Keyword(s):  
Sex Ratio ◽  
Protected Areas ◽  
Reproductive Cycle ◽  
Sexual Maturity ◽  
Sea Cucumber ◽  
Size Structure ◽  
Natural Populations ◽  
Gonad Index ◽  
Size At Sexual Maturity ◽  
Spawning Periods

The population and reproductive biology of the commercial sea cucumber Holothuria mexicana (Ludwig, 1875) was studied in Southern Belize (Caribbean Sea), including the sex ratio, size at sexual maturity and reproductive cycle, as well as the size structure among habitats located inside and outside protected areas. Individuals found inside marine protected areas were consistently larger than individuals found outside these boundaries. The male:female sex ratio was 1.1:1.0 with a unimodal size distribution composed mainly of sexually mature individuals (87 %). Size at sexual maturity was established to be ~10 cm based on measures of gamogenetically mature individuals during the peak of the gametogenic maturity period. Juveniles and small adults measuring ≤ 15 cm (13 %), were collected exclusively in sandy and muddy areas of seagrass habitats associated with mangroves. Larger adults were commonly found on hard substrates in both seagrass-associated and coral-reef-associated habitats. Based on histology and gonad indices, the first sign of early gametogenesis was detected in August in both sexes. Gametes developed and matured throughout the colder months between November and February. Decreases in gonad index in both years suggest annual spawning, starting in March-April 2014 (single major event) and March-April and July-August 2015 (two smaller events) for both males and females. The spawning periods were correlated with warmer or increasing temperatures, low rainfall and increasing or high chlorophyll-a concentrations. These data will hopefully guide management and protection of the natural populations of H. mexicana, which are already suffering from overfishing in Belize and neighboring countries. 

scholarly journals ASPEK BIOLOGI DAN DINAMIKA POPULASI IKAN LAYANG BIRU (Decapterus macarellus Cuvier, 1833) DI PERAIRAN LAUT SULAWESI

2019 ◽  
Vol 11 (3) ◽  
pp. 137
Author(s):  
Achmad Zamroni ◽  
Adi Kuswoyo ◽  
Umi Chodrijah
Keyword(s):  
Sex Ratio ◽  
Growth Parameters ◽  
Economic Value ◽  
Gonad Index ◽  
Fork Length ◽  
Spawning Season ◽  
Fish Length ◽  
Population Parameters ◽  
Gonad Maturity ◽  
Fish Samples

Ikan layang biru (Decapterus macarellus) merupakan salah satu jenis ikan pelagis kecil yang dominan tertangkap dan mempunyai nilai ekonomi yang tinggi, terutama untuk daerah dengan perairan yang lebih oseanik seperti di perairan Indonesia bagian timur. Tujuan penelitian ini adalah untuk mengidentifikasi parameter populasi ikan layang biru khususnya tertangkap di Laut Sulawesi. Pengambilan sampel ikan untuk diukur panjang cagak dan diamati kematangan gonad dilakukan secara acak setiap bulan. Informasi parameter populasi yang diperoleh dalam penelitian ini adalah hubungan panjang-berat, nisbah kelamin, tingkat kematangan gonad, nilai L50% dan Lm, parameter pertumbuhan serta tingkat pemanfaatan. Hasil penelitian menunjukkan bahwa sebaran ukuran panjang cagak ikan (fork length = FL) berkisar antara 10,25 - 32,25 cm, pola pertumbuhannya bersifat allometrik negatif. Nisbah kelamin ikan layang biru antara jantan : betina tidak berimbang yaitu 1 : 1,963. Ikan layang biru yang tertangkap didominasi oleh ikan dalam kondisi kematangan gonad tingkat III, artinya gonad masih dalam kondisi berkembang. Berdasarkan analisis tingkat kematangan gonad dan nilai indeks gonad dapat diketahui bahwa puncak musim pemijahan ikan terjadi pada bulan Maret. Perbandingan nilai L50% dan Lm diperoleh (L50% > Lm), artinya secara umum ikan telah mengalami matang gonad sebelum ikan tersebut ditangkap. Nilai eksplotasi lebih tinggi dari nilai eksploitasi optimal 0,5 per-tahun. Diduga puncak rekruitmen yang terjadi pada bulan Juni berasal dari musim pemijahan yang terjadi pada bulan Maret.Mackerel scad (Decapterus macarellus) is one of the dominant small pelagic fish species with high economic value, especially for areas with more oceanic waters such as eastern Indonesia. The purpose of this study was to identify the population parameters of the Mackerel scad especially those caught in the Celebes Sea. Fish samples were randomly taken to measure for length measurements and gonad maturity observation every month. Information on population parameters obtained in this study is the length-weight relationship, sex ratio, gonad maturity level, L50% and Lm values, growth parameters, and exploitation rates. The results showed that the distribution of fish length range from 10.25 - 32.25 cm of fork length, with the growth pattern was negative allometric. The sex ratio between males: females was not balanced (1: 1,963). The Mackerel scad caught was dominated by fish in the condition of level III maturity, meaning that each gonad was in a developing condition. Based on the analysis of gonad maturity and gonad index, it can be estimated that the peak of the spawning season occurs in March. A comparison of the values of L50% and Lm obtained was L50% > Lm, meaning that in general, the fish has reached gonad ripening before they were caught. The exploitation rate was higher than the optimal exploitation value of 0.5 per year. It is likely that the peak of recruitment occurred in June came from the spawning season occurred in March.

scholarly journals Some biological characteristics of the Far Eastern sea cucumber (Apostichopus japonicus) from the Severnaya Bay of the Slavyanka Gulf (Japan Sea)

2021 ◽  
pp. 63-68
Author(s):  
I. V. Matrosova ◽  
A. A. Politayeva
Keyword(s):  
Sex Ratio ◽  
Body Length ◽  
Sea Cucumber ◽  
Apostichopus Japonicus ◽  
Gonad Index ◽  
Japan Sea ◽  
Biological Characteristics ◽  
Biological Traits ◽  
Far Eastern

Some of biological traits of the Far Eastern sea cucumber from the Severnaya Bay were examined in 2016 and 2017. Body length of sea cucumber individuals varied from 3.6 to 23.4 cm. Dermo-muscular bag weight was higher in 2017 (137.5 g). Individual ages were 1–4 years in 2016 and 1–5 years in 2017. Sex ratio was near 1:1 in 2016 and 2017. During the period of the research gonad index was maximal in June – 10.6%. Spawning began in the 2nd decade of June and finished in the 2nd decade of July.

scholarly journals Sex-specific deaths in Norway and Sweden during the COVID-19 pandemic: Did mandates make a difference?

2021 ◽  
pp. 140349482110100
Author(s):  
Ralph Catalano
Keyword(s):  
Sex Ratio ◽  
Infection Control ◽  
Temporal Variation ◽  
Risky Behavior ◽  
Control Strategies ◽  
Sex Ratios ◽  
Female Mortality ◽  
All Cause Mortality ◽  
Societal Expectations ◽  
Male To Female

Aims: To determine whether differences between Norway’s and Sweden’s attempts to contain SARS-CoV-2 infection coincided with detectably different changes in their all-cause mortality sex ratios. Measuring temporal variation in the all-cause mortality sex ratio before and during the pandemic in populations exposed to different constraints on risky behavior would allow us to better anticipate changes in the ratio and to better understand its association with infection control strategies. Methods: I apply time Box–Jenkins modeling to 262 months of pre-pandemic mortality sex ratios to arrive at counterfactual values of 10 intra-pandemic ratios. I compare counterfactual to observed values to determine if intra-pandemic ratios differed detectably from those expected as well as whether the Norwegian and Swedish differences varied from each other. Results: The male to female mortality sex ratio in both Norway and Sweden increased during the pandemic. I, however, find no evidence that the increase differed between the two countries despite their different COVID-19 containment strategies. Conclusion: Societal expectations of who will die during the COVID-19 pandemic will likely be wrong if they assume pre-pandemic mortality sex ratios because the intra-pandemic ratios appear, at least in Norway and Sweden, detectably higher. The contribution of differences in policies to reduce risky behavior to those higher ratios appears, however, small.

scholarly journals Effect of thermal stimulation on gonad maturation in sea cucumber Phyllophorus sp. (Grube, 1840)

2018 ◽  
Vol 23 ◽  
pp. 39-46
Author(s):  
S Andriyono ◽  
N Masruroh ◽  
ED Masithah ◽  
J Triastuti ◽  
D Winarni
Keyword(s):  
Sea Cucumber ◽  
Histological Analysis ◽  
Temperature Treatment ◽  
Thermal Stimulation ◽  
Gonad Maturation ◽  
Marine Animals ◽  
Sea Cucumbers ◽  
Fishery Products ◽  
C 32 ◽  
The Ideal

Sea cucumbers, marine animals from the class Holothuroidea, have been widely known as fishery products for consumption in Indonesia. The Madura Strait is productive waters for sea cucumbers in eastern Indonesia, including sea cucumber species Phyllophorus sp. The exploitation of it mainly for consumption even though there are pharmaceutical beneficial of sea cucumber already known. The study of temperature effect is ideal inducement method for sea cucumber, but less research about this stimulation for Phyllophorus sp. for domestication purposes. The research showed that thermal stimulation treatment at the temperature of 30°C, 32°C and 34°C were in contrast to the that of control histological analysis proof that some of Phyllophorus sp. showed altered levels of gonadal maturation toward growth and advanced growth phase after thermal stimulation, respectively. The ideal stimulation treatment for gonad maturation was shown with stimulated temperature treatment of 32°C.J. bio-sci. 23: 39-46, 2015

scholarly journals Preliminary Study On Gonad Maturity Stages of the Sea Cucumber Paracaudina australis from Kenjeran Water, Surabaya, Indonesia

2018 ◽  
Vol 116 ◽  
pp. 012035
Author(s):  
Widianingsih Widianingsih ◽  
Muhammad Zaenuri ◽  
Sutrisno Anggoro ◽  
Hermin Pancasakti Kusumaningrum ◽  
Retno Hartati
Keyword(s):  
Sea Cucumber ◽  
Gonad Maturity ◽  
Maturity Stages ◽  
Preliminary Study

scholarly journals The Effect of China’s Two-Child Policy on the Child Sex Ratio: Evidence From Shanghai, China

2022 ◽  
Vol 59 ◽  
pp. 004695802110679
Author(s):  
Di Tang ◽  
Xiangdong Gao ◽  
Jiaoli Cai ◽  
Peter. C. Coyte
Keyword(s):  
Sex Ratio ◽  
Sex Ratio At Birth ◽  
Difference In Differences ◽  
Female Sex ◽  
One Child Policy ◽  
Child Policy ◽  
Pregnancy Status ◽  
The One ◽  
Male To Female ◽  
Municipal Level

Objective: The bias towards males at birth has resulted in a major imbalance in the Chinese sex ratio that is often attributed to China’s one-child policy. Relaxation of the one-child policy has the potential to reduce the imbalance in the sex ratio away from males. In this study, we assessed whether the bias towards males in the child sex ratio was reduced as a result of the two-child policy in China. Medical records data from one large municipal-level obstetrics hospital in Shanghai, East China. Design: Matching and difference-in-differences (MDID) techniques were used to investigate the effect of the two-child policy on the imbalance in the sex ratio at birth after matching for pregnancy status and socioeconomic factors. Results: Analyzing 133,358 live births suggest that the relaxation of the one-child policy had a small, but statistically significant effect in reducing the imbalance in the male to female sex ratio at birth. Conclusion: The results demonstrate that relaxation of the one-child policy reduced the imbalance in the male to female sex ratio at birth from 1.10 to 1.05 over the study period at one of the major obstetrics and gynecology hospitals in China.

scholarly journals Ascitic Fluid Cytology Seen in a Tertiary Hospital in Nigeria

2020 ◽  
pp. 345-350
Author(s):  
CC Nwafor ◽  
K Obioha ◽  
TO Akhiwu
Keyword(s):  
Sex Ratio ◽  
Patient Care ◽  
Ascitic Fluid ◽  
Age Groups ◽  
Tertiary Hospital ◽  
Age Group ◽  
Malignant Cells ◽  
Female Ratio ◽  
Male To Female ◽  
Fluid Cytology

Ascites is a symptom that can originate due to diverse pathologies. A lot of investigations including ascitic fluid cytology (AFC) can be done on it to help determine its origin. The aim of this study, is to document the findings and highlight the importance of AFC in patient care in Uyo. All AFC reports and slides in the Department of Histopathology, University of Uyo were retrieved, reviewed and used for this study. The age ranged from 1.5 – 80 years with mean age, 41.79 (±17.23) years. About 71.8% of the ascitic fluid (AF) specimens were from patients between the 3rd and 6th decade. Females predominated in all age groups expect 10-19 year's group, with a male to female sex ratio of 1:2.4. Malignant cells were seen in 28.7% of all the samples, while 51.2% were negative for malignant cells. Malignant cells were seen in 4 (6.7%), 11 (18.3%) and 6 (10%) of the AFC performed due to various liver pathologies, ovarian malignancies and intra-abdominal malignancies respectively. Malignant cells were found more in females with a male to female ratio of 1: 3.6. Age group 40-49 years accounted for most of the malignant cases (26.6%). The pattern of AFC in Uyo is similar to the pattern in other parts of Nigeria

Medullary thyroid carcinoma

2011 ◽  
pp. 625-630
Author(s):  
Friedhelm Raue ◽  
Karin Frank-Raue
Keyword(s):  
Sex Ratio ◽  
Thyroid Carcinoma ◽  
Medullary Thyroid Carcinoma ◽  
Hereditary Disease ◽  
C Cells ◽  
Biochemical Screening ◽  
Medullary Thyroid ◽  
Histological Features ◽  
Sporadic Disease ◽  
Male To Female

Medullary thyroid carcinoma (MTC) is a rare calcitonin-secreting tumour of the parafollicular or C cells of the thyroid. As the C cells originate from the embryonic neural crest, MTC often have the clinical and histological features of neuroendocrine tumours. They account for 8–12% of all thyroid carcinomas and occur in both sporadic and hereditary forms (1). The majority of patients have sporadic MTC (70%), while 30% have hereditary MTC. The sex ratio in sporadic MTC is 1:1.3 (male to female), while both sexes are nearly equally affected in the familial variety (2). The highest incidence of sporadic disease occurs in the fifth decade of life, while hereditary disease can be diagnosed earlier, depending on the possibility of genetic and biochemical screening.

Variations in eastern oyster (Crassostrea virginica) sex-ratios from three Virginia estuaries: protandry, growth and demographics

2012 ◽  
Vol 93 (2) ◽  
pp. 519-531 ◽  
Author(s):  
Juliana M. Harding ◽  
Eric N. Powell ◽  
Roger Mann ◽  
Melissa J. Southworth
Keyword(s):  
Sex Ratio ◽  
Shell Length ◽  
Sex Ratios ◽  
Eastern Oyster ◽  
Reproductive Capacity ◽  
Older Individuals ◽  
Population Demographics ◽  
Disease Mortality ◽  
Predominantly Female ◽  
Male To Female

Oyster population reproductive capacity and dynamics are controlled at the most basic level by the observed sex-ratios. Since oysters are sequential, protandric hermaphrodites the population sex-ratio is related to the demographics (shell length, age, and biomass). Oysters were collected from June through to August 2008 at twelve bars in the James, Rappahannock and Great Wicomico Rivers, Virginia, USA. Bars were aggregated into five groups on the basis of similar age–length relationships. Sex-ratios (fraction female), age–length, and biomass–length relationships were determined for each group. The fraction female increased within increasing shell length, age, and biomass at all sites. Simultaneous hermaphrodites were rarely observed. Group specific differences in shell length (SL, mm) and age (yr) for the timing of the protandric shift were observed with the earliest shift from male to female occurring at ~60 mm SL and ~1.6 yr. The proportion of females observed in the larger or older individuals was at least 70–80%. Sex-ratios from summer 2008 were used to develop sex–length, sex–age, and sex–biomass keys that were applied to autumn-survey data from 2006, 2007, 2008 and 2009. In these years, sex-ratios by shell length and age were strongly biased towards males while the sex-ratio by biomass was strongly biased towards females. Disease mortality compounds natural and fishing mortality resulting in age/size specific cropping yielding truncated population demographics and an earlier protandric shift in populations on the extremes of the range examined. Regardless of location, market (>76 mm SL) oysters are predominantly female.

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