scholarly journals Sexual dimorphism in size, age, maturation, and growth characteristics of boarfish (Capros aper) in the Northeast Atlantic

2012 ◽  
Vol 69 (10) ◽  
pp. 1729-1735 ◽  
Author(s):  
Karin Hüssy ◽  
Julie Olivia Coad ◽  
Edward D. Farrell ◽  
Lotte W. Clausen ◽  
Maurice W. Clarke
Keyword(s):  
Sexual Dimorphism ◽  
Size Distribution ◽  
Specific Growth ◽  
Growth Characteristics ◽  
Biological Information ◽  
Seasonal Effects ◽  
Stock Structure ◽  
Northeast Atlantic ◽  
Structure And Dynamics ◽  
Significant Difference

Abstract Hüssy, K., Coad, J. O., Farrell, E. D., Clausen, L. W., and Clarke, M. W. 2012. Sexual dimorphism in size, age, maturation, and growth characteristics of boarfish (Capros aper) in the Northeast Atlantic – ICES Journal of Marine Science, 69: 1729–1735. Boarfish (Capros aper) have, in recent years, become of increasing commercial importance due to their apparent increase in abundance in the Northeast Atlantic. This study presents detailed biological information relevant to understanding stock structure and dynamics. Boarfish are a long-lived species that reach a maximum age of >30 years. The size distribution is skewed towards larger sizes, as expected from an unexploited stock with sexual dimorphism, where females are, on average, larger than males. No seasonal effects occur in size distribution and sex ratio, indicating that females and males stay together in shoals throughout the year. Females become increasingly dominant in abundance at larger sizes and older ages. There is no significant difference in length at maturity nor age at maturity between the two sexes, with L50 = 9.7 cm and A50 = 3.4 years. Growth is dimorphic following von Bertalanffy growth characteristics, with a common t0 = –2.897, but significantly different K and Linf values, where females have K = 0.145 and Linf = 16.519 and males have K = 0.181 and Linf = 14.437. The sexual dimorphism in size is thus caused by sex-specific growth and longevity patterns.

scholarly journals The use of river hopper barges as facilities for aquaculture: The growth characteristics of carp (Cyprinus carpio) depending on stocking density

2010 ◽  
Vol 55 (2) ◽  
pp. 147-155
Author(s):  
Stefan Skoric ◽  
Branislav Mickovic ◽  
Slobodan Regner ◽  
Zeljka Visnjic-Jeftic ◽  
Aleksandar Hegedis
Keyword(s):  
Cyprinus Carpio ◽  
Growth Rates ◽  
Specific Growth ◽  
Stocking Density ◽  
Growth Characteristics ◽  
Significant Difference ◽  
Weight Distributions ◽  
Carp Cyprinus Carpio ◽  
Specific Growth Rates

Carps (Cyprinus carpio) were farmed on a river hopper barge at two stocking densities, 10 and 20 individuals per m3. A comparison of average weights, specific growth rates and weight distributions was performed. The obtained results show that there was no statistically significant difference in any of the parameters studied with regard to stocking density.

scholarly journals Size Distribution, Length-Weight Relationship, and Size at Morphometric Maturity of the Mud Spiny Lobster Panulirus polyphagus (Herbst, 1793) in the Johor Strait

2021 ◽  
Vol 8 ◽  
Author(s):  
Khor Waiho ◽  
Hanafiah Fazhan ◽  
Alexander Chong Shu-Chien ◽  
Muyassar H. Abualreesh ◽  
Hongyu Ma ◽  
...  
Keyword(s):  
Size Distribution ◽  
Fishery Management ◽  
Function Analysis ◽  
Piecewise Linear ◽  
Linear Regression Analysis ◽  
Spiny Lobster ◽  
Biological Information ◽  
Weight Relationship ◽  
Significant Difference ◽  
Johor Strait

Spiny lobsters of the genus Panulirus are economically important and support local fishing communities. However, mud spiny lobster Panulirus polyphagus is among the least known species within this genus in terms of their biological information. This study relates to the size distribution, length-weight relationship, and size at morphometric maturity of P. polyphagus in the Johor Strait. Within the year 2010, 300 specimens were collected off the coast of Johor Strait, Malaysia. There was no significant difference in body size (cephalothorax length, CL) and body weight (BW) between sexes. CL and BW were highly correlated and males of P. polyphagus displayed positive growth allometry, whereas the opposite was observed in females. Based on the merus (ML) and carpus length (CPL) of the third right walking leg, the piecewise linear regression analysis estimated that the size at maturity for male was 6.58 cm CL (based on ML) and 7.58 cm CL (based on CPL), whereas it was 8.18 cm CL (based on ML) and 6.75 cm (based on CPL) for females. Two discriminant functions of high classification and revalidation rates (> 98.6% in males and > 98.7% in females) that can discern maturation status in males and females of P. polyphagus were derived using the discriminant function analysis. Biological information derived from this study serves as an essential baseline for future fishery management and conservation of P. polyphagus.

Sexual dimorphism and biology of the large deepwater mastigoteuthid squid Idioteuthis cordiformis (Cephalopoda, Mastigoteuthidae) off Tasmania, Australia

2021 ◽  
pp. 1-7
Author(s):  
George D. Jackson ◽  
Christine H. Jackson
Keyword(s):  
Sexual Dimorphism ◽  
The Body ◽  
Total Weight ◽  
Mantle Length ◽  
Biological Information ◽  
Bright Orange ◽  
Significant Difference ◽  
Males And Females ◽  
Content Information ◽  
Total Fluid

Abstract This study provided biological information on 146 specimens of the poorly known deepwater mastigoteuthid squid Idioteuthis cordiformis. Mantle length ranged from 200–500 mm for males and 270–702 mm for females. The largest female weighed just under 12 kg. The majority of males were mature and all females were immature. The fins were larger and thicker than the mantle. Mantle weight of males and females was 44.8% and 55.2% of fin weight, respectively, and were significantly different. There was a significant sex effect on mantle length, total weight, mantle weight and fin weight, with females having greater values in all categories. There was a small season effect for mantle weight and fin weight. There was little ingested prey material except fluid and oil in the caecum that was typically bright orange or red. Total fluid volume ranged from 23–230 ml and 20–550 ml for males and females, respectively. The per cent oil component of total fluids in the caecum ranged from 6.9–50% and 10.8–50% for males and females, respectively, with no significant difference in per cent oil between males and females. There was a significant positive relationship between total weight and oil volume for females, and for males and females combined. The function of the oil is uncertain. While this study provided information on sex differences in the body size, sexual dimorphism and caecum oil content, information is still incomplete regarding reproduction due to the lack of any mature females captured in this study.

scholarly journals Assessment of Seasonal Variability in Soil Nutrients and Its Impact on Soil Quality under Different Land Use Systems of Lower Shiwalik Foothills of Himalaya, India

2021 ◽  
Vol 13 (3) ◽  
pp. 1398
Author(s):  
Tavjot Kaur ◽  
Simerpreet Kaur Sehgal ◽  
Satnam Singh ◽  
Sandeep Sharma ◽  
Salwinder Singh Dhaliwal ◽  
...  
Keyword(s):  
Land Use ◽  
Soil Quality ◽  
Surface Soil ◽  
Sandy Loam ◽  
Monsoon Season ◽  
Soil Layer ◽  
Seasonal Effects ◽  
Land Use Systems ◽  
Post Monsoon ◽  
Significant Difference

The present study was conducted to investigate the seasonal effects of five land use systems (LUSs), i.e., wheat–rice (Triticum aestivum—Oryza sativa) system, sugarcane (Saccharum officinarum), orange (Citrus sinensis) orchard, safeda (Eucalyptus globules) forest, and grassland, on soil quality and nutrient status in the lower Satluj basin of the Shiwalik foothills Himalaya, India. Samples were analyzed for assessment of physico-chemical properties at four soil depths, viz., 0–15, 15–30, 30–45, and 45–60 cm. A total of 120 soil samples were collected in both the seasons. Soil texture was found to be sandy loam and slightly alkaline in nature. The relative trend of soil organic carbon (SOC), macro- and micro-nutrient content for the five LUSs was forest > orchard > grassland > wheat–rice > sugarcane, in the pre- and post-monsoon seasons. SOC was highly correlated with macronutrients and micronutrients, whereas SOC was negatively correlated with soil pH (r = −0.818). The surface soil layer (0–15 cm) had a significantly higher content of SOC, and macro- and micro-nutrients compared to the sub-surface soil layers, due to the presence of more organic content in the soil surface layer. Tukey’s multiple comparison test was applied to assess significant difference (p < 0.05) among the five LUSs at four soil depths in both the seasons. Principle component analysis (PCA) identified that SOC and electrical conductivity (EC) were the most contributing soil indicators among the different land use systems, and that the post-monsoon season had better soil quality compared to the pre-monsoon season. These indicators helped in the assessment of soil health and fertility, and to monitor degraded agroecosystems for future soil conservation.

scholarly journals Time series analysis of the relationship between diarrhea in children and Rota 2 vaccine in the Fanteakwa District of the eastern region of Ghana

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
James Atampiiga Avoka ◽  
Elvis J. Dun-Dery ◽  
Issah Seidu ◽  
Armel N. E. Abou ◽  
Paul Twene ◽  
...  
Keyword(s):  
Pearson Correlation ◽  
Developed Countries ◽  
Seasonal Effects ◽  
Eastern Region ◽  
Least Developed Countries ◽  
R Software ◽  
Significant Difference ◽  
Severe Gastroenteritis ◽  
Access To Medical Care ◽  
The Relationship

Abstract Background Rotavirus is considered the main causal factor of severe gastroenteritis among infants and children globally. The association with severe rotavirus infection is mostly worse among the least developed countries, mainly due to inadequate access to medical care and poverty. This study was conducted to determine the seasonal effects in respect of diarrhea cases in children, the association between diarrhea cases and Rota2 vaccine in the Fanteakwa District of the Eastern Region of Ghana. Methods The study compares monthly diarrhea cases against children vaccinated with Rota2 extracted from DHIMS2 spanning May 2012 to December 2017 in Fanteakwa District. A univariate association between diarrhea cases and children vaccinated with Rota 2 was conducted using the R-software version 3.4.4 with the use of forecast, tseries and TSAPred. Pearson Correlation coefficient was also computed between monthly diarrhea cases and Rota 2 as well as lagged values of Rota 2 and Diarrhea cases. Results The study shows that February recorded the highest average number of diarrhea cases (172) over the period 2012 to 2017 with a standard deviation of 59. However, a one-way analysis of variance shows a significant difference amongst the monthly averages with an F-statistic of 0.042 and P-value of 0.064. It is observed that the correlations between each of the Rota2 doses and the lagged cases are positive, showing higher Rota2 doses a month ago ((Xt − 1),0.346 to0.735), two months ago ((Xt − 2),0.383 to 0.746), three months ago ((Xt − 3), 0.330 to 0.737) and four months ago ((Xt − 4), 0.236 to 0.723) are associated with lower diarrhea cases. The results also show that an increase in the previous two month’s Rota2 figures by 100 is associated with a significant decrease in the currently expected diarrhea cases by approximately 36. Conclusion Seasonal variations exist in the occurrence of diarrhea in children, with January recording the highest number of diarrhea cases (172). There is a relationship between episodes of diarrhea in children and Rota2 (p-value = 0.064); thus, the more children are vaccinated with Rota2, the less diarrhea cases are recorded. Diarrhea cases in Fanteakwa district are generally low, except 2013 and 2016 where the cases are higher than the rest of the other years.

scholarly journals Gender Determination by Linear Dimension of Permanent Canine: An Odontometric Analysis

2014 ◽  
Vol 2 (1) ◽  
pp. 23-27
Author(s):  
B Sharma ◽  
N Balaji ◽  
MK Sumathi
Keyword(s):  
Sexual Dimorphism ◽  
Sex Determination ◽  
Linear Dimension ◽  
Medical Sciences ◽  
Medical College ◽  
Type Iv ◽  
Racial Background ◽  
Significant Difference ◽  
Natural Change ◽  
The Individual

Background and objectives: Identification, an aspect of forensic anthropology, is the recognition of an individual based on the physical characteristics unique to the individual. Among the four main attributes i.e. gender, age, stature and ethnic or racial background of an individual’s biological identity, sex determination is usually the first step in the human identification process. Teeth can be used as a means of sex determination as teeth are resistant to post-mortem degradation and survive deliberate, accidental or natural change. This study was carried out with an objective to determine the sexual dimorphism of maxillary and mandibular canine by linear tooth diameter for permanent dentition in Moradabad population. Material and Methods: A total number of 40 subjects (20 Males and 20 Females) were included in this study. After obtaining an informed written consent, alginate impression was taken with help of perforated impression trays and study models were prepared with type IV dental stone. Linear (MD, BL, Crown Height) were taken with digital vernier caliper. Results: It was observed that males’ shows more mean linear crown diameter as compared to females. Also, the mesiodistal and buccolingual measurement shows statistically significant difference for all canines, being higher for males than females. Conclusion: The present study has expressed sexual dimorphism of permanent canine using Student’s test and indicate that linear dimension of maxillary canine can be used for sexual diamorphism with accuracy along with other accepted procedure for sex determination. DOI: http://dx.doi.org/10.3126/jmcjms.v2i1.11392   Janaki Medical College Journal of Medical Sciences (2014) Vol. 2 (1): 23-27

Small mammal mycophagy in hemiboreal forest communities of Lithuania

2011 ◽  
Vol 6 (3) ◽  
pp. 446-456 ◽  
Author(s):  
Marija Kataržytė ◽  
Ernestas Kutorga
Keyword(s):  
Small Mammals ◽  
Small Mammal ◽  
Fungal Spores ◽  
Seasonal Effects ◽  
Deciduous Tree ◽  
Myodes Glareolus ◽  
Mammal Species ◽  
Hypogeous Fungi ◽  
Fecal Samples ◽  
Significant Difference

AbstractThe diets of small mammals in different hemiboreal spruce-dominated, oak-dominated and mixed forests in western part of Lithuania were studied by examination of fungal spores in fresh fecal pellets of caught animals. In the diets of mice (Apodemus spp.), bank voles (Myodes glareolus), and common and pygmy shrews (Sorex araneus and S. minutus), 22 different fungal taxa were identified, 15 of which were hypogeous fungi. The sporocarp abundance and the spores in fecal samples of Elaphomyces fungi prevailed in study area during this investigation. Although most of the captured individuals consumed fungi, the consumption varied among small mammal species. The data show that the fungi were more frequent and taxonomically diverse in Myodes glareolus than in Apodemus spp. diets. The study provided evidence that the fungal component in the diets of insectivorous Sorex species is more diverse than previously known. The availability of sporocarps and the fungal component in the diets of small mammals showed seasonal effects. Annual hypogeous and epigeous sporocarp abundances did not vary significantly across forest types. The significant difference in mycophagy was observed across all forest cover types, with the greatest fungal diversity in fecal samples collected in mixed coniferous-deciduous tree stands.

scholarly journals The genetic structure of Pandalus borealis in the Northeast Atlantic determined by RAPD analysis

2006 ◽  
Vol 63 (5) ◽  
pp. 840-850 ◽  
Author(s):  
Iciar Martinez ◽  
Michaela Aschan ◽  
Taran Skjerdal ◽  
Salah M. Aljanabi
Keyword(s):  
Genetic Structure ◽  
Barents Sea ◽  
Rapd Analysis ◽  
Rapd Marker ◽  
Arbitrary Primers ◽  
Pandalus Borealis ◽  
Northeast Atlantic ◽  
The Barents Sea ◽  
Local Selection ◽  
Significant Difference

Abstract The genetic structure of shrimp (Pandalus borealis) in the Northeast Atlantic was examined by RAPD analysis on specimens caught at eight stations in the Barents Sea, three off Svalbard, two off Jan Mayen, and in two northern Norwegian fjords (19 < n > 31 per station). A total of 34 polymorphic markers generated by seven 10-mer arbitrary primers was used to assess the genetic population structure using analysis of molecular variance (AMOVA). There was considerable RAPD diversity (>90%) among shrimp at all stations. The two Norwegian fjords and the Jan Mayen stations were different from all the others, and the Jan Mayen stations also differed from each other. More than 98% of the genetic variation between Barents Sea and Svalbard was ascribed to individual diversity, and there was no significant difference between the two areas, although there seemed to be a subpopulation structure in the Barents Sea. Principal component analysis on the frequency of each RAPD marker on each sampled station confirmed the presence of three populations: Barents Sea and Svalbard, northern Norwegian fjords, and Jan Mayen. We postulate that the large genetic variability found at an individual level may provide the total population with a diverse genetic pool from which traits can be selected to respond to variations in local environmental conditions, and that this local selection may be the cause of the subpopulation structure observed.

Physiochemical properties and reproducibility of air-based sodium tetradecyl sulphate foam using the Tessari method

2016 ◽  
Vol 32 (6) ◽  
pp. 390-396 ◽  
Author(s):  
Mike R Watkins ◽  
Richard J Oliver
Keyword(s):  
Size Distribution ◽  
Bubble Size ◽  
Bubble Size Distribution ◽  
Foam Density ◽  
Physiochemical Properties ◽  
Significant Difference ◽  
Experienced Operator ◽  
Sodium Tetradecyl Sulphate ◽  
Foam Production ◽  
Made In

Objectives The objectives were to examine the density, bubble size distribution and durability of sodium tetradecyl sulphate foam and the consistency of production of foam by a number of different operators using the Tessari method. Methods 1% and 3% sodium tetradecyl sulphate sclerosant foam was produced by an experienced operator and a group of inexperienced operators using either a 1:3 or 1:4 liquid:air ratio and the Tessari method. The foam density, bubble size distribution and foam durability were measured on freshly prepared foam from each operator. Results The foam density measurements were similar for each of the 1:3 preparations and for each of the 1:4 preparations but not affected by the sclerosant concentration. The bubble size for all preparations were very small immediately after preparation but progressively coalesced to become a micro-foam (<250 µm) after the first 30 s up until 2 min. Both the 1% and 3% solution foams developed liquid more rapidly when made in a 1:3 ratio (37 s) than in a 1:4 ratio (45 s) but all combinations took similar times to reach 0.4 ml liquid formation. For all the experiments, there was no statistical significant difference between operators. Conclusions The Tessari method of foam production for sodium tetradecyl sulphate sclerosant is consistent and reproducible even when made by inexperienced operators. The best quality foam with micro bubbles should be used within the first minute after production.

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