scholarly journals Length-Weight Relationship, Condition Factor, and Age Estimation of Commercially Important Trawl Species from Mersing Coastal Waters, Johor, Malaysia

2021 ◽  
Vol 50 (1) ◽  
pp. 1-7
Author(s):  
Simon Kumar Das ◽  
Wee Xiang Tou ◽  
Noorashikin Md Noor ◽  
Moumita De ◽  
Abdullah Samat

Trawl fishing contributes to majority of the total fishes’ landings, supporting the choice of using age, growth determination, and condition factors (K) as part of the monitoring method for the fishes in Malaysia waters. This research specifically examines the use of age, length-weight relationship (LWR), and K to monitor the status of the commercially important fishes in Malaysia waters. LWR, K, and age of 10 commercially important trawl species (Gerres erythrourus, Drepane punctata, Otolithes ruber, Anodontostoma chacunda, Drepane longimana, Dendrophysa russelii, Sillago parvisquamis, Cynoglossus bilineatus, Sardinella brachysoma,and Alepes kleinii) from Mersing coastal waters, Johor, Malaysia, were studied. LWR (W=aLb) indicated positive allometric growth (b > 3) for G. erythrourus and D. punctata but negative allometric growth (b < 3) for the other species. Results indicated that the species collected were in good conditions (average K, Kn > 1) in Mersing coastal waters, Johor, Malaysia. The daily growth rings of scale counts confirmed that the ages of the 10 species were typically less than 1 year (age range: 50-170 days; mean age: 95 days). The data obtained from this study will be useful for understanding the population growth pattern, age, and well-being of commercially important trawl species, which will facilitate better management techniques of these important fishery resources.

2019 ◽  
Vol 27 (1) ◽  
pp. 27-31
Author(s):  
Caroline Ireti Ayo-Olalusi ◽  
Adedolapo Abeke Ayoade

Abstract The length-weight relationship and condition factor of Sphyraena afra from the Lagos coast (LC) and the Lagos lagoon complex (LLC) in the coastal waters of Lagos State were studied for a period of two years. Parameters a and b of the length-weight relationship were estimated using the equation W = a x TLb, while the condition factor was calculated with the equation K = 100 x BW x TL-3. The relationships of fish condition factor and body length, sex, and seasons in Lagos coastal waters were determined. The species exhibited negative allometric growth (b < 3, P < 0.05) for males, females, and combined sexes with the length exponent (b) ranging from 2.72 to 2.85. Correlation coefficient r ranged from 0.89 to 0.98. The allometric growth values obtained in LC and LLC from the length-weight relationship indicated that the fish species exhibited increases in length rather than in weight. The overall mean condition factors (K) for S. afra from the LC and the LLC were 0.97 ± 0.11 and 1.17 ± 0.12, respectively. The mean condition factors of females were higher than those for males at most of the sampling stations, and S. afra was observed to be in better condition during the dry season.


Author(s):  
Sangeeta Mandal ◽  
Kuldeep K. Lal ◽  
Rajeev K. Singh ◽  
Rama Shanker Sah ◽  
J. K. Jena ◽  
...  

The hilsa shad <em>Tenualosa ilisha</em> (Hamilton, 1822), is a commercially important and highly relished food fish. This paper presents the length-weight relationships (LWR) and condition factor of hilsa, throughout its geographical distribution in India. A total of 910 samples of <em>T. ilisha</em>, comprising 404 males and 288 females collected from various locations of east and west coasts of India were used for analyses. Heterogeneity in the LWR of males, females and pooled population was noticed. The regression coefficient (b) ranged from 2.07-3.68 for pooled, 0.75-3.03 for males and 1.78-2.97 for females. The coefficient of determination (R2) varied between 0.72-0.98 in pooled, 0.73-0.94 in males and 0.76-0.97 in females. Fulton’s condition factor (K) ranged from 0.47-3.05 in pooled, 0.47-1.63 in male and from 0.77-3.05 in female samples whereas relative condition factor (Kn) varied from 0.48-2.51 in pooled population, from 0.47-1.56 in males and 0.76-2.33 in females. Mean Fulton’s condition factor (K) ranged from 0.7-1.33 in pooled population, 0.92-1.28 in males and from 0.95-1.39 in females whereas the mean relative condition factor (Kn) varied between 0.98-1.04 in pooled population, 0.98-1.04 in males and 0.98-1.03 in females. These parameters (b, K, Kn) have been found useful in evaluating the well-being of different populations of this species. Most of the populations under study showed concordance to ideal value of b, thereby indicating isometric growth. However, significant negative allometric growth was observed for pooled samples from Padma, Hoogly and males from Padma and significant positive allometric growth was observed in the pooled samples collected from Hoogly. Comparative study of recent data with the decadal old data (1999-2000) revealed differences in mean size of the fish. This study also indicates overexploitation of the species in the recent years, which might be due to intensive fishing efforts.


2018 ◽  
Vol 10 (7) ◽  
pp. 11863
Author(s):  
Kamlesh Kumar Yadav ◽  
Rani Dhanze

Assessment of length-weight relationship (LWR), length-length relationship (LLR) and condition factor was carried out for Bangana dero in northeastern India, mainly from the Brahmaputra and Irrawaddy (Manipur) River system.  We report a value of ‘b’ 3.1269 and 3.1426 for LWR with respect to total length and standard length respectively, indicating positive allometric growth. The value of ‘b’ for LLR is less than one, which indicates that growth in total length is less with per unit increase in standard length.  The value of ‘K’ and ‘Kn’ is 0.91 and 0.72 depicts normal well being of fish in its habitat. 


2015 ◽  
Vol 20 (3) ◽  
pp. 321 ◽  
Author(s):  
Carolina Vargas-Caro ◽  
Carlos Bustamante ◽  
Julio Lamilla ◽  
Michael B Bennett

Longnose skates may have a high intrinsic vulnerability among fishes due to their large body size, slow growth rates and relatively low fecundity, and their exploitation as fisheries target species places their populations under considerable pressure. They are found circumglobally in subtropical and temperate coastal waters. Although longnose skates have been recorded for over 150 years in South America, the ability to assess the status of these species is still compromised by critical knowledge gaps. Based on a review of 185 publications, a comparative synthesis of the biology and ecology was conducted on two of the most commercially important elasmobranchs in South American waters, the yellownose skate <em>Zearaja chilensis</em> and the roughskin skate <em>Dipturus trachyderma</em>; in order to examine and compare their taxonomy, distribution, fisheries, feeding habitats, reproduction, growth and longevity. There has been a marked increase in the number of published studies for both species since 2000, and especially after 2005, although some research topics remain poorly understood. Considering the external morphological similarities of longnose skates, especially when juvenile, and the potential niche overlap in both depth and latitude occupied, it is recommended that reproductive seasonality, population structure and connectivity be assessed to ensure their long-term sustainability.


2020 ◽  
Vol 9 ◽  
pp. 35
Author(s):  
Mistura Temitope Adeleke ◽  
Oladunni Nimota Adekunle ◽  
Olusegun Adebayo Lawal ◽  
Fayokunfe Mayowa Adeyemi

The knowledge of length-weight relationship parameters has numerous practical applications in fishery research and management. Currently, there is a dearth of information on the growth pattern and state of well-being of Parachanna africana in Ijede and Agbowa Lagoons. This study period was between December 2017, and June 2018 investigated the allometry and condition factor of P. africana inhabiting the Ijede and Agbowa Lagoons, South-western Nigeria. Two hundred fish samples of P. africana was gotten from fishermen at both locations. The length and weight measurements were taken to the nearest centimetres and grams. Descriptive, correlation and regression tools, was used to 2analyse the data collected. Results obtained showed that the length-weight relationship had r values of  0.186, 0.196, 0.191 and 0.341, 0.001, 0.098 for Ijede and Agbowa respectively, at a significant level of  P<0.05 for male, female and combined sexes. The b values of 0.193 for Ijede and 0.165 for Agbowa were not significantly different (P> 0.05). The mean condition factors of 0.365 ±0.141 and 0.329±0.169 were obtained in Ijede and Agbowa, respectively. It was observed that the species in both lagoons exhibited negative allometric growth patterns with values 0.365 and 0.330 for Ijede and Agbowa lagoons respectively with no variations in the condition factors of both locations which indicate the need to assess human and domestic activities surrounding these water bodies.


GeroPsych ◽  
2019 ◽  
Vol 32 (1) ◽  
pp. 41-52
Author(s):  
Matthew C. Costello ◽  
Shane J. Sizemore ◽  
Kimberly E. O’Brien ◽  
Lydia K. Manning

Abstract. This study explores the relative value of both subjectively reported cognitive speed and gait speed in association with objectively derived cognitive speed. It also explores how these factors are affected by psychological and physical well-being. A group of 90 cognitively healthy older adults ( M = 73.38, SD = 8.06 years, range = 60–89 years) were tested in a three-task cognitive battery to determine objective cognitive speed as well as measures of gait speed, well-being, and subjective cognitive speed. Analyses indicated that gait speed was associated with objective cognitive speed to a greater degree than was subjective report, the latter being more closely related to well-being than to objective cognitive speed. These results were largely invariant across the 30-year age range of our older adult sample.


Author(s):  
Dr. S. Radhakrishnan . ◽  
Mrs. Sunita Yadav ◽  
Dr. Bhagwan Singh

Waste is generated by various day to day human activities. Adopting improper waste handling and disposal methods can harm the well-being of public and environment. Waste management creates new opportunities for entrepreneurs in terms of social causes and it affects the economic structure and economic status of any country. One of the new approaches in waste management and income generation is Social entrepreneurship. But in Bharat i.e. India the young entrepreneurs have a dearth of consciousness towards social entrepreneurship. This paper discusses the status of solid waste management in India and Government initiatives for managing Solid Waste at Dharamshala. The main objectives of study are 1) to check awareness of people in managing solid waste at Dharamsala 2) and how to convert the plastic waste into theme based parks as skilled initiative for entrepreneurs at tourist spots in Himachal Pradesh. The paper thus explores the scope for entrepreneurs in waste management. The study reveals that Solid waste management concept attracted the attention of government around 1970s. But till now we believe in filling the waste in the ground or putting them in the dustbin. Government of India has created few acts and rules on waste management which are listed in this paper. Through this study it is revealed that people of Dharamshala welcome to the construction of themed parks made from plastic bottles. Majority of these people believe in separating waste at home and according to them conditions of waste disposal at Dharamshala are not very good. There is a positive correlation between people’s opinion of constructing theme parks and using plastic bottles in park’s construction. Study believes that the quantity of plastic waste in our country is endless which creates lot scope and opportunity to the social entrepreneurs.


Author(s):  
Xueli Wei ◽  
Lijing Li ◽  
Fan Zhang

Pumping elephantThe COVID-19 pandemic has adversely affected the lives of people around the world in millions of ways . Due to this severe epidemic, all countries in the world have been affected by all aspects, mainly economic. It is widely discussed that the COVID-19 outbreak has affected the world economy. When considering this dimension, this study aims to examine the impact of the COVID-19 pandemic on the world economy, socio-economics, and sustainability. In addition, the research focuses on multiple aspects of social well-being during the pandemic, such as employment, poverty, the status of women, food security, and global trade. To this end, the study used time series and cross-sectional analysis of the data. The second-hand data used in this study comes from the websites of major international organizations. From the analysis of secondary data, the conclusion of this article is that the impact of the pandemic is huge. The main finding of the thesis is that the social economy is affected by the pandemic, causing huge losses in terms of economic well-being and social capital.


Author(s):  
Ascensión Fumero ◽  
Rosario J. Marrero ◽  
Alicia Pérez-Albéniz ◽  
Eduardo Fonseca-Pedrero

Bipolar disorder is usually accompanied by a high suicide risk. The main aim was to identify the risk and protective factors involved in suicide risk in adolescents with bipolar experiences. Of a total of 1506 adolescents, 467 (31%) were included in the group reporting bipolar experiences or symptoms, 214 males (45.8%) and 253 (54.2%) females. The mean age was 16.22 (SD = 1.36), with the age range between 14 and 19. Suicide risk, behavioral and emotional difficulties, prosocial capacities, well-being, and bipolar experiences were assessed through self-report. Mediation analyses, taking gender as a moderator and controlling age as a covariate, were applied to estimate suicide risk. The results indicated that the effect of bipolar experiences on suicide risk is mediated by behavioral and emotional difficulties rather than by prosocial behavior and subjective well-being. Specifically, emotional problems, problems with peers, behavior problems, and difficulties associated with hyperactivity were the most important variables. This relationship was not modulated by gender. However, the indirect effects of some mediators varied according to gender. These results support the development of suicide risk prevention strategies focused on reducing emotional difficulties, behavioral problems, and difficulties in relationships with others.


2021 ◽  
Vol 193 (7) ◽  
Author(s):  
Heini Hyvärinen ◽  
Annaliina Skyttä ◽  
Susanna Jernberg ◽  
Kristian Meissner ◽  
Harri Kuosa ◽  
...  

AbstractGlobal deterioration of marine ecosystems, together with increasing pressure to use them, has created a demand for new, more efficient and cost-efficient monitoring tools that enable assessing changes in the status of marine ecosystems. However, demonstrating the cost-efficiency of a monitoring method is not straightforward as there are no generally applicable guidelines. Our study provides a systematic literature mapping of methods and criteria that have been proposed or used since the year 2000 to evaluate the cost-efficiency of marine monitoring methods. We aimed to investigate these methods but discovered that examples of actual cost-efficiency assessments in literature were rare, contradicting the prevalent use of the term “cost-efficiency.” We identified five different ways to compare the cost-efficiency of a marine monitoring method: (1) the cost–benefit ratio, (2) comparative studies based on an experiment, (3) comparative studies based on a literature review, (4) comparisons with other methods based on literature, and (5) subjective comparisons with other methods based on experience or intuition. Because of the observed high frequency of insufficient cost–benefit assessments, we strongly advise that more attention is paid to the coverage of both cost and efficiency parameters when evaluating the actual cost-efficiency of novel methods. Our results emphasize the need to improve the reliability and comparability of cost-efficiency assessments. We provide guidelines for future initiatives to develop a cost-efficiency assessment framework and suggestions for more unified cost-efficiency criteria.


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