Age, growth and spatial and interannual trends in age composition of jackass morwong, Nemadactylus macropterus, in Tasmania

2001 ◽  
Vol 52 (4) ◽  
pp. 641 ◽  
Author(s):  
Alan R. Jordan
Keyword(s):  
Growth Parameters ◽  
Life History Strategy ◽  
Growth Curves ◽  
Von Bertalanffy ◽  
Age Classes ◽  
Age Composition ◽  
Significant Difference ◽  
Males And Females ◽  
Recruitment Variability ◽  
The Relationship

Transverse sections of sagittae were examined. The first and second annual increments were defined by examination of the progression of otolith radius and length of the 0+ and 1+ cohorts. Growth in both sexes is rapid until ~5 years old (32–35 cm), and then slows appreciably. There was a broad range of lengths within individual age-classes, with a maximum of 12 age-classes present in a 1 cm length-class. Maximum ages of males and females were 41 and 30 years, respectively, which is considerably higher than previously estimated from whole otoliths. There was no significant difference in the growth curves between males and females, although this is influenced by the large number of juveniles and by the examination of relatively few large, older fish. The sex-specific von Bertalanffy growth parameters are: L∞ 38.4 cm FL, t0 –0.07 years, K 0.36 year–1 for females and L∞ 36.2 cm FL, t0 0.15 years, K 0.42 year–1 for males. The age composition was dominated by 4–7 year olds but showed evidence of considerable recruitment variability, particularly in the strong 1988 year-class. The relationship between the life-history strategy of N. macropterus and recruitment variability is discussed.

scholarly journals Growth of the Silverside Atherinella brasiliensis in Tramandaí Estuary, Southern Brazil (Actinopterygii: Atherinopsidae)

2007 ◽  
Vol 5 (4) ◽  
pp. 485-490 ◽  
Author(s):  
Giovana Bervian ◽  
Nelson F. Fontoura
Keyword(s):  
Growth Parameters ◽  
Growth Curves ◽  
Von Bertalanffy ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Beach Seine ◽  
Frequency Distributions ◽  
First Reproduction ◽  
Males And Females ◽  
One Year

The growth of Atherinella brasiliensis (Quoy & Gaimard, 1824) was studied through monthly samples taken at Tramandaí Lagoon, Imbé County, Rio Grande do Sul, Brazil. Animals were captured using a beach seine net. Length-weight relationships and age- growth curves for males and females were adjusted. The growth parameters of the von Bertalanffy growth formulae are Linf=16.0 and k=0.883 for males and Linf=17.0 and k=0.825 for females. First reproduction occurred one year after recruitment. Once reaching maturity, adults of A. brasiliensis reproduced once more in the next spring with two-year-olds and disappeared soon after from size frequency distributions. A few captured animals showed a size compatible with an age of three years.

scholarly journals Spatial variation in growth of the green tiger prawn (Penaeus semisulcatus) along the coastal waters of Kuwait, eastern Saudi Arabia, Bahrain, and Qatar

2003 ◽  
Vol 60 (4) ◽  
pp. 806-817 ◽  
Author(s):  
Y. Ye ◽  
J.M. Bishop ◽  
N. Fetta ◽  
E. Abdulqader ◽  
J. Al-Mohammadi ◽  
...  
Keyword(s):  
Saudi Arabia ◽  
Coastal Waters ◽  
Growth Parameters ◽  
Arabian Gulf ◽  
Growth Curves ◽  
Growth Equation ◽  
Cooperative Approach ◽  
Penaeus Semisulcatus ◽  
Significant Difference ◽  
Males And Females

Abstract Shrimp (Penaeus semisulcatus) length-frequency data collected from the coastal waters of Kuwait, Saudi Arabia, Bahrain, and Qatar during a 23-month study from 1999 to 2001 were analyzed to estimate parameters of von Bertalanffy growth equation. All growth curves show a strong seasonal oscillation and a difference in size between males and females. The estimates of l∞ exhibit a southward decreasing trend with increasing temperature and salinity. A single variable of annual mean temperature explains 94 and 81% of the variations in l∞ for males and females, respectively. Likelihood ratio tests compared growth parameters among survey areas. A significant difference in growth was found between Kuwait and Kufji, and between Manifa and Dareen. Based on these results, we conclude that three separate populations of P. semisulcatus are present in the western Arabian Gulf: one in Kuwait, one in Kufji and Manifa, Saudi Arabia, and a third occupying Dareen, Saudi Arabia, Bahrain, and Qatar waters. Countries sharing unit stocks should implement a cooperative approach to the management of each.

scholarly journals Evaluating the Effects Related to Restocking and Stock Replenishment of Penaeus penicillatus in the Xiamen Bay, China

2021 ◽  
Vol 9 (10) ◽  
pp. 1122
Author(s):  
Jia-Qiao Wang ◽  
Yi-Jia Shih ◽  
Liang-Ming Huang ◽  
Jun Li ◽  
Wei-Wen Li ◽  
...  
Keyword(s):  
Assessment Tool ◽  
Growth Parameters ◽  
Stock Assessment ◽  
Evaluation Model ◽  
Brood Stock ◽  
Xiamen Bay ◽  
Significant Difference ◽  
Males And Females ◽  
The Relationship ◽  
Juvenile Shrimp

The quantitative evaluation of restocking and stock replenishment is essential for providing operational feedback and implementing adaptive management for future restoration projects. Since 2010, approximately 700 million juvenile shrimp (Penaeus penicillatus) have been released into Xiamen Bay, Fujian Province, China, each year, through stock replenishment programs. The recruited shrimp were sampled through three-year bottom trawl surveys from 2014 to 2017. The biological characteristics and catch equation were used to evaluate the effect of restocking and stock replenishment. The analysis uses the FAO-ICLARM Stock Assessment Tool (FISAT II) program. In general, there are two sources of recruitments—one from spawning brood stock and the other from released juvenile shrimp. We constructed an evaluation model for an effect evaluation based on Baranov’s catch equation to separate the initial recruitment volume using survey data. The relationship between body weight and total length was W =1.638 TL2.9307. There is no statistically significant difference between males and females. The von Bertalanffy growth parameters derived for prawns, using FiSAT II, were L∞ = 209.6 mm and K = 0.51 per year. In spring 2014, the initial resource amount was 49,200, while the ratio of effective recruitment and parent amount was 3.92. The survival rate of the released shrimp larvae, 1.88‱, seems to be very unsatisfactory. The resource amount in summer and autumn is higher than in winter and spring. Obviously, the restocking effect is lower and the programs need to be improved. To improve the restocking effect, the replenishment performance should be adjusted to reduce the mortality rate and increase its release effectiveness. Therefore, corresponding implementations are recommended, including standard extensive culture, reduction in stress during transportation, and temporary culture.

Age, growth and maturity of a New Zealand endemic shark (Mustelus lenticulatus) estimated from vertebral bands

2000 ◽  
Vol 51 (1) ◽  
pp. 35 ◽  
Author(s):  
Malcolm P. Francis ◽  
Caoimhghin Ó Maolagáin
Keyword(s):  
Growth Rates ◽  
East Coast ◽  
Growth Curves ◽  
Von Bertalanffy ◽  
Frequency Data ◽  
Length Frequency ◽  
Significant Difference ◽  
Growth Bands ◽  
Males And Females ◽  
Length Frequency Data

Rig (Mustelus lenticulatus) specimens were aged by counting growth bands in whole vertebrae that were illuminated laterally with fibre-optic lights. Bands were counted by two readers who used information on the diameter of the vertebrae of new-born young and 1-year-old juveniles to identify the inner bands. The greatest estimated age was 12.1 years for a female of 137 cm total length, but few rig were more than 8 years old. For west coast South Island (WCSI) rig, there was no significant difference in growth rates of males and females. After pooling both sexes, there was no significant difference in growth rates between WCSI and east coast South Island (ECSI) rig. The combined WCSI and ECSI von Bertalanffy growth curve was Lt = 147.2 (1 – e −0.119[t + 2.35]). This curve agreed well with growth curves derived from length–frequency data, but validation of the ageing technique is still required. WCSI males mature at ~85 cm and 5–6 years, and females at ~100 cm and 7–8 years. ECSI rig probably mature at similar lengths and ages. Tagged rig have been recaptured after nearly 14 years at liberty. Longevity probably exceeds 15 years, and may exceed 20 years.

scholarly journals Age and growth of franciscana dolphins, Pontoporia blainvillei (Cetacea: Pontoporiidae) incidentally caught off southern Brazil and northern Argentina

2010 ◽  
Vol 90 (8) ◽  
pp. 1493-1500 ◽  
Author(s):  
Silvina Botta ◽  
Eduardo R. Secchi ◽  
Mônica M.C. Muelbert ◽  
Daniel Danilewicz ◽  
Maria Fernanda Negri ◽  
...  
Keyword(s):  
Growth Models ◽  
Growth Curves ◽  
Small Sample ◽  
Age And Growth ◽  
Buenos Aires Province ◽  
Von Bertalanffy ◽  
Southern Brazil ◽  
Data Set ◽  
Males And Females ◽  
Pontoporia Blainvillei

Age and length data of 291 franciscana dolphins (Pontoporia blainvillei) incidentally captured on the coast of Rio Grande do Sul State (RS), southern Brazil, were used to fit growth curves using Gompertz and Von Bertalanffy growth models. A small sample of franciscanas (N = 35) from Buenos Aires Province (BA), Argentina, were used to see if there are apparent growth differences between the populations. Male and female franciscana samples from both areas were primarily (78–85%) <4 years of age. The Von Bertalanffy growth model with a data set that excluded animals <1 year of age provided the best fit to data. Based on this model, dolphins from the RS population reached asymptotic length at 136.0 cm and 158.4 cm, for males and females, respectively. No remarkable differences were observed in the growth trajectories of males and females between the RS and BA populations.

Age, growth estimates for pink ling, Genypterus blacodes (Schneider), and gemfish, Rexea solandri (Cuvier), from Eastern Bass Strait, Australia

1989 ◽  
Vol 40 (2) ◽  
pp. 215 ◽  
Author(s):  
AF Withell ◽  
JWJ Wankowski
Keyword(s):  
Growth Parameters ◽  
Age And Growth ◽  
Frequency Method ◽  
Slow Growth Rate ◽  
Growth Functions ◽  
Significant Difference ◽  
Marginal Increment ◽  
Males And Females ◽  
Cent Error ◽  
Age Determinations

Age and growth were estimated from counts of otolith annuli for pink ling (Genypterus blacodes) and gemfish (Rexea solandri). Sections of otoliths were preferable for age determinations of pink ling, whereas whole otoliths were preferable for gemfish. Validation of the assigned age classes was not achieved. Petersen's length-frequency method was unsuccessful and marginal increment methods were unsuitable for the species studied. Growth of males and females did not differ significantly for either pink ling or gemfish. Both species had a relatively slow growth rate, had a moderately long life-span and could reach body lengths in excess of 1 m. Maximum ages of pink ling and gemfish were, respectively, 21 and 13 years. Mean length-at-age and the von Bertalanffy growth functions were estimated. For pink ling (all individuals combined), K = 0.095 and L∞ = 135.5 cm. For gemfish the best estimates were K = 0.153 and L∞ = 112.3 cm. Precision of age determinations made independently by two readers for pink ling and gemfish, respectively, was 65% and 95% within �1 annulus; average per cent error, respectively, was 4.7% and 3.1%. Paired t-tests on ages assigned to each species by the two readers indicated no significant difference between ages assigned to gemfish, but there was a significant, albeit unbiased, difference for ages assigned to pink ling. However, for pink ling, estimates of the growth parameters derived separately from age determinations by the two readers were virtually identical.

scholarly journals Student Perceived and Determined Knowledge of Biology Concepts in an Upper-Level Biology Course

2014 ◽  
Vol 13 (2) ◽  
pp. 322-330 ◽  
Author(s):  
Brittany Ziegler ◽  
Lisa Montplaisir
Keyword(s):  
Learning Process ◽  
Student Perception ◽  
Metacognitive Skills ◽  
Lower Quartile ◽  
Significant Difference ◽  
Males And Females ◽  
Upper Level ◽  
The Relationship

Students who lack metacognitive skills can struggle with the learning process. To be effective learners, students should recognize what they know and what they do not know. This study examines the relationship between students’ perception of their knowledge and determined knowledge in an upper-level biology course utilizing a pre/posttest approach. Significant differences in students’ perception of their knowledge and their determined knowledge exist at the beginning (pretest) and end (posttest) of the course. Alignment between student perception and determined knowledge was significantly more accurate on the posttest compared with the pretest. Students whose determined knowledge was in the upper quartile had significantly better alignment between their perception and determined knowledge on the pre- and posttest than students in the lower quartile. No difference exists between how students perceived their knowledge between upper- and lower-quartile students. There was a significant difference in alignment of perception and determined knowledge between males and females on the posttest, with females being more accurate in their perception of knowledge. This study provides evidence of discrepancies that exist between what students perceive they know and what they actually know.

Examination of data normalization procedures for expressing peak VO2 data

1993 ◽  
Vol 75 (5) ◽  
pp. 2288-2292 ◽  
Author(s):  
M. J. Toth ◽  
M. I. Goran ◽  
P. A. Ades ◽  
D. B. Howard ◽  
E. T. Poehlman
Keyword(s):  
Regression Modeling ◽  
Fat Free Mass ◽  
Ratio Method ◽  
Data Normalization ◽  
O2 Uptake ◽  
Peak Vo2 ◽  
Significant Difference ◽  
Males And Females ◽  
The Relationship ◽  
Spurious Results

Peak O2 uptake (VO2) has traditionally been compared among individuals differing in body composition by dividing measured values (1/min) by fat-free mass (FFM) (i.e., ratio method). However, the ability of the ratio method to mathematically remove the confounding influence of FFM from peak VO2 has recently been questioned. Therefore, we compared the effectiveness of the ratio method vs. regression modeling to normalize peak VO2 in a large cohort of males and females for differences in FFM. Regression modeling adjusts peak VO2 according to the relationship derived from the regression of peak VO2 on FFM. Results showed that peak VO2 was 60% higher in males (3.53 +/- 1.01/min) than in females (2.22 +/- 0.6 l/min; P < 0.01). With the ratio method (i.e., peak VO2/FFM), peak VO2 was 15% higher in males (54.6 +/- 12 ml.kg FFM-1.min-1) than in females (47.4 +/- 11 ml.kg FFM-1.min-1; P < 0.01). In contrast, when a regression-based approach was employed to normalize values, no significant difference in adjusted peak VO2 was observed between males and females (3.04 +/- 0.9 vs. 3.01 +/- 1.0 l/min). In conclusion, dividing peak VO2 by FFM can produce spurious results, because this approach does not take into account the nonzero intercept. Therefore, a regression-based approach should be used to normalize peak VO2.

scholarly journals Age, growth and mortality of the European Seabass, (Dicentrarchus Labrax) in Bardawil lagoon, North Sinai, Egypt

2021 ◽  
pp. 042-046
Author(s):  
El-Desoki Menna O ◽  
Younis Younis M ◽  
A Youssef El-Dakar ◽  
Ahmed Salem M ◽  
Ahmed Kassem S ◽  
...  
Keyword(s):  
Growth Parameters ◽  
Age Groups ◽  
Dicentrarchus Labrax ◽  
Mortality Rates ◽  
Von Bertalanffy ◽  
Fishing Mortality ◽  
European Seabass ◽  
Exploitation Rate ◽  
The Relationship ◽  
North Sinai

Age, growth, and mortality of European Seabass (Dicentrarchus labrax) were studied from a small-scaled fishery of Bardawil lagoon, (North Sinai, Egypt). 181 specimens (16.6 to 35 cm total Length and 39.8 to 367.2 g total weight). The relationship between length and weight was W = 0.0054L3.1428. Age was determined by otoliths and age groups I to IV years were observed. Growths in length and weight at the end of each year were calculated. The growth parameters of von Bertalanffy equation were calculated as (L∞ = 48.69 cm, K = 0.1677 yr -1 and t0 = -0.447 yr -1). Growth performance index was calculated (φ = 2.60 for length and 1.25 for weight). Mortality rates were 0.867 yr-1, 0.25 yr1and 0.617 yr-1 for total, natural and fishing mortality, respectively. The currently exploitation rate E = 0.712 yr-1 indicating that, the population of this species is being heavily exploited.

scholarly journals A Sense of Harassment and its Relationship to the Level of Professional Educational Adjustment among a Sample of Employees in the Directorate of Education in Damascus

2017 ◽  
Vol 11 (2) ◽  
pp. 278
Author(s):  
Raghdaa A. Naiseh
Keyword(s):  
Negative Correlation ◽  
Analytical Approach ◽  
Significant Negative Correlation ◽  
Female Workers ◽  
Significant Difference ◽  
Government Education ◽  
Institutional Sector ◽  
Males And Females ◽  
Level Of Significance ◽  
The Relationship

The study aimed to identify the level of a sense of harassment among a sample of workers and institutional sector of government education. It defines the professional level of compatibility among a sample of workers in farming Damascus Directorate. And the study of the relationship between the sense of harassment and professional compatibility among a sample of workers in farming Damascus Directorate. And to identify the level of significance of differences in the answers to the study sample the sense of harassment and scale professional compatibility scale according to the variables of the study: (sex, and marital status), and has been relying on the descriptive and analytical approach, and used two tools of the study: a sense of harassment measure, and the measure of professional compatibility, and amounted to a sample study (144) factor and running in working in the farming Damascus Directorate. Among the most important findings of the study were: The level of the sense of harassment among workers in the Directorate of Education in Damascus was moderate; the professional level of compatibility among workers in the Directorate of Education in Damascus was moderate; a statistically significant negative correlation between the sense of harassment and the professional compatibility; the presence of statistically significant difference between males and females on the sense of harassment and in favor of male workers; a statistically significant difference between the average of married and non-married on harassment and in favor of non-married employees; a statistically significant difference between the average of males and females on the compatibility and in favor of female workers. There was no statistically significant difference between the average married and non-married on the compatibility scal

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