Derivation of Average Lengths of Different Age-Groups in Fishes

1969 ◽  
Vol 26 (11) ◽  
pp. 3073-3076 ◽  
Author(s):  
V. G. Jhingran ◽  
A. V. Natarajan
Keyword(s):  
Average Length ◽  
Age Groups ◽  
Length Frequency ◽  
Average Growth Rate ◽  
Average Growth ◽  
Fish Stocks ◽  
Growth Variation ◽  
Modal Values ◽  
The Tropics ◽  
Length Frequency Analysis

Fishes in general show much growth variation between years from environmental influences, food availability, and stock density, and this variation is especially more pronounced in the tropics. Average growth rate and average length at age of constituent age-groups of fish stocks, under the circumstances, appear more appropriate especially for yield computations. By the method elaborated in this note, the modal values of sizes of constituent age-groups (derived from Petersen's method of length-frequency analysis) as obtained each month for all months over a number of years (9 years, in the present case, covering the period 1957–65) are simultaneously plotted and this results in as many oblique rows as there are age-groups. Regression lines corresponding to the oblique rows of scatters of modal plots are statistically derived and used to read off the average lengths at ages. The slopes of the lines represent the average growth rates for the size ranges delimited by regression lines.

Growth and Reproduction of the Lanternfish Stenobrachius leucopsarus

1970 ◽  
Vol 27 (7) ◽  
pp. 1265-1275 ◽  
Author(s):  
William Smoker ◽  
William G. Pearcy
Keyword(s):  
Frequency Analysis ◽  
Age Groups ◽  
Von Bertalanffy ◽  
Length Frequency ◽  
Otolith Analysis ◽  
Size Groups ◽  
Back Calculation ◽  
The Times ◽  
The One ◽  
Length Frequency Analysis

Growth and reproductive patterns of the common lanternfish Stenobrachius leucopsarus (Eigenmann and Eigenmann) are described by length-frequency analysis, otolith analysis, and examination of ovaries. Length-frequency analysis showed that growth is approximately linear, 1.59 mm standard length per month, during the 2nd, 3rd, and part of the 4th year of life. Yearling fish average 23 mm long, 2-year-olds 41 mm, and 3-year-olds 59 mm.Otolith analyses indicate that some fish may live to be 8 years old, but confidence in this method is limited to fish 5 years old or younger. Fitting mean lengths of age-groups defined by otolith analyses with the von Bertalanffy equation gave L∞ = 85 mm, k = 0.34. Back calculation of lengths at the times of formation of otolith annuli gave another set of estimated mean lengths of age-groups, which, fitted by the von Bertalanffy equation, describes a growth curve similar to the one described by otolith analyses. The inflection in growth in weight occurs at about 4 years of age.Time of spawning, determined from egg measurements, occurs from December to March. Reproductively mature individuals are 4 years old and older. Recruitment of young size groups is also seasonal, 20- to 25-mm individuals appearing in largest proportions in trawl samples in the winter, presumably about 8 months after spawning.Comparison with other studies indicates that spawning may occur earlier in Monterey Bay, California, than off Oregon, but growth rates and sizes of age-groups I–V are similar. Comparisons with published results of otolith analyses show similar age determinations for the smaller size groups.

scholarly journals PARAMETER POPULASI IKAN BAWAL PUTIH (Pampus argenteus) DI PERAIRAN TARAKAN, KALIMANTAN TIMUR

2015 ◽  
Vol 7 (3) ◽  
pp. 165
Author(s):  
Prihatiningsih Prihatiningsih ◽  
Nurainun Mukhlis ◽  
Sri Turni Hartati
Keyword(s):  
Frequency Analysis ◽  
Average Length ◽  
Total Mortality ◽  
Assessment Tools ◽  
Growth Equation ◽  
Population Parameters ◽  
Length Frequency ◽  
Pampus Argenteus ◽  
Exploitation Rate ◽  
Length Frequency Analysis

Ikan bawal putih (Pampus argenteus) mempunyai nilai ekonomis penting dan sebagai salah satu komoditas unggulan di perairan Tarakan. Informasi tentang biologi perikanan ikan tersebut masih terbatas. Penelitian ini bertujuan untukmengestimasi parameter populasi meliputi pertumbuhan, umur, mortalitas dan tingkat eksploitasi ikan bawal putih. Data frekuensi panjang bulanan dikumpulan pada Februari – Nopember 2013 dengan bantuan enumerator. Sebaran frekuensi panjang ikan dipisahkan kedalam sebaran normal menggunakan metode Bhattacharya pada progran FiSAT (FAO-ICLARM Stock Assessment Tools). Estimasi parameter populasi dengan aplikasi model analitikmenggunakan program ELEFAN-1 (Electronic Length Frequency Analysis). Hasil penelitian menunjukkan ukuran panjang ikan bawal putih berkisar antara 9,0 cm–35,0 cmFL. Hubungan panjangberat ikan bawal putih yang tertangkap dengan jaring insang bersifat allometrik negatif mengikuti persamaan W= 0,187L2,374. Nilai rata-rata panjang ikan pada saat pertama kali tertangkap (Lc) sama dengan ukuran pertama kali matang gonad (Lm). Laju pertumbuhan (K) sebesar 0,52/tahun dan panjang asimptotik (L ) sebesar 37,28 cmFL. Persamaan pertumbuhan dari Von Bertalanffy sebagai Lt = 37,28 (1 – e-0,52(t-+0,07)). Mortalitas alami (M) adalah 1,11/tahun, mortalitas karena penangkapan (F) = ,65/tahun dan mortalitas total (Z) = 1,65/tahun. Laju pengusahaan (E) sebesar 0,60 berarti tingkat eksploitasinya sudah melebihi dari nilai optimal (E=0,5) atau populasi ikan bawal putih dalam keadaan lebih tangkap (over exploited). Untuk itu diperlukan kebijakan pengelolaan secara hati-hati dengan mempertimbangkan aspek biologi dan aspek penangkapan yang sedang berjalan.White pomfret (Pampus argenteus) is one of the economically important fish and includes leading commodity in Tarakan waters. Information of fishing biology of those species were still limited. This study aims to determine the population parameters including growth, age, mortality and exploitation rate of white pomfret. Monthly length frequency data have been collected by enumerator from February to November 2013. Fish lengthfrequency distribution was separated into a normal distribution using the Bhattacharya method with software of FiSAT (FAO-ICLARMStock Assessment Tools). Estimation of population parameters were use analytical model application with ELEFAN-1 (Electronic Length Frequency Analysis) program. The results showed that lengths distribution of white pomfret ranged beetwen 9.0 cm -35.0 cmFL. Length-weight relationship was negatively allometric. Estimating the average length at first captured (Lc) was equal with average length at first maturity (Lm) with growth equation of Lt = 37.28 (1 - e-0, 52 (t +0.07)). Natural mortality (M) was 1.11/year, fishing mortality (F) was 1.65/yearand total mortality (Z) was 1.65/ year. The exploitation rate (E) was 0.60. It is mean that more higher than optimal exploitation so that the white pomfret fish population in a state of over fished. It is necessary to better policy in the management of white pomfret through precaution approach and describing of biologycal and fishing aspect in Tarakan, Kalimantan Timur.

scholarly journals 946 GROWTH AND DEVELOPMENTAL RESPONSES OF POINSETTA TO CALCIUM NITRATE AND TO 6-BA

HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 569c-569
Author(s):  
Lisa Grishow ◽  
Alejandro Ching
Keyword(s):  
Growth Rate ◽  
Shoot Growth ◽  
Average Length ◽  
Calcium Nitrate ◽  
Average Growth Rate ◽  
Lateral Shoot ◽  
Average Growth ◽  
Lateral Shoots ◽  
Lateral Bud ◽  
Developmental Responses

Some studies have shown that the presence of calcium ions greatly influence the growth of lateral shoots in poinsettia. Rooted cuttins were transplanted in 13.14 cm dia. plastic pots and grown on Metro-mix soil, fertilized with 20-10-S osmocote and watered as needed. Plants were sprayed with 300 & 600 ppm of ca(NO3)2. Others treated with 500 ppm of 6-BA, plus 300 and 600 ppm of Ca(NO3)2 and then with 500 ppn of 6-BA. Some plants were left without treatments as check. The average number of lateral bud breaks were highest on plants treated with 6-BA when compared to plants treated only with Ca(NO3)2 and the check. The number of lateral bud breaks increased from an average of 11 on the 5th day to 15 on the 30th day whenever 6-BA was applied. The average length of lateral shoots also increased from an average of 10mm the 5th day to over 23mn on the 30th day when 6-BA was applied, but the presence of Ca(NO3)2 at 300 ppm lateral shoot growth was greater than at 600 ppm. In general, the average growth rate in height increased in all treatments compared to the check and the presence of Ca(NO3)2 further increased the growth in height. Finally, the foliage growth rate (in diameter) was greatly influenced by 6-BA and 600 ppm of Ca(NO3)2.

Transplantation of coral fragment, Acropora formosa (Scleractinia)

2014 ◽  
pp. 1
Author(s):  
Hanny Tioho ◽  
Maykel A.J Karauwan
Keyword(s):  
Fragment Size ◽  
Observation Time ◽  
Minimum Size ◽  
Average Growth Rate ◽  
Average Growth ◽  
Significant Difference ◽  
Acropora Formosa ◽  
Survival And Growth ◽  
One Way Anova ◽  
Better Than

The minimum size of coral transplants, Acropora formosa, was assessed to support their survival and growth. For this, 150 coral fragments of different sizes (5, 10, 15 cm) were transplanted close to the donor colony. Their survivorship and growth were observed for 12 months. At the end of the observation time, 90% of 15 cm-transplanted coral fragments survived, while the others (10cm and 5 cm) did 86% and 82% respectively. The average growth rate of 5 cm-coral fragments was 0.860 cm/month, while 10 and 15 cm-fragments were 0.984 cm/month and 1.108 cm/month respectively. One-way ANOVA showed that there was significant difference (p<0.05) among the three (5, 10, 15 cm) transplant initial sizes in which the longest fragment size tended to survive longer than the smaller one.  However, the smaller transplants grew better than the bigger one, 10.318 cm/year (206%) for 5 cm-transplant, 11.803 cm/year (118%) for 10 cm-transplant, and 13.299 cm/year (89%) for 15 cm-transplant, respectively. Ukuran minimal fragmen karang Acropora formosa yang ditransplantasi diduga untuk mendukung ketahanan hidup dan pertumbuhannya. Untuk itu, 150 fragmen karang ditransplantasi ke lokasi yang berdekatan dengan koloni induknya.  Ketahanan hidup dan pertumbuhan semua fragmen karang yang ditransplantasi diamati selama 12 bulan.  Pada akhir pengamatan, 90% dari fragmen karang berukuran 15 cm yang ditransplantasi dapat bertahan hidup, sedangkan yang lainnya (ukuran 10 cm dan 5 cm) masing-masing sebesar 86% dan 82%.  Rata-rata laju pertumbuhan fragmen karang dengan ukuran awal 5 cm adalah 0,860 cm/bulan, sedangkan ukuran fragmen 10 dan 15 cm masing-masing adalah 0,984 cm/bulan and 1,108 cm/bulan. ANOVA satu arah menunjukkan adanya perbedaan yang nyata (p<0.05) antara ketiga ukuran fragmen yang berbeda, di mana ukuran fragmen karang yang lebih panjang cenderung mempunyai ketahanan hidup yang lebih baik. Namun demikian, ukuran transplant yang lebih kecil memiliki pertumbuhan lebih baik dibandingkan dengan ukuran yang lebih besar, yakni10,318 cm/tahun (206%) untuk transplant berukuran 5 cm, 11,803 cm/tahun (118%) untuk 10 cm, dan 13,299 cm/tahun (89%) untuk ukuran 15 cm.

Age and growth pattern of the thin-lipped mullet Liza Ramada in the Eastern coast of Libya.

2016 ◽  
Vol 5 (06) ◽  
pp. 4620
Author(s):  
Manal M. Khalifa ◽  
Ramadan A. S. Ali ◽  
Abdalla N. Elawad* ◽  
Mohammad El. ElMor
Keyword(s):  
Frequency Distribution ◽  
Age Groups ◽  
Age Determination ◽  
Age And Growth ◽  
Eastern Coast ◽  
Growth Equation ◽  
Length Frequency Distribution ◽  
Length Frequency ◽  
Scale Reading ◽  
Von Bertalanffy Growth Equation

Age and growth characteristics of the thin-lipped Grey Mullet (Liza ramada) were investigated in Eastern coast of Libya. Aging was done by two methods: counting annuli on scales and by length frequency distribution, a total of 218 scales were studied for age determination, in addition of 334 fishes specimen for length frequency distribution reading. Four age groups were determined from scale reading, and five age groups from length frequency distribution methods, the parameters of the Von Bertalanffy growth equation for both sex of all individuals were estimated at 35.4 cm, 0.187 per year, -1.14 years and 2.4, for male were estimated at 35.7 cm, 0.17 per year, -1.367 and 2.3, for female were 38.6 cm, 0.156 per year, -1.383 and 2.4, for L∞, k and t0, and φ′, respectively.

scholarly journals The incidence of pneumonia in the paediatric population in Poland in light of the maps of health needs

2021 ◽  
Author(s):  
Joanna Lange ◽  
Jerzy Kozielski ◽  
Kinga Bartolik ◽  
Paweł Kabicz ◽  
Tomasz Targowski
Keyword(s):  
Average Length ◽  
Age Groups ◽  
Paediatric Population ◽  
Incidence Rates ◽  
Education Development ◽  
Average Length Of Stay ◽  
Significant Difference ◽  
Social Fund ◽  
Hospital Deaths ◽  
Reported Data

Abstract In Poland, no statistical data are available concerning the analysis of the incidence of pneumonia in inpatient children. The requirement for these data results mainly from the need to prepare systemic and economic solutions. Aim This study aimed to use reported data for evaluating pneumonia incidence rates among hospitalised children and other parameters in various age groups. Subject and methods A detailed analysis was performed as part of the Operational Programme Knowledge Education Development co-financed by the European Social Fund. Services reported to the National Health Fund in 2014 were considered, including pneumonia incidence among hospitalised children and mortality in specific age groups. Results In 2014, a total of 68,543 children were hospitalised for pneumonia (68% of all hospitalisations for acute respiratory diseases). Within each of the analysed age groups, boys were hospitalised more frequently. Irrespective of the place of residence, infants were most commonly hospitalised. It was observed that there was a significant difference between the incidence rate of pneumonia among hospitalised children in all analysed groups depending on the province. The average length of stay was 7.29 days, with infants requiring the longest stays (7.96 days), and 1.8% of children were rehospitalised within 30 days due to recurrence of pneumonia. The most commonly coded pathogens responsible for pneumonia included Mycoplasma pneumoniae, Streptococcus pneumoniae and Chlamydia spp. A total of 19 inpatient hospital deaths in the course of pneumonia were reported. Conclusions Based on our findings, it is warranted to utilize epidemiological knowledge for the planning of an appropriate level of service commissioned both in outpatient and inpatient facilities as well as for the estimation of institutional and staff needs necessary to secure these services.

Survival and growth of understory trees in oak forests of the Hudson Highlands, New York

1981 ◽  
Vol 11 (3) ◽  
pp. 689-695 ◽  
Author(s):  
Craig G. Lorimer
Keyword(s):  
New York ◽  
Growth Rates ◽  
Red Oak ◽  
Northern Red Oak ◽  
Average Growth Rate ◽  
Average Growth ◽  
Red Oaks ◽  
Oak Trees ◽  
Survival And Growth ◽  
Understory Trees

Mortality and growth rates of trees in various crown classes and size classes were analyzed from 40-year permanent plot records of slope and ravine forest dominated by chestnut oak (Quercusprinus L.) and northern red oak (Quercusrubra L.). Average 5-year mortality rates for suppressed trees ≥2.5 cm dbh of chestnut oak and red oak in the slope forest were 26 and 45%, respectively. None of the suppressed red oaks survived the 40-year period, compared with 14% of the chestnut oaks and 33% of the red maples (Acerrubrum L.). Mortality of oak trees in the intermediate crown class was less than half that of suppressed trees, but still much higher than that of maples and birches on the tracts. Survival was reasonably high for oaks as long as the top of the crown was receiving direct sunlight, but the expected 40-year survival rate of red oaks in such a position is only 20%, with an average growth rate of 1.0 mm in diameter per year. Curves and equations expressing average mortality and growth rates at various levels of competition are presented for each species.

Homeostatic Characteristics of Single Species Fish Stocks in Arctic Lakes

1983 ◽  
Vol 40 (7) ◽  
pp. 987-1024 ◽  
Author(s):  
Lionel Johnson
Keyword(s):  
Stock Returns ◽  
Dominant Species ◽  
Size Structure ◽  
Arctic Charr ◽  
Arctic Lakes ◽  
Large Individual ◽  
Total Biomass ◽  
Length Frequency ◽  
Initial State ◽  
Fish Stocks

The results of investigations on the fish stocks of seven Arctic lakes covering a period of 23 yr are described. These lakes have remained largely undisturbed since their formation in late glacial times; all but one are completely autonomous and of comparatively small size. Such lakes provide a unique opportunity for the development and testing of conceptual models. In all cases the only fish species present is Arctic charr, Salvelinus alpinus. Length frequency distributions derived from gillnet catch curves are shown to be, within reasonable limits, representative of the actual populations in the lake, and not artifacts of the sampling procedure. Length frequency curves show a unimodal or bimodal distribution and this structure, in the absence of perturbation, appears to remain constant indefinitely. Individuals are of great age but age-at-length is highly variable. Age and size structure are shown to be comparable with the age and size structure of the dominant tree species in a climax forest; it is concluded that forces of great generality fashion these configurations. It is hypothesized that all species tend to move towards a state of least energy dissipation; this can be most readily seen in the dominant species at the climax in an autonomous system. The dominant species is characterized by large individual size, a high degree of uniformity, high total biomass, great mean age, indeterminate age-at-death, and a low incidence of replacement stock. After severe perturbation it is shown that the charr stock returns to a state of least dissipation without oscillation. Absence of oscillation during the return to the initial state, combined with the long-term stability shown in control lakes, indicates the presence of an effective damping mechanism; this in turn indicates the existence of organization within the stock as a whole. Organization develops through an interactive mechanism described under the doctrine of homeokinesis, which is responsible for energy equipartitioning and the maintenance of uniformity. These concepts help to explain phenomena observed in more complex systems and help our understanding of ecosystem functioning.

Age Wise Internal Morphometrical Studies on the Heart of Pre-natal Non-descript Sheep

2021 ◽  
Author(s):  
S.K. Sahu ◽  
U.K. Mishra ◽  
S. Sathapathy ◽  
S.M. Nanda
Keyword(s):  
Right Ventricle ◽  
Average Length ◽  
Age Groups ◽  
Circulatory System ◽  
Average Diameter ◽  
Left Ventricular ◽  
Vital Functions ◽  
Internal Parameters ◽  
Measuring Cylinder ◽  
Central Organ

Background: Heart is the central organ of circulatory system that pumps blood into the blood vessels and performs many vital functions. Its development before birth must be studied to safeguard the animal from the occurrence and consequences of various developmental anomalies. The detailed morphometry of different internal parameters of heart especially in pre-natal sheep has not yet been reported. Methods: The foeti of sheep were divided into two age groups viz. mid prenatal (51-100 days) and late prenatal (101 to 150 days) with fifteen animals in each age group. The various internal parameters were recorded by using digital weighing machine, graduated measuring cylinder, digital Vernier’s calliper, non-stretchable nylon thread and graduated scale. The data recorded was statistically analysed by independent t test with IBM SPSS 25.0 version software. Result: The average thickness of left ventricular wall of heart was measured as 2.85±0.15mm and 4.28±0.07mm in mid prenatal and late prenatal stages respectively with significant (p£0.01) differences between the ages. Similarly, the average diameter of left atrio-ventricular opening of heart was measured as 2.06±0.27mm and 6.08±0.36mm in mid prenatal and late prenatal stages respectively with significant (p£0.01) differences between the ages. The average length of septal papillary muscle in right ventricle was measured as 1.12±0.10mm and 3.29±0.21mm in mid prenatal and late prenatal stages respectively with significant (p£0.01) differences between the ages. Further, the average length of moderator band in heart was measured as 1.45±0.11mm and 4.34±0.23mm in mid prenatal and late prenatal stages respectively with significant (p£0.01) differences between the ages. Similarly, the average length of chordae tendinae in right ventricle of heart was measured as 0.97±0.09mm and 3.50±0.34mm in mid prenatal and late prenatal stages respectively with significant (p£0.01) differences between the ages. 

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