scholarly journals Some Aspects of the Growth Features and Condition Factor of Arius Gigas (Boulenger, 1911) from Obuama Creek (Rivers State, Nigeria)

2021 ◽  
Vol 23 (2) ◽  
pp. 63-74
Author(s):  
Olaniyi Alaba Olopade ◽  
Henry Eyina Dienye ◽  
Esther Ifeyinwa Nwosu
Keyword(s):  
Condition Factor ◽  
Management Strategies ◽  
Mean Value ◽  
Basic Information ◽  
Allometric Growth ◽  
Length Frequency ◽  
Frequency Distributions ◽  
Biological Features ◽  
Rivers State ◽  
Growth Features

Abstract Length-frequency distributions, length-weight relationships, length-length relationships and condition factors (Fulton’s KF, allometric KA, and relative KR) of Arius gigas in the Obuama Creek in Rivers State, Nigeria were investigated. 217 samples were collected from artisanal fishermen fishing on the Obuama Creek from March to September 2019. The parameter b of the length-weight relationship was 2.52 indicating negative allometric growth. The KF ranged from 0.51 to 2.03 with a mean value of 0.85 ± 0 while the overall low values of KR and KA, in this study are generally a characteristic of fish in poor health. This study provides basic information on some of the biological features of A. gigas which should be useful for facilitating management strategies and regulations of the stocks.

scholarly journals Biometric Indices and Condition factors of Pomadasys jubelini (Cuvier, 1830) from Obuama Creek, Nigeria

2020 ◽  
Vol 25 (2) ◽  
pp. 45-52
Author(s):  
Olaniyi Alaba Olopade ◽  
Henry Eyina Dienye ◽  
Cynthia Chigazu Okonkwo
Keyword(s):  
Condition Factor ◽  
Fork Length ◽  
Allometric Growth ◽  
Length Frequency ◽  
Protection Measures ◽  
Morphometric Characters ◽  
Frequency Distributions ◽  
A Value ◽  
Rivers State ◽  
Biometric Indices

Biometric indices of Pomadasys jubelini from Obuama Creek, Rivers state, Nigeria were investigated using length frequency distributions (LFDs), length-weight relationships (LWRs), length-length relationships (LLRs), condition factors (allometric, KA, Fulton’s, KF and relative, KR). Specimens were captured in a stretch of the creek from March to September 2019. A total of 229 specimens were examined with the total length (TL) and weight (W) ranging from 8.7 to 50.4 cm and 8.7 to 834.5 g respectively. The standard length (SL) ranged from 5.3 to 46.8 cm, fork length (FL) was between 6.5 to 48.7 cm and the girth length (GL) varied from 4.7 to 38.7 cm. The relationships of weight-length showed a negative allometric growth pattern with a value of "b" of 2,666. Fulton's condition factor (KF) ranged from 0.10 to 5.45, with an average of 1.21±0.66 indicating perfect wellbeing for the species. The LLR's allometric coefficient ' b ' between TL vs. FL and TL vs. GL showed positive allometric growth, while SL vs. FL, SL vs. TL, SL vs. GL, and GL vs. TL showed negative allometric growth, although the values were close to 1. These findings also provided some new and updated information on some of the morphometric characters of Pomadasys jubelini in Obuama Creek that could be useful for fisheries management and fish species protection measures in the creek and adjacent habitats.  

scholarly journals Growth pattern of three species of Mullets (Pisces: Mugilidae) in Sombreior River, Rivers State, Niger Delta, Nigeria

2020 ◽  
Vol 5 (2) ◽  
pp. 68-72 ◽  
Author(s):  
Henry Eyina Dienye ◽  
Olaniyi Alaba Olopade
Keyword(s):  
Fish Species ◽  
Growth Pattern ◽  
Niger Delta ◽  
Condition Factor ◽  
Well Being ◽  
Biological Information ◽  
Allometric Growth ◽  
Good State ◽  
Abiotic And Biotic Factors ◽  
Rivers State

Length-weight relationships (LWRs) and condition factor are important biological information to assess the growth pattern and wellbeing of fish species influenced by numerous abiotic and biotic factors. To date, no data on the LWRs and condition of mullets in Sombreior River, Niger Delta. Hence, this research was conducted to determine abundance, length–weight relationship and Fulton’s condition factor (K) of three species of fish belonging to family Mugilidae in Sombreior River, Nigeria. There were a total of 248 samples from five sampling stations for a period of months. Fish species were of various sizes ranging from 24.66±0.40 to 26.35±0.26cm in length and 141.41±6.30 to 161.56±5.87g in weight. For the three species, slope (b) values ranged from 2.18 to 2.68 indicating a negative allometric growth of all fish species. The mean condition factor ranged from 0.89±0.03 forsix Mugil cephalus to 0.93±0.03 for Parachelon grandisquamis while the coefficients of determination (R2) of the LWR regressions ranged between 0.64 (Neochelon falcipinnis) and 0.79 (Parachelon grandisquamis). It was concluded that the mullets in the Sombreior River had a negative allometric growth pattern and the condition is showing the species were in good state of well-being since mean K values are  greater than 1.

scholarly journals Abundance, seasonality and size of Atlantic salmon smolts entrained on power station intake screens in the Severn Estuary

1994 ◽  
Vol 74 (3) ◽  
pp. 527-534 ◽  
Author(s):  
P.N. Claridge ◽  
I.C. Potter
Keyword(s):  
Atlantic Salmon ◽  
Standard Length ◽  
Condition Factor ◽  
Early Summer ◽  
Length Frequency ◽  
Power Station ◽  
Severn Estuary ◽  
Frequency Distributions ◽  
The Mean ◽  
One Year

Atlantic salmon smolts were sampled from the intake screens of the Oldbury power station in the inner Severn Estuary at weekly intervals between July 1972 and June 1977. These catches, and those taken over nearly three years from the nearby Berkeley power station, demonstrated that the abundance of smolts in the estuary peaked in autumn (October) and, to a far greater extent, in spring (April and May). However, small numbers of smolts were occasionally found in all other months of the year except July. Standard length-frequency distributions of smolts remained unimodal throughout the year. Lengths ranged from 76 to 187 mm, mean 130·2 ±1·87 mm (95% CL), and wet weights ranged from 5·4 to 68·0 g, mean 26·9 ±1·17 g. The mean monthly standard length of smolts increased slightly between the autumn of one year and the spring/early summer of the next year, suggesting that, on average, the former were six months younger than the latter. The condition factor was significantly greater in autumn (1·40) than in spring (1·23). It is estimated that the total number of salmon smolts entrained annually on the screens at Oldbury during the five years ranged from 92 to 791, with a mean of 405. Total estimated numbers at Berkeley ranged from 196 to 788 per annum. The numbers at Oldbury are lower than those estimated for the downstream migrants of the Twaite shad, another anadromous species, and far lower than those of the most abundant of the marine fish species that use the Severn Estuary as a nursery area.

scholarly journals Comparison of Length and Weight Characteristics of O. niloticus and O. aureus from Garmat Ali River, Iraq

2021 ◽  
pp. 39-51
Author(s):  
Abdul-Razak M. Mohamed ◽  
Ayat N. Salman
Keyword(s):  
Fish Species ◽  
Condition Factor ◽  
Age Groups ◽  
Age And Growth ◽  
Allometric Growth ◽  
Frequency Distributions ◽  
Cichlid Species ◽  
Relative Condition Factor ◽  
Dominant Fish ◽  
Management And Conservation

Cichlid species invaded the Iraqi waters in the mid-2000s and are now dominant fish species. The present study was carried out to investigate the age and growth of two cichlid species, Oreochromis niloticus and O. aureus in Garmat Ali River, Iraq from October 2019 to September 2020. A total of 2707 specimens of O. niloticus ranging from 7.0 to 25.5 cm and 1664 of O. aureus varying from 7.0 to 26.3 cm were examined which were captured by various fishing gears. The length-frequency distributions revealed that fish lengths (13.0-18.0 cm) formed 64.1% of the total catch of O. niloticus and 67.2% of O. aureus. The length-weight relationships were W=0.012*L3.109 for O. niloticusand W=0.015*L3.075 for O. aureus, and both species indicated positive allometric growth. The highest values of the relative condition factor were obtained during spring and the values decrease when length of two species increase. Seven age groups were determined for O. niloticus: 9.9, 12.9, 15.6, 17.9, 19.4, 20.4 and 22.2 cm, and for O. aureus: 9.3, 12.5, 15.2, 18.0, 19.4, 21.3 and 22.2 cm. The theoretical maximum length (L∞) was 29.2 cm for O. niloticus and 28.6 cmfor O. aureus. These results can assist in fisheries management and conservation of the fish species in Iraqi waters.

scholarly journals Relationships between fish and otolith dimensions of Pomatomus saltatrix (Linnaeus, 1766) (Perciformes: Pomatomidae) in southeastern Brazil

2019 ◽  
Vol 17 (1) ◽  
Author(s):  
Geysa M. de Souza ◽  
Rafael de A. Tubino ◽  
Cassiano Monteiro-Neto ◽  
Marcus R. da Costa
Keyword(s):  
Food Habits ◽  
Condition Factor ◽  
Specific Model ◽  
Southeastern Brazil ◽  
Length Frequency ◽  
Pomatomus Saltatrix ◽  
Relative Growth ◽  
Frequency Distributions ◽  
Growth Constants ◽  
Species Specific

ABSTRACT The bluefish, Pomatomus saltatrix (Linnaeus, 1766), was used as a species-specific model to study morphometric relationships between otolith size and relative growth variables. Length-weight relationships between Otolith (Length-OL, Height-OH, and Weight-OW) and fish measurements (Total Length-TL and Total Weight-TW) were determined for fishes captured monthly during the year 2015 off the southeastern coast of Brazil. The ANCOVA and Kruskal-Wallis analysis did not indicate significant differences in the relative growth constants between sexes and length frequency distributions (p > 0.05). The condition factor also did not present significant differences between sexes, and right and left otolith measurements (p > 0.05). A total of 398 specimens were sampled: TL = 43.6-67.0 cm, TW = 365-2400 g, OL = 9.65-15.25 mm, OH = 3.65 - 5.45 mm and OW = 0.03-0.11 g. The LWR for grouped sexes was TW = 0.050TL2.55 and otoliths OW = 6.17E-05OL2.59. The best adjustments were TL vs OL (r2 = 0.90); OL vs OW (r2 = 0.90); TW vs OW (r2 = 0.81); and TW vs OL (r2 = 0.80). These results showed that such relationships are helpful tools for predicting the fish size and weight from otoliths, which may be used in food habits and paleontology studies, and other fisheries management applications.

scholarly journals Food and initial size influence overwinter survival and condition of a juvenile marine fish (age-0 Atlantic cod)

2021 ◽  
Vol 78 (4) ◽  
pp. 472-482 ◽  
Author(s):  
Emilie A. Geissinger ◽  
Robert S. Gregory ◽  
Benjamin J. Laurel ◽  
Paul V.R. Snelgrove
Keyword(s):  
Food Availability ◽  
Gadus Morhua ◽  
Condition Factor ◽  
Atlantic Cod ◽  
Size Variation ◽  
Length Frequency ◽  
Initial Size ◽  
Frequency Distributions ◽  
Winter Temperatures ◽  
Feeding Trials

In subarctic Newfoundland, age-0 Atlantic cod (Gadus morhua) settle into coastal habitats in several summer–autumn pulses, resulting in broad length-frequency distributions before winter. Low winter temperatures and potential decreases in food availability pose challenges for young-of-year fish. To examine how size variation affects overwintering success under contrasting food scenarios, we conducted 114-day laboratory feeding trials at ambient overwinter sea temperatures, using demersal age-0 cod collected from Newman Sound, Newfoundland. We reared two size classes of juvenile cod under four daily ration levels (starvation, low, medium, high). We used Fulton’s K condition factor to interpret effects of food availability and fish size on survival over winter. We showed that small amounts of consumed food (<1% BW·day−1) maximized winter growth and condition potential of juvenile cod in Newfoundland waters. With no food, survival of small cod dropped below 80% on Day 47, whereas survival of large juveniles remained >80% until Day 74. Therefore, we expect higher survival of earlier settlers and increased size-selective mortality in age-0 cod during either unproductive or protracted winters, when food abundance is often low.

scholarly journals PÜLÜMÜR NEHRİ'NDE YAŞAYAN Acanthobrama marmid Heckel, 1843 POPULASYONUNUN BAZI BÜYÜME ÖZELLİKLERİNİN BELİRLENMESİ

2020 ◽  
Vol 15 (4) ◽  
pp. 121-133
Author(s):  
Ebru İfakat Özcan
Keyword(s):  
Condition Factor ◽  
Growth Parameters ◽  
Age Groups ◽  
Age Determination ◽  
Von Bertalanffy ◽  
Allometric Growth ◽  
Sex Distribution ◽  
Male Ratio ◽  
Growth Equations ◽  
Growth Features

In this study, some growth features have been investigated like sex distribution, length and weight relationship, age determination, von Bertalanffy growth parameters and condition factor of population Acanthobrama marmid Heckel, 1843 in Pülümür River. 276 samples examined during the study consisted of 157 females and 119 males and the female/male ratio was calculated as 1/0.758. It was determined that the total length and weight values varied between 7.8-21.1cm and 5.6-121.21 g in all individuals. The population has showed distribution between I-V age groups. Length-weight equation in were determined as W=0.0063L3.248 (R2=0.960) in females, W=0.0062L3.252 (R2=0.958) in males and W=0.0063L3.249 (R2=0.959) in all individuals. Positive allometric growth was observed for both sexes due to the “b” values were statistically different from 3. The von Bertalanffy growth equations were determined Lt=27.00 [1–e–0.247(t+0.876)] and Wt =249.66 [1-e–0.247(t+0.876)]3.248 for female, Lt=27.55 [1–e–0.232(t+0.952)] and Wt=280.02 [1–e–0.232(t+0.952)]3.252 for male, Lt=27.34 [1–e–0.238(t+0.916)] and Wt=261.55 [1–e–0.238(t+0.916)]3.249 for all individuals. Growth performance index (Ф') value was calculated as 2.250 for all individuals. Condition factor varies between 0.548-1.653 in female and 0.567-1.670 in male. It was observed that the value of the condition factor generally increased with age.

Reference points for the length-based indicator Lmax5% for use in the assessment of data-limited stocks

2019 ◽  
Vol 76 (7) ◽  
pp. 2125-2139 ◽  
Author(s):  
Tanja Miethe ◽  
Yves Reecht ◽  
Helen Dobby
Keyword(s):  
Life Histories ◽  
Stock Assessment ◽  
Reference Points ◽  
Length Frequency ◽  
Frequency Distributions ◽  
Simulation Tools ◽  
Spawning Potential Ratio ◽  
The Mean ◽  
Commercial Sources ◽  
Length Frequency Data

Abstract In the absence of abundance indices from scientific surveys or commercial sources, reliable length frequency data from sampled commercial catches can be used to provide an indirect assessment of fishing mortality. Length-based indicators are simple metrics which describe length frequency distributions. The length-based indicator Lmax5%, the mean length of the largest 5% of individuals in the catch, combined with appropriately selected reference points, can be used to evaluate the presence of very large individuals in the catch and hence determine exploitation level. Using analytical per-recruit models, we derive reference points consistent with a spawning potential ratio of 40%. The reference points depend on the life history parameters for natural mortality, maturity, and growth (M, Lmat, L∞, k, CVL∞). Using available simulation tools, we investigate the sensitivity of the reference points to errors in these parameters and explore the usefulness of particular reference points for management purposes for stocks with different life histories. The proposed reference points are robust to uncertainty in length at first capture, Lc, and take into account the maturation schedule of a species. For those stocks with high M/k ratios (&gt;1), Lmax5%, combined with the appropriate reference point, can be used to provide a data-limited stock assessment.

Size Distributions and Growth of the Fan-shell Pinna bicolor Gmelin (Mollusca : Eulamellibranchia) in South Australia

1979 ◽  
Vol 30 (1) ◽  
pp. 25 ◽  
Author(s):  
AJ Butler ◽  
FJ Brewster
Keyword(s):  
South Australia ◽  
Adductor Muscle ◽  
Size Distributions ◽  
Limited Data ◽  
Length Frequency ◽  
Age Classes ◽  
Frequency Distributions ◽  
Growth And Survival ◽  
Random Samples ◽  
Variable Success

Fourteen random samples of Pinna bicolor were collected over a period of 31 months from 6 m depth in Gulf St Vincent off Edithburgh, South Australia. The length-frequency distributions suggest that: P. bicolor larvae settle in spring but with variable success; growth of newly settled young is rapid over summer; by age 1 year their modal shell length is about 20 cm; by age 2 it is about 26 cm; they may survive substantially longer than 3 years so that a length-class of mode c. 35 cm is always present and is composed of several age-classes not necessarily equally represented. These suggestions are corroborated by limited data on adductor muscle scars, the development of epibiota on the shells, and the growth and survival of tagged animals over 9 months.

Application of the otolith weight – age relationship for the pilchard, Sardinops sagax neopilchardus

1995 ◽  
Vol 52 (4) ◽  
pp. 657-664 ◽  
Author(s):  
W. J. Fletcher
Keyword(s):  
Maximum Size ◽  
Steady Increase ◽  
Average Weight ◽  
Fish Length ◽  
Natural Mortality ◽  
Length Frequency ◽  
Age Classes ◽  
Frequency Distributions ◽  
Southwestern Australia ◽  
Sardinops Sagax

Adult pilchard (Sardinops sagax neopilchardus) from southwestern Australia held in fish cages for 1 year showed minimal increase in mean length but a steady increase in mean otolith weight (1.61–1.83 mg); this increase (0.22 mg) closely parallels the previously calculated mean difference between adjacent age classes (0.24 mg). Modes in otolith weight frequency distributions of fishery-caught pilchards, previously suggested as corresponding with separate year classes, generally persisted and progressed through subsequent samples. By contrast, fish length frequency distributions of these samples showed no consistent modal progression. The average weight of otoliths for year classes 2–8 were used to calculate growth rates: following sexual maturity, at age 2, males grew to a significantly smaller maximum size than females (L∞ = 162 and 172 mm respectively). The otolith weight – age relationship, validated by following a cohort of unusually low abundance as it moved through the fishery, indicated that recruitment to the fishery generally began at age 2 but was not complete until age 4. These data have been successfully used in forecasting the catch rate of the fishery up to 2 years in advance and providing an estimate of the rate for natural mortality of 0.43.

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