LENGTH-WEIGHT RELATIONSHIP OF 55 SPECIES OF FISH CAUGHT BY ARROWHEAD FIXED TRAPS “CURRAIS” IN THE COAST OF PERNAMBUCO (BRAZIL)

Length weight relationship is important in describing several biological aspects of fish species found under cultured and natural condition. Length weight relationship provides information about whether somatic growth was isometric or allometric. While condition factor provide information about the well being fish. In the present study the individuals of Schizothorax plagiostomus were collected from river Jhelum from different locations for the determination of length weight relationship and condition factor during the period of 2014–2016. Length weight relationship was computed using the equation W = aL b , which was further transformed into LogW = Loga + bLog L. Results showed that the value of b in length weight relationship of male S. plagiostomus ranged from 2.316–2.965, while in female fishes the value of b ranged from 2.01–3.66. The results clearly show allometric type of growth in male and isometric type of growth in females. The regression coefficient between males and female did not shows any significant difference, (p > 0.05) whereas significant difference (P < 0.01) could be noticed between males and between females (p < 0.01). However, condition factor (K) of S. plagiostomus fluctuates between 0.82–1.58 in male and between 0.870–1.31 in female, indicating the robustness of the fish inhabiting in river Jhelum.

The creation and retention of accurate records reflecting the makeup of a pipeline is a critical aspect of pipeline safety. In the U.S., 49 CFR 192 provides guidance on the verification of pipeline material properties for populations of like pipe, including the development of alternative sampling plans for populations that lack complete documentation. But the code provides little guidance on how to formulate such a plan and how to process the samples as they arrive. Various statistical approaches exist for developing lower bounds on material properties based upon measurements. On one hand, frequentist (or classical) approaches are sometimes simpler to understand and implement. On the other hand, Bayesian approaches allow for the incorporation of natural prior information to improve the estimate. Estimating the yield strength (YS) is often one of the most important objectives of an alternative sampling plan. This paper presents a study of frequentist and Bayesian statistical approaches to developing a lower bound on YS using simulations of alternative sampling plans. Various hypothetical pipe populations with different distribution assumptions, indicative of different possible manufacturing patterns at the pipe mill, are simulated then alternative sampling plans are conducted for each simulated population under both frequentist and Bayesian statistical approaches. For each approach, the resulting lower bound on YS is estimated and compared with the true population lower bound. This direct comparison is possible since full information on the simulated populations is available. The relative merits of each statistical approach are compared, and recommendations about which approaches are most suitable are provided.

The fish assemblage in a mangrove tidal creek was studied in monthly collections between August 1998 and July 1999 in the quadrature low tide and high tide, using a fyke net of 30 m x 1.5 m and meshes of 8 and 10 mm. Simultaneously with the biological collections, temperature, salinity, pH, water transparency, and current speed data were obtained. The collections resulted in the capture of 36,873 fish representing 22 families and 52 species. Immature individuals abounded (63.8%), and among the adult specimens there was a larger number of females. The species Anchoa parva, Harengula clupeola, Genidens genidens, and Bairdiella ronchus, contributed to 84.9% of the total capture of fish, however the contribution in mass was of 55.2%, indicating a predominance of small individuals. A smaller number of fish and species seem to occupy the area in the period between August and December, in comparison to the period between February and July, when the larger aggregations appear, mainly of the species Anchoa parva, Harengula clupeola, Opisthonema oglinum, Genidens genidens, Diapterus rhombeus, and Bairdiella ronchus. The environmental factors, pH, water transparency, and rainfall seem to have an influence in the structure of the observed biological patterns.

Length-weight relationships and condition factor of Salmo trutta fario (Brown trout) at Kokernag trout fish farm, Anantnag, Jammu and Kashmir was estimated for a period of one year. During the present study the fish samples was within the range of 30cm to 45.8cm in length and 250g to 750g in weight were originally used to provide information on the condition of fish and to determine whether somatic growth was isometric or allometric. The relationship was analysed using the formula W = a L b which was further transformed into Log W = a + b log L. The equation obtained for females was log W= 1.61 + 3.33 logL and for males was log W = 1.81 + 3.22 logL. Females show 'b' value slight more than males. Studies on condition factor revealed that the fluctuations in K values can be attributed to the spawning cycle. The condition factor 'K' was above 1 indicating robustness or well being of the experimental fish.

The objective of this study was to identify any seasonal differences in the fish assemblage from the Paranagua Bay Estuary, Parana, using a “capechade” stow net. The samples were obtained between July 2006 to June 2007. A total of 39711 individuals, representing 69 species belonging to 32 families were collected, with Atherinella brasiliensis, Harengula clupeola, Sardinella brasiliensis, Diapterus rhombeus, Eucinostomus argenteus, Pomadasys corvinaeformis, Bairdiella ronchus, Sphoeroides greeleyi and Sphoeroides testudineus being the most prevalent species. Anchoa lyolepis and Harengula clupeola represented more than 61% of the total number, while Pomadasys corvinaeformis contributed to 28% of the total weight, followed by Harengula clupeola (16%). The average standard (± SE) length and weight were 87.6 mm (± 32.2 mm) and 22.5 g (± 27.8 g), respectively; demonstrating a dominance of small individuals, most of which were juveniles. There were no significant differences between months in terms of the Margalef diversity (D), Shannon-Wiener diversity (H’) and Pielou’s evenness index (J’). There was seasonal variation in the numbers of individuals and species and their capture weight and standard length. The average numbers of individuals and species were greater during warmer months, while biomass were greater at the end of autumn and winter, and standard lengths higher in May and June.

The length – weight relationship (LWR), condition factor (K), sex ratio, gonadosomatic index (G S I) and hepatosomatic index (H S I) of 412 specimens of Pseudotolithu s s enegalensis (Valenciennes, 1833) from Tombo , a coastal fishing community in the western rural district of Sierra Leone were studied for twelve months . Samples used for the study were collected from the catches of artisanal fishers and measurement s of length and weight of samples were done in situ using the facilities of the Ministry of Fisheries and Marine Resources. Samples for the reproductive study were preserved in an ice box and taken to the laboratory of the Department of Aquaculture and Fisheries Management, Njala University , Sierra Leone for analysis. The parameters "a" and "b" of the length - weight relationship were estimated using the equation described by Ricker ( W = aL b ) while the condition factor was calculated using Fulton`s equation (K = W1 00 / L 3 ) . The reproductive biology of the fish was estimated using Gonadosomatic index ( GSI ) and Hepatosomatic index ( H S I ) . The combined LWR for both sexes showed that a, b and r values were – 2.57 , 3. 3 5 and 0. 899 , respectively. The r – values obtained show a strong linear relationship between the length and weight of the species. The length - weight relationship indicated allometric growth for P . senegalensis in the study area. The condition factor (K) varied from 0.64 – 1.0 ; this may be attributed to environmental conditions of the water . The species clearly exhibited a positive allometric growth pattern ( tα ( 2) , 0.05, 411 &gt; 1.965) . The sex ratio of males to females was 1:1. 15 and was not significantly different from the expected 1:1 ratio. Estimation of GSI and HSI was carried out from December, 2010 to May, 2011 to determine the spawning behaviour of P. senegalensis . The mean GSI obtained indicate d that March and April , respectively are the two peak spawning period for the species . Gonado somatic index ranged between 1.1 % and 2.8% for the females. The results of this study revealed that P. senegalensis doe s not have obligatory spawning month but exhibit multiple spawning behaviour. T he length - w eight relationships and condition factor of the study indicated that the fish were thriving very well in the coastal water of Sierra Leone. Sustainable management of the species , therefore , require s that the environment be protected against anthropogenic pollution and imposition of closed fishing season especially during the t wo peak spawning period is recommended to enable the species recruit effectively.

The results of the study of the distribution and biology of the duskyfin glassy perchlet Parambassis wolffii (Bleeker, 1850) in the Mekong Delta in 2019–2020 are presented. It is established that the species reaches the highest abundance and biomass in the freshwater part of the delta. The water temperature at which individuals of the species were encountered was 27.8–34.1°C, salinity, up to 1.51‰, depths, from 2 to 35 m. The maximum total length of females and males was 20.0 and 14.7 cm, respectively, and the maximum age was 6 years. The parameters of the von Bertalanffy equation are as follows: the maximum length is 17.2 cm, the growth rate constant is 0.18, t0 = −2.35. The value of the coefficient b in the equation on the weight-length relationship is 3.002 ± 0.056 for females (isometry) and 2.774 ± 0.064 for males (negative allometry). Intersexual differences by the in Fulton’ condition factor were established: in females 3.71 ± 0.04, in males 3.53 ± 0.03. The first mature individuals were found at a length of 7–8 cm at the age of 1+.

Summary This study presents a historical review, a meta-analysis, and recommendations for users about weight–length relationships, condition factors and relative weight equations. The historical review traces the developments of the respective concepts. The meta-analysis explores 3929 weight–length relationships of the type W ¼ aL b for 1773 species of fishes. It shows that 82% of the variance in a plot of log a over b can be explained by allometric versus isometric growth patterns and by different body shapes of the respective species. Across species median b ¼ 3.03 is significantly larger than 3.0, thus indicating a tendency towards slightly positive-allometric growth (increase in relative body thickness or plumpness) in most fishes. The expected range of 2.5 < b < 3.5 is confirmed. Mean estimates of b outside this range are often based on only one or two weight–length relationships per species. However, true cases of strong allometric growth do exist and three examples are given. Within species, a plot of log a vs b can be used to detect outliers in weight–length relationships. An equation to calculate mean condition factors from weight–length relationships is given as Kmean ¼ 100aL b)3 . Relative weight Wrm ¼ 100W/ (amL b m ) can be used for comparing the condition of individuals across populations, where am is the geometric mean of a and bm is the mean of b across all available weight–length relationships for a given species. Twelve recommendations for proper use and presentation of weight–length relationships, condition factors and relative weight are given.

Macrobrachium amazonicum (Heller, 1862) is a freshwater prawn occurring in rivers and reservoirs of Central and South America. Given its broad geographical distribution, the species shows great intraspecific morphological, reproductive, physiological and ecological plasticity. Furthermore, it also stands out for its economic importance, especially in the states of North (Para and Amapa) and Northeast Brazil. Despite the wide geographic distribution and economic importance of M. amazonicum, the biology of this species is poorly known, particularly in Northeast Brazil. We analyzed the length-weight relationships and condition factor of males and females of M. amazonicum. Specimens were collected monthly from September 2008 to August 2009 at the Pedra do Cavalo Reservoir, city of Cabaceiras do Paraguacu, State of Bahia. All specimens were sexed, measured and weighted. After that, length-weight relationships and the allometric (K) and relative (Kr) condition factors were calculated. Altogether 2,974 specimens were analyzed, 334 of which were males (11%) and 2,640 were females (89%). Females were larger and heavier than males. Males and females showed isometric and negative allometric growth, respectively. Monthly variations in the condition factor were similar for both sexes, and correlated strongly with rainfall regime and temperature in the region. Such variations are not correlated with the reproductive cycle of the species, but are probably correlated with food availability and somatic growth.

In Ethiopia, the tilapia, Oreochromis niloticus , is an extremely important fish from ecological, economic and social point of view. Information on biological parameters like the size at first maturity (L50), Fulton’s condition factor (K) and length – weight relationship are very crucial for the sustainable management of the fishery. Therefore, the present study aims at providing information on the length-weight relationship, condition factor and size at first maturity (L 50 ) of Oreochromis niloticus in Lakes Koka, Ziway and Langano. Fish samples were collected on monthly basis from October 2005 to February 2006. Length-weight relationships (total length (L) in cm; total weight (W) in g were calculated for O. niloticus in Lakes Koka ( W = 2.61*10 -2 L 2.89 ; n = 205; r 2 W = 1.04* 10 −2 L 3.19 ; n = 279; r 2 = 0.97) and Langano ( W = 1.64*10 −2 L 3.04 ; n = 525; r 2 = 0.88). The average K value of O. niloticus from Lake Koka (1.87) is slightly higher than Ziway (1.81) and Langano (1.84). The size at first maturity (L 50 ) of O. niloticus is smaller in Lake Ziway (Female =18.1cm, male=19.6cm) and Langano (both sexes 19.5cm) than Lake Koka (both sexes 23.5cm) which is contrary to the generally accepted principle that fish mature earlier in smaller water bodies than larger ones. Hence, the nutritional status and the level of fishing pressure appear to be important factors for the variations observed in the present study. Keywords/phrases: Condition factor; Lakes Koka, Ziway, Langano; L50; Length-weight relationship; O. niloticus Ethiop. J. Biol. Sci ., 7(2): 139-157, 2008

The purpose of this study is to estimate some population parameters such as length-length and length-weight relationships and condition factor of Squalius cephalus individuals living in Tabakane Stream (Ordu-Turkey). A total of 326 S. cephalus individuals were sampled from Tabakane Stream, located in Ünye district in the Ordu province, by using an electroshocker. It was determined that the mean total, fork and standard lengths of the fish samples were 7.58±0.143 cm, 7.06±0.133 cm, and 6.30±0.121 cm, respectively, and their average weight was 6.05±0.322 g. The length-weight relationship of the species was calculated as W=0.0088TL3.0648 R²=0.993. As a result of our analyzes, it was determined that the S. cephalus population in Tabakane Stream showed a positive allometric growth. In the present study, it was determined that the 95% confidence interval of the b value in the length-weight relationship equation was between 3.0566-3.0678 and there was a strong relationship between body weight and total length. Relationship equations between total, fork and standard lengths were calculated as TL=1.0724FL+0.0086 (r2=0.9978), TL=1.1763SL+0.167 (r2=0.9972), and FL=1.0961SL+0.1529 (r2=0.9979) and it was determined that there are strong relationships between standard, fork and total length measurements of S. cephalus individuals living in Tabakane Stream. It was determined that the condition factor values of S. cephalus ranged between 0.73971 and 1.27570. The average condition factor was 0.99831±0.005. There is no previous study on the population of S. cephalus living in Tabakane Stream. In this study, the condition factor, length-weight and length-length relationships of S. cephalus in this habitat were reported for the first time.

The aim of this study is to determine the length-weight relationship, length-length relationship, and Fulton’s condition factor (K) of Capoeta tinca, which is endemic to Turkey. A total of 52 samples were obtained from Bayat Pond in 2017. The total length (TL) of the samples ranged between 20 and 34 cm. Total weights (W) of they also varied from 85 to 446g. Strong correlations were found between length and weight. In the length-weight relationship equation, a and b was found as 0.0144 and 2.9028, respectively. b value was not statistically different from 3 (t-test, P&gt;0.05). Therefore, this species showed isometric growth in the Bayat Pond. The value of Fulton’s condition factor was 1.0485. Total length - Fork length (FL), Total Length - Standard length (SL) and Fork length - Standard length conversion equations were calculated. There was a high correlation between all length types. In this study, the length-weight relationship, length-length relationship, and Fulton's condition factor values of Capoeta tinca inhabiting Bayat Pond were determined for the first time.

Fish found in natural tropical and sub-tropical water system experience frequent growth fluctuations. The study was conducted to determine the length-weight relationship and condition factor of Clariid species (Clarias gariepinus, Heterobranchus longifilis and Synodontis clarias) in Kano state of Nigeria. About 177 fish samples were collected from six rivers (Thomas, Ghari, Tiga, Duddurun-Gaya, Karaye and Bagwai) across the length and breadth of Kano state. Body weight (BW=248.48g), total length (TL=32.74cm) and standard length (SL=26.16cm) were determined. The length-weight relationship and condition factors were also determined. The condition factors showed varying degree of well-being of fish sampled from their habitat, and ranged from K = 0.37 to 0.89. The equation for the lengthweight relationship for the three strains is: C. gariepinus = -329.86+17.56TL, H. longifilis = -241.49+14.28TL and C. clarias = -428.51+22.72TL. Body weight and length had positive and significant relationship (r = 0.73 TL; r = 0.75 SL).

The objective of the present study was to examine the length-weight relationships and condition factors of snapperLutjanus russellii, ponyfishAurigequula fasciataand white-spotted spinefootSiganus canaliculatusharvested from Ulelhee Bay, Banda Aceh City, Indonesia. These species are the predominant fishes caught by traditional beach trawl in Ulelhee Bay, Banda Aceh City, Indonesia. The sampling was conducted for three months from April to June 2015 at one-week interval. A total of 900 fish samples (300 individuals for each species) were measured for the total length and body weight. The length-weight relationships were calculated using Linear Allometric Model (LAM), while the relative weights (Wr) and Fulton’s condition (K) factors were calculated to assess the condition of the fish samples. The results showed that thebvalue of 3.04 in snapper indicates isometric growth pattern, while ponyfish and white-spotted spinefoot fish had the b values of 1.41 and 1.75, respectively, and these species display an allometric growth pattern. The average Fulton’s condition factor (K) of snapper was 3.01 for male and 2.49 for female; female ponyfish has the K value of 2.92 and 2.92 for male. In addition, the average K value of white-spotted spinefoot was 2.61 and 2.59 for female and male, respectively. The relative weight condition factor ranges from 58.73 to 166.09 for snapper, from 70.55 to 129.65 for ponyfish, and from 71.63 to 133.53 for white-spotted spinefoot. In general, the relative weight condition factors tendedto be 100. It is concluded that snapper has isometric growth pattern, while ponyfish and white-spotted spinefoot display the negative allometric growth pattern. The condition factors are in excellent condition and indicate a balance of prey and predator.

In many application domains, occurrences of related spatial features may exhibit co-location pattern. For example, some disease may be in spatial proximity of certain type of pollution. This paper studies the problem of regional co-locations with arbitrary shapes. Regional co-locations represent regions in which two spatial features exhibit stronger or weaker co-location than that in other regions. Finding regional co-locations of arbitrary shapes is very challenging because: (1) statistical frameworks for mining regional co-location do not exist; and (2) testing all possible arbitrarily shaped regions is computational prohibitive even for very small dataset. In this paper, we propose frequentist and Bayesian frameworks for mining regional co-locations and develop a probabilistic expansion heuristic to find arbitrary shaped regions. Experimental results on synthetic and real world data show that both frequentist method and Bayesian statistical approach can recover the region with arbitrary shapes. Our approaches outperform baseline algorithms in terms of F measure. Bayesian statistical approach is approximately three orders of magnitude faster than the frequentist approach.