Length-weight Relationship Parameters Research Articles

LENGTH-WEIGHT RELATIONSHIPS OF THE ESTUARINE FISH SPECIES IN THE SECOND LARGEST MANGROVE AREA IN THE WORLD, BRAZIL

Length-weight relationship (LWR) parameters are necessary to understand the life cycle of fish to describe the biological aspects of species. In this sense, LWRs were determined for 17 estuarine species from the second largest mangrove area in the world, Northern Brazil. The sampling was carried out during the dry and wet seasons of 2015 and 2018 in 3 estuaries described as conservation units in the rivers Pará, Caeté, and Parnaíba. Fish were collected by using manual beach seine, block nets and sieves. Overall 488 specimens were analyzed using the equation W = a TLb. The a values ranged from 0.000001 to 0.000019 and b values ranged from 2.7230 to 3.2821. This study brings new data on estuarine fish from Brazil with additional information contributing to the conservation and management of the fish stocks.

Length-Weight Relationships for 32 Species of Cryptobenthic Reef Fishes from the Red Sea

Cryptobenthic reef fishes (CRFs) are often neglected in reef biodiversity assessments, trophodynamic studies, and biomass models. This oversight is due to the challenges associated with recording them in traditional underwater visual surveys and the scarcity of literature detailing their life history, ecology, and body growth parameters. Given their pivotal role in the functioning and maintenance of coral reef ecosystems, addressing these information gaps for CRF species is of great importance. In this study, we have computed the length-weight relationships (LWRs) for 32 CRF species spanning seven families in the Red Sea. This marks the first comprehensive report of LWR parameters for CRFs from this region, and for 31 of these species, it serves as their first LWR data report. The coefficient of determination (r2) ranged from 0.82 to 0.99, indicating a good fit for the LWRs. Half of the presented species belong to the Gobiidae family, including three undescribed species. In addition, we present LWRs for species from the families Blenniidae (5 spp.), Tripterygiidae (2 spp.), Apogonidae (4 spp.), Pseudochromidae (3 spp.), Plesiopidae (1 spp.), and Scorpaenidae (1 spp.). This research contributes invaluable insights into the growth patterns of CRFs not only in a global context but also beyond, as 50% of the recorded species are endemic to the region. The data generated holds great significance for conducting functional diversity analyses, ecosystem assessments, and coral reef health monitoring. By capturing this critical information, this work provides foundational metrics to take significant strides toward the conservation of these essential coral reef fishes.

Kuzeydoğu Ege Denizi’nde (Türkiye) Diplodus sargus (Linnaeus, 1758)'un bazı biyolojik özellikleri

In the study, the age, growth, mortality parameters and length-weight relationship parameters of Diplodus sargus (white seabream) collected by a small-scale fisherman between August 2020 and July 2021 along the northeastern coast of Aegean Sea (Türkiye coast), were investigated. D. sargus had a range of total length and weight from 14.3 cm to 36.7 cm and from 50.5 g to 836.5 g, respectively. The length-weight relationships (LWRs) were calculated as W=0.02368*L2.881 for females, W = 0.01847*L2.959 for males and W = 0.01989*TL2.936 for both sexes. Using data from fish scales, the maximum age was determined to be 11 years. von Bertalanffy growth parameters have been calculated as follows L∞=39.01 cm TL, K=0.13 year-1, and t0= -2.58 year for both sexes combined. Total (T), natural (N) and fishing (F) mortalities were defined as Z: 0.83 year-1, M: 0.33 year-1 and F: 0.50 year-1 for both sexes combined. The exploitation rate (E) was calculated as 0.70, 0.44 and 0.60 for females, males and combined, respectively.

Length-Weight Relationships and Growth Patterns of Eight Indigenous Fish Species from Lancang River, Southwest China

The Lancang-Mekong River watershed has extremely high fish biodiversity. With the rapid population growth and economic development in the river basin, fish diversity and fishery resources of this river are experiencing serious threats. Basic biological information on most fish species in the Lancang River, required to improve conservation in this area, is limited. This study aimed to provide new estimates of length-weight relationships (LWRs) by using the linear regression of W = aLb for eight indigenous fish species from the Lancang River, Southwest China. From 2018 to 2021, 534 specimens belonging to 3 families and 8 genera were collected using various types of fishing techniques. Standard length (SL) and body weight (BW) of each specimen were measured to the nearest 0.1 cm and 0.1 g, respectively. This study presents the first public records of LWR parameters of Schizothorax lissolabiatus, Poropuntius huangchuchieni, Tor sinensis, Scaphiodonichthys acanthopterus, Mystacoleucus lepturus, Hemiculterella macrolepis, Glyptothorax lampris, and Schistura porthos. The range of b values for the LWRs was 2.5378–3.1732, and the r2 values for all LWRs estimates ranged from 0.9102 to 0.9952. Intraspecific difference of b values across population and/or season was observed in S. lissolabiatus, T. sinensis, P. huangchuchieni, S. acanthopterus, and M. lepturus. The range of mean condition factor (K) and mean relative weight (Wr) was 0.97–2.39 and 100.29–108.18, respectively. This study updated information for FishBase and provided new record of maximum standard length for five species, namely, S. lissolabiatus, P. huangchuchieni, T. sinensis, S. acanthopterus, and M. lepturus. The findings of this study are essential for the management and conservation of locally indigenous fish and fisheries.

Length-Weight Relationships (LWRs) of Four Loach Species of the Cobitidae Family from the Surma River, Bangladesh

Four loaches, namely, Lepidocephalichthys guntea (Hamilton, 1822), Lepidocephalichthys annandalei (Chaudhuri, 1912), Lepidocephalichthys thermalis (Valenciennes, 1846), and Lepidocephalichthys berdmorei (Blyth, 1860) from the Cobitidae family, were collected from the Surma River, Bangladesh. Of the total 376 speciminia, 193 males (51.32%) and 183 females (48.67%) in number; were collected with the support of local fishermen using a variety of nets at 15-day intervals from November 2022 to April 2023. The length-weight relationship (LWR) parameters were analyzed using the equation W = a L b . L. annandalei displayed a notable isometric growth pattern, with a condition factor (K) ranging from 0.725 to 0.734. In addition, L. thermalis exhibited isometric growth among males, while females showcased positive allometric growth with a condition factor (K) varying between 0.697 and 0.714. L. guntea exhibited a consistent positive allometric growth pattern across all aspects, with a condition factor (K) ranging from 0.729 to 0.738. In contrast, L. berdmorei demonstrated positive allometric growth, but males and females both exhibited a negative allometric growth pattern. The condition factor (K) for L. berdmorei ranged from 0.699 to 0.702. This suggests a complex growth pattern influenced by both length and weight in every experimental loach. The research underscores the importance of recognizing gender-specific variations in growth patterns within species.

Length–weight relationships and condition factors of six notothenioid fish species occurring off King George Island and Northern Victoria Land (Antarctica)

This research was conducted to study length–weight relationships (LWR) and condition factors of six Antarctic notothenioidei fish species including blackfin icefish (Chaenocephalus aceratus), single-angle icefish (Chionodraco hamatus), marbled rockcod (Notothenia rossii), black rockcod (Notothenia coriiceps), emerald rockcod (Trematomus bernacchii), and dusky rockcod (Trematomus newnesi) from the King Sejong Station on King George Island and Jang Bogo Station on the Northern Victoria Land. A total of 232 specimens were collected by fishing on the icebreaking research vessel ARAON from December 2020 to February 2021. The LWR parameters and condition factors differed depending on species, which can be affected by their distribution, species characteristics, and gravidity status. The exponent b values in LWR (W = aLb) ranged from 2.593 to 5.184. Four species including C. aceratus, C. hamatus, N. rossii, and T. bernacchii followed positive allometric growth, T. newnesi followed negative allometric growth, and only N. coriiceps showed isometric growth. These results can be helpful in understanding the ecological and growth conditions of six fish species living in the Antarctic Ocean, providing more information for future research on Antarctic fish.

Length-Weight Relationships of Twenty-Nine Native Fish Species from Hongshui River, Southern China

Twenty-nine native freshwater fish species belonging to the four orders and eight families were collected from the Hongshui River, which belongs to the upper reaches of the Pearl River, to analyze their length-weight relationships (LWRs). Twenty-nine freshwater native fish were sourced using cages (0.2 m in height, 0.25 m in width, and 8 m in length, with a mesh size of 5 mm) and triple gillnets (20–40 m long, 1–3 m high, and mesh size, 2−3 cm) between December 2021 and July 2022. For each freshwater fish, the total length (TL) and weight were measured to the nearest 1.0 mm and 0.1 g. All LWR parameters of the twenty-nine species were statistically significant P < 0.001 . The length-weight relationships for the nine species were new to the FishBase and new maximum lengths were recorded for the twenty species. The LWR values provided for the first time will help to validate the accuracy and predictability of the Bayesian models for estimating the species-specific growth parameters of the data-poor species.

Population dynamics and yield estimation of Common Carp (Cyprinus carpio, Linnaeus, 1758) in Ayalew reservoir, Gamo Zone, Southern Ethiopia

Common carp (Cyprinus carpio) is an introduced fish species in Ayalew reservoir. This study provides the first results on fishery dynamics of the species in the reservoir. The study was aimed at estimating important population dynamics parameters and production potential. Total length (TL) and total weight (TW) data were collected from a total of 276 fish samples (141 females and 135 males). The obtained data were analyzed using FiSAT II software. Jones length-based cohort analysis model and length-based Thompson and Bell yield prediction models were employed to estimate the population and production potential. The mean total length was 26 cm and the dominant length groups ranged from 17 to 33 cm were 87%. The length-weight relationship parameters were (TW = 0.0565TL2.53, R2 = 0.95) and the condition factor K = 1.29. The parameters of von Vertalanffy growth curve were L∞ = 41 cm, k = 0.52, to = -2.29, θ = 2.9 and A0.95 = 5.5 years. The estimated values of the total, natural and fishing mortalities were Z = 1.23, M = 0.55 and F = 0.68, respectively. The current exploitation rate was 0.55 which indicates slightly overexploitation. The estimated fish population and the annual fish yield were 59,304 and 1.5 tons, respectively. However, investigation on reproductive biology, limnolocal aspects and stock enhancements should be required for the sustainability of these resources.

Length-Weight Relationship of 20 Cryptobenthic Fish in Coral and Rocky Reefs in the Gulf of California, Mexico

We present the length-weight relationships (LWRs) in 20 cryptobenthic reef fish species in the Gulf of California (Mexico). Nine of these species had no LWR records yet. However, the other species had LWRs based on in-formalin specimens collected more than 20 years ago. This conservation method has likely affected LWRs parameters. Our study showed higher estimations of the parameter a obtained on fresh specimens than in-formalin individuals. On the other hand, parameter b was not affected. Therefore, the biomass estimates using previous LWRs were strongly underestimated. Ergo, the similitude in parameter b between the two conservation methods highlights that the shape of the LWRs is conserved and did not change over the last 20 years. Finally, we compared the LWRs of shared species in the region’s two main types of shallow reefs, i.e., coral and rocky reefs. We found that the body fitness was not affected by reefs type, which means that both habitats seem to offer similar living conditions for shared species.

Length-weight relationship, sex ratio, and diet of three fish species (Actinopterygii: Teleostei) in streams of the Pomba River basin, Paraíba do Sul river drainage, Southeastern Brazil

This study aimed to estimate the parameters of length-weight relationship, sex ratio, and diet of three freshwater fish species that inhabit streams in the Pomba River basin (Rio de Janeiro, Brazil). Fishes were sampled with seine nets (2.0 × 1.20 m, 2 mm mesh size) and dip nets (0.46 × 0.33 m, 2 mm mesh size) from October to December 2018. Measurements were taken for total length (TL - 0.1 cm precision) and total weight (TW - 0.01 g precision). Growth model parameters were estimated. This study provides new length-weight relationship data for Deuterodon intermedius (Eigenmann, 1908), Australoheros paraibae Ottoni & Costa, 2008, and Hypostomus punctatus Valenciennes, 1840. All of them ingested a wide variety of food items, including plant material like algae, animal material such as terrestrial and aquatic insects, and undefined matter such as detritus or mud. The three species showed a higher number of females. Our study provides basic information for functional diversity studies, as well as for future investigations associated with the evaluation of anthropic impacts, either occasional or chronic, on the fish assemblage structure of the Pomba River basin.

Effect of a fishing closure on Chamelea gallina stocks along the Turkish coast

Abstract The striped venus clam Chamelea gallina (SVE), plays an important role as an infaunal filter-feeder in the ecosystem, besides an important economic role in the Black Sea coasts of Turkey. It is caught using hydraulic dredge boats, then processed, and the final product (frozen meat) is exported to EU countries. SVE fishing requires a special licence and regulations. Also, SVE beds were closed to fisheries for the recovery of stocks for 2 years. In the study, SVE beds were investigated during the closed season over two years to assess stock density. Additionally, the number of macrobenthic species that share the same habitat as the SVE was determined. The sampling area was divided into five sub-areas and four strata by depth and then stratified random sampling was applied to collect data. In 2011, SVE stock sizes in the sub-areas were 11,723.58 ± 5167.262 tons (Cide), 35,082.94 ± 27,510.95 tons (İnebolu), 10,077.05 ± 4970.68 tons (Türkeli), 3304.36 ± 3215.1 tons (Ayancık) and 1431.3 ± 1703.5 tons (Sarıkum). In 2012, these estimated stocks were 13,820.41 ± 6977.86 tons, 34,841.94 ± 14,623.71 tons, 8148.27 ± 5006.74 tons, 3420.72 ± 3093.67 tons and 2023.74 ± 2832.63 tons, respectively. However, the estimated SVE total biomass did not change significantly during the period when the fields were closed (P > 0.05). The results indicate that length-weight relationship parameters varied of b from 2.9011–2.9072 in two years. Shell damage during fishing, environmental factors, food competition and consumption by the main predator all have a significant impact on stock densities, and changes occurring in these conditions should be considered in fisheries management.

Length-weight relationships of 55 mesopelagic fishes from the eastern tropical North Atlantic: Across- and within-species variation (body shape, growth stanza, condition factor).

We present estimates of length-weight relationships (LWRs) of 55 mesopelagic fish species of 13 taxonomic families based on data collected in the eastern tropical North Atlantic (ETNA) in March/April 2015. Our data include novel records for 19 species, while for 25 species LWRs are based on the most robust sample sizes, and for 21 species they are based on the most representative size ranges available up to now. In 31 species, body lengths were within the maximum range of body lengths recorded in the area, with new records of maximum lengths for 13 species. Most values for b fell between 2.5 and 3.5 with a mean exponent b of 3.08 (median 3.12) and a mean a of 0.0172 (median 0.0113). Body shape as covariate ('elongated', 'fusiform' and 'short-deep') strongly determined the variation in log a as a function of parameter b. For the mesopelagic fish species investigated, the form factor a3.0 indicated a significant increase of median a3.0 from 'elongated' to 'fusiform' to 'short-deep' body shapes. Large variability existed in parameter b between species of the same taxonomic family. Isometric growth was indicated in only nine species, whereas a positive allometry was suggested in 22 species. Using segmented regression analysis, we investigated ontogenetic variation in LWRs in 30 species. Of these, 20 species showed a breakpoint in LWR, whereby nearly equal numbers exhibited an increase or a decrease in slope following the breakpoint. Seven out of nine species showed significant regional variation in the slope of the relationship of the relative condition factor Krel vs. body length between two or more regions of the ETNA [eastern and western part of the oxygen minimum zone (LO-E, LO-W), northern and central equatorial region (EQ-N, EQ-C)]. A conspicuous pattern was an increase in Krel with body size in the LO-E (in six out of eight species), whereas in the LO-W and the equatorial regions the majority of species showed a related decrease. These findings support the idea that growth patterns in mesopelagic fishes in tropical regions show species-specific ecological niche and life-history adaptations that are finely tuned to small-scale regional environmental conditions. Comparison of our data with those of other studies emphasises that, regarding the small adult sizes of many mesopelagic fish species, estimates of LWR parameters are strongly influenced by sampled size distributions.

Skeletal Deformities in Invaded Population of Amazon Sailfin Catfish Pterygoplichthys pardalis (Castelnau, 1855) in the East Kolkata Wetland, India

The incidence of severe vertebral deformity was reported in the specimens of the Amazon sailfin catfish Pterygoplichthys pardalis (Castelnau, 1855) for the first time in India. Fish samples were collected on bimonthly basis during June 2019 to December 2020, from wastewater-fed large aquaculture impoundments (locally called ‘bheries’) of north-western part of the East Kolkata Wetlands, India. Sampling were performed using seine nets of mesh size 15 mm–30 mm and covering more or less 5,000 sq m area each time. Deformities were found in 18 specimens of Pterygoplichthys pardalis. Two types of spinal deformities, scoliosis and kyphosis, were determined visually and reconfirmed by radiography using medical X-ray system. The total length and body weights of individual fish (normal and deformed) were measured and the length-weight relationships parameters were calculated and compared. A significant difference was observed between b values of deformed (b ~1.679) and normal specimens (b>2.5) of Pterygoplichthys pardalis. Various environmental and genetic factors could contribute to the development of this deformity in the Pterygoplichthys pardalis, but based on the available data, it is impossible to confidently identify the key factor(s). However, as the fishes were from a wastewater-fed fisheries system, which receive about 600 million litres of industrial and municipal discharge of the city every day, metal and other organic contaminants could be a reason of this impairment in Pterygoplichthys pardalis.

Length–weight relationships of six freshwater fish species from the middle section of the Yangtze River basin, China

Six freshwater fish species belonging to two families were sourced from the middle section of the Yangtze River to analyze their length–weight relationships (LWRs). Fish specimens were collected seasonally using triple gillnet (30–50 m long, 2–4 m high, and mesh size, 2–3 cm) between September 2020 and August 2021. For each fresh specimen total length (TL) and weight were measured to the nearest 1.0 mm and 0.1 g. All LWR parameters of the six species were statistically significant (p < .001). New maximum TL measures for four of the six fish species are recorded, and the LWRs of Ancherythroculter nigrocauda, Megalobrama mantschuricus, and Culter oxycephaloides are published herein for the first time. These results will contribute to fishery research, management, and conservation of the Yangtze River ecosystem.

Length–weight relationships of 78 fish species from São Francisco River basin, Brazil

We established the length–weight relationships (LWR) for 78 fish species from the São Francisco River basin, Brazil. Samples were originated from different scientific projects performed between 1993 and 2019. Fishing gears used were mainly gillnets and cast nets of various mesh sizes. Specimens varied from 0.6 to 128 cm (18.1 ± 11.8 cm) and from 0.01 to 26,900 g (317.9 ± 733.6 g). The allometric coefficient b varied from 2.509 to 3.494. For 66 species, the LWR parameters were completely novel and, for the other 12 species, are present for the first time for the São Francisco River basin.

Length–weight relationship of eight native fish species from Paraguaçu River basin, Brazil

This study reports the first record of Length-Weight Relationships (LWR) of eight endemic freshwater fish species from the Paraguaçu River basin, Northeast Brazil. Sampling was conducted in thirteen streams using electrofishing. Only Kalyptodoras bahiensis specimens from the middle section of Paraguaçu river were obtained from local fishermen. Fishes were fixed with 4% formalin before measurement, so some shrinking should be considered. Total weight (TW) was measured to the nearest 0.1 g and standard length (SL) to the nearest 0.1 cm. The LWR parameters were determined using the linear regression model: log TW = log a + b log SL, where ‘a’ is the intercept and ‘b’ is the slope of the linear regression. All LWRs were significant (p < .01) with r2 values ranging from 0.796 to 0.97. The allometric coefficient ‘b’ values ranged from 2.39 to 3.32. New maximum lengths are recorded for Geophagus diamantinensis and Copionodon lianae.

Biological aspects of Hypostomus affinis (Siluriformes: Loricariidae) in Brazilian coastal rivers

Abstract Aim Determine the length-weight relationship (LWR), the period of reproduction, and evaluate the variation of the condition factor (K) of Hypostomus affinis from two coastal drainages in southeastern Brazil, assessing the influence of the rainfall on these biological aspects. Methods fish were sampled quarterly between April 2008 and April 2010 in tributaries of the Doce River basin (DRB) and the Paraíba do Sul River basin (PSRB). Specimens were caught using gillnets. LWR parameters were assessed by location and sex through a t-test. We used the frequency of mature specimens (FM) to evaluate the breeding period. Both FM and K values were assessed by a sinusoidal equation. Results A total of 492 specimens was captured, of which 128 were from the Doce River basin (DRB) and 364 from the Paraíba do Sul River basin (PSRB). In both areas, specimens showed a negative allometric growth type. We collected mature specimens along the studied period in both drainages, with the highest frequency observed at the beginning of the rainy season. We found a positive correlation between the rate of matures and the local rainfall variation. The condition factor (K) was lower for specimens from DRB and did not show a cyclic trend. On the other hand, we observed a cyclic chance of the K values for the individual from the PSRB, peaking in the transitional dry-rainy period. However, it was not possible to correlate it to the rainfall variation. Conclusions LWR parameters of H. affinis were consistent with data already available in the literature. The rainfall may influence the FM but not the K values. In this case, biological characteristics such as reproduction and (or) feeding may be jointly driving a discrete variation of K values. The reduction in K values in the rainy periods suggests a remarkable energetic cost for the reproductive process. In short, our results help us to understand the life cycle of a fish species within a highly modified environment, especially by dams.

Length‐weight relationship of five species of Nemipteridae family along the Gulf of Mannar, Eastern Indian Ocean

The parameters 'a' and 'b' of the length-weight relationship of five Nemipteridae species viz., Nemipterus bipunctatus (Valenciennes, 1830), Nemipterus randalli Russell, 1986, Scolopsis bimaculata Ruppell, 1828, Scolopsis xenochrous Gunther, 1872 and Scolopsis vosmeri (Bloch, 1792) are reported from the Gulf of Mannar, Eastern Indian Ocean. The fish samples were collected fortnightly from the trawlers of Thoothukudi Fishing Harbour between September 2020 and June 2021. The trawlers operate at a depth of 40–150 m with a 2–2.30 hours hauling period. These are operating bottom trawl nets and have a total length of 40 m with a cod-end mesh size of 35 mm. The total length of the fish was measured to the nearest 0.1 cm and weight to the nearest 0.01 g, respectively. The descriptive statistics and estimated length-weight relationships (LWRs) parameters were detailed in the paper.

Evaluation of length-weight relationship for a native goby, Awaous jayakari (Teleostei: Gobiidae) in the Middle East

Parameters of length-weight relationship of freshwater and marine fishes have long been of interest as a longstanding theme fisheries sciences and have been estimated for many fishes around the world. In this study, for the first time, length weight relationship (LWR) was estimated for a native fish, the long nose goby Awaous jayakari (Gobiidae) collected from the inland waters of Oman in 2020 using foldable shrimp and crab fishing traps (mesh size of 3*3mm). The parameter of b for male and female specimens based on standard length (SL) was within the range of 2.666-4.377 and 2.852-3.374 respectively. As proposed for different fishes there was high and significant correlation coefficients with between length and weight of (0.970-0.983). Bailey’s ‘t’ test revealed that b value significantly deviated from 3 for both males and females.

Temporal variations of length, weight and condition of the Asian stinging catfish Heteropneustes fossilis (Bloch, 1794) in the Ganges river (NW Bangladesh)

The present study revealed on temporal variations of length, weight and condition of Heteropneustes fossilis (Bloch, 1794) in the Ganges River, Northwestern Bangladesh. Total 1161 individuals of H. fossilis were caught by various habitual fishing gears such as seine net, cast net and gill net during January to December 2019. For every specimen, body weight (BW) was taken by digital balance to the accuracy of 0.01 g and total length (TL) was taken using a measuring board. Relative condition factor (KR) was assessed by KR = W/(a×Lb), where W is the BW in g, L is the TL in cm and a and b are length-weight relationships parameters. The value of KR ~ 1 specifies good health, &gt;1 specifies over bodyweight as compared to length, whereas &lt;1 suggests a fish in poor condition. The TL varied from 8.5-28.7 cm whereas the BW was 37.17–2250 g. The overall KR for H. fossilis was 0.99-1.06 in the Ganges River. The highest KR was observed in May while the lowest was in January. The KR was significantly correlated with BW in the Ganges River. The outcomes of the study will be helpful for future management of this fish in the Ganges river ecosystem as well as adjacent water bodies.&#x0D; Res. Agric., Livest. Fish.8(2): 259-266, August 2021