Length-weight Relationship Research Articles

Evaluation of the toxic metals, proximate composition and length-weight relationships of selected fish species from the Gadananathi River, Southern Tamil Nadu.

The present study reveals toxic metals, proximate composition, and growth conditions in seven fish species, aiding their nutritional importance and conditions. The samples of seven different small indigenous fish species, including Xenentodon cancila, Glossogobious giuris, Pseudambassis ranga, Puntius dorsolis, Mystus vittatus, Dawkinsia filamentosa, and Dawkinsia tambraparaniei, were collected in river Gadananathi, Tamilnadu, India. A total 14 fish samples were analyzed for lead, cadmium, and copper using atomic absorption spectrometry. The standard procedures were used to determine the length-weight and proximate composition of the seven fishes. The findings revealed that the seven fish species had variable amounts of metal buildup. Cu levels were highest in D. tambraparniei gills and lowest in M. vittatus gills and livers; nonetheless, substantial amounts of Cu were found in P. dorsalis livers. In the length-weight correlations of the regression parameters of coefficient value r2, the "a" and "b" values revealed a positive allometric growth rate in all fish species except G. giuris and M. vittatus. However, X. cancila had the highest composition in the proximate analysis, while D. tambraparniei and D. filamentosa had the highest protein content mean value at a significant level (P ≤ 0.05). Overall, discrepancies in nutritional content might be related to species, environmental circumstances, fish age and size, and food availability.

Estimation of Economic Losses in Trammel Nets Fisheries Using the Length–weight Relationship

Estimation of Economic Losses in Trammel Nets Fisheries Using the Length–weight Relationship

Analysis of Feeding Habits and Biological Aspect of Yellow Stripe Trevally (Selaroides leptolepis) Caught at the Lekok Coast, Pasuruan, East Java

The fish population in waters can decrease due to the uncontrolled utilization of fish resources. Food is one of the determining factors for the population and condition of fish in the waters. Considering the economic and ecological importance of the yellow trevally in food webs, this research was conducted to analyze the feeding habits and biological aspects of the yellow trevally in Pesisir Lekok. This study used a descriptive data analysis with complete randomized design. The research was conducted from May to July 2023 at Pesisir Lekok, Pasuruan, East Java. The results showed that the yellow trevally is carnivorous with the dominant food found being zooplankton from the genus Microcalanus sp. with a frequency of occurrence of 41%. The highest plankton composition found in the stomach of the yellow trevally was the phytoplankton of the Aulacoseira genus, which was 22.2%. Meanwhile, the foods most preferred by the yellow trevally are Rotifera and Charophyta with an index value of +1. The biological aspect of the yellow trevally seen from the length-weight relationship shows that the growth pattern of the yellow trevally is negative allometric with a b value of 2.651. While the condition factor range average values are 1.009 – 1.027. The results of this study are expected to be the basis for efforts to support the sustainable management of fisheries resources, especially the yellow trevally in the coastal waters of Lekok.

Asymmetrical individual both left and right otoliths of Tuna Scombrini collected from the Java Sea

Otolith can be used as a natural marker of fish stock or anomalies between individuals within fish stock. This research aims to study the relationships between fish length and otolith length and confirm differences in otolith shape between species in the Scombrini tribe and Carangidae family (Decapterus ruselli). Sample used in our analysis were collected around July - September 2023 from three different location, Rastrelliger brachysoma (Lekok waters, Pasuruan), Scomber australasicus (Bali Strait waters) and Decapterus ruselli (Sendang Biru, South Malang). Total 96 specimens were identified based on morphological character as Rastrelliger brachysoma, Scomber australasicus and Decapterus ruselli. Each of following samples were cut horizontally at the frontal head to open the skull and remove sagitta otolith below the hindbrain using dissecting set, then cleaned and stored dry in microtube 1,5 ml separately for left and right to further documented using Celestron Digital Microscope Pro Gray USB 44308. Otolith morphometric data collected includes maximum length using TpsDig and weight using analytical balance. The relationship between Forked Length (FL) and otolith length, length-weight relationship of otolith was determined using simple linear regression on software Statistical Product and Service Solutions (SPSS). Paired sample t-test was applied to determine asymmetrical size of left and right otoliths. In this study, it was found that the shape of the otoliths between species has differences in the rostrum, antirostrum, ventral and dorsal parts. FL-otolith length relationship of S. australasicus, R. brachysoma and D. ruselli are Y=0,725+0,164X, r2= 0,519; Y=0,191+0,230X, r2= 0,911; Y=3,156+0,075X, r2=0,071 respectively. The LW sagitta relationship shows that there is a very strong relationship (P<0,05) between L and W of otoliths. The results of the Paired Sample T-test showed that there was no significant difference in the size of the left and right otoliths (Sig>0.05). Otolith shape is influenced by fish behaviour, diet and environment and it may be used as additional information to distinguish between tribe or even species. Otherwise, its asymmetric relationship and LW relationship may be potential new methods for stock discrimination and have other implications such as stock assessment, understanding natural asymmetry, and its potential applications in fisheries management and conservation.

A Novel Frontier in the Geographic Distribution of the Japanese Sea Cucumber Apostichopus japonicus (Selenka, 1867) (Stichopodidae: Holothuroidea) in the World

The natural distribution of the Japanese sea cucumber (Apostichopus japonicus Selenka, 1867), a sea cucumber species, is characterized by the Northwest Pacific. Long-term monitoring studies from 2020 to 2024 document a significant deviation from the known natural distribution of A. japonicus and its ability to extensively colonize the Gulf of Izmit, the easternmost part of the Sea of Marmara. This record is also the first documentation of the species from the Mediterranean Sea. Population data extracted from 67 samples allowed the determination of size and weight distribution, length-weight relationship, and condition factor. The study delves into the implications for fisheries management by evaluating the species’ dispersion beyond its natural range and its adaptation, shedding light on potential threats from illegal hookah diving fisheries. While its presence offers potential economic benefits through fishing income, its emergence as an invasive species can pose critical ecological risks to the receiving ecosystem.

Age and Growth of Japanese Anchovy (Engraulis japonicus, Temminck &amp; Schlegel, 1846) in Coastal Waters around Shandong Peninsula, China

Japanese anchovy (Engraulis japonicus) is a small pelagic fish with commercial and ecological importance. In spite of its importance, in recent years, specific research on anchovy in the Shandong Peninsula area has been relatively scarce and outdated. This study aims to estimate the age and growth characteristics of anchovy through year-round seasonal sampling from 2016 to 2017, utilizing length–frequency and otolith microstructure analysis. The higher coastal abundance and larger size observed in the spring and summer suggest a potential peak spawning period for anchovies dominated by larger-sized individuals. Based on otolith analysis, anchovies range in age from 0 to 4 years, with a limited presence at age 0 and dominance in the age-1 group. The length–weight relationship (LWR) equation shows hyper-allometric growth for each season, with a mean relative condition factor (Kn) of 1.025 ± 0.005, indicating good health. Additionally, the von Bertalanffy growth equation of can be expressed as Lt = 154.40 [1 − e−0.604 (t + 0.965)], suggesting a medium growth rate (K = 0.604). These findings contribute to the understanding of anchovy age and growth patterns, emphasizing the continuous need for research and monitoring to support rational and sustainable fisheries management and conservation efforts.

Length frequency distribution, length-weight relationship and condition factors of Hilsa Shad, Tenualosa ilisha from Bangladesh

Hilsa shad, Tenualosa ilisha, a cherished and economically vital species, thrives in the waters of Bangladesh. It holds a prominent role in bolstering the nation's food security and influencing the ecological dynamics of aquatic ecosystems along the Bangladeshi coast and estuaries. This comprehensive study encompasses data collection efforts on the Hilsa fish species, conducted at 12 commercial landing centers throughout Bangladesh over the course of 2020. The study describes some fundamental components, including length frequency distribution, length-weight relationships, and condition factors, offers invaluable insights into the growth, health, and overall well-being of Hilsa population. Notably, the length-weight relationship analysis revealed size ranges of 11.5-59.2 cm and 11.0-49.0 cm total length for females and males, respectively. The observed b values indicated positive allometric growth (b &gt; 3.00) for female population and negative allometric growth (b &lt; 3.00) for male population in the length-weight relationship. Among the condition factors scrutinized, Fulton's condition factor emerged as the most reliable indicator for assessing the health and condition of the Hilsa population. This study offers valuable insights for biologists, aiding in the assessment of the species' status and providing essential information for fishery biologists and conservation biologists. Such insights are instrumental in the management and ultimate conservation of this iconic species in Bangladesh.

Length-Weight Relationship and Condition Factors of Sea Cucumber on Mare and Moti Islands Conservation Areas in North Maluku

This work aimed at determining the growth patterns and condition factors of three sea cucumber species, namely Holothuria atra, Bohadschia marmomata, and B. vitiensis in seagrass beds of Mare and Moti Islands. Samples were collected in March 2023 using a roaming survey method in a block area with an area of 5000 m2.  As amount of 54 sea cucumbers were analysed from Mare Island and 58 individuals from Moti Island. The results of this study indicate that the correlation (r) length-weight relationship for the three sea cucumber species is stronger (r &gt; 0.6) on Moti Island than Mare Island.  H. atra and B. marmorata have a negative allometric growth pattern, while B. vitiensis has a positive allometric growth pattern on both islands. The Fulton condition factors for the sea cucumbers assessed on Mare Island were recorded for H. atra of 2.84 ± 2.01, B. marmorata of 3.13 ± 2.47 and B. vitiensis of 9.24 ± 5.73. Meanwhile, at Moti Island were found for H. atra of 12.49 ± 11.66, B. marmorata of 9.58 ± 7.38, and B. vitiensis of 8.87 ± 3.68. This is indicated that all sea cucumber species are in good physical condition. Meanwhile, the relative weight condition factor (Wr) of the three species of sea cucumbers on both islands were in the range above 100, which indicated a food surplus in their habitat. The results of this research can be important as the preliminary data in terms of sustainable management of sea cucumber stocks in North Maluku.

Length-Weight Relationship and Condition Factor of a Commercial Food Fish Labeo rohita (Hamilton, 1822) from Ghaghara River, Uttar Pradesh, India

The present study provides first-hand information about the length-weight relation of Labeo rohita (Hamilton) from Ghaghara River, Uttar Pradesh. We collected 107 specimens and took length and weight for better conservation techniques and proper management for rohu. A total of 107 specimens were examined for the study, which has ranging from 25.2-56.13 cm TL (Total length) and 183.3-2409.78 gm (weight) were used for the study of LWRs and condition factors. Our study represented that L. rohita exhibited a negative allometric growth (b &lt; 3) indicating that the fish grows faster in length compared to their weight. The values of the correlation coefficient (r2) and condition factor (K) are 0.8601 and 1.27 respectively. This research will be useful for fishery research, stock assessment, conservation, and estimation of the fish condition of this Himalayan River.

Length-weight relationships of four difficult-to-sample Caspian endemic gobies (Teleostei: Gobiidae): Benthophilus persicus, Benthophilus baeri, Knipowitschia longecaudata, and Hyrcanogobius bergi

The present study provides the length-weight relationships (LWRs) for four difficult-to-sample Caspian endemic gobies for the first time: Benthophilus persicus, Benthophilus baeri, Knipowitschia longecaudata, and Hyrcanogobius bergi. They were collected from shallow and deep waters of the southwestern Caspian Sea using various methods, including beach seining, scuba diving, and deepwater bottom beam trawls. The slope (b) of LWRs ranged from 2.874 for B. baeri, to 3.408 for H. bergi with coefficient of determination higher than 0.918. The b values showed significant differences between the sexes of all species.

Early-Life Population Parameters and Hatch-Date Analysis of Sharpsnout Seabream (Diplodus puntazzo Walbaum, 1792) Juveniles in the Sea of Marmara, Türkiye

This research aims to determine early-life population parameters and hatch date of sharpsnout seabream (Diplodus puntazzo Walbaum, 1792) juveniles using microstructure analyses of sagittal otoliths collected from the Sea of Marmara, Türkiye. Specimens were collected using an experimental beach seine at 12 stations from November 2021 to March 2022. The mean catch per unit effort (CPUE) was 1.1 individuals per haul, with 44.4% of the total D. puntazzo specimens collected at the Erdek Station. A negative allometric growth was calculated from the length-weight relationship equation (W=0.0178L2.698). The daily age ranged between 39 days-1 and 141 days-1, with a mean of 78.9 ± 2.29 days-1. The daily growth rate and mortality ratio were calculated as 0.213 mm/day and 4.38%, respectively. The hatching mainly occurred in September and October.

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.

On the biology of blackbellied angler, Lophius budegassa Spinola, 1807, in the north-western Mediterranean

In the Mediterranean Sea, the blackbellied angler, Lophius budegassa Spinola, 1807, represents a relevant fraction of the commercial by-catch of bottom trawling and small-scale fisheries that use passive gears (e.g., set nets, bottom longlines, etc.). Despite its importance, there are no comprehensive studies on the population dynamics of this species, and there is still scarce and scattered knowledge of its biology and ecology. Biomass, morphometric, and biological data of the blackbellied angler were collected from 1994 to 2021 by means of the Mediterranean International Bottom Trawl Survey (MEDITS) programme in the Ligurian and northern Tyrrhenian Seas, and in the EU Data Collection Framework during the period of 2006-2021. Furthermore, ageing was performed on specimens collected from 2013 to 2021 during the MEDITS programme. There were high values for the density indices and the spatial distribution of biomass in the central sector of the investigated area (the Tuscan Archipelago), mostly on the continental shelf. The length-weight relationship showed negative allometric growth when considering the sexes together, and no difference between the sexes. The size at first maturity (L50) was estimated at 39.4 cm total length (TL) in females and at 29.2 cm TL in males. The obtained Von Bertalanffy growth parameters were: in females, L∞ = 74.50 cm, k = 0.10 years-1, and t0 = -0.40 years; in males, L∞ = 61.30 cm, k = 0.14 years-1, and t0 = -0.38 years. There were differences in growth between males and females for L∞ (χ2 = 10.04; p &lt; 0.05) and k (χ2 = 6.12; p &lt; 0.05).

Livelihood status of the fishing community of Mahakanadarawa reservoir in Anuradhapura, Sri Lanka

Mahakanadarawa reservoir located in Anuradhapura is one of the major, perennial reservoirs in Sri Lanka, extending over 1,457 ha. It provides livelihood opportunities through fisheries, irrigation for agriculture, and fostering economic growth in the surrounding region. Yet the fisheries-based livelihoods of the Mahakanadarawa reservoir have not been fully assessed. Hence, this study investigated the fishery and fisher profile of the reservoir. Primary data were collected from  eight landing sites. A pre-tested questionnaire was used to interview 72 fishermen using a mixed method. Main variables including social, human, physical, natural, and financial capitals, fishery profile, fish and fisheries-based post-harvesting techniques, market chain analysis, and fisheries management practices, catch per unit effort for the gillnet fishery were calculated. Secondary data including stocking fish fingerlings and species-wise harvesting data for the past 10 years were collected from the district aquaculture extension office (Anuradhapura) of the NAQDA. A secondary study on the length-weight relationship of Oreochromis niloticus along with its condition factor value was performed. It was revealed that O. niloticus had negative allometric fish growth (b = 2.6667) with a condition factor value of 1.9092. The female fish had a higher mean total length compared to the male fish. In the fishing community, 95.83% of males and 4.17% of females were engaged in fishery activities. Mainly gill nets and non-mechanized fiberglass canoes were used for fishing. The average CPUE was 0.000339 kgm-2day-1. A strong positive (r =0.841) correlation was reported for fish stocking and fish production. Fish smoking and sun drying were the common fish processing techniques. The fish supply chain targeted the regional market. A cooperative level co-management system was identified among the reservoir fishing community. The current study discloses the livelihood capitals of the fishing community along with the existing supply chain which can be utilized for the sustainable management strategy of the Mahakanadarawa reservoir in the long run.

Morphometry, Growth, and Condition of Hatchery-Reared Cisco (&amp;lt;i&amp;gt;Coregonus artedi&amp;lt;/i&amp;gt;) and Bloater (&amp;lt;i&amp;gt;Coregonus hoyi&amp;lt;/i&amp;gt;)

The re-introduction of native species that have been extirpated or in low abundance in the Great Lakes has been a binational initiative between the United States and Canadian governments. Recently, new management programs have been underway that use current hatchery facilities for the restoration of native forage fishes in Lake Ontario. These species include Bloater (&amp;lt;i&amp;gt;Coregonus hoyi&amp;lt;/i&amp;gt;), which has been extirpated from Lake Ontario for approximately four decades, and Cisco (&amp;lt;i&amp;gt;C. artedi&amp;lt;/i&amp;gt;), which exists at a fraction of its former abundance. We assessed morphometrics, length-weight relationships, and condition factors during early life development for eight cohorts of Cisco and Bloater reared from 2012-2019. Weekly samples for Cisco and Bloater were measured from hatch until release (29-45 weeks, 133-1,002 samples annually). Head width, gape, mandible length, and mouth height metrics were all larger for Cisco than Bloater at any given size but increased at similar rates for both species. Average condition factors for Cisco and Bloater were 0.54317 and 0.55892, respectively. This information may also improve field identification of these species, helping managers evaluate the relative success of different release strategies for rehabilitation of populations of these native species.

The length-weight relationship and condition factors of coastal small-sized adult and juvenile fish species following dense mucilage in the Sea of Marmara, Türkiye

The length-weight relationship and condition factors of coastal small-sized adult and juvenile fish species following dense mucilage in the Sea of Marmara, Türkiye

Length–Weight Relationships of Commercial Fish Species Captured by Small-Scale Fisheries in the Northern Pacific of Colombia

Length–Weight Relationships of Commercial Fish Species Captured by Small-Scale Fisheries in the Northern Pacific of Colombia

Length-Weight, Length-Length Relationships and Condition Factor of &lt;i&gt;Crossocheilus diplochilus&lt;/i&gt; (Heckel) from Dal Lake of Kashmir Himalayas

Length-Length Relationships (LLRs) and Length-Weight Relationships (LWRs) are vital tools in the management of fisheries to facilitate a proper understanding of the condition of fish species and the growth pattern from different environments. Despite numerous studies on LWRs and LLRs of fish species, the majority of those have focused on the food fish creating a lacuna in the biometric assessment studies of forage fish. Against this backdrop, the current work was undertaken to estimate the LLRs, LWRs and condition factor of Crossocheilus diplochilus, a forage fish from Dal Lake of Kashmir Himalayas. The fish was reported to show negative allometric growth, attaining a maximum length of 14.8 cm and a maximum weight of 17.19 g. The overall condition factor was reported to be 0.86 ± 0.10, reflecting a poor condition of growth. The fish forms a vital trophic link of the lake, as such timely biometric studies could help in managing its stock properly.

The trophic state of the reservoir influences the allometric coefficient and condition factor of Giant Freshwater Prawn (Macrobrachium rosenbergii) cultured in perennial reservoirs of Sri Lanka

Giant Freshwater Prawn (Macrobrachium rosenbergii) is an essential crustacean species in culture-based fisheries of Sri Lanka. Studying the morphometric characteristics and empirical models in fishing and aquaculture is highly beneficial; thus, it is the most accurate way of analyzing growth patterns. The present study aimed to establish the length-weight relationship and compute the relative condition factor for the M. rosenbergii cultured in trophically different perennial reservoirs in Sri Lanka, considering the trophic status of the reservoirs. The allometric coefficient and condition factor of M. rosenbergii concerning the trophic state of the reservoir were empirically ascertained from the samples collected from twenty-five dry-zone perennial reservoirs of Sri Lanka. Carlson's Trophic State Index (TSI) was calculated based on the chlorophyll-a content. The allometric coefficient and relative condition factor were computed using the total length and weight of the M. rosenbergii. The TSI ranging between 44.09±0.47 and 65.15±0.24 differed significantly (p&lt;0.05). Sexual dimorphism in the growth of males over the female M. rosenbergii was ascertained with the aid of allometric coefficient (b value) 3.2306 (positive allometric growth) and 2.9534 (negative allometric growth), respectively. In eutrophic perennial reservoirs, Giant Freshwater Prawns showed the highest allometric coefficient in both sexes. There was a positive correlation between the allometric coefficient and TSI among males, r(23)=0.7210, p&lt;0.001, and combined sexes, r(23)=0.7900, p&lt;0.001, respectively. The results of the present study revealed that the trophic state of the reservoir influences the allometric coefficient and condition factor of M. rosenbergii cultured in perennial reservoirs of Sri Lanka.&#x0D;