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From December 2012 to June 2014, 796 Pacific guitarfish were caught in 183 fishing sets in northern Peru. Catch occurred in 86.3% of sets. Most individuals caught were mature with a bias toward males. The mean total length for females and males was 83.4 cm, and 91.1 cm, respectively. The capture per unit effort (CPUE) was 12.6 ± 3.4 guitarfish (km.12 h) -1 . The length-weight relationships showed that this species presents a sexual dimorphism in growth. These results support the importance of Sechura Bay as a key area for this species. This study represents the first species-specific fishery data for the Pacific guitarfish., (© 2024 Fisheries Society of the British Isles.)

<b>Background and Objective:</b> Studies on fish biology are essential for the sustainable management and conservation of fish biodiversity. This study observed the length-weight relationships and condition factors of common rudd fish, which give us some information about the ecological and nutritional conditions of fish. This information is crucial to fishery management. <b>Materials and Methods:</b> The length-weight relationship (LWR) and condition factors (K) of 270 <i>Scardinius erythrophthalmus</i> caught in Anzali Lagoon from April to August, 2015. <b>Results:</b> The total length and body weight of <i>S. erythrophthalmus</i> ranged from 94-179 mm and 11.98-98.5 g, respectively. A strong positive relationship was observed between length and weight (r = 0.96). There were no significant differences in the condition factors of males and females (p>0.05). The lowest K value was observed in April (K = 1.5±0.04) and the highest in July (K = 2.25±0.34). The sex ratio of 1.0 male: 1.15 female was observed, with no significant difference between males and females (p>0.05). <b>Conclusion:</b> In this study, the regression coefficient (b) in males and females was 3.35 and 3.29, respectively, more than 3.0, which means they have positive allometry growth in both sexes.

Quantitative and qualitative measures of fish health and welfare are essential for management of both wild capture and aquaculture species. These measures include morphometric body condition indices, energetic condition and aquaculture operational welfare indicators (OWIs). Measures vary in ease of measurement (and may require destructive sampling), and it is critical to know how well they correlate with fish health and welfare so appropriate management decisions can be based on them. Lumpfish (Cyclopterus lumpus) is a new farming species that needs nondestructive OWIs to be developed and validated. In this study, we developed a C. lumpus fin damage score. Four different body condition indexes based on individual weight relative to either length-weight relationships or relative to other fish in its local environment were tested (using model selection) as predictors of individual fin damage. Results showed severity of fin damage was predicted by small size relative to the other individuals in the tank or cage. Body condition based on length-weight relationship was not found to predict fin damage, indicating that using established indices from fisheries or from other species would not predict welfare risks from fin damage. Implications are that especially in hatchery conditions grading will improve the condition index, and is expected to mitigate fin damage, but that low weight at length was not of use in predicting fin damage. Model selection to choose between a suite of possible indices proved powerful and should be considered in other applications where an easily measured index is needed to correlate with other health measures., (© 2021 The Authors. Journal of Fish Biology published by John Wiley & Sons Ltd on behalf of Fisheries Society of the British Isles.)

Length-frequency data of Nile tilapia (Oreochromis niloticus) was studied using 1250 specimens of both sexes combined with maximum length and weight of 44.5 cm (TL) and 1050 g respectively through gill net catch at different landing sites of Halali Reservoir, Madhya Pradesh. The data were grouped into classes of 10-mm intervals and various parameters of population dynamics of fish were analysed and computed using the FiSAT-II software package (FAO-ICLARM Stock Assessment Tools). The length-weight parameters were found to be at W = 0.001 L 2.96 where b = 2.96 and a = 0.001. Growth parameters L∞ and K of the species were L∞ = 46.73 cm and K = 0.63/year respectively; the annual rates of natural (M) and fishing mortality (F) were found to be 0.60 and 0.72 respectively. The estimated values for the exploitation rate (E) using the length-converted catch curve and virtual population analysis were 0.54 and 0.42 respectively. The recruitment pattern shows that O. niloticus was recruited in the fishery during April with one peak. Based on the data analysis, the stock in the Halali Reservoir does not exceed the maximum fishing pressure (Emax = 0.55) and there is selective mortality towards adult fish sizes. The introduction of Nile tilapia improved the total catch per unit of effort (CPUE), as well as increased the number of active fishers. Conversely, a significant reduction in the CPUE of other commercially important indigenous species was observed after the introduction of Nile tilapia in the reservoir. Therefore, for management purpose, this study suggests that the existing effort in terms of gill net mesh size which target size (TL-15.0 to 25.0 cm) individuals of length group is to be increased to exert more fishing pressure on Nile tilapia population in the reservoir to decline its abundance in the long term.

Squids play vital ecological and economic functions as keystone species in marine food webs and integral components of global capture fisheries. However, a comprehensive understanding of their diversity and life history characteristics in Indonesian waters is still poorly understood. This study aimed to identify squids that inhabited Java's northern and southern coasts and examine their growth pattern through morphometric analysis. Six hundred eighteen squid samples were collected fishers caught from May to September 2022 in Blanakan and Palabuhanratu Bay, representing two areas of interest. The body size and the shape of sucker rings of squids were observed using morphometric method. Kruskall-Wallis test, Principal Component Analysis, and Spearman's correlation were performed to investigate morphometric variation and relationships. The length-weight relationships were estimated for each species. This study reported three species of squid on the north and south coasts of Java, namely the mitre squid (Uroteuthis chinensis), the Indian squid (Uroteuthis duvaucelii), and the purpleback flying squid (Sthenoteuthis oualaniensis). There were significant differences observed in ten morphometric variables among the three species of squid (p < 0.05), with fin width, fin length, and sucker ring teeth identified as the key distinguishing feature for the squids. Spearman's correlation indicated stronger associations between mantle and fin variables (ρ = 0.666-0.967, p < 0.05) than those between mantle and head variables (ρ = 0.380-0.864, p < 0.05). Mantle length-weight relationships revealed a hypoallometric growth pattern for U. chinensis and U. duvaucelii, while S. oualaniensis exhibited an isometric growth pattern. The finding of this study provides valuable insights concerning the growth of squids that reflect variation in ontogenic development, trophic ecology, and environmental conditions in Indonesian waters. [ABSTRACT FROM AUTHOR]

Intertidal fish are a key component of littoral food webs, contributing to the diets of birds and commercial fish species. Ascertaining their growth and condition can therefore help understand the health status of local communities.Lipophrys pholis is a fish of the rocky intertidal with a wide distribution throughout the North‐eastern Atlantic (NE Atlantic) that has been recommended for use as an indicator in the environmental biomonitoring of marine ecosystems. However, it is unclear yet if this species is sensitive to the reserve effect.In this study, the size, growth and body condition of specimens caught at protected and unprotected rocky shores of two contrasting marine provinces of the NE Atlantic were analysed to address whether L. pholis is sensitive to the reserve effect.L. pholis were larger, grew faster in weight and were in better condition in the protected shores of both provinces. A faster growth rate was observed in the populations of the warmer province.Inshore waters of unprotected sites in the Northern European Seas sampled in this study have recently been incorporated into a protected area. Thus, these results can help assess the success of the marine conservation programme and the time L. pholis needs to improve its population's health at these shores.Regulating access to shores to avoid trampling and harvesting is a protection measure that can help enhance the health and conservation of L. pholis populations. [ABSTRACT FROM AUTHOR]

The Ailia coila, a small indigenous freshwater fish species in Kaptai Lake, plays a crucial role in providing employment, food, and financial security for the local people. With a high market demand, the average production of this species over the last 5 years reached about 112.27 metric tons. However, there has been a notable decline in Ailia coila fish production in Kaptai Lake in recent years. Therefore, to understand the current stock status of this species, this study employed a length‐based stock assessment method the "length‐based spawning potential ratio (LB‐SPR)". Between August 2022 and March 2023, a total of 1219 individuals were collected through fortnightly sampling from two fish landing centers (BFDC fishery ghat and Kaptai boat ghat) and two local markets (Banarupa Bazar and Reserve Bazar). The maximum length of Ailia coila was recorded at 15.7 cm in total length, with an average length of 11.1 (±4) cm. The length‐weight relationship was estimated as W = 0.01084 L2.599 (R2 = 0.75). The value of shape parameter 'b' is smaller than three which indicate a negative allometric growth pattern. The estimated asymptotic length (L∞) and length at first maturity (L50%) were found to be 16.84 and 10.54 cm, respectively. The LB‐SPR revealed that the fishery is currently experiencing overfishing, with the spawning biomass (SPR = 32%) below the target reference point. The mean estimate of fishing mortality relative to natural mortality (F/M) was 3.07, more than three times the threshold F/M = 1, indicating extreme fishing mortality in this fishery. The estimated length at first capture (SL50%) was significantly higher than the length at first maturity (L50%), suggesting that the fishing is predominantly targeting mature fishes. To enhance the spawning biomass and ensure the sustainability of the fishery, it is imperative to reduce the current fishing pressure and implement appropriate management measures. [ABSTRACT FROM AUTHOR]

Horse mackerel is a semi-pelagic fish widely distributed in the eastern Atlantic, where it represents a species of interest for fisheries and is subject to intense exploitation, leading to its global classification as a vulnerable species by IUCN. In the Northwestern (NW) Mediterranean Sea, the knowledge of their distribution, abundance and main biological parameters is fundamental to achieve their sustainable exploitation and contribute to the ecosystem approach to fisheries management. The time series (2009–2020) data set analyzed in this study came from two geographical subareas (GSAs) defined by the General Fisheries Commission for the Mediterranean (GFCM), Northern Spain (GSA06) and Northern Alboran Sea (GSA01) sampled in July during the MEDiterranean International Acoustic Survey (MEDIAS). Our results suggest that in summer, a higher concentration and aggregation of fish exists in GSA01, with a density ten times greater than in GSA06. Possible life history changes can be inferred through the analysis of the biological parameters of Trachurus trachurus in the NW Mediterranean Sea. In both GSAs, the annual decline of the size at first maturity (L50) and condition factor (Kn) was prominent. Moreover, the population structure lacked adult modes that could guarantee a successful recuperation of future stocks. Nonetheless, fish inhabiting GSA01 seem to have a better adaptive response to the events responsible for these alterations. In comparison, GSA01 is under less fishing pressure and the upwelling occurring in this area contributes to a higher availability of food, in addition to reducing the increases in sea surface temperature due to climate change during the study period. [ABSTRACT FROM AUTHOR]

Physiculus cynodon is a member of the Moridae family and possesses a ventral bioluminescent organ. Although it has been captured by commercial vessels for decades, our understanding of its biology and ecology remains fragmented. This paper provides data on the species' spatial and vertical distributions; age and growth; size, age, sex compositions; and sex ratio in the waters around the Emperor Seamounts and the northwestern Hawaiian Ridge. This information is based on the analysis of multi-year Russian data obtained from scientific surveys and observations on commercial fishing vessels. The northernmost capture of this species has been recorded at Nintoku Seamount. Additionally, this species was regularly encountered at depths ranging from 53 to 900 m on seamounts such as Lira (Annei), Koko, Milwaukee (Yuryaku and Kammu), Colahan, and C-H of the Emperor Seamounts and Hancock, Zapadnaya, and Academician Berg of the northwestern Hawaiian Ridge. Catch rates of P. cynodon gradually decreased in a southeastern direction. Notably, the relative abundance of this species in bottom trawl catches significantly surpasses that in pelagic catches. The age of the fish in the catch varied from 9 to 37 years, and its growth is described by the VBGF equation with the following coefficients: L∞ = 858.6, k = 0.030, t0 = 3.5. While the growth patterns for males and females were similar, it is worth mentioning that males rarely survive beyond the age of 25 years. [ABSTRACT FROM AUTHOR]

Abstract Background Although the apple snail Pila globosa is used as indicator species for human consumption locally and as fish feed, research on it in general is very scanty. It is used in food industry, in aquaculture as fish bait and used as food in many regions of India and many other countries, but research on it has been started in the 1970s. Only 40 articles are available on this organism in PubMed indicating an urgent need of basic research on it especially work on its spatiotemporal morphometry Therefore, sampling of P. globosa was done from different parts of India in different seasons (summer, winter and rainy), and different morphometric studies were performed on this organism to draw baseline information. Analysis was conducted to study morphometry, the relationship between shell length and the weight and relative condition factor of Indian apple snail Pila globosa collected from five zones (east, west, north, south and centre) of India during 2018–2019 year. Results The shell length (SL) (46.5 ± 13.33), shell width (SW) (40.22±11.5 mm), spire length (SPL) (2.99±0.15 mm), base length (BL) (12.53±2.94 mm), aperture length (AL) (21.95±4.36 mm), aperture width (AW) (2.74±0.47 mm) and shell weight (WT) (31.08±13.76 g) were observed to be varied among the individual sampled across India. Different relationships for SL/SW (Log SW=0.9889 Log SL + 0.9444), SL/SPL (Log SPL = 0.1452 Log SL+0.3815), SL/BL (Log BL=0.7789 Log SL+0.5814), SL/AL (Log AL= 0.6518 Log SL+0.9111) and SL/AW (Log AW=0.4475 Log SL+0.1422) were observed by considering shell length as basic index. The relationship between shell length and shell weight was found to be Log WT=2.0263 Log SL+0.1098. The relative condition factor revealed uninterrupted and good environmental condition observed for apple snails. A negative allometric growth pattern was observed from the length–weight relationship. Conclusion The environments of apple snail in India are not contaminated, and the results can be used as baseline data in aquaculture for model analysis and can be used as a reference for drawing relationship among different morphometric indices of P. globosa in India, as there is no such information available on it. The data can also be used for mass scale production of P. globosa for consumption by human and use in aquatic industries as fish feed.

The article is dedicated to Prof Tonko Šoljan and Dr. Dinko Morović, scientists from the Institute of Oceanography and Fisheries in Split, Croatia. From 1940 to 1970, they investigated European eel in the River Neretva estuary and provided first data on their biology, ecology and fisheries for this area. Samples of the European eel, Anguilla anguilla from two different habitats in the River Neretva estuary region were analysed using two different traditional fishery gear, in the period from 2016 to 2019. The monthly eel catches in ten traditional fyke nets in Parila lagoon varied from 4.4 to 12.7 kg (±2.45 kg) in 2016 and 2.4 to 9.6 kg (±2.01 kg) in 2019. There were no statistical differences between monthly and total weights recorded in 2016 and 2019 (t=1.04; p=0.312). The b-coefficient of the length-weight (LW) relationship for the freshwater eel samples varied from 3,1036 to 3,3206 during two-year period of the sampling. The LW relationship for the brackish population was significantly lower (b-coefficient 2,6513). The dominant eel stage in both sites was yellow eel, while silver stage was scarce. The fishery with traditional devices revealed that efficiency of these artisanal tools is low, pointing to poor abundance of eel in their common habitats. The recorded catch using bigger traditional eel trap gear during autumn spawning migrations was also dominated with yellow stage, while silver eel represented only 15,4% of the catch. The infestation of eels with the parasite, Anguillicoloides crassus was significantly higher in freshwater habitat (41% of eel specimens infested) than in brackish, Parila lagoon (7%). Poor efficiency of traditional gear, bad length and weight structure of the population and low b-coefficients of eels in their most important habitat, indicate poor status of European eel population and River Neretva estuarine ecosystems. [ABSTRACT FROM AUTHOR]

Background: Although the apple snail Pila globosa is used as indicator species for human consumption locally and as fish feed, research on it in general is very scanty. It is used in food industry, in aquaculture as fish bait and used as food in many regions of India and many other countries, but research on it has been started in the 1970s. Only 40 articles are available on this organism in PubMed indicating an urgent need of basic research on it especially work on its spatiotemporal morphometry Therefore, sampling of P. globosa was done from different parts of India in different seasons (summer, winter and rainy), and different morphometric studies were performed on this organism to draw baseline information. Analysis was conducted to study morphometry, the relationship between shell length and the weight and relative condition factor of Indian apple snail Pila globosa collected from five zones (east, west, north, south and centre) of India during 2018–2019 year. Results: The shell length (SL) (46.5 ± 13.33), shell width (SW) (40.22±11.5 mm), spire length (SPL) (2.99±0.15 mm), base length (BL) (12.53±2.94 mm), aperture length (AL) (21.95±4.36 mm), aperture width (AW) (2.74±0.47 mm) and shell weight (WT) (31.08±13.76 g) were observed to be varied among the individual sampled across India. Different relationships for SL/SW (Log SW=0.9889 Log SL + 0.9444), SL/SPL (Log SPL = 0.1452 Log SL+0.3815), SL/BL (Log BL=0.7789 Log SL+0.5814), SL/AL (Log AL= 0.6518 Log SL+0.9111) and SL/AW (Log AW=0.4475 Log SL+0.1422) were observed by considering shell length as basic index. The relationship between shell length and shell weight was found to be Log WT=2.0263 Log SL+0.1098. The relative condition factor revealed uninterrupted and good environmental condition observed for apple snails. A negative allometric growth pattern was observed from the length–weight relationship. Conclusion: The environments of apple snail in India are not contaminated, and the results can be used as baseline data in aquaculture for model analysis and can be used as a reference for drawing relationship among different morphometric indices of P. globosa in India, as there is no such information available on it. The data can also be used for mass scale production of P. globosa for consumption by human and use in aquatic industries as fish feed. [ABSTRACT FROM AUTHOR]

The present study investigates the gut contents and feeding habits of Crenidens crenidens in the Red Sea coast of Jeddah, Saudi Arabia. Gonadosomatic index, length-weight relationship and relative condition factor were also determined. Samples were collected monthly during the period from November 2018 to October 2019. Stomach contents were identified and assessed by the frequency of occurrence, numerical and gravimetric methods. The total number of specimens collected was 375, of which 139 were having empty stomachs. Feeding intensity was the highest between April (80.0%) and September (90.9%) and the lowest from November (27.8%) to January (16.7%) and February (41.2%). The maximum value of Fullness index (FI%) was found in Summer (88.11%) and lowest in Winter (26.42%). Whereas the maximum value of Vacuity index (VI%) in Winter (73.56%) and lowest in Summer (11.89%). The results showed that C. crenidens mainly feeds on seaweeds, seagrasses, small mollusks and nematodes, and thus it is omnivorous fish. Seaweeds were the most important food items (IRI%, 38.33), then seagrasses (IRI%, 29.9) and unidentified small plant parts (IRI%, 22.0). The length-weight relationship could be described by the power equation: W = 0.0173 L3.00 (R2 = 0.96) where the slope 'b' equal to '3' indicating that the growth of this species is isometric. The relative condition factor Kn was found affected by the feeding intensity and spawning activity. [ABSTRACT FROM AUTHOR]

In this study, some biological properties of Merlangius merlangus(Linnaeus, 1758) were examined. In this context, relationship of length-weight, distribution of length-frequency, sex ratios and condition factors were examined. A total of 303 individuals were taken by random sampling from fishing vessels (beam trawl) in the Sea of Marmara. Minimum length and weight values of all sample individuals was found 10.0 cm and 6.6 g, maximum length 41.2 cm and 535 g was found. The average length was found 17.15±0.49 cm and the average weight was 47.03±7.57 g. Length-weight relationship for all samples as W=0.0044TL3.1777 regression coefficient r2 =0.98 was determined. Growth type, positive allometric was determined for all samples and both sexes (b=3; P=0.05). The sex ratio (F:M) was calculated as 1:1.27. The mean values of condition factor (K) were calculated as 0.729±0.089, 0.733±0.091 and 0.737±0.081 for male, female and combined sex respectively. There are no significant differences between male and female (P=0.05). [ABSTRACT FROM AUTHOR]

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The present study provides the basic information in the fisheries biology and stock assessment for the cobia, Rachynentron canadum in the Southern part of the Arabian Gulf off the United Arab Emirates. A total of 371 individuals were sampled. The length-weight relationships of R. canadum were estimated as W=0.0022*L3.2536, R²=0.99 for all individuals, W=0.0028*L3.1875 R²=0.98 for males and W=0.0022*L 3.258 R²=0.99 for females. According to b values, the growth type of this species was positive allometric growth (b>3), (t-test: p<0.05). Condition factors ranged from 0.60 to 0.77 for males and from 0.61 to 0.85 for females, while the relative condition factor for males ranged between 0.92 and 1.07 and between 0.96 and 1.14 for females. The monthly calculated mean values of the gonado-somatic index (GSI) of females increased from April, reaching the highest value in May then declined in July. The male/female ratio of this species was 1/1.82. The length at first sexual maturity for R. canadum was estimated at 63.31cm and 75.08cm TL for males and females respectively. [ABSTRACT FROM AUTHOR]

Growth characteristics and age structure of 439 specimens of Dentex maroccanus captured by fishermen in December 2012 - March 2014 from Izmir Bay, Aegean Sea, Turkey, were studied. Of the 346 fish specimens whose sex was determined, 206 were female and 140 were male. The length-weight relationships of females, males and the entire population were described by the equations W=0.0194*L2.924, W=0.0269*L2.789 and W=0.0228*L2.856, respectively. The highest condition factor of the population was 1.59 and was recorded in spring. According to the age identification using otoliths, the population was in the age range of I-V. With 39%, the II age group had the highest ratio. The infinite length value for the entire population was calculated to be L8 =27.43*(1-e-0.21 (t-(-0.68))). The growth performance index was 2.20. [ABSTRACT FROM AUTHOR]

Sardine Sardina pilchardus (Walbaum, 1792) and anchovy Engraulis encrasicolus (Linnaeus, 1758), besides being ecologically very important pelagic resources, are also the most numerous fish species in Croatian fisheries landings. Hence, the aim of this study was to compare sardine and anchovy growth parameters: length, length-weight relationship, condition and age population structure. All samples (N=3313) were collected from purse seine catches of eastern Adriatic Sea, during period June 2015 - August 2016. Total lengths of sardine and anchovy ranged from 10.5 to 17.5 cm (average ± SD: 13.94 cm ± 1.07) and from 10.0 to 17.5 cm (average ± SD: 14.09 cm ± 0.88), respectively. Both sardine and anchovy length-weight relationship indicated positive allometry, although allometric coefficient was higher in anchovy (b=3.201) than in sardine (b=3.069). In general, condition of both species grew with fish length. Sardine and anchovy age composition varied from one to five years, while most of the analysed samples belonged to the 3 year class. Growth parameters were for anchovy: L∞=18.36cm; K=0.317; t0= -1.89 and for sardine L∞=19.71 cm; K=0.286; t0= -1.82. [ABSTRACT FROM AUTHOR]

Length–weight relationships of bivalve species collected during razor clam (Ensis minor) surveys along Italian coastal waters (Northern Adriatic and Tyrrhenian Sea) in the 3-year period 2016–2018 are reported. A total of 13,588 individuals, belonging to 12 bivalve species and 20 populations between the Adriatic and Tyrrhenian Seas, were sampled for this study. Analyzing growth parameters for each population, we found 11 allometries and nine isometries. About half of the species investigated showed different growth characteristics between the two areas. [ABSTRACT FROM AUTHOR]

Length-weight relationship and relative condition factor of T. ilisha was conducted for one year (2014-15) at Narmada estuary, Gujarat, India. Fish samples were collected from Bharuch, Bhadbhut, Mehgam and Ambetha landing sites covering 72 km of estuarine stretch. Two distinct fishing seasons were observed at Narmada estuary, viz., June-October and January-March, though the bulk of the harvest comes from monsoon season. A total of 312 fish samples were collected, 270 during monsoon and 42 during the winter season. The mean length and weight were recorded 35.37±11.36 cm and 625.83±39.81 g during monsoon and 36.84±3.82 cm and 537.44 ± 17.45 g during the winter season. The ‘b’ value was found to be 3.07 and 2.76 and relative condition factor was 1.02 and 1.01 during monsoon and winter seasons, respectively. [ABSTRACT FROM AUTHOR]

Length‐weight relationships (LWRs) were presented for 15 fish species which caught in the East China Sea during 2009–2014. All of the samples were caught by commercial and scientific survey bottom trawl vessels. The commercial fishery survey used one‐single bottom trawl with the smallest mesh size 25 cm and light seine fishing with the smallest mesh size 38 cm, however, the scientific survey only used one‐single bottom trawl with the smallest mesh size 20 cm. The length and weight of all the fish were measured to the nearest millimeter and milligram, respectively. The application of these estimated values should be limited to the studied waters and observed length ranges. The development and adoption of a standardized sampling format for all studies aiming to determine LWRs should be undertaken. [ABSTRACT FROM AUTHOR]

Four species of Carangid fishes from Matang Mangrove Estuaries, Perak, Peninsular Malaysia were selected for the study of length-weight relationships (LWR) and lengthlength relationships (LLR). A total of 308 individuals were collected from September 2015 to August 2016 by push net (mesh sizes ranges from 2.5 to 5.0 cm). Overall, the growth coefficient (b) values were 2.005, 3.014, 3.452 and 3.194 for Carangoides malabricus, Atule mate, Decapterus macrosoma and Selaroides leptolepis, respectively. Growth coefficient of three species (A. mate, D. macrosoma and S. leptolepis) in the present study were within expected range of 2.5 - 3.5 and this indicated that those species have normal growth pattern. This research serves as the first record of LWR and LLR data for four species of Carangid fishes in the Matang Mangrove Estuaries and surrounding ecosystem, Malaysia. [ABSTRACT FROM AUTHOR]

Length-weight relationships (LWR) were estimated for three main Songkhla Lagoon fish species occurring in the lower gulf of Thailand. Samples were collected monthly during monsoon and after monsoon season (September 2017 to April 2018). Fishes were captured by three methods: fishing gear, crab gear and shrimp gear. This study is the first reference on LWR equation parameters of Pellona ditchella (Valenciennes, 1847), Sardinella gibbosa (Bleeker, 1849) and Alepes vari (G. Cuvier, 1833) in the lower gulf of Thailand, this good document would be used to compare these fish condition with many coastal areas in the world. This work provides the important information of fish migration between lagoon and lower gulf of Thailand as well as for two species from which we present a wider size range in FishBase, Pellona ditchella (Valenciennes, 1847) and Sardinella gibbosa (Bleeker, 1849). [ABSTRACT FROM AUTHOR]

Abstract: The Western Ghats of India harbours an exceptional diversity of endemic freshwater fishes, which are threatened because of various anthropogenic stressors, including biological resource use. Lack of organized studies on the population dynamics and exploitation levels of endemic species, however, has hindered the development and implementation of systematic conservation action plans in this region. This is especially true for large cyprinid fishes threatened because of overharvest. This study examined length–weight relationships and length‐structured population dynamics of an endemic large cyprinid (Hypselobarbus kurali), based on data obtained from an artisanal gill‐net fishery in Malampuzha Reservoir. Length–weight analysis suggested the fish exhibited significantly lower exponents than expected under isometry, indicating the growth of H. kurali in the reservoir was negative allometric. The von Bertalanffy growth formula fitted to the length‐frequency data indicated H. kurali grew relatively slower than other large cyprinids in this region. Statistical analysis of recruitment revealed two peaks, implying the fish have two spawning bouts each year. Analysis of mortality and exploitation of the species revealed large‐sized individuals were targeted by the fishers, resulting in an exponential decline in the survivors in the virtual population analysis. Relative yield‐per‐recruit and relative biomass‐per‐recruit analysis indicated the current exploitation rate for the population was greater than the exploitation rate under which the stock would be reduced to half its unexploited biomass. Further, the current exploitation level was more than 60% of the expected maximum exploitation above which the population could collapse. The results of this study identify a serious need to develop and implement management plans to guide the future sustainability of the reservoir fishery of H. kurali. [ABSTRACT FROM AUTHOR]

Samples (6404) of Nile perch were collected monthly from commercial catches between June 2014 and June 2015. The total length (cm), weight (g) and sex of fish were all determined in the field, with 3771 (59%) being male and 2059 (32%) being female fish, for an overall sex ratio of 1.83:1.00 (male: female). The average length and weight for all fish were 55.38 ± 0.14 cm TL and 2355.10 ± 22.30 g, respectively. The size of male fish ranged from 15.5 to 128.5 cm TL and weighed between 190 and 25 000 g, whereas that of female ranged from 21.0 to 130.0 cm TL and weighed between 124 and 25 800 g. The value of the regression slope b of the length-weight relationship was equal to 3.04. The mean (± SD) condition factor for all fish was 1.23 ± 0.13. The condition factor was different in the length groups, with the highest (1.32 ± 0.13) and lowest (1.12 ± 0.20) values recorded in length groups 100-110 and <30 cm TL, respectively. The highest and lowest condition factors were recorded between January and March, respectively. The length-weight relationship and condition of Nile perch in Lake Victoria have deteriorated greatly, this finding being linked to the reduction of its prey species in the lake. [ABSTRACT FROM AUTHOR]

Commercial interest on sea cucumber species from the NE Atlantic and the Mediterranean is increasing. Holothuria polii , Holothuria tubulosa , Holothuria mammata and Holothuria arguinensis are the new target species. The scarce biological and ecological knowledge on these species along their geographical distribution, is a major problem for their fisheries management. To address it, we carried out a morphometric study to describe the baseline population size structure, focused on the length–weight relationship and size–weight distribution. In the NE Atlantic, the largest mean size and heaviest mean weight of H. mammata and H. arguinensis were found in localities with upwelling, but another factors could be influencing on these results. In the Mediterranean, Girona and Mallorca showed the heaviest specimens of H. polii , H. tubulosa and H. mammata , and the smallest were registered in Crete and Kusadasi. Significant differences in length and weight between populations were found for each species. These results could be linked with local environmental conditions. Size frequency distribution was multimodal for all species except for H. mammata ; the weight frequency distribution was only unimodal for H. polii and H. mammata . This study provides novel data, helpful for stock and population assessment which could support the implementation of effective management for the European sea cucumber target species. [ABSTRACT FROM AUTHOR]

Typically, growth can be defined as the change in size (length, weight) over time. The length-weight relationship (LWR) and annual condition factor of an economically important snow trout, Schizothorax niger, from Dal lake of Kashmir was studied and reported in this communication. A total of 120 specimens were collected with the help of traditional fishing gear during 2012-2013. The coefficient 'b' value of the LWR suggested allometric growth throughout the year except in April, July and September where the growth was isometric (b=3). A trend line graph was applied to compare condition of fish in different months as per the relationship, which indicated declining growth condition. The condition factor showed an overt variation with highest value during the breeding season. The result obtained in this study will be useful for fishery managers to impose adequate regulations for fishery and sustainable management. [ABSTRACT FROM AUTHOR]

Scanty information exists pertaining to the length-weight relationship (LWR) and length-length relationship (LLR) parameters of longsnouted catfish, Plicofollis argyropleuron in lotic systems throughout the northern part of Peninsular Malaysia. It is vital to reveal these biological properties of P. argyropleuron in Kuala Muda and Merbok estuary for future management and to increase knowledge about this fish stocks. The fish samples were randomly collected in the estuary area of Kuala Muda and Merbok, Kedah for 10 months from March 2009 to December 2009. The values of the exponent b in the LWR equations (W = aLb) were approximately 3, indicating an isometric growth with high correlation coefficient (r2). The value of LLR (r2>0.9) indicated that they are highly significant and highly correlated. These parameters are essential for evaluating the relative condition of fish and species managements as well as their fisheries and stock assessment. [ABSTRACT FROM AUTHOR]

Abstract: Length–weight relationships (LWRs) are presented for 39 major fish species in the Kenyan artisanal marine fishery. Captures were made between the years 2001 and 2009. The parameters a and b of the equation W = aL b were estimated. The parameter b ranged from 2.030 (Nomorhamphus weberi) to 3.987 (Lutjanus fulviflamma) with a mean of 3.08 (S.E. 0.02) and 72% of its estimates were between 2.6 and 3.2. Whenever possible, the b values for the species obtained both in this study and some of the previously reported in other studies were compared. The estimated parameters should only be applied to the species analyzed. [Copyright &y& Elsevier]