Morphological characteristics of smoothbelly sardinella, Amblygaster leiogaster (Val.) in the Bay of Bengal

As morphometric information for Hooghly croaker Panna heterolepis Trewavas, 1977 is absent in the most extensively accessed and world’s largest online database for fishes (FishBase); this study was undertaken to provide the complete informative description on morphometric relationships and meristic counts of various fin rays. A total of 200 individuals were sampled from the Bay of Bengal (Bangladesh) during July 2018 to June 2019, using several traditional fishing gears. Meristic counts were computed using a magnifying glass. Body weight (BW) and several length measurements were taken through an electronic balance and digital slide calipers for each individual. LWRs (Length-weight relationships) were calculated as: W = a×L b . All LWRs and LLRs (length-length relationships) were found significant with r 2 ≥ 0.919 ( p < 0.0001) and 0.928 ( p < 0.001), respectively. BW vs. TL and TL vs. SL were the best fitted models for LWRs and LLRs, respectively. Fin formula was: dorsal, D. 43–55 (VIII–X+i/34–44); pectoral, P. 15-17 (i/14–16); pelvic, Pv. 6 (I/5); anal, A. 7–10 (II/5–8); and caudal, C. 17–19 (ii/15–17). These results will a) make a vital contribution for species identification in the marine and coastal waters of Bangladesh and adjoining countries, and b) provide information for Fish Base.

This study on flathead sillago, Sillaginopsis panijus (Hamilton 1822) estimates the first morphometric relationships from the marine ecosystem, Bay of Bengal, Bangladesh using multi-linear dimensions. Additionally, meristic counts for different fin-rays were done. Alltogether, 204 specimens were captured during July 2018 to June 2019 by several gears including seine net and long lines. Morphometric measurements as well as body weight (BW) were recorded for each individual. The LWRs (length-weight relationships) were assessed as: W = a × L b . Lateral line scales and fin rays were observed by magnifying glass. The LWRs and LLRs (length-length relationships) were found significant ( p < 0.0001), with the r 2 values being ≥ 0.913 and ≥ 0.952, respectively. Based on r 2 values, LWRs by BW vs. SL and for LLRs, TL vs. FL were found as the best model. Fin formula observed for S. panijus is D 1 IX; D 2 I/24-28; P . 17-20; P v. 1/5; A I-II/24-27; C 2/16-18. Scales on lateral line were ~82-86. This investigation should be helpful for resource management in the marine ecosystems of Bangladesh and other subtropical countries.

This study focuses on relative growth through length‐weight relationships (LWRs) and length‐length relationships (LLRs) using a total of 15 linear dimensions of Minor carp Labeo bata (Hamilton, 1822) from the Ganges River, northwestern (NW) Bangladesh. Also, meristic counts covering various fin rays and scales from different body parts (including lateral line scales) of L. bata (Hamilton, 1822) have been studied. A total of 300 individuals of L. bata were sampled occasionally from the Ganges River from July 2013 to June 2014, using various traditional fishing gears (e.g., Cast net, Gill net and Square lift net). Number of fin rays from all fins and scales were counted using magnifying glass. Additionally, a total of 15 different lengths were measured to 0.1 cm and whole body weight (BW) was taken to the nearest 0.1 g for each individual. Fin formula of L. bata is as follows: dorsal, D. 10–12 (i–ii/9‐10); pectoral, P1. 12–16 (iii–iv/9–12); pelvic, P2. 9 (i/8); anal, A. 6–7 (ii/4–5); and caudal, C. 20–24 (iv–vi/16–18), respectively. Minimum and maximum lengths were found as 8.0 to 25.1 cm in total length (TL) and body weight (BW) ranges from 4.8 to 161.0 g. All LWRs were highly significant (p < .001) with r2 values ≥0.960. Based on r2 value, LWR by BW versus TL was the best fitted model among 13 equations. In addition, the LLRs were also significant with r2 values ≥ 0.959. According to r2 value, LLR by TL versus FL was the best fitted model among 15 equations. This study would be very effective for species identification and stock assessment in the Ganges River, NW Bangladesh and surrounding ecosystems.

This study ascertains the morphometric traits and meristic counts of Pomadasys hasta (Bloch 1790) in a mangrove fetched ecosystem (River Arpangasia) from south-west coast Bangladesh. A total of 83 specimens of P. hasta were sampled periodically from the River Arpangasia during July 2020 to June 2021, using cast net and seine net having a mesh size of 1.50-3.00 cm & ~2.50 cm, respectively. A magnifying glass was used to compute the fin rays. Seven distinct morphometric lengths were evaluated and body weight (BW) was measured for each individual. The explored fin formula was: D. XII/11-12; P1. 13-15; P2. I/5; A. iii/8-9; C. 18. Least and highest total length (TL) were 11.65 and 28.00 cm, whereas BWs were 81.60 and 446.34 g, respectively. Entire length-weight relationships (LWRs) were enormously significant (P < 0.001) with r2 ≥ 0.949. Off the nine equations, BW = 0.0416*(TL) 2.77 was the most precise model based on the magnitude of r2 value. Alongside, considering the r2 values, TL vs. SL of length-length relationships (LLRs) was the classical model among eight equations. These data will aid to recognize the species and further assessment of stock/biomass and conservation of P. hasta in mangrove fetched river Arpangasia and other ecosystems of different geographic region.

The present study was conducted to understand the morphometric and Meristic characteristics of stripped catfish (Pangasianodon hypophthalmus, Sauvage 1878) culture in south Gujarat. For the morphometric measurement and Meristic count total 815 fish specimens were randomly collected from the described culture systems. For the morphometric measurements of the fish, total length (TL), standard length (SL) and body weight were taken. Meristic counts were included to count number of spine and rays for dorsal fin, pectoral fin, pelvic fin, anal fin and caudal fin. In present study, morphometric observation including total length (TL) 18.500-48.00 cm with mean 34.760±0.185, standard length (SL) 16.500-39.000 cm with mean 28.791±0.154 and weight (WT) 100.00-930.00 g with mean 376.720±5.615 was observed in studied fish. The morphometric relationship of the variables (TL vs WT, SL vs WT and TL vs SL) shows the linear relationship among the variables respectively. The values of intercept (a = -1.882, -1.546 &amp; -0.024), correlation coefficient (r = 0.820, 0.816 &amp; 0.910) and growth constant (b = 2.832, 2.802 &amp; 0.962) were noted respectively. The Meristic characteristics of the studied fish were counted as dorsal fin spine and rays (1/6), Pectoral fin spine and rays (1/9), Pelvic fin spine and rays (1/7) and anal fin rays (29-30). It is very much essential to record the morphological and meristic characters of the studied fish for identification. All such information can also be considered an initial step for studying evolutionary relationships of fish species.

Bighead carp (Hypophthalmichthys nobilis) is an economically important aquaculture species valued for its rapid growth and filter-feeding ability. Objective: To examine the morphometric parameters specifically the length–weight relationship (LWR), length–length relationships (LLRs), and condition factor of Hypophthalmichthys nobilis (bighead carp) fingerlings reared in hatcheries in Bahawalnagar, Pakistan. Methods: A total of 35 fingerlings were sampled. Morphometric measurements including total length (TL), standard length (SL), fork length (FL), head length (HL), and body weight (W) were recorded. The LWR was calculated using the formula W = aTLᵇ, and the LLRs were derived through linear regression between different length parameters. The condition factor (K) was determined using the Fulton’s formula. Results: The mean ± SD values for TL and W were 10.21 ± 0.52 cm and 9.53 ± 1.45 g, respectively. The LWR showed a negative allometric growth pattern with constants a = –1.5671 and b = 2.52, and a strong correlation (r = 0.887). Strong positive correlations were observed in LLRs: TL vs. SL (b = 1.03), TL vs. FL (b = 0.74), and TL vs. HL (b = 0.85). The mean ± SD condition factor was 0.89 ± 0.06, indicating moderately good fish health. Conclusions: This study presented updated, population-specific data on morphometric relationships and the condition factor of Hypophthalmichthys nobilis fingerlings in Pakistan. These findings provide a valuable baseline for region-specific stock assessments and contribute to informed, sustainable management strategies for bighead carp in hatchery settings.

The length-weight (LW) and length-length (LL) relationships of 39 demersal fish species belonging to 19 families were calculated. Fish samples were collected monthly during the open (September–February) and close (March–August) shrimp fishing seasons from 2014 to 2022 by the artisanal fishery in the Bahía Magdalena-Almejas lagoon system (BMA), using small boats and a shrimp bottom trawl with 16–17 m top rope and 38 mm mesh opening. Total (TL) and standard (SL) lengths and total weight (TW) were measured for all fish specimens. The b parameter of the LW relationship ranged from the minimum of 2.483 for Cynoscion parvipinnis to 3.775 as the maximum for Bagre panamensis while, for the LL relationship, the parameter b ranged from 0.685 for Balistes polylepis to 0.994 for Orthopristis cantharinus. Both LW and LL relationships were highly correlated (r2&gt;0.95; P&lt;0.05. The parameter b of the LW relationship indicated that 59% of the fish species showed isometric and 41% allometric growth. Information on LW and LL relationships is updated for thirteen species, and four are reported for the first time: Citharichthys xanthostigma, Ophidion galeoides, Pleuronichthys guttulatus, and P. ritteri. This study will be useful to update the LW relationship parameters for data-poor fish species and contribute to the accuracy of fish stock assessment in the BMA fisheries.

Biometrics such as weight-length relationships (WLRs), length-length relationships (LLRs), as well as form factor (a3.0) were investigated for three flatfish species, Cynoglossus lingua, Cynoglossus arel, and Brachirus pan which were captured using seines and gill nets between September 2021 and March 2022 from the Bay of Bengal, Bangladesh. The lengths were measured to adjacent 0.1 cm accuracy with a digital caliper and weights to the accuracy of 0.01 g with a digital balance for each individual. The WLRs were accurately adjusted for all species (r2 &gt; 0.9500). Brachirus pan had the lowest b value of 2.9543, whereas C. arel had the highest b value of 3.2924 amongst the three species. For the investigated species of fish, LLRs were also highly significant (r2 &gt; 0.9600, p &lt; 0.01). The estimated form factor values were 0.0023 for B. pan, 0.0026 for C. arel, 0.0027 for C. lingua. New maximum total lengths for C. arel and B. pan have also been recorded. Since there are no weight-length relationships (WLRs), length-length relationships (LLRs), as well as form factor (a3.0) data for these species in Bangladesh; the information supplied here expands the depth of knowledge for these species.

The striped snakehead, Channa striata, is a commercially and ecologically significant freshwater fish species in India. This study provides a comprehensive morphometric and meristic analysis of its population in Nagapur Dam, Parli Vaijnath, Beed District, Maharashtra. A total of 176 specimens were collected from January 2023 to December 2024. Sixteen morphometric characters and five meristic counts were recorded. The population showed a wide size range, with total length (TL) from 15.2 to 55.0 cm and body weight (BW) from 32.5 to 1380.5 g. The length-weight relationship was determined as W = 0.021L³.⁰⁵, indicating positive allometric growth (b &gt; 3). Linear regression analysis revealed highly significant (p &lt; 0.001) relationships between TL and all other morphometric characters, with coefficients of determination (R²) exceeding 0.98 for most parameters, demonstrating strong morphological integration. Meristic counts were stable, with dorsal fin rays (DFR) ranging from 37-45 and pelvic fin rays (PFR) showing 97.7% consistency at 6 rays. The results confirm a healthy, well-adapted population and establish crucial baseline data for the sustainable management and future monitoring of this valuable fishery resource in Nagapur Dam.

Size frequency, length-weight relationships (LWRs), and length-length relationships (LLRs) for an estuarine fish Taenioides cirratus (Blyth, 1860) from the Noakhali coast, Bay of Bengal was studied. Specimens were caught with the fixed purse net of two mesh sizes (0.2 to 0.5 in. and 2.0 to 2.5 in.) from March to July 2019. The maximum total length for male T. cirratus (36.2 cm) reported in this study is a new record for this species. The length-weight relationships for male, female, and unsexed T. cirratus was highly significant (p < .001), and adjusted r2 values were 0.967, 0.922 and 0.955 for males, females, and unsexed, respectively. The calculated growth coefficient (b) for male, female, and unsexed T. cirratus was 2.546, 2.948, and 2.618, respectively. The length-length eq. TL = 1.1974 SL + 0.4403 for the males and TL = 1.1712 SL + 0.7096 for the females were highly significant (p = 0.001, r2 ≥ 0.978 for both males and females). Our estimated LWRs and LLRs parameters for male and female T. cirratus can be useful for the management and conservation purpose of this species.

This study aimed to reveal the morphometric and meristic variations, length-weight relationships, and condition factor of Channa orientalis collected from three regions (Kurigram, Rangpur, and Lalmonirhat districts) of Northwestern Bangladesh. Fifteen morphometric and six meristic characteristics were selected. Eight morphometric characteristics were significantly different (p&lt;.05) among the regions; three characteristics were highly significant (p&lt;.001) in Kurigram (Pre-orbital distance, PrOD; Lower-jaw length, LJL; Upper-jaw length, UJL) indicating C. orientalis population of Kurigram was significantly different (p&lt;.001) from the other two locations. On the other hand, among six meristic characteristics, number of dorsal fin rays (DFR), pectoral fin rays (PFR), anal fin rays (AFR), and branchiostegal rays (BR) were found to be significantly different among three locations. The values of PFR varied significantly (p&lt;.05) in Kurigram, which distinguishes the other two regions. Likewise, DFR and BR showed significant variations in the Rangpur region, whereas AFR significantly (p&lt;.001) separated the Lalmonirhat population from the others. In length-weight relationships, the generalized relationship between total length (TL) and body weight (BW) were BW=0.007TL3.147 (r2=0.945), BW=0.03TL2.573 (r2=0.916) and BW=0.008TL3.084 (r2=0.899) for Kurigram, Rangpur, and Lalmonirhat, respectively. The growth pattern showed positive allometric in Kurigram (b=3.14) and Lalmonirhat (b=3.08). Negative allometric was observed in Rangpur (b=2.57). The study exhibited a higher condition factor (K) value in Kurigram (1.068) and Rangpur (1.049) whereas the lowest in Lalmonirhat (0.978). The study reveals that the C. orientalis population`s morpho-meristic and growth status were comparatively better in Kurigram region.

Golden ponyfish Photopectoralis aureus and Goldstripe ponyfish Karalla daura are small fish with less economic value. Many marine fish population parameters were not investigated because of their low commercial value. Therefore, the primary goals of this study were to determine the size frequency, length-weight relationship (LWR), length-length relationship (LLR), and Fulton’s condition factor (Kn) of two tropical ponyfishes from Saint Martin’s Island. From March to April 2022, specimens were caught using fixed purse nets. A total of 409 specimens of P. aureus and K. daura were measured to determine size frequency, LWRs, LLRs, and Fulton's condition factor. For P. aureus, the maximum total length (TL) of 12.9 cm sets a new record. The LWRs for P. aureus and K. daura were highly significant (p&lt;0.001), where the coefficient of determination (r2) was 0.985 and 0.869 for P. aureus and K. daura, respectively. The estimated slope (b) for P. aureus and K. daura were 3.147 and 2.986, respectively. The LLR equations were TL = 1.1089 SL + 0.2689 for P. aureus and TL = 0.6792 SL + 3.3309 for K. daura. The Kn value had no significant difference between the species of different length classes for P. aureus (0.97-1.40) and K. daura (1.19-1.26). There has never been any prior reporting of LWRs or length-length relationships (LLRs) for P. aureus in literature or FishBase. The study's findings may benefit the management and conservation of these ponyfishes. Res. Agric. Livest. Fish. Vol. 11, No. 1, April 2024: 105-114

In the present study, an attempt was made to evaluate the body weight of barred spiny eel based on morphologic traits. Ten morphometric characters and five meristic counts were measured for 38 specimens, ranging in standard length from 77.80 to 149.60 mm and 2.02 to 17.89 g in weight. All the data sets were standardised using the z-transformationmethod. The Kaiser-Meyer-Olkin (KMO) test was performed to measure the sample adequacy level, which was found to be 0.85. The significance of the correlation matrix in all traits was tested with Bartlett’s test of sphericity, which was found to be significant (χ2 = 793.360, df = 105, p&lt;0.01). Four of the fifteen principal components (PCs) explained around 85% of the total variation. The first principal component (PC1) contributed 57.52% of the total variation and was represented by significant positive high-loading factors for pre-dorsal (PDL), pre-anal (PAL), and standard length (SL). The second principal component (PC2) explained 10.90% of the total variation and was represented by significant positive high-loading factors for anal fin rays (AFR) and dorsal fin rays (DFR). The third and fourth principal components explained 9.26 and 7.41% of total variation and showed high loading factors for pectoral fin (PFR), and caudal fin rays (CFR), respectively. The estimated communalities ranged from 0.658 for eye diameter (ED) to 0.978 for pre-dorsal fin length (PDL). The species’ body weight was predicted using stepwise multiple regression of interdependent morphometric traits and four extracted PCs. Stepwise multiple regression revealed that a combination of three interdependent variables, such as pre-dorsal length (PDL), body depth (BD), and post-orbital length (POL), to be the best to predict the body weight of species based on the coefficient of determinant value (r2 = 93). Therefore, the study confirms that the species’ body weight is function of the three interdependent variables rather than orthogonal variables. Keywords: Body measurements. Macrognathus pancalus, Meristic counts. Prediction model

Length–weight relationships (LWRs) and length–length relationships (LLRs) of three ecologically important fishes (Aplocheilus panchax, Danio rerio and Esomus danrica) were reported from a wetland, northeastern Bangladesh (23 58 N, 89 38 E). Samples were collected monthly using traditional fishing gear including fine meshed (2.0 mm) push net and fine meshed (3.0–4.0 mm) surrounding net during January to December 2014. For each individual, total length (TL), fork length (FL) and standard length (SL) was measured to 0.1 cm, while body weight (BW) was measured to 0.01 g accuracy. Allometric coefficient (b) values were 3.10 for A. panchax, 3.38 for D. rerio and 3.52 for E. danrica. In addition, the LLRs were also highly significant with r2 ≥ 0.954.

Length-weight (LWR) and length-length relationships (LLR) were determined for a freshwater catfish Mystus bleekeri (Day, 1877) collected from Nala Daik, Sialkot, Pakistan. A total of 105 specimens (56 males; 49 females) were collected from February to March, 2010. Each specimen was weighed (g) and measured (cm). The total length of specimens studied ranged from 5.5 to 7.8 cm. Linear regression analysis was used, first to compute the degree of relationship between length and weight and then among total (TL), standard (SL) and fork lengths (FL). LWR exhibited a highly significant correlation (P < 0.001). The overall value of the exponent of LWR (b = 2.62) suggested negative allometric growth. Results for LLRs indicated that these are highly correlated (P < 0.001). Furthermore, the first reference for separate male, female and combined sex of length-weight and length-length relationships for Mystus bleekeri was provided. Key words : Mystus bleekeri , length-weight relationship, length-length relationship, predictive equations.