Positive Allometric Growth Pattern Research Articles

Life History Traits of Ambassidae Fish, Chanda nama (Hamilton, 1822) From the Old Brahmaputra River of Northeastern Bangladesh

ABSTRACTThe present study provides a comprehensive analysis of the population structure (length–frequency distributions), growth pattern (length–weight relationships [LWRs] and length–length relationships), physiological condition factors (allometric [KA], Fulton's [KF] and relative [KR]), relative weight (WR) and form factor (a3.0) of Chanda nama. A total of 1200 specimens were collected from the Old Brahmaputra River, northeastern Bangladesh, for 12 months by traditional fishing gear, including seine net and cast net. The total length (TL) of several individuals varied from 2.3 to 7.2 cm. The highest percentage contributed to the population's 4.0–4.5‐cm‐sized group. The LWRs indicated a positive allometric growth pattern (b > 3.0). Fulton's condition factor significantly correlated with TL and body weight (p < 0.0001). The calculated WR ranged from 67.38 to 137.64. No significant variations from 100 were found using the Wilcoxon rank test (p = 0.034), suggesting that C. nama might live there in a balanced predator–prey environment. Furthermore, the measured value for the form factor (a3.0) was 0.0105. In addition, fish with a TL of 7–8 cm should be caught since they are in good condition and have enough meat. The study's findings will greatly contribute to the efficient and enduring management of C. nama in the Old Brahmaputra River and its adjacent ecosystems.

Physiological traits and population dynamics of Schizothorax niger (Heckel, 1838): Insights from Dal Lake and the Jhelum River, Kashmir, Himalayan region.

This study examines the physicochemical characteristics, morphometric features, biometric growth parameters, biological indices, physiological parameters, and biochemical profiles of Schizothorax niger population. The physicochemical analysis revealed a maximum temperature of 12.93 ± 1.33°C and hardness of 156.53 ± 12.82 mg/L in Dal Lake, whereas the Jhelum River had a minimum level of 10.94 ± 1.12°C temperature and 128.31 ± 11.62 mg/L of hardness. Dal Lake had a neutral pH (7.5 ± 0.2) and lower dissolved oxygen (6.8 ± 0.4 mg/L) compared to the Jhelum River (pH 7.2 ± 0.3; dissolved oxygen 7.5 ± 0.5 mg/L). Morphometric analysis showed significant differences (p < 0.05) in fish length (Dal Lake: 18.4 ± 2.1 cm; the Jhelum River: 21.0 ± 1.8 cm) and weight (Dal Lake: 74.5 ± 9.8 g; the Jhelum River: 92.2 ± 7.4 g) between the sites. Biometric growth parameters demonstrated a positive allometric growth pattern, with Dal Lake having a steeper slope (b = 3.15) than the Jhelum River (b = 2.98). Biological indices revealed gender-based variations in the gonado-somatic index (GSI) and hepato-somatic index (HSI), with GSI being higher in Dal Lake (0.21 ± 0.02) and HSI in the Jhelum River (1.04 ± 0.09). Haematological and biochemical analyses showed significant differences in parameters such as haematocrit (Dal Lake: 29.2 ± 2.1%; the Jhelum River: 32.4 ± 1.8%), glucose (Dal Lake: 85.3 ± 5.4 mg/dL; the Jhelum River: 68.1 ± 4.2 mg/dL), and total protein (Dal Lake: 6.2 ± 0.4 g/dL; the Jhelum River: 5.8 ± 0.3 g/dL) between sites. These findings provide valuable insights into the physiological traits and population dynamics of S. niger, informing species-specific conservation strategies and ecosystem management practices.

Length-weight relationship and condition factor of Nile tilapia (Oreochromis niloticus) fed diets supplemented with guava and star gooseberry leaf extract

Background Nile tilapia (Oreochromis niloticus) is predominant cultured species in aquaculture. However, there is a scarcity of literature regarding relationship between guava and star gooseberry leaf extract and the condition factor. Thus, the present study aims to investigate the effect of guava and star gooseberry leaf extract-supplemented diets on the specific growth rate, length-weight relationship, and condition factor of Nile tilapia. Methods Six hundred and thirty Nile tilapia (8.7±0.4 g) were randomly distributed among twenty-one tanks (30 fish per tank) within a recirculation system. Over a 60-day period, the fish were fed diets supplemented with 5g/Kg and 10g/Kg of guava leaf extract (GLE-5, GLE-10), star gooseberry leaf extract (SGLE-5, SGLE-10), and a mixture of both (MxLE-5, MXLE-10). Subsequently, specific growth rate, length-weight relationship, and condition factor were determined. Results After 60 days, the specific growth rate was significantly higher in all the GLE, SGLE, and MxLE groups compared to the control group. The final lengths and weights differed significantly both in the control group and all the GLE, SGLE, and MxLE groups. The analysis of the regression equation indicated a positive correlation (r = 0.970, 0.977, 0.976, 0.974, 0.974, 0.974, and 0.969) between the length and weight of Nile tilapia in the control group and in all the GLE, SGLE, and MxLE groups. The regression exponent “b” values in all the GLE, SGLE, and MxLE groups were &gt;3, indicating a positive allometric growth pattern in Nile tilapia compared to the control (b=2.866), which exhibited a negative allometry. The final condition factor values did not differ significantly in either the control group or any of the plant extract groups. Conclusions Nile tilapia exhibited positive allometric growth patterns and maintained good health when fed with GLE, SGLE, and MxLE groups. Therefore, these plant extracts demonstrate suitability for commercial Nile tilapia production.

A Comparative Study on Growth Rates and Length-weight Relationships of Snow Trout (Schizothorax sp.) from Rasuwa, Nuwakot, and Okhaldhunga Districts of Nepal

Aims: Snow trout (Schizothorax spp.) are vital to Nepal's aquatic biodiversity and economy, yet little research has addressed their growth potential under controlled conditions. This study aimed to evaluate the growth performance of snow trout from three regions of Nepal (Okhaldhunga, Nuwakot, and Rasuwa) in captivity. Study Design: Original Research Article. Place and Duration of Study: Fisheries Research Station (FRS), Trishuli Nepal, between August 18 November 24, 2023. Methodology: Schizothorax species were collected from Okhaldhunga, Nuwakot, and Rasuwa districts and acclimated to the environment of the FRS in three separate raceways prior to the feeding trial. From each location, a population of 450 apparently healthy and uniform sized snow trout (initial weight: 20.00 + 1.2g) were then distributed into 3 raceway tanks, altogether 9 raceways for 3 groups, feeding upon the commercial feed (48% crude protein) in the form of dough at 3% of the body weight for 90 days. At the end of the feeding trial, growth parameters, including weight gain, specific growth rate (SGR), condition factor (K) and Length-weight relationship (LWR) were measured. Survival rate and water quality parameters were also measured. Statistical analysis for group’s means differences was conducted using one-way ANOVA in R Studio for Windows at a 5% level of significance. Results: Results indicated Fish from Nuwakot exhibited the highest weight gain (3.61 ± 1.82 g) and SGR (0.23 ± 0.12% per day), though these differences were not statistically significant (P &gt;0.05). The condition factor (K) was highest for Rasuwa fish (0.98), followed by Nuwakot (0.97) and Okhaldhunga (0.97) (P &gt;0.05), indicating that the fish were relatively thin, possibly due to poor nutrition or stressful conditions. The LWR analysis revealed high length-weight correlations for all groups, with Rasuwa fish exhibiting a positive allometric growth pattern (b=3.02), whereas Okhaldhunga (b=2.93) and Nuwakot (b=2.94) fish showed negative allometric growth patterns. This may suggest that snow trotu from Rasuwa were in relatively good physiological condition and adapting well to the rearing conditions at the FRS. Although with no statistical difference, the survival rate was highest for fish from Nuwakot (86.67%), followed by Rasuwa (80.00%) and Okhaldhunga (77.33%) (P &gt;0.05). This may indicate the adequacy of the water quality (average temperature 11.75 ± 0.42℃, dissolved oxygen more than 7 mg/L, and pH 7.71 ± 0.16) maintained during the study. Conclusion: The findings suggest that while the snow trout demonstrated the ability to survive yet grow slowly under captivity, their growth performance may be significantly enhanced by optimizing rearing conditions, particularly slightly higher water temperature. This study underscores the need for targeted improvements in aquaculture practices to support the effective domestication and conservation of snow trout in Nepal.

Food composition and trophic niches of blue swimming crab (Portunus pelagicus, 1758) in Madura Strait, Pamekasan, East Java

Abstract Blue swimming crab (Portunus pelagicus) is the main fishery commodity in the Madura Strait, Pamekasan Regency. The sustainability of the crab depends on the suitability of the habitat and the availability of food in the waters. This study aims to analyze the food composition and trophic niches of blue swimming crab in the Madura Strait, Pamekasan Regency. Sampling was conducted using the simple random sampling technique. The analysis included composition of the collection based on length frequency distribution, gastric fullness index, trophic niche area, food niche overlap, crab food composition, and growth (carapace width-weight relationship, and condition factor). The results of the index study showed that the index of stomach content of the female was generally greater than that of the male. Blue swimming crab is classified as a carnivore with the main food being fish. The overlap of the niches of male and female crabs of 0.9328 indicates a high level of competition for food. The male crab has a negative allometric growth pattern, while the female crab has a positive allometric growth pattern. The condition of the crab factor in each month of observation is greater than 0.5 indicating the availability of food and water conditions suitable for crab life.

Spatial and seasonal variations in the growth of the populations of tongue sole fish (Cynoglossus quadrilineatus Bleeker, 1851) along four different stations of Makran coast by using the von Bertalanffy model

BackgroundGrowth is a most important life-history trait that defines the maximum size and age, maturation stage, and mortality of any fish species and is also involved in stock assessment models commonly used in fisheries conservation or management. ObjectivesThe present study focused on assessing the growth patterns and related parameters to the population of tongue sole (Cynoglossus quadrilineatus) along different sites of the Makran coast in temperate regions. MethodologyA total of 987 tongue sole fishes were collected seasonally from four different sites along the Makran coast (Gwadar, Pasni, Ormara, and Sur Bandar). Growth parameters i.e., length-weight relationships, length-frequency distribution, von Bertalanffy (VBGF) growth model, and stock status were analyzed. ResultsThe overall results of the length-weight relationship (LWRs) of this species showed only a significantly positive allometric growth pattern (b < 3.0; p < 0.05) observed during three seasons along the four selected sites of Makran Coast. The estimated von Bertalanffy (VBGF) growth parameters of C. quadrilineatus at four stations were described as; maximum observed length (Lmax) = 31.65 cm, asymptotic length (L∞) = 33.32 cm, size at sexual maturity (Lm) = 17.98 cm, Lopt = 20.55 cm, growth coefficient per year (k) = 0.55 year -1, t0 = 0.04 year -1, f = 2.79, Tmax = 2.80 years, tm = 0.78 year, M = 1.64 per year, topt = 1.30 years. The present study also noted seasonal variations in the length frequency distribution (LFD) data between the four selected sites. ConclusionsThus, our study concluded that the von Bertalanffy growth model (VBGF) is the best-fitted model for analyzing the growth patterns of C. quadrilineatus at different sites and during various seasons along the Makran Coast. This model demonstrated superior predictive ability and effectively described changes in growth patterns or body size across sub-populations of C. quadrilineatus at the four study sites. Thus, our research provides valuable insights into the population dynamics and life history traits of this tongue sole population in the Makran coast. Moreover, as the first study on the growth of this species, our findings offer essential information for informing sustainable exploitation, conservation, and fishery management strategies.

Length-weight relationship and condition factor of Nile tilapia ( Oreochromis niloticus) fed diets supplemented with guava and star gooseberry leaf extract.

Nile tilapia ( Oreochromis niloticus) is predominant cultured species in aquaculture. However, there is a scarcity of literature regarding relationship between guava and star gooseberry leaf extract and the condition factor. Thus, the present study aims to investigate the effect of guava and star gooseberry leaf extract-supplemented diets on the specific growth rate, length-weight relationship, and condition factor of Nile tilapia. Six hundred and thirty Nile tilapia (8.7±0.4 g) were randomly distributed among twenty-one tanks (30 fish per tank) within a recirculation system. Over a 60-day period, the fish were fed diets supplemented with 5g/Kg and 10g/Kg of guava leaf extract (GLE-5, GLE-10), star gooseberry leaf extract (SGLE-5, SGLE-10), and a mixture of both (MxLE-5, MXLE-10). Subsequently, specific growth rate, length-weight relationship, and condition factor were determined. After 60 days, the specific growth rate was significantly higher in all the GLE, SGLE, and MxLE groups compared to the control group. The final lengths and weights differed significantly both in the control group and all the GLE, SGLE, and MxLE groups. The analysis of the regression equation indicated a positive correlation (r = 0.970, 0.977, 0.976, 0.974, 0.974, 0.974, and 0.969) between the length and weight of Nile tilapia in the control group and in all the GLE, SGLE, and MxLE groups. The regression exponent " b" values in all the GLE, SGLE, and MxLE groups were >3, indicating a positive allometric growth pattern in Nile tilapia compared to the control ( b=2.866), which exhibited a negative allometry. The final condition factor values did not differ significantly in either the control group or any of the plant extract groups. Nile tilapia exhibited positive allometric growth patterns and maintained good health when fed with GLE, SGLE, and MxLE groups. Therefore, these plant extracts demonstrate suitability for commercial Nile tilapia production.

A Study of Length-Weight, Relationship and Condition Factor of Bagrus Bayad in Kiri Reservoir Shelleng Local Government Area Adamawa State, Nigeria

The Bagrid fishes are commonly known as naked catfishes, they are commercially important species found in Nigeria fresh waters especially in Rivers and Lakes such as Niger, Kaduna, Benue, Lake Chad, and other inland waters. The study is aimed at investigating the length- weight, relationship and condition factor of Bagrus bayad. A total of 282 individuals of B. bayad were randomly sampled for a period of 6 months. B. bayad sample collected were dissected. All the data collected were subjected to one-way analysis of variance (ANOVA). Descriptive statistic, regression analysis, graph (bar chart) mean and standard deviation were used in calculating the data for analysis. Result from the data analysis showed the slope (b) value for male = 1.996 which is less than 3.0, hence the male fish shows a negative allometric growth pattern. While that of the female showed that the b value was 3.2971 which is positive allometric growth pattern and the combined sexes analysis shows that b = 2.330, which indicated a negative allometric growth pattern. The condition factors showed that the Male has K = 2.893, Female has K = 3.122 and the Combined Sexes Condition factor is K = 3.002. B. bayad exhibited both negative and positive allometric growth pattern with a strong positive correlation between the total length and weight of the species and also the species are in good physiological condition in the Reservoir.

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.

THE LENGTH-WEIGHT RELATIONSHIP OF Butis sp. IN THE TAMBUN RIVER, TOLITOLI DISTRICT, CENTRAL SULAWESI

Butis sp. is a type of fish that possesses physical characteristics such as small scales and a yellowish belly. Information regarding the existence and growth of this type of fish is still limited to the Tambun River, Tolitoli Regency. Analyzing the length and weight of the fish is one of the methods used to determine the biological conditions and fish stocks, there by facilitating the management of biodiversity sustainability. The aim of this study was to determine the relationship between the length and weight of Butis sp. in order to understand fish growth patterns. This research was carried out for 2 months in Sungai Tambun, Tolitoli Regency, Central Sulawesi Province. The location for collecting sample were divided into 3 stations. The test parameters observed were the relationship between length and weight and habitat conditions. The research results of Butis sp. in Sungai Tambun, Tolitoli Regency showed a positive allometric growth pattern (b= 3,25). The water quality in the Tambun River still supports the growth of Butis sp. (temperature 25-28oC, pH 5,5-8,5).Keywords : Biodiversity, fish biology, growth, positive allometrics

Osmoregulation pattern, condition factor, and gonadal maturity level of sea urchins in the various ecosystems of Panjang Island, Jepara, Indonesia

Abstract. Suryanti S, Anggoro S, A’in C, Widyorini N. 2024. Osmoregulation pattern, condition factor, and gonadal maturity level of sea urchins in the various ecosystems of Panjang Island, Jepara, Indonesia. Biodiversitas 25: 502-509. Panjang Island has a diversity of ecosystems. It is also famous for its abundance of echinoids, especially sea urchins. Currently, research on sea urchins in Panjang Island is mostly limited to studies on the abundance and maturity of gonads. This study investigates the osmoregulation patterns, condition factors, and maturity indices of sea urchin gonads in different ecosystems that are sea urchin habitats on Panjang Island, Jepara, Indonesia. Sampling is done randomly, while the research method is a case study. The results showed that there are 2 species of sea urchins found on Panjang Island, namely Diadema setosum Leske, 1778 and Echinothrix calamaris Pallas, 1774. Analysis of osmoregulation patterns showed that sea urchins at station 1 were hyperconformers, while sea urchins at stations 2 and 3 were hypo-conformers. Sea urchins at 3 stations had a positive allometric growth pattern (b&gt;3) and a high condition factor (K&gt;1). The average Gonadosomatic Index (GI) calculation result was 8.72%, while the type of ecosystem of the research stations influenced the color and texture of different gonads. Sea urchins are in immature, mature, and spawning stages, so the sea urchins on Panjang Island were partially spawned.

Age, growth, reproduction and mortality of Xenocypris argentea (Günther,1868) in the lower reaches of the Tangwang River, China.

To investigate various population biological parameters of Xenocypris argentea in the lower reaches of the Tangwang River (China), a comprehensive study was conducted for the first time. A total of 1,003 samples were collected from April to November 2022. The collected samples revealed that female X. argentea had total lengths ranging from 12.4 cm to 25.7 cm (weighing 15.86 g to 159.55 g), and male X. argentea had total lengths ranging from 10.8 cm to 23.9 cm (weighing 9.27 g to 121.06 g). The age of the samples was determined using otolith analysis, indicating that the ages ranged from 1 to 5 years old in both females and males. The length-weight relationships were further analyzed, uncovering the allometric growth index (b) was 3.1296 for females, indicating a positive allometric growth pattern. Differently, males exhibited a b value of 3.0274, suggesting an isometric growth pattern. Furthermore, the von Bertalanffy growth formula provided insights into the growth characteristics of X. argentea, revealing an asymptotic total length (L∞) of 36.096 cm and a growth coefficient (K) of 0.121. The analysis of the gonadal somatic index (GSI) and ovarian development period indicated that the spawning period occurred from April to July, with peak spawning in June. The study also explored fecundity-related traits, finding that individual absolute fecundity (FA) ranged from 11,364 eggs to 56,377 eggs, while eviscerated body weight relative fecundity (FW) ranged from 209 eggs/g to 823 eggs/g. The exploitation rate (E) for X. argentea was calculated as 0.574, suggesting that the population of X. argentea has been overexploited. By revealing previously unknown data on the key life history traits of X. argentea, this study has provided valuable insights that are crucial for the development of conservation strategies and policies.

Population structure of Indian river shad, Gudusia chapra (Hamilton, 1822) from the Rupsha River, south-west Bangladesh

The Indian river shad, Gudusia chapra, is a well-known species of potamodromous fish belonging to the Clupeidae family. The main focus of this study is to state the sex ratio, growth pattern, length-length relationship, form factor, Fulton’s condition factor and relative weight of G. chapra harvested from the Rupsha River (south-west Bangladesh). Altogether 300 specimens (male=166 and female=134) were harvested with the help of commercial fisher folks on seasonal basis (summer, rainy and winter) during 2022. Body weight and length of individual specimen were recorded with digital balance and measuring board. Total length varied between 12.7 to 16.5 cm for males and 13.0 to 17.3 cm for females. Further, body weight ranged between 15.82 to 42.48 g for male and 18.36 to 46.65 g for female. As a whole, both sexes revealed positive allometric growth pattern (b&gt;3.00). Moreover, the length-length relationships were found highly correlated for both sexes. The estimated form factor was 0.0087 indicated fusiform body shape for G. chapra population. The mean Fulton’s condition factor was recorded close to 1 indicated a pleasant health condition for this species. Further, mean relative weight revealed a sound ecological atmosphere regarding prey-predator status. The research outcomes would be helpful to execute a sound management policy in the Rupsha River and connected ecosystem in the south-west Bangladesh.&#x0D; &#x0D;

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.

Some biological aspects of indian mackerel (Rastelliger kanagurta Cuvier, 1817) in Bali Strait waters

Indian mackerel (Rastrelliger kanagurta Cuvier, 1817) is a small pelagic fish species which is the main catch commodity in purse seine and jukung fleets in the Bali Strait waters. Sustainable management is urgently needed for indian mackerel populations in Bali Strait waters to remain sustainable fishery. The availability of basic information such as biological aspects is very important as a fundamental resource in the management of indian mackerel in Bali Strait waters. The aims of this study were to reveal several biological aspects of mackerel such as growth patterns, condition factors, sex ratio, and size at first maturity of indian mackerel in Bali Strait waters. Sampling was carried out in May-September 2018. Samples of fish were taken from purse seine and jukung fleets using trawl nets and gill nets. Fish sample was measured, weighed and dissected to observe the sex and the gonadal maturity stage. The total number of indian mackerel samples was 167 individuals. Mackerel in the Bali Strait waters has a positive allometric growth pattern with fish in good condition. The sex ratio was in an unbalanced condition with the number of male fish being more than the female fish. The size at first maturity was 19.34 cm for male fish and 19.76 cm for female fish.

Length and Weight Relationship of Mackerel Fish (Auxis rochei) at Fish Collector Markets in Ampenan, Lombok

Lisong tuna (Auxis rochei) is one of high economic potential value of fish because of its abundance and often found in the fish market in Ampenan. Evaluating the impact of fishing to the growth pattern of length-weight of tuna is needed to ensure the sustainability of lisong tuna population. It is feared that the high intensity of tuna (A. rochei) fishing can cause growth disturbances and a decrease in local tuna populations. This study aimed to determine the relationship between the weight and length of lisong tuna (A. rochei) to their growth patterns in the fish market of Ampenan. Thirty individuals of lisong tuna were collected from two fish markets, Bintaro and Kebon Roek, in Ampenan. The equation of Linear Allometric Model is used to evaluate the length and weight relationship in growth patterns of lisong tuna. This study resulted in the positive allometric growth pattern of lisong tuna with slope value more than 3 (b=3.79). It indicated that the lisong tuna which were collected in Bintaro and Kebon Roek markets have a weight growth rate faster than their length growth rate. It means that the lisong tuna sold in Ampenan markets is quite fleshy and has a good growth rate.

Unraveling the mating system of the burrowing shrimp Lepidophthalmus siriboia (Decapoda Callichiridae) based on life history traits

Natural history studies are important in helping to understand the origin and evolution of social organization as well as the evolution of specialized morphological structures linked to mating behavior of animals. Here we describe the burrow use pattern, sex ratio, and sexual dimorphism of the burrowing shrimp Lepidophthalmus siriboia to test a series of evolutionary hypotheses. To this end, a total of 259 individuals of L. siriboia were collected from the northeast region of Brazil. No shrimp pairs or burrows inhabited by more than one shrimp were detected during the study period. A solitary habit is a non-random behavior in this species because single shrimps were found with a greater frequency than expected by chance. All ovigerous females were found living solitarily, which suggests that males abandon these females shortly after insemination. Contrary to the expectations of an anisogamous species, L. siriboia produced a female-biased operational sex ratio (OSR), contradicting the hypothesis that only males compete for mates. The latter was supported by the existence of sexual dimorphism in cheliped size, a condition that argues in favor of female–female competition in this species. In the same line of reasoning, heterochely was present in adult males, although it was also present to a lesser degree in adult females. Female asymmetry of chelipeds suggests the evolution of an unconventional role in female major cheliped use. The major cheliped showed a positive allometric growth pattern through the ontogeny of both sexes. However, when growth patterns of the major and minor chelipeds were compared, the fitted regression lines for each sex had different slopes, indicating that the cheliped could be an appendage sexually selected by individuals of the opposite sex during mating.

Distribution and Growth Patterns of Crab (P. pelagicus) Based on Environmental Characteristics in Candi Waters, Pamekasan Regency, East Java Province

Blue swimming crab (BSC) is a fishery commodity with high economic value and great demand in domestic and foreign markets. P. pelagicus swimming crabs are commonly found in Indonesian sea waters, one of the largest contributors to the country's foreign exchange after shrimp and tuna. The high demand for blue crab resources will trigger an increase in fishing efforts. If this is done continuously, it is feared that it could endanger the population structure. Moreover, disrupting the sustainability of blue swimming crab resources in the waters, this study examines the morphometric distribution and growth pattern of P. pelagicus crabs based on environmental characteristics in Candi waters, Pamekasaan Regency. Census sampling was carried out using the census method; the census method was carried out by taking all crab samples caught by fishermen. The results obtained found 33 individual crabs, which were divided into three classes, namely small (&lt;10 cm), medium (&gt;10 cm), and large (&gt;12 cm) size classes. Male crabs dominated the research locations with wider straps than female crabs. The analysis results show that the width-weight relationship's b values are 1.47 (males) and 2.00 (females). In addition, male and female crabs have a positive allometric growth pattern. Blue swimming crabs are often found in habitats with a substrate of dusty mud, high salinity and organic matter.

Pola pertumbuhan dan laju mortalitas Kepiting Bakau (jantan dan betina) jenis Scylla tranquebarica dan Scylla olivacea di Perairan Teluk Bintuni, Provinsi Papua Barat

The purpose of this study was to determine the shape of the growth pattern of the relationship between carapace width and weight, growth parameters, and mortality and exploitation rate of mangrove crabs in the waters of Bintuni Bay Regency. This research was conducted in Teluk Bintuni Regency, West Papua Province. The sampling locations were spread in three locations, namely Bintuni, Manimeri and Babo. Mangrove crab samples obtained from fishing traps caught by fishermen in the waters of Bintuni Bay, identified gender (male or female), and measured carapace width and weight, then the measurement data were analyzed using the help of several data analysis formulas. Based on the results of the analysis, it is evident that the mangrove crab S. tranquebarica has a value of b = 3.6223 (male) with a positive allometric growth pattern and b = 2.8100 (female) with a negative allometric growth pattern, while the type of S. olivacea has a value of b = 2.8612 (male) and b = 2.1581 (female). The growth parameter values for male and female of S. olivacea were able to reach asymptotic carapace width (CW∞) = 20.90 cm, while males and females of S. tranquebarica (CW∞) = 18.90 cm and 19.21 cm, respectively. Natural mortality of S. tranquebarica in the waters of Bintuni Bay is estimated at 0.90 per year (male) and 1.31 per year (female), while S. olivacea is 1.02 per year (male) and 1.12 per year (female).

Population dynamics and stock assessment of two major eels (Muraenesox bagio and Congresox talabonoides) from the marine waters of Bangladesh

Muraenesox bagio (black eel) and Congresox talabonoides (brown eel) are two major eels (Muraenesocidae) species which are commercially significant in the marine catch of Bangladesh, but population dynamics and stock assessment of marine eel fishery in Bangladesh are yet to be studied. This study is the first endeavour to analyze the population dynamics and stock assessment of this marine eels collected from July 2021 to May 2022 using three length-based methods namely TropFishR, the Length Based-Spawning Potential Ratio (LB-SPR) &amp;amp; the length-Based Indicators (LBI) and two catch-based methods including Depletion-Based Stock Reduction Analysis (DB-SRA) and the Catch-Maximum Sustainable Yield (CMSY). A slightly positive allometric growth pattern (b=3.10) for the black eel and a negative allometric growth pattern (b=2.33) for the brown eel were observed in the length-weight relationship. The parameters of von Bertalanffy Growth Function (VBGF) and the linearized length-converted catch curve (LCCC) analysis for black eel and brown eel were L∞=190.67cm and 166.63cm, k=0.18 year-1 and 0.16 year-1, and the total mortality, Z=0.70 year-1 and 0.45 year-1. The eel fishery is calculated to be overfished due to overexploitation and the stock’s spawning biomass (SPR=19% for black eel and 21% for brown eel) is close to the limit reference point but well outside the targeted range because the majority of the catches were found to have below-maturity levels. This study advised an optimum length limit to catch from 93 to 114 cm for black eel and 83 to 101 cm for brown eel. Though the estimated reference points of the CMSY were more optimistic than those from the DB-SRA, the tendency of the status of eel stock has been displayed moving towards overexploitation from a safe stock scenario. This study, therefore, recommended an annual landing limit of 250 mt as OFL (Over fishing limit) for the next ten years in association with existing management measures to maintain the present stock biomass of eel fishery over the BMSY level.