growth

The aim of the present study is to estimate the optimal catch length for two mullet species , namely the leaping mullet (Chelon saliens) and the golden grey mullet (Chelon auratus), while considering uncertainty and sensitivity analysis. To record length, weight, and age data, 50 and 32 specimens of these two species were collected respectively from seining catches along the Golestan coasts during the period from October 2022 and April 2023. The parameters of infinite length (L∞ ) and growth rate (k) were estimated using two methods Ford-Walford and nonlinear least squares, while the natural mortality rate (M) was calculated using ten different approaches. The optimal catch length (Lopt ) for the two fish species was estimated under two scenarios: (1) calculating natural mortality from growth parameters estimated by the Ford-Walford method, and (2) calculating natural mortality from growth parameters estimated by the nonlinear least squares method. The age composition ranged from 0 to 7 years (with a fork length range of 13.8-28.8 cm) for the leaping mullet and 1 to 13 years (with a fork length range of 13.9-52.0 cm) for the golden grey mullet. The length-weight relationship analysis revealed slope values (b) of 2.81 for the golden grey mullet and 3.04 for the leaping mullet. Using the Ford-Walford method, the asymptotic fork length (L∞​) and growth rate (K) were estimated at 30.7 cm and 0.25 year⁻¹ for the leaping mullet, and 61.3 cm and 0.11 year⁻¹ for the golden grey mullet, respectively. Nonlinear least squares analysis yielded L∞​ and K values of 25.2 cm and 0.25 year⁻¹ for the leaping mullet and 47.7 cm and 0.16 year⁻¹ for the golden grey mullet. These same parameters estimated by the nonlinear least squares method for the leaping mullet were 25.2 cm fork length and 0.25 per year, and for the golden grey mullet, they were 47.7 cm fork length and 0.16 per year. The range of estimated natural mortality rates varied from 0.176 to 0.543 for the golden grey mullet and from 0.4 to 1.23 for the leaping mullet. The optimal catch length for the leaping mullet varied between 16.3–22.3 cm (mean: 18.6 cm) in Scenario 1 and 17.3–21.1 cm (mean: 19.6 cm) in Scenario 2. For the golden grey mullet, optimal lengths ranged from 24.1–42.3 cm (mean: 29.3 cm) in Scenario 1 and 23.6–33.3 cm (mean: 26.9 cm) in Scenario 2. The differences in optimal catch length calculations between Scenarios 1 and 2 were 18.2 cm and 9.7 cm for the golden grey mullet and 5.9 cm and 3.8 cm for the leaping mullet, respectively. These results indicate the significant impact of growth parameters and natural mortality on the estimation of optimal catch length. The final recommendation of this study for sustainable fishing management and the formulation of related regulations is to set the optimal catch lengths for the leaping mullet and golden grey mullet at 20 cm and 26 cm, respectively.

In this experiment, the effect of using pectin and natozyme multi-enzyme separately and in combination on blood serum biochemical indicators in common carp fry (Cyprinus carpio) was investigated. For this purpose, the number of 540 common carp fry with an average weight of about 10 gr for 8 weeks with experimental diets with nine treatments and each treatment with three repetitions including basic diet (0), 1% pectin, 2% pectin 0.05% natozyme multi-enzyme, 0.1% natozyme multi-enzyme, combination of pectin (1%) and natozyme multi-enzyme (0.05%), pectin combination (2%) and natozyme multi-enzyme (0.05%), Pectin composition (1%) and natozyme multi enzyme (0.1%), pectin composition (2%) and natozyme multi enzyme (0.1%) were fed. . For genetic study, liver, brain and kidney tissues were sampled; RNA extraction and cDNA synthesis were performed using kits. Growth-related genes (GH and IGF-1) and immunity (IL1-β and Lyz) were evaluated using real time PCR. The data were evaluated by two-way analysis of variance using SPSS software. In the results of the separate and combined effects of natozyme and pectin on the expression of growth genes, no significant difference was observed in the separate treatments of natozyme and pectin (P>0.05), but the combined treatment with an interaction effect showed a significant difference with other treatments (P≤0.05). The results of separate effects of natozyme and pectin on LYZ and IL-1 gene expression, there was a significant difference between the separate treatments of natozyme and pectin, so that pectin was higher than natozyme (P≤0.05). In addition, combined treatment with interaction effect showed a significant difference with other treatments (P≤0.05). The results of this experiment showed that the use of 0.1% natozyme multienzyme and 2% pectin in the diet of common carp can have a positive effect on the expression of growth and immunity genes in this fish.

The aim of this study was to evaluate the effects of adding cottonseed meal along with the yeast Saccharomyces cerevisiae strain PTCC5052—either iron-enriched or non-enriched—on the economic justification of production, biochemical blood characteristics, microbial flora, and histopathological status of the intestine in juvenile rainbow trout. Fish were distributed in four treatments with four replications. One control diet without cottonseed meal, one diet containing 15% cottonseed meal, and two diets containing 15% cottonseed meal + 1 × 108 cfu/g of yeast or iron-enriched yeast were provided to the fish for 8 weeks. The results indicated no significant differences in fish production efficiency, plasma biochemical indices, and histopathological status of the intestine among the treatments. The cost of feed per unit of fish production in the treatments containing cottonseed meal significantly decreased compared to the control treatment, with the lowest cost was observed in the treatment without yeast. No significant differences in microbial abundance were observed between the control treatment and the cottonseed meal treatment; however, the addition of yeast or iron-enriched yeast to the diet resulted in an increased density of the genus Saccharomyces, a reduction in the density of the genera Aeromonas and Vibrio, and a decrease in the density of Yersinia ruckeri in the fish intestine. The results of this study indicate that adding 15% cottonseed meal to the diet of rainbow trout can enhance the economic justification for fish production, and the addition of yeast to this diet improves the microbial flora in the fish's intestine

This study aimed to investigate the growth and mortality parameters rates and the reproductive biology of T. vitrirostris on Hormozgan inshore waters (the northern Persian Gulf). 1211 specimens were selected by Stake-Nets, shrimp trawling fisheries, Trichiuridae in Qeshm Island located in the Persian Gulf during January 2010 to December 2010. 260 specimens was obtained to determine the sex ratio. growth parameters obtained from otolith ageing and length frequency analyses with FISAT and ELEFAN1method agreed well. The minimum and maximum length of the fish specimens were calculated 2/3 cm and 24.4 cm and length-weight 0.2g and 78.8 g, respectively. The a value of the length-weight relationship was obtained 0.0047 and for b was 3.121 that showed positive allometric growth. Estimated Von Bertalanffy growth parameter values were (L∞ = 23.42 cm, K = 0.62 and t0 = -0.279 year) and (L∞ = 25.12 cm, K = 0.41 and t0 = -0.421 year) for male and female, respectively. Also infinity weights (W) were estimated nearly to 17.563. The annual total mortality, fishing mortality, and natural mortality coefficients were estimated 2.138, 1.118 and 3.256 per year, respectively. Also, the exploitation coefficient 0.656 was obtained, which indicates that the stock was not overexploited.

This research aimed to investigate the effect of gamma-aminobutyric acid supplementation on the growth and survival indicators of rainbow trout fry kept at high density, for this purpose, 585 fry with an average weight of 5 ± 0.03 grams in 5 experimental treatments with High density (129 pieces in 69 liters) and a negative control group with normal density (69 pieces in 69 liters) were included. The test treatments included a positive control group, treatments 100, 200, and 300, which were fed with gamma-aminobutyric acid supplement sprayed to the commercial diet at the rate of 0, 100, 200, and 300 mg/kg, respectively during 7 weeks, . At the end of the breeding period, the growth indices including weight gain, food conversion coefficient, specific growth coefficient, specific growth rate, condition factor, protein yield ratio, and survival percentage were examined. In all the growth indices, there was a significant increase in the feeding groups. Gamma-aminobutyric acid supplement compared to the negative control group was observed, the highest of which was related to the treatment of 300 mg of GABA supplement (P < 0.05). The lowest food conversion factor among the experimental treatments was related to the 300 mg group, which had a statistically significant difference with the positive control group (P<0.05, no deaths were observed in any of the groups. The results showed that adding a gamma-aminobutyric acid supplement to the diet of rainbow trout raised in high density moderates the negative effects of stress resulting from high density on growth indicators and improves these indicators.

Due to the decline in the population of Caspian salmon (Salmo caspius) in the southern part of the Caspian Sea, the age and growth of this fish were studied in the Dohazar River in Tonekabon to improve conservation programs. In December 2018, 63 fish samples were collected using an electroshocker. Among these, 21 females and 42 males were captured, resulting in a sex ratio of 2:1, with a significant difference between the sexes (p<0.05). The length range of males and females was 7.5–18.5 cm and 6.5–21.5 cm, respectively, while their weight ranges were 3.99–65.5 g for males and 2.51–95.42 g for females. Age determination was conducted using scales. The age range of the population was from +1 to +5, with females distributed across 5 age groups and males across 4 age groups. The highest age frequency in all cases was in the 1+ and 2+year age groups. The von Bertalanffy growth equations for males and females were calculated as Lt = 230.462{1-exp(-0.327(t-(-0.240)))} and Lt = 300{1-exp(-0.213(t-(-0.139)))} respectively. The mean Monro index for the total sample was 2.26, with 2.23 for males and 2.28 for females. The study results show a significant decrease in the growth parameters of the species across all age groups. Both the growth coefficient and the asymptotic length of the species have decreased compared to previous years.

The aim of this study was to determine the optimal salinity for rearing the juveniles of Starry Sturgeon (Acipenser stellatus) in enclosed environments. Sturgeon with an average initial weight of 54.11 ± 1.54 g were raised in 500-liter fiberglass tanks (average temperature 22.58 ± 0.14 °C)in a control group (freshwater) and two treatment groups (6  and 12 ppt) in 3 replicates for 60 days. They were fed with commercial feed (Faradaneh) twice a day. At the end of the rearing period, specific growth rate (SGR), weight gain (WG), condition factor (CF) and hepatosomatic index (HIS) in experimental fish (12 ppt) were significantly elevated compared to control fish (p≤ 0.05). Food conversion ratio (FCR), on the other hand, was significantly reduced in the experimental fish (p≤ 0.05). The survival rate of fish was 100%. Intestinal villi length and internal space were significantly elevated and reduced in 12 ppt salinity, respectively (p≤ 0.05). The results suggest that the optimal salinity at this point of Starry Sturgeon life is the Caspian Sea water salinity (12 ppt) which provides the conditions for introducing this species as a suitable species for rearing in enclosed environments in natural water resources. Considering that A. stellatus lives in waters with diverse salinities at different stages of its life, it is important to know the appropriate weight and salinity for releasing in order to increase the percentage of survival and improve growth.

Considering the cultivation of Artemia as a valuable food source for feeding aquatic larvae and the importance of using healthy water resources, this study investigates the cultivation of Artemia urmiana in treated wastewater and salty ground water, examining their effects on growth, survival, and reproductive factors. Artemia was cultured under six treatments, each with three replicates, including two control groups (salinities 60 and 120 ppt), two salinized treated urban wastewaters (salinities 60 and 120 ppt) and two salty ground waters (salinities 60 and 120 ppt). During the culture period, all groups were equally fed with the single-cell algae Dunaliella salina and wheat bran suspension. Growth, survival, and reproduction factors were measured on days 8, 11, 14, 17, 20, and 23. The results showed that the growth rate of Artemia in the salinized treated Urban wastewater (salinity 120 ppt) was significantly higher than in other treatments (P<0.05). The survival rate was lower in the treated wastewater compared to the control group, but this difference was not statistically significant (P>0.05). The number of offspring and nauplii were significantly higher in Artemia grown in urban wastewater (salinity 120) than in the control group (P<0.05). From these results, it can be concluded that unconventional waters have the potential to create a suitable environment for the cultivation of A. urmiana.

Quercetin is a flavonoid, abundantly present in plants and has gained considerable interest for its antioxidant properties.  The present study was designed to assess and compare the influence of both free and nano-encapsulated quercetin on growth indices and survival in Penaeus vannamei. The ionic gelation method was used to prepare quercetin loaded nanoparticles (Qu-ChiNPs), and their characteristics were determined using DLS method. The finding related to the characterization of Qu-ChiNPs demonstrated that hydrodynamic size and Zeta potential were 160/1 nm and 33/8 mV, respectively, and in vitro release of drug from Qu ChiNPs illustrated burst release in the initial period. For feeding trial, shrimps with an average weight of 2/27 ± 0/18 g with 5 diets including: basic diet without Qu, Qu-Chi and Chitosan nanoparticles supplement (control), supplement with 0.5 g Querectin, 0.25 g Qu-Chi, 0.5 g Qu-Chi and 0.5 g Chitosan nanoparticles per kg of diet were fed. Shrimp were randomly divided into 5 groups, with 3 replicates in each group and 50 shrimp in each replicate. After a 2-month feeding period, results showed that final weight (Wf), weight gain (WG) and mean daily weight gain (ADG) of shrimp fed Qu-Chi 0.5 g were higher than the other treatments (P˂ 0.05). However, there was no significant difference in survival rate (SR) between treatments. The results showed that the use of Qu-Chi 0.5 g in the diet can have a positive effect on growth performance and survival of Penaeus vannamei.

Carotenoids are a group of natural fat-soluble pigments that are mainly produced from natural sources such as plants and animals, however, carotenoids are also synthetically produced and used in various sectors of the aquaculture industry. The present study was conducted with the aim of investigating the function of carotenoid supplements in improving skin pigmentation and growth of aquatic animals, especially fish. One of the most important functions of carotenoids is their pseudo-antioxidant function against free radicals and oxidizing agents, increasing the body's immunity against bacterial and fungal diseases. In addition, they play a vital role in improving the growth, survival and reproduction of aquatic animals, as well as, interfering with the infant stages or the early stages of feeding. So far, various researches have been reported about the addition of carotenoid supplements to the diet of aquatic animals, which have had positive and significant effects on improving skin color and also increasing the growth of many aquatic species. Among these aquatic species are Atlantic salmon (Salmo salar), Red tilapia (Oreochromis niloticus), Hyphessobrycon callistus, koi carp (Caprinus carpio L.), goldfish (Carassius auratus), rainbow trout (Oncorhynchus mykiss), Larimichthys crocea, green swordtail (Xiphophorus hellerii), bighead catfish (Clarias macrocephalus) and channel catfish (Ictalurus punctatus). The results showed that regarding the adverse effects of artificial carotenoids on the growth of aquatic animals, it is necessary to use plant sources in aquatic food in order to improve the color of the skin and also to increase the growth and survival rate of aquatic animals in aquarium environments. The present study focuses on the extraction of carotenoids from plant sources, including various microalgae such as Haematococcus pluvialis, Chlorella vulgaris, Dunaliella salina, and Arthrospira maxima in the implementation of this matte. The implementation of these activities can help to further promote the ornamental aquatic industry at the international level and also to create sustainable employment in Iran.

Ensuring food and nutritional security is a top issue for global food-producing sectors among the projections of a 60% increase in food consumption by 2050 due to population growth. To address this challenge sustainably, the food and feed industry must conserve resources while feeding a growing population (Saiprasad et al., 2023a). This rapid expansion of aquaculture has led to increased demand for protein sources for feed production (Wang et al., 2023) and straining the supply of natural protein ingredients, such as fishmeal and plant protein sources. As a necessary way to reduce protein inclusion levels in aquaculture feed, lipids and carbohydrates are extensively used. Lipids can serve as an energy source with high energy density, and fish has good lipid absorption and utilization ability. Carbohydrate is a cheaper energy source than lipids and protein, which also serves as a swelling and stabilizer agent in fish feed (Kamalam et al., 2017). However, numerous studies have demonstrated that long-time ingestion of a high lipid/carbohydrate diet causes disturbance of lipid metabolism, excessive hepatic lipid accumulation, and mitochondria stress, thus inducing fatty liver disease and affecting the physiological condition and growth of fish (Ding et al., 2020; Jin et al., 2019a; Jin et al., 2020; Lin et al., 2018; Wang et al., 2021; Wang et al., 2020). Using functional feed additives is an effective way to relieve hepatic metabolic stress and improve fish health which has drawn considerable attention in the aquaculture nutrition field. Up to now, L-carnitine (Jin et al., 2019a), choline (Jin et al., 2019b), herb extract (He et al., 2021; Liu et al., 2021; Wang et al., 2021), and other feed additives showed positive effects on fish metabolic disorder. Bile acids (BAs) play important roles in lipid metabolism. They are synthesized from cholesterol exclusively by the liver. In the intestine, BAs act as detergents to emulsify and facilitate the absorption of dietary fats and lipid-soluble vitamins. Therefore, the objective of this study was to evaluate the effects of dietary BA supplementations on growth performance, carcass biochemical composition and Biochemical Factors of rainbow trout (Oncorhynchus mykiss).

A 75- day feeding experiment was conducted to investigate the effects of dietary bile acids (BAs, Roneon 30%) on nutritional index, growth, carcass biochemical composition, Biochemical Factors and economic return coefficient of rainbow trout (Oncorhynchus mykiss). An experiment was designed with four treatments each with three replicates. Experimental diets were made by supplementing a control diet (BA0) with 300, 600 and 900 mg bile acid (BA) kg− 1 diet, respectively. 600 juvenile rainbow trout average initial weight of 52±5 g (±SD) were assigned to twelve 2000 L experimental tanks. Fish were sampled on day 75 and growth performance indices including Food conversion ratio (FCR), Protein efficiency ratio (PER), Specific growth rate (SGR), Condition factor (CF), and Weight gain percentage (WGP) were compared among the treatments. Also carcass composition (protein, fat, ash, moisture) and bichemical factors of serum including Aspartate transaminase enzyme (AST), Alanine transaminase enzyme (ALT), Alkaline phosphatase enzyme (ALP), Lactate Dehydrogenase, Glucose, Triglyceride, Albumin and total protein were analyzed.

At the end of the experiment food conversion ratio, (<1) in the treatment of 900 mg/kg showed the best performance among the experimental treatments. The final weight (187.33±7.28 g) had a significant difference compared to other treatments(P<0.05). Specific growth rate, Condition factor, Protein efficiency ratio and Weight gain percentage were improved in fish fed with diets 600 and 900 mg/kg bile acid supplementation compered with other treatments. Also Treatments receiving bile acid supplementation had more crude protein and less ash than the control treatment and the 300 and 600 mg treatments had higher moisture content than other treatments (P<0.05). Glucose, Triglyceride, Albumin and Lactate Dehydrogenase did not change by the addition of bile acid supplementation (P>0.05). Cholesterol content was significantly higher in fish fed diet containing 900 mg/kg bile acid supplementation compared with control group (P< 0.05). Aspartate transaminase enzyme in the treatment of 900 mg/kg compared to the control group and 300 mg/kg, Alanine transaminase enzyme in the treatment of 900 mg/kg and Alkaline phosphatase enzyme in the treatment of 300 mg/kg compared to other treatments showed significant differences (P<0.05) (Tables 1- 3).Different lowercase letters in the same row indicate statistically significant differences (P<0.05).

Discussion and conclusion :

The changes of serum biochemical factors as well as the relative improvement of growth and nutrition factors indicated the positive performance of using 900 mg/kg bile acid supplementation in the diet of juvenile rainbow trout, while the effects of increasing Liver enzymes, the Serum Biochemical Factors in the mentioned treatment should be studied and investigated. Bile acid supplementation could also enhance crude protein and decrease of ash and moisture in treatment of 900 mg/kg while bile type, level and fish species must be considered. This study discusses these aspects in regard to fish nutrition to help increase the inclusion of dietary fishmeal alternatives and thus enhance aquaculture sustainability.

The color of ornamental fish is effective factor on sale and economic value. Recent year, due to the expensive price of synthetic pigments, a lot of research were done to evaluate the potential of natural materials as a pigment. The aim of this study was to investigate the growth performance and tonality of Severum fish fed with experimental diets supplemented with different levels (0, 3, 6, 9 and 12%) of safflower powder for 8 weeks. Each treatment triple replicates water and 10 fish were used in each replication. In order to evaluate the growth performance, biometry of fish was done every two weeks and indices such as final weight, weight gain, feed consumption, feed conversion ratio, specific growth rate, feed efficiency, condition factor, price index, and survival rate were calculated. At the end of the feeding period, digital photograph, were taken reom 6 fish per treatment with constant and uniform light distribution and to assess the rate of change of the color obtained colorimetric system L * a * b * was evaluated using the Photoshop software and Hab values and chroma was determined. Statistical analysis of data was performed by One -Way ANOVA with Duncan test at the level of 95 % using SPSS 16. Statistical significance was set at the level of P < 0.05 with ± standard deviation (SD). The results showed that some indices, such as feed conversion ratio, specific growth rate, feed efficiency, condition factor, price index and survival rate in second treatment (6%) were significantly improved compared with the other groups. According to the findings of this study, remarkable differences were not observed in fish skin (in fin and trunk) coloration indices among experimental groups, however, these components in the T2 (6%) was improved, relatively.