Iranian Journal of Fisheries Sciences
Volume:21 Issue: 3, May 2022

Reproduction and spawning patterns of the Yellowtail scad (Atule mate) were studied in the Persian Gulf and Oman Sea (Hormozgan coastal waters) from December 2016 to November 2017. A total of 447 fish were collected from Bandar Lengeh, Qeshm Island, Bandar Abbas, and Bandar Jask landing sites. Minimum and maximum fork lengths of this species were 10 and 33 cm, with average 20.63±1.73 cm. The total weight ranged from 12.9 to 363.2 g, with average 113.08±31.69g. The relationship between length and weight was obtained as W=0.017L 2.89(R2=0.92) which showed that the fish has an isometric growth. Monthly analysis of the reproductive stages and gonadosomatic index showed that reproductive cycle beginning in January and continued with a sharp decreasing trend from March. The mean length at first maturity (Lm50%) for female was 19.8 cm. The sex ratio )F:M) was 1.5:1.

A 56-day research was carried out to determine the interactive effects of water temperature (WT) and salinity (WS) on physiological responses of yellowfin seabream, Acanthopagrus arabicus (Iwatsuki, 2013) (10.0±0.2 g). Three salinities (S; 12, 35 and 50 ‰) and four temperatures (T; 16, 23, 30 and 35°C) were selected to design 12 experimental treatments. The husbandry system consisted of thirty-six 300-L cylindrical polyethylene tanks that were filled with 250 L of water. Each treatment had three replicates (tanks) containing 20 fish in each tank. Fish were handfed on a commercial feed (440 g kg-1 crude protein and 180 g kg-1 crude fat) twice daily at visual satiation. Five fish from each tank were transferred into an experimental chamber to evaluate their oxygen consumption and ammonia excretion. There was a positive correlation between fish oxygen consumption and WT (r=0.594; p=0.001). In addition, there was a negative relationship between WS and ammonia excretion (AE) (r = -0.865; p=0.029), meanwhile the relationship between WT and AE was positive (r=0.422; P=0.01). Growth parameters were significantly affected by WT, WS and their interactions so that the highest final body was recorded in the highest temperature and salinity treatment. On the other hand, the lowest body weight was observed in the lowest WT (i.e., 16℃) irresponsive to WS. The moisture level in the whole body was affected by WT (p=0.012). The crude lipid in the whole body was influenced by only WS (p=0.04). The ash content in the whole body was profoundly affected by WT (p=0.0001), WS (p=0.0001) and their interaction effect (p=0.04). The energy content of the whole body was only affected by WT (p=0.025). The energy budget of fish was influenced by WT (p=0.0001) and its interaction with WS (p=0.015). In summary, the present findings indicated that the preferred WT for A. arabicus is between 30 to 35°C in brackish water.

Acid soluble collagen (ASC) from the skin (ASC-S) and bone (ASC-B) of shabout (Arabibarbus grypus Heckel, 1843) were isolated and characterized. Both ASC-S and ASC-B from shabout contained glycine as the major amino acid and high amount of proline (Pro), hydroxyproline (Hyp), alanine and glutamic acid. On the basis of dry weight, yields of ASC-S and ASC-B were 6.79 and 2.57%, respectively. Furthermore, fourier transform infrared spectroscopy (FTIR) proved that both collagens were integrated and native. The denaturation temperature of ASC-S and ASC-B were 31.59 and 32.25°C, respectively. Additionally, the results of X-ray diffraction (XRD) proved that the two products retained their helical structures. These collagens had prominent absorptions at 230 nm by UV-Vis spectra. Additionally, the scanning electron microscope (SEM) studies have shown that ACS-S and ASC-B are porous and exhibited fibrous nature. According to the UV–Vis and FTIR results, extracted collagens were characterized as Type I collagen based on their amino acid profile. In the current study, the total amount of amino acid (Pro+Hyp) was 19.28% and 19.55% for ASC-S and ASC-B, respectively. The results of the current study suggested that the collagen isolated from shabout can potentially be an alternative source for use in the food, pharmaceutical and biomedical industries.

In the present work, extraction of an endosymbiont from a host of Stichodactyla haddoni collected from the coast of Hormuz Island (the Strait of Hormuz) and afterwards identification, determination of the optimal cultivation conditions and then finding out the parameters and how they affect its bioactive compounds were conducted. The sequence of ITS2 region from the endosymbiont of S. haddoni clustered with 17 sequences representing clade C. The sequence was deposited to the GenBank under accession number MT448855. The study results showed that ASP12 medium and a temperature of 23°C were optimal to cultivate Symbiodinium sp. outside its host. Under these conditions, the highest cell density was 12×105 cell ml-1 and the maximal amount of chlorophyll-a and peridinin were 22.81 and 47.86 mgL-1, respectively. Further cultivation of the obtained strain in a Twin-Layer photobioreactor at light intensities of 50, 100 and 250 μmol photons m-2 s-1 for 16 days demonstrated that the biomass content was observed to be 35.72, 54.77 and 57.12 g m-2 at 50, 100 and 250 µmol photons m-2 s-1; the peridinin content was 0.26, 0.63 and 0.79 g m-2, respectively; total lipid content was 19.5 and 27.77% of dry weight at 50 and 250 µmol photons m-2 s-1.

Shrimp culture, one of the most profitable industries, needs to be modified by modern techniques in Iran. The present study was focused on the effects of applied biofloc technology (BFT) on Pacific white-leg shrimp (Litopenaeus vannamei) culture, as a new system (zero-water exchange) to improve the immunity of shrimp and the water-quality factors in challenge with Vibrio harveyi. Biofloc systems were established by increasing the carbon/nitrogen (C/N) ratio by adding sugar as a carbohydrate source to the culture media. The immune system indices, and growth factors of shrimp were then measured along with water quality parameters and loads of Vibrio harveyi compared to the traditional water-exchange system. The results showed that using BFT led to decreasing levels of the toxic nitrogenous substances such as TAN, NO3, and NO2, which in turn resulted in decreasing the water exchange frequency. It was also observed that the shrimp could feed on flocs resulted in improvement the growth factor and immune system. On the other hand, despite the increased loads of V. harveyi bacteria, there was no significant difference in shrimp survival between the biofloc and traditional systems. These observations were confirmed by evaluating immune system factors (total hemocyte count (THC), total plasma protein and phagocytosis activity of the hemocytes. Generally, this study showed that rearing pacific white-leg shrimp in BFT in can preserve water quality and enhance shrimp’s growth and immune responses, compared to the traditional systems.

This study was carried out to evaluate the feasibility of chitosan, a natural antimicrobial substance to improve the caviar shelf life. The effect of chitosan coating was carefully studied within 150 days storage time at -3°C in a standard situation. Both the caviar wrapped  by chitosan and the control sample, were packed in commercial glass Jars. Chemical, microbiological and sensory analyses were done during storage time. Results showed that the effect of chitosan coating on caviar samples was to maintain their good quality characteristics and extend the shelf life of caviar significantly (p<0.05) about 60 days in contrast with standard sample.

Steroid hormones in teleost have an important role in gonadal development and sexual maturity. Hilsa shad (Tenualosa ilisha) is important for fisheries in the South of Iran. Any information on steroid hormones of Hilsa shad brooders and their relationship with the spawning period provides a vital step for studies on the propagation and culture of this species. Fish samples were captured from four location-time stations: September-fresh water (Salinity: 5.2±0.35 ppt, Temperature: 27±0.17 ºC, DO: 7.9±0.23 mg/L; Karoon river, Khorramshahr; 1st station), September-marine water (Salinity: 44.01±0.5 ppt, Temperature: 26.5±0.41 ºC, DO: 7.45±0.52 mg/L; Bahrakan Port, Persian Gulf; 2nd station), October-marine water (Salinity: 41.77±0.25 ppt, Temperature: 15.27±0.32 ºC, DO: 9.36±0.10 mg/L; Bahrakan Port, Persian Gulf; 3rd station), and November-marine water (Salinity: 40.01±0.28 ppt, Temperature: 14.91±0.37 ºC, DO: 9.45±0.18 mg/L; Bahrakan Port, Persian Gulf; 4th station). Blood samples were immediately collected by a 5 ml syringe from the caudal vein, and serum was separated after centrifuging (7640 g,10 min). Also, gonad developmental stages and Gastro-somatic index (GSI) were determined after necropsy of euthanized fish. The enzymatic Immunological Assay method is used for hormone measurements, including thyroxin (T4), triiodothyronine (T3), 17-β estradiol (E2), and testosterone (T). More samples at the 1st station were on the 5th gonadal development stage with the highest GSI index. The maximum and minimum serum E2 levels were recorded at the 1st and 2nd stations, respectively. The serum testosterone concentration at the 1st station was significantly higher than the other ones and the maximum T3 and T4 concentrations were recorded at the 4th station. The results of this study proposed that Hilsa shad females are ready for spawning in September and this time is proposed for collecting broodstocks from the Karoon river (Khorramshahr, Khuzestan) for artificial propagation.

Endosulfan is one of the organochlorine pesticides which has been used worldwide for decades. The purpose of the present study was to investigate the effect of endosulfan on hematological and P450 gene expression in Rutilus caspius. Fish were exposed to the 10% and 20% LC50 for 21 days and were sampled on days 1, 7, 14 and 21. Results showed that there were significant differences in hematological parameters among the control and treated fish (p<0.05). The highest amount of Hb, Ht and RBC was observed in the control, while WBC was highest in the 20% endosulfan treated group on day 21. According to the results alkaline phosphatase, aspartate aminotransaminase and alanine amino transaminase levels increased during the experiment. The highest levels were observed with 20% endosulfan on day 14 which were significantly different with those in the control (p<0.05). In addition, the CYP450 gene expression had the same results. We conclude that exposure to the endosulfan (especially 20%) can enhance the innate immune system in Rutilus caspius.

Seaweed Gracilaria verrucosa is one of the potential marine natural resource commodities in Karawang Regency, Indonesia. Solid soap is one of the added value products that can be developed from seaweed since it has a potential antibacterial function for human skin. The solid soap with seaweed enrichment sale could increase the seaweed farmers and coastal community income. This study aims to produce solid soap with the addition of different seaweed G. verrucosa formulations and examine the sensory, physicochemical parameters, and antibacterial activity of the soap. This study applied five variants: solid soap with the addition of 0.025%, 0.050%, and 0.075% seaweed water extract (W250, W500, and W750), 0.075% seaweed ethanol extract (E750), and seaweed pulp (SWP). The variant W500 and SWP have the highest attributes according to the sensory (aroma, color, amount of foam, and power of detergency) and physicochemical (pH, foam stability, and unsaponifiable fat content) parameters, respectively. The variant SWP and W500 also have a strong antibacterial activity. From the results, the variant SWP and W500 can be the candidates for further product development.

This study combined socio-economic data with long time series data for Kilka species' annual catch and effort from 2003 to 2017, in the Iranian waters of the Caspian Sea. This analysis was conducted to estimate maximum sustainable yield, maximum economic yield, and their respective effort levels to manage and exploit the Kilka spices in a sustainable manner. According to our estimation, MSY was 22850 t, with a total income of $5587715 at an effort value (fmsy) of 9498 vessel night. The figure for MEY were 21988 t, with a total income of $5376847 with a substantially lower fishing effort value (fmey) of 7653 vessel night. Comparing the landing of Kilka, in 2017 (22602 tonnes) with the results of the surplus production model analysis, it is suggested that in order to conserve stocks of common Kilka, it is necessary to decrease the level of catch and fishing efforts based on the results of the present study.

The aim of this study was to investigate the effect of using hydrolyzed protein (HP) prepared from rainbow trout viscera in the fish diet on its shelf life in terms of chemical spoilage, bacterial load, and chemical composition at ambient temperature. HP was prepared from rainbow trout viscera using Alcalase (1.5% v/w, 55°C, pH 8.5). Five experimental diets were prepared to contain different levels of HP (0, 5, 10, and 20 g of HP/kg) and one diet containing 200 mg/kg of butyl hydroxytoluene (BHT). The prepared treatments were kept at 25±3°C for 18 weeks. The lowest mean TBA index was observed in the feeds with 20 g/kg of HP and Butylated hydroxytoluene (BHT) treatment (p˂0.05). The lowest Total volatile basic nitrogen (TVB-N) index was measured in HP-containing treatments until the 14th week (p˂0.05). The lowest bacterial count was measured in the HP-containing treatments from the 4th week to the end of the experiment (p˂0.05). The highest total protein content belonged to the HP-containing treatments. The highest fat content was recorded in HP-containing and BHT treatments (p˂0.05). According to the results, the addition of HP (20 g/kg) is recommended to maintain the quality of fish feed.

This study was conducted to determine the feeding and reproductive biology of Saurida tumbil and Rastrelliger kanagurta in the northern Oman Sea in 2020 -21. A total of 134 and 157 specimens of S. tumbil and R. kanagurta were collected from landing sites of Sistan and Baluchistan waters, respectively. The results of S. tumbil feeding analysis showed that the main diets of this species are fishes, mollusks and shrimps. Gastric emptying index (CV) indicated that this species was highly fed in winter and was identified as a gluttonous species. The results show the lowest value of Gonado-Somatic Index (GSI) in spring and the highest in summer. The reproduction of S. tumbil occurred after summer. Length (TL) at first maturity (LM50) for this species was estimated to be about 37.9 cm. The Food Preference (Fp) index showed that the main diets of R. kanagurta are phytoplankton and algae and CV reaches its maximum value in autumn. GSI of this species also shows the lowest level in spring and the highest in summer, which indicates that the peak of reproduction of R. kanagurta occurred after summer. Length (TL) at first maturity (LM50) for this species estimated to be about 25.2 cm.

In this study, the combined effect of glazing and coriander (Coriandrum sativum) leave extract were evaluated on the chemical spoilage indices of narrow-barred Spanish mackerel (Scomberomorus commerson) at frozen temperature. Antioxidant activity (DPPH, ABTS and FRAP) of coriander leaf hydroalcoholic extract was examined, however, 5 treatments including: Unglazed (UG) without immersion in water and coriander extract; Water glazed (WG); 0.5% of coriander extract-glazed (CG 0.5%); 1% of coriander extract-glazed (CG 1%); and 1.5% of coriander extract-glazed (CG 1.5%) were prepared for mackerel fillets storage. They were then stored at -18°C. The examined parameters in frozen samples were water holding capacity (WHC), drip loss, cooking loss, total volatile basic nitrogen (TVB-N), peroxide value (PV) and thiobarbituric acid (TBA) after 1, 2, 3, 4, 5 and 6 months at -18°C. The results showed that DPPH, ABTS and FRAP and the percent of inhibition significantly increased as the concentration of the extract increased reaching 68.58%, 9.25 mM trolox/kg dw and 13.46 mM trolox/kg dw at concentration of 700 mg/l, respectively. Variation range of PV, TVN and TBA after 180 days increased to 10.221-14.450 meq O2/kg lipid, 0.460-0.635 mg MDA/kg and 28.76-37.31 mg/100g, respectively. After six months WHC and drip loss of UG, and CG 1.5% treatments reached 49.23%, and 63.36% and to 15.23% and 10.55%, respectively. The CG 0.5%, CG 1%, and CG 1.5% treatments had a low average cooking loss among all the groups. According to the results of the performed parameters (TVB-N and TBA), the shelf life of fish fillets kept at -18 ºC was up to 180 in the acceptable range, but in terms of PV, it was outside the standard range, while in the control treatment, the parameters examined on day 150 were outside the standard range.

This study focuses on density and species composition of phytoplankton during bloom in the southwestern Caspian Sea off Anzali. The eighteen sampls were took  between Apri and July 2021. The findings displayed, the  phytoplankton bloom speices was distanguited in the study as cyanobacteria Nodularia spumigena  Mertens as bloom in the southwestern Caspian Sea in 2005. A total of 8  phytoplankton species were distinguished during the bloom, the phytoplankton abundance were calculated  as 8,640,000 cells.l-1. Contributions of cyanophyta (5,720,000 cells. l-1) to total phytoplankton were higher than any other group. The cyanobacteria Nodularia spumigena abundance as 512,000,000 cells.l-1 provided the biggest contributions to the total phytoplankton during the bloom. Vertical distribution of  N. spumigena at the bloom region revealed that most N. spumigena abundance occurred in the upper layer (0-5 m) almost 5,000,000 cells.l-1. After bloom period, the number of phytoplankton species increased sharply and identified 18 species. Bacillariophyta were dominant (60,000 cells.l-1). Cyanobacteria (12,600 cells.l-1) were the second most important group, contributing to the total phytoplankton abundance. The phtytoplankton abundance was declined  sharply almost 83,400 cells.l-1 after bloom as compared with bloom period. The total phosphorus and nitrogen consenterations rised sharply as 0.59  and 9.91 µM. l-1 during bloom. There is strong relationship between N. spumigena abundance and environments factors. The very low wind, strong heating of the upper layer almost 29 ºC and increasing of  nutrients levels were the most reasons of N. spumigena bloom in the southwestern Caspain Sea Anzali offshore.

In this study, beak length characteristics were described and used to predict the individual size and separate 2 morphologically similar species of the family Loliginidae: Uroteuthis edulis and Uroteuthis duvauceli. The samples were collected using bottom trawl methods in May, September and December from the southern East China Sea in 2015. The data presented here indicates that identification was possible with a high accuracy using various ratios of beak lengths indices. Differences were observed among various length indices and the corresponding ratios. Also, the beak length indices were affected presumably due to the individual growth of each specimen. Additionally, relationships between a durable beak measurement versus both mantle length (ML) and body weight (BW) were studied. Rostral length (RL) linearly increased with ML and BW. The beak lengths did not change with the fluctuation of the ML. Significant differences (P < 0.05) were observed between 5 upper beak ratios and 6 lower beak ratios. The data presented here indicated that beak ratios could be used as a variable to identify the two species in a stepwise discriminant analysis. Additionally, linear discriminant functions of upper and lower beak morphological variables were developed for the two loliginids. The data presented here indicate results that have a high level of correctness in species classification.