Marine Biology & Stock Assessment

Small pelagic fishes particularly anchovy (Encrasicholina punctifer) and sardine (Sardinella sindensis) have an important role to support the Iranian fisheries and are distributed along the coastal waters of the Persian Gulf and Oman Sea. Using a logbook on small pelagic fisheries, a GIS-based environmental modeling approach was applied to investigate the presence and abundance of anchovy and sardine in relation to environmental variables. Redundancy analysis (RDA) was applied to provide a preliminary view of the relationships between fish presence/absence and environmental variables. Generalized Additive Models (GAMs) indicated the presence/absence of fish was related to distance from the nearest coast, depth, sea surface Chlorophyll-a, and SST. Results of the EFH showed that sardine is concentrated in specific areas of more favorable conditions, such as north of the Persian Gulf and all areas of the northwest of the Oman Sea. However, EFH of anchovy showed a more widespread distri...

In this study, the feeding habits and reproductive behavior of narrow-barred Spanish mackerel, Scomberomorus commerson, in the northern Persian Gulf during five months from October 2011 to December 2012 have been investigated. Specimens were purchased from the fishermen at several landing sites. Feeding and nutrition results showed that sardines are the major prey items of S. commerson. Secondary prey species included ponyfish, halfbeak and Indian mackerel fishes. Mature females (Stages III, IV) were mostly observed between April to July. By July, most of the studied fishes were in recovery or spent stages (Stages IV, V) indicating the end of the spawning season. The result of gonado-somatic index (GSI) study in 184 male and female specimens indicated the highest reproductive activity from April to July with the peak in July. The total sex ratio of 69 males and 115 females was 0.6:1 and it was not significantly different during study periods except autumn season. The minimum and max...

The Indian mackerel (Rastrelliger kanagurta) is one of the commercial pelagic fish in the Persian Gulf and Oman Sea. In the current research, food preference index (FP), fullness index (FI), and stomach contents of Rastrelliger kanagurta were evaluated to assess the quantity and type of food which this species consumes in the study area. The samples were collected randomly from Bandar - Abbas and Qeshm Island landing sites. A total of 573 specimens were collected during 2011-2012 of which 299 specimens were female and other 274 specimens were male. The minimum and maximum total lengths were 13.9 and 35.5cm, respectively with the highest frequency in length group of 22-24cm. Results showed that 21.3% of stomachs were full, 44.5% were semi-full and 34.2% were empty. Planktons as well as random food such as bony fish were the main food of this species. Fullness index and Vacuity index for this species were calculated 21.3 and 34.2, respectively. Stomach contents analysis revealed that ...

This document analyses some population parameters of Yellowfin Tuna (Thunnus albacares) taken by drift gillnet operation from southern part of Iranian coast in the Oman Sea during 2007 to 2009. A total of 9,345 specimens of T. albacares were sampled in the size range of 37 cm to 172 cm fork length (FL). The mean length was estimated to be 86.12 cm. There was influence from seasonal variation on the length distribution of individuals, and it showed a tendency of gradual increase in the model length with the fishing season. The temporal change in length distribution is more likely to be an indication of feeding migration of medium-sized Yellowfin Tuna from the western Indian Ocean into the Oman Sea during January to June. The statistical analysis of lengthweight relationship was achieved by sex. The electronic package "ELEFAN I" was chosen for describing the species' von Bertalanffy growth equation; parameters were L∞= 183.3 cm, K= 0.45 year-1, and t0= -0.184 year. Natur...

Analysis of the shape properties of fish otolith is one way to identify stocks of different species in the marine environment. Length, width, area, perimeter, form factor, aspect ratio, roundness, circularity, ellipticity and rectangularity analyses of otoliths were undertaken to assess patterns of spatial and temporal stock structure of a wide-ranging fish, the Arabian yellow fin sea bream Acanthopagrus arabicus. Fish were sampled from 125 stations across the distribution range of the species in the Northern Persian Gulf & Oman Sea from June 2014 to May 2016. Analysis of morphometric parameters of otolith showed the minimum size in Khuzestan waters and the West Strait of Hormuz and the maximum size in the East Strait of Hormuz. In Bushehr waters, the amount of form factor was in the lowest and circular factor showed the highest. These findings are in agreement with the most irregularity in otoliths margin of this area. The highest aspect ratio of otolith indicated the great growth ...

Otoliths are considered as very useful structures of fishes for various studies. This investigation was aimed to compare morphometric parameters between right and left otoliths of males and females fishes amongst four species belong to the family Carangidae from the northern Persian Gulf. The morphometric parameters such as weight, length, width, area and perimeter were measured and then compared between males and females and pairs of sagittal otoliths. The relationships between otolith morphometric parameters (length, width, weight) and fork length were also examined. According to the results from independent sample t-test, significant differences were found in length, width, and area of otoliths between males and females of C. malabaricus, meanwhile no significant differences were found for three other species. The otolith weight of C. caeruleopinnatus and M. cordyla were significantly different between left and right otoliths (P<0.05). Likewise, a significant difference was fo...

This study examined the ecological factors associated with feeding in Rachycentron canadum (cobia) in the waters of Persian Gulf and Oman Sea. Seasonally variation of stomach condition of cobia male, females, pooled and size wise were analyzed. In general, 577 cobia were collected (340 males, 237 females) (20–161 cm Total length) from Sept. 2014 to Sept. 2015 by the Ferdows-1 survey ship and from the landing areas in Bandar Abbas harbor seasonally. Our results provide the first estimates of trophic level (Tr.L) (4.32±0.76, mean±Se), consumption per biomass (Q/B) (6.13), and aspect ratio of the caudal fin (ARc.f) (3.1) for R. canadum in the Hormuzgan Province. We also found that bony fish made up more than 80 percent of the relative importance of particular prey (IRI %), indicating R. canadum primarily preys on these species. The immature group (20–40 cm,T.L), tended to feed on Penaeidae family, small crabs, and mollusks. Hierarchical clustering revealed that the frequencies of diffe...

The population parameters of Encrasicholina punctifer (Buccaneer anchovy) from commercial fishery in the Persian Gulf and Oman Sea coastal waters were studied from October 2014 to September 2015. A total of 13951 length-frequency data collected monthly by pair-boat purse seine and beach seine methods. The asymptotic length (L∞) and Von Bertalanffy growth function (K) were 11.5 cm and K = 1.4 per year, respectively. The value of to was calculated as -0.14 year. The  longevity estimated 2 years. The total length ranged from 2.9 to 10.1 cm, with average 6.5 cm. The probability of capture were calculated in total length as L25=6.05 cm, L50=6.48 cm and L75=6.93 cm.  Four cohorts distinguished annually with mean length of 4.56, 5.77, 7.21 and 8.50 cm. The length-weight relationship was determined as W= 0.0051 L 3.1114. Total, natural and fishing mortality parameters were estimated, 6.15, 2.84 and 3.32 yr-1 respectively. The current rate of exploitation (E) was given as 0.54, the values of...

Monthly length frequency data of banana shrimp, Penaeus merguiensis were collected from the coastal waters of the north east of the Persian Gulf, from January 2012 to January 2013. Software package FiSAT was used to analyze the length frequency data. Growth parameters, mortalities, exploitation rate and recruitment pattern were estimated from the carapace length in the area. Based on length – weight relationships, the estimated parameter a was 0.0015 for males and females and b was 2.8015 for males and 2.7852 for females. The estimated growth parameters: L∞=39.5 mm, K=1.8 year −1 and t0=-0.08 year −1 for males and L∞=50 mm, K=1.5 year −1 and t0=-0.09 year −1 for females. Longevity was estimated 1.67 and 2.00 years for males and females, respectively. The estimated mortality coefficients, were Z=5.9 (4.89 – 6.92) year −1 (α=0.05), M=2.9 year −1 and F=3.0 year −1 for males and Z=5.7 (4.94–6.37) year −1 (α=0.05), M=2.5 year −1 and F=3.2 year −1 for females. The length at first capture,...

Monthly samples of Acanthopagrus latus (Hottuyn, 1782) were used to determine (1) feeding habits and (2) reproduction characteristics of the species in relation to its size, spawning season and sex in the Northern part of the Persian Gulf from January to December 2013. The smaller length classes of all samples were dominated by male fish. All gonads examined, were ovotestis during the spawning period from February till May. Male and female ovotestes were dimorphic in structure which represented a transitional stage in a protandrous sex change. Length at first sexual maturity of female A. latus was 24.40 cm. A. latus fed predominantly on bivalves, gastropods, cephalopods, stomatopods, fish and decapods which showed changes according to the season and body size. According to our results, it appears that A. latus feeds throughout the year; the highest value of gastrosomatic index (GaSI) for both sexes was recorded in February, which was significantly different from that in other months...

In this study, the feeding habits and reproductive behavior of narrow-barred Spanish mackerel, Scomberomorus commerson , in the northern Persian Gulf during five months from October 2011 to December 2012 have been investigated. Specimens were purchased from the fishermen at several landing sites. Feeding and nutrition results showed that sardines are the major prey items of S. commerson . Secondary prey species included ponyfish, halfbeak and Indian mackerel fishes. Mature females (Stages III, IV) were mostly observed between April to July. By July, most of the studied fishes were in recovery or spent stages (Stages IV, V) indicating the end of the spawning season. The result of gonado-somatic index (GSI) study in 184 male and female specimens indicated the highest reproductive activity from April to July with the peak in July. The total sex ratio of 69 males and 115 females was 0.6:1 and it was not significantly different during study periods except autumn season. The minimum and m...

One of the mainly popular consumed colloid protein materials in pharmaceutics, medical, food and military industries is Gelatin. Especially from warm-water fish gelatin report posses similar characteristics to mammal’s gelatin .Yellow fin tuna (Thunnus albacares) gelatin skin, lots of waste in form of skin and bone of the fish are produced every day. Analysis factors were extracted alkaline gelatin from skin, physiochemical and rheological test (amino acid composition, SDS- page electrophoreses, FTIR (Fourier transform infrared), moisture content, pH, setting point and setting time, melting point and melting time, color and gelatin yield).  In contrast cool water fish gelatin, yellowfin tuna had higher gelatin content (Proline and Hydroxyproline) than mammalian gelatin content. SDS-electrophoresis for yellow fin gelatin showed protein band (α, β, γ) same as mammalian protein band. FTIR (Fourier transform infrared) had the same spectra for both of them. Factors were pH (6.1), Moistur...

In the present study, various species of Sparidae family in the Persian Gulf and Oman Sea and the population structure of the dominant and significant species of the genus Acanthopagrus were studied based on morphometric and meristic characteristics from June 2014 to May 2016. Fish samples were collected monthly from five different areas in the Persian Gulf and Oman Sea including Khuzestan, Bushehr, the western and the eastern parts of the Strait of Hormuz, and Sistan and Baluchistan. Overall, 54 characteristics of samples comprising 41 morphometric and 13 meristic characteristics were measured and 9 species from Sparidae family were identified including Acanthopagrus arabicus, Acanthopagrus bifasciatus, Acanthopagrus berda, Argirops spinifer, Crenidense crenidens, Diplodus sargus kotschyi, Sparidentex hasta, Rhabdosargus sarba and Rhabdosargus haffara. The results of Duncan’s test on data from analysis on classification of morphometric and meristic characteristics, Principal Compon...

Received: 29 September, 2014 Accepted: 11 November, 2014 Published: 20 December, 2014 Population dynamic parameters of common carp (Cyprinus carpio) were estimated from April 2011 to March 2012 in the Shadegan Wetland. 049 specimens were collected from five stations namely Mahshar, Rogbe, Khorosy, Salmane and Ateish in the Shadegan Wetland in Khuzestan province (Iran). Population dynamic parameters were calculated for C. carpio as below, L∞: 537 (mm); K: 0.36 (yr ); t0: -0.20, Ф’: 3.01. The estimated value of total mortality, natural mortality and fishing mortality were Z: 1.44, M: 0.66, F: 0.78 respectively. Relative yield per recruitment (Y'/R):0.02, relative biomass per recruitment, (B'/R):0.3; Exploitation ratio maximum sustainable yield, Emax: 0.43; precautionary average target (Fopt=0.51 yr ) and limit (Flimit=0.67 yr ) biological reference points for this stock was calculated. The results showed exploitation ratio of C. carpio is more than optimum level and no increase in fishing effort should be made in the area. © 2014 PSCI Publisher All rights reserved.