Identification, analysis and ranking of factors affecting productivity of Bushehr fishing companies using Group Analytical Hierarchy Process (GAHP) Technique

Fishing companies play significant role in value-added generation in Bushehr province. According to the current conditions and based on natural potentials, fisheries are the main sector in economic development of the Bushehr province. The purpose of this paper is to identify, analyze and rank factors affecting productivity of Bushehr fishing companies using group analytical hierarchy process (GAHP) technique. We applied two standard questionnaires which were filled with 100 fishermen and 18 fishery experts. The first group of questionnaires was used to assess the two main factors: Internal and external and five subfactors including: Governmental, structural, natural, soft and hard ware aspects. The second group was used to rank the same indentified factors in the first group of questionnaires. Results indicated that fishery headquarter of the governmental sub-factor, economic changes of the structural sub-factor, management approaches of the software sub-factor and the catch tonnage and its composition of the hardware sub-factor are the main parameters affecting productivity. Suggestions were made to improve productivity of the fishing companies in Bushehr province

Age determination of john's snapper (Lutjanus johni) using otolith sections

The age structure of John's Snapper (Luyanus johni) in Hormozgan waters, south Iran was studied. We conducted monthly sampling starting in May 1996 and ending in July 1997. Totally, 613 fish specimens were collected, of which 567 and 308 specimens were aged based on whole and sectioned otoliths respectively. The snappers were found to be aged from I to 17 years old. Results showed that each year only one pair of opaque and translucent zones was formed. Age determination based on the two methods was significantly different especially in the fish aged 1 to 6 years (P<0.05). Age-length relationship of the species based on sectioned otolith reading and total fish length using the least squares method was obtained as Lt = 89(1-e^ 165.476)). Also, the lengths weight relationship for the fish was determined as W=(4x10w5)xL2.8214

Growth pattern and daily growth increment in lanternfish (Benthosema pterotum) of the Oman Sea

Lanternfish (Benthosema pterptum) is one of the most important fish species in the Oman Sea. We randomly sampled 300 myctophids from different depths in spring and winter 2009 in the Oman Sea using mid-water trawls. Male to female sex ratio was 0.36:0.64. The thin sections (60-80µm) of sagitta otoliths of the fish were prepared using polishing method. These sections showed that increment growth rings of lanternfish otolith are formed daily and the age condition is distinguishable on a daily basis. We found the life span of the species to be short (with a maximum of 349 micro-increments counted) and probably less than a year. The relationship between standard length (SL) and daily growth increment (D) was expressed as the linear equation: SL=0.87D+12.37 (R 2=0.97). The relationship between lanternfish weight (W) and daily growth increment (D) was expressed as power equation: W=0.00003D1.754 (R2=0.95). Furthermore, morphometrical characteristics of otolith including otolith weight and length and daily growth increment relationships were expressed as linear equation (R2=0.96 and R 2=0.83). The results showed that lanternfish growth rate were in the range 0.241mm/d-1 to 0.138mm/d-1 and decreased by body size and age in this range

Short communication: Morphometric variation and growth rate of Uroteuthis duvaucelii (Cephalopoda: Loliginidae) in the Persian Gulf and Oman Sea using gladius increments

Loliginid squids occur in temperate and tropical coastal waters where they have been considered economically important (Valinassab et al., 2006; Anderson, 2000). Uroteuthis (Photololigo) duvaucelii (Orbigny, 1835) or Indian squid is the most abundant group of Teuthida (Family Loliginidae) in the Persian Gulf and Oman Sea (Valinassab, 1993). These squids demonstrate complex population structures, and are generally characterized by different biological features such as growth rates, size and age of maturity. Over the past 30 years age determination through interpretation of growth increments in the microstructure of the hard structures of squids has accounted for many of the issues and limitations. Naef (1921) was the first to identify growth increments on gladius. The gladius is the internal chitinous shell present in squids, which supports mantle muscles, fins and inner organs. Increments were observed in the middle plate on the dorsal surface of the gladius (Arkhipkin et al., 2012). The series of increments of gladius indicate the amount of daily growth in these species (Perez et al., 2006)

Evaluation of feeding indices of catfish Arius dussumieri in Oman Sea (Sistine & Baluchistan)

Due to study the food regime of Arius dussumieri, a total of 132 specimens were collected from Oman sea waters, Sistine & Baluchistan province. The stomach content, were taken into consideration and it was found that the amount of full, semi-full and empty stomachs were 31, 33 and 36 percent, respectively; of which the highest frequency was in winter (74%) and the lowest was in summer (24%). On the other hand, the fullness index was studied with the highest and lowest value for spring (44%) and winter (5%), respectively. The GaSI shows that A. dussumieri, has better feeding in spring and summer but feeding (up in male) was decreased in autumn and winter. The Food Preference (FP) Index was estimated as: Fishes (39%), Crustacean (40%) and Molluscs (20%) namely all of them are considered as minor food in all four seasons. The most important food items were identification as fishes: Carangidae, Engraulidae & Leiognathidae; crabs: Portunidae & Porcellanidae; shrimp: Alpheidae; cephalopods: Loliginidae & Opisthoteuthidae; gastropods: Muricidae & Naticidae

Age determination and morphology of otolith in Alburnus chalcoides (Guldenstaedt, 1772) in the southern Caspian Sea

The aim of this study was to provide necessary information on the age, growth and sex ratio of one of commercially important cyprinid species, Alburnus chalcoides in the southern Caspian Sea (North of Iran) from 2010 through 2011. 53 specimens of both sexes (males and females) were collected monthly. The samples were transported to the laboratory for further biological measurements and otolith extraction. The maximum and minimum age of A. chalcoides was 4+(FL=26.0 cm) and 1+ (FL= 18.1 cm), respectively. The mean fork length of A. chalcoides was 20.21±0.287 cm; and the sex ratio was 1.00: 2.12. The calculated length-weight relationships for all individuals were as W=0.141TL2.199 (R2= 0.648). Different regressions were prepared between age and morphological measurements of fish and otolith, of which the highest correlation was between age and body length as a linear regression of TL=1.959Age+16.32 (r= 0.66). There was no significant correlation between morphometric measurements of otolith and fish morphological parameters (p> 0.05), and an allometric growth was found with a slope of b=1.926 for the study area

Investigation of genetic variation and sexual diversity of different populations of Gracilaria corticata in the Persian Gulf and Oman Sea using ISSR markers

ISSR markers were used to determine the genetic variation and sex determination of the three life-stages of 41 samples of Gracilaria corticata from two regions of the Persian Gulf and Oman Sea namely Bostaneh and Lipar. The specimens were cultured in PES media to observe the different life stages. DNA was extracted by modified CTAB method. After screening of 20 ISSR primers, four primers were selected that produced clear reproducible fragments and were suitable to find sexual diversity for further analyses. The four primers generated 75 bands ranging from 250 to 3000 bp, corresponding to an average of 18.75 bands per primer. A set of four anchored primers amplified 75 bands out of which 100% were polymorphic among 41 samples. PIC value ranged from 0.28 to 0.33 and marker index ranged from 4.48 to 6.51 per primer. The mean value of Shannon’s index was 0.45. By using primer "AB","ABC_1" were identified three life stages of this alga. Primers "A" and "C" were also able to detect diploid tetrasporophyte but haploid males and females were determined by "A" and "C" respectively. Gst value was 0.058, indicating that 83% of the genetic diversity resided within the population. Clustering analysis using WARD algorithm based on Nei's Unbiased Measures of Genetic distance, classified the G. corticata individuals into five major groups. The PCOA data confirmed the results of clustering. The results of this study reveal that ISSR markers could be used efficiently for genetic differentiation of G. corticata individuals in different regions

Biomass distribution and pattern of myctophids in the Oman Sea

In conformity with programming to harvest from virgin resources of Myctophids (Benthosema pterotum) in the Oman Sea (Iranian waters), a series of research cruises and trial fishing were carried out from 1992 to 1998. Assessment of B. pterotum stocks was carried out using the data obtained from a series of seven cruises conducted by R/V Ferdows1 in the Iranian waters using modern scientific echo sounder of EK500 system in 1993-94, with complementary monitoring surveys in the following years. The biomass estimates ranged from 1 to 4 million tones with an average of 2.3 million tons. A number of fishing operations using mid-water trawls were also performed in 1994-1998 using the same vessel. Distribution of B. pterotum was found to be all around the Oman Sea. The dense schools of this species were found in the northwest areas of the Iranian waters. Also the F/V Jahad Fanoos was applied during 1994-95 to do some trial fishing and its maximum catch was 50 t/h

Biological survey on cuttlefishes of Systan-o-Baluchistan waters (southeastern Iran)

Species of cephalopoda and biological characteristics of Sepia pharaonis, were investigated in the fishing grounds of “Goitre" to "Gallak" corresponding to 61.31– 59.30 eastern longitude and 25.10- 25.23 northern latitude respectively. The balk of the study was confined to Chabahar estuary during which 8 cephalopoda species were identified with Sepia pharaonis being the dominant one. Spawning of S. pharapnis occurs between the two southwest and northeast monsoon periods in December and November. Although spring spawning is demonstrated to occur, it is Autumn spawning which contribute mostly to regeneration of S. pharapnis. Water temperature in spawning season varies between 22 to 28.5 degrees centigrade. Fishing season in this area overlaps with spawning or S. pharaonis and in this period they have been found to migrate from deeper waters to shallower waters in littoral zone. The best fishing grounds in Systan-o- Baluchistan province are recognized to be "Ties” and "Pozm". A series of analyses carried out on the meat, ink and cuttlebone of S. pharaonis and the ratio of ingredients were determined

Age determination and morphological study using otoliths in Cyprinus carpio Linnaeus, 1758 in the Southern Caspian Sea

The relationships between sagitta otolith morphology and fish size were examined for common carp in the Southern Caspian Sea; and also the aging of different length groups were determined. Statistical tests to examine correlation between left and right otoliths dimensions were carried out and no statistically significant difference between them was found. The biggest otolith had 0.032g weight belongs to an individual with BW= 428g and FL=36cm; and the smallest otolith had 0.014g for a fish with BW=220g and FL= 26cm. Regression model relations to each otolith morphometric parameter to fish length are provided. Also, the aging of this species was done by sectioning of sagitta otolith and a high significant correlations was found between fish age and morphometric parameters of both body weight and fork length and also otolith weight and length. The maximum age was determined 6+ years. The length-weight relationship was BW= 0.006 TL^3.232 (r = 0.963). According to the morphometric relationships obtained, it was concluded that otolith length and weight are good indicators of fish body weight and fork length