Reproduction and feeding biology of Sind Sardinella (Sardinella sindensis) from coastal waters of Qeshm Island, Persian Gulf

Sardinella sindensis is one of the dominant small pelagic fishes of Persian Gulf, especially in Qeshm Island's coastal waters. Investigation on some of the biological parameters of Sind Sardinella was carried out from April 2005 to March 2006. Sind Sardinella is economically the most important small pelagic fish species mainly caught by double boat purse seine in this area. Reproductive studies showed that peak maturity season occurred in May. The female to male ratio was calculated at 1:1.08 and chi-square analysis showed the difference in ratio was not statistically significant (P>0.05). LM_(50) is attained at a total length of 112 mm. The average absolute and relative fecundity were estimated to be 23396 (± 5337) and 739 (±117), respectively. This fish is planktonivore, and we found the diet of the species consisted of a broad spectrum of food types, but Crustaceans were dominant, comprising 44% of the food. The other major food groups and their share were Dinophyceae 17%, Bacillariophyceae 15%, Cyanophyceae 13%, fish eggs, larvae, scale 7% and finally Euglenahyceae, Chlorophyta, and others 4%. Analysis of monthly variation in the stomach fullness indicated that feeding intensity fluctuated throughout the year, with a high level during March and April. Vacuity index indicated this species is a semi-voracious fish

Reproduction and feeding of Buccaneer anchovy (Encrasicholina punctifer) from coastal waters of Qeshm Island, the Persian Gulf

Encrasicholina punctifer is one of the dominant small pelagic and economically most important fishes of the Persian Gulf, especially in Qeshm Island's coastal waters. Specimens of the fish were collected monthly from the fishing area in the coastal waters of Qeshm Island by random sampling method. Investigation on biological parameters of E. punctifer continued from April 2005 to March 2006. E. punctifer is mainly caught by double-boat purse seine in this area. Reproductive studies showed that maturity season of the fish occur in August. The sex ratio fulfill the theoretical 1:1 (P>0.05). L sub(M50) was attained at a total length of 84 mm. The absolute fecundity was estimated at 1217 plus or minus 331. We showed that the species is planktonivore, its diet consisted of a board spectrum of food types, but crustaceans dominated the food with copepods and their eggs, naplius and semi digested copepods constituting 54% of the diet. The next major food groups found in the diet of the fish were Cyanophyceae 21%, Bacillariophyceae 11%, fish egg and scale 6%, Dinophyceae 4%, with Euglenahyceae, Chiorophyta, Dinoflagellates and others items consisting only 4% of the diet. Analysis of monthly variation in the stomach fullness indicated that feeding intensity fluctuated throughout the year, with the highest value in winter. Vacuity Index indicated this species was of semi-voracious appetite fishes

Population dynamics of Sind Sardine, Sardinella sindensis, in coastal waters of Qeshm Island

Sardinella sindensis is economically the most important small pelagic fish species in the coastal area of Qeshm Island. Population dynamics of Sind sardinella from Qeshm Island coastal waters, during April 2005 to March 2006 were studied. The asymptotic length (Lx) and growth coefficient (K) were estimated at 178mm and 1.11yr ^(-1), respectively. The minimum and maximum T.L was recorded at 42 and 172mm respectively. The value of t0 was calculated at -0.17, and Tmax was estimated at 2.7 year. The Von Bertalanffy growth equation was obtained at L_(t) = 178^(1-exp(-1.1 l(t-(-0.17))) for this species. Total mortality (Z) rate was estimated to be 3.48yr ^(-1) (r ^(2) = 0.88) on length-converted catch curve method. The rates of natural mortality (M) based on Pauly's empirical equation, fishing mortality (F) and exploitation ratio were estimated at 1.13yr ^(-1), 2.35yr ^(-1) and 0.67, respectively. Four cohorts were distinguished annually based on Bhattacharya's method with mean length of 56, 89, 107 and 141mm. Maximum recruitment was in September at 18.62 percent. The length-weight relationship was determined as W= 0.000005 L ^(3.1399)

Investigation on feeding of sardines and major tuna fishes in west of Oman Sea (Jask area)

Feeding habits of three dominant species of tuna fishes (Thunnus tonggol, Thunnus albacares, Euthynnus affinis) and dominant species of sardine (Sardinella sindensis) were investigated from December 2006 to November 2007 in the western waters of Oman Sea. Seasonally samples of three species of these tuna and monthly samples of sardine were collected. Feeding studies on 101 longtail tuna (T.tonggol) indicated that the bony fishes were main food of this species (98.3%) and followed by random foods included cephalopods (1.7%) and crustaceans (1.7%). Among the bony fishes, anchovy (66 %) and sardines (25.9 %) were most important than the other fishes. FI and CV for this species were calculated 26.4 and 21.8 respectively. Stomach content analysis of 85 specimens of E.affinis demonstrated that bony fishes were only food for this species (100%). Sardines (49.3%) and anchovy (11.9%) were foremost food items for E.affinis. Moreover FI and CV were calculated 64.7 and 15.3 correspondingly. The stomach of 120 yellowfin tuna (T.albacares) were analyze. Results showed that bony fishes,cephalopods and crustaceans were formed food items of this species .Yellowfin tuna were preferable fed on bony fishes (87.7%) specially sardines(41.2%),flying fish(13.9%)and M.cordyla(10.4%) and followed by cephalopoda (43.8%) specifically Loligo sp.(84.5%) and crustaceans(11.2%) . FI and CV were calculated 38.3 and 25.8.Study on 320 stomachs were determined that zooplankton and phytoplankton formed food of S.sindensis. Zooplankton (crustacean and molluscs) were main food (90%) and phytoplankton (Bacillariophyceae and Dynophyceae) were least food items (10%). Copepoda (crustaceans) with 58% were preferable food and bivalves and after that bivalves (molluscs) with 14%, Bacillariophyceae (8%) and Cyanophyceae (2%) CV and FI were 30.3 and 29.4 respectively

Monitoring of commercial marine stocks around Hormuzgan (bandar-e-Lengeh) artificial reefs

Over-fishing of marine resources has endangered many commercial fish species in the world; with aquaculture development, setting up artificial reef systems is an important way for marine stocks and fishing enhancement. The present study was designed to monitor fish abundance and species changes around a small and newly established artificial reef system in Moloo area at Bandar-e-Lengeh during two years after installation (Sep. 2005 to Sep. 2007). The artificial reef includes three types of concrete structures arranged in a seven by three grid. Each cross point considered as a sampling station and two other stations selected from two sides of the system as control stations. Based on obtained results CPUE (P = 0.00001), frequency (P = 0.001) and species diversity of captured fishes (P = 0.024) showed significant differences between three types of sampling traps. With type of structures, The CPUE and frequency of fishes in transect 7(mixed structures) showed the significant differences with other six transects (p= 0.001, P = 0.009). No diversity relationships were seen between transects (p= 0.100). In this study there were no significant differences between depths. Although the means of CPUE between seasons were different, but the ANOVA test could not show the significant differences because of the differention between variances. The T-Test showed no significant differences between the numbers per trap per day dominant species (Epinephelus coioides, Plectorhinchus shotaf, Diagrama pictum, Siganus javus) in different seasons. Movie prepared from artificial reefs showed diversity of fish were more than that of fishing by trap. Although fishes increased but there was no enough causes evidences for product in artificial reefs. Therefore, the study need to continue in this area

Feasibility study on development of artificial reefs in the Persian Gulf (Hormuzgan province)

Persian Gulf waters (areas of Hormuzgan province) in order to determine the best location for installation of Artificial reefs were studied seasonally from December 2006 to March 2007. Distribution of fauna and flora and estimation of deposit depth by SCUBA diving method, density and frequency of macrobenthose communities, frequency of ichthyoplankton communities, determination of organic carbon (OC) and Grain size and measurement of water physical factors including salinity, saturation oxygen, dissolved oxygen, temperature, chlorophyll a, in transect and subtransect was studied for recognizing the best placement to installation of artificial reefs. All areas of Shipping, military areas, around of Islands, natural habitats and entrance to jetty were introduced for excluding areas. South of Qeshm Island (transects of Bahman jetty, Bandar Masen and Bandar Salakh) are catching area for small pelagic (sardine and anchovy fishes), therefore in these areas installation of artificial reefs have confined with this restriction. Also entrance to Bahman jetty, sea plant habitats (sea grass and algae) in transects of Bahman jetty and Bandar Masen were considered as restricted areas. In this area, suitable areas for installation of artificial reefs was determined based on distribution of Ichthyoplankton societies for every transect, for macrobenthose enrichment Bahman jetty transect was calculated middle, but transects of Bandar Masen, Hengam island and Bandar Salakh was done good indicator. The deposition depth in transects of Bandar Masen and Hengam island was determined as good factor but this index was known as average factor for transects of Bahman jetty and Bandar Masen. Also, two another indicators, primary production and bottom sturdiness, were calculated as middle factor for Bahman jetty transect, but these indicators were known as good factors for other transects in this area (Bandar Masen, Hengam island and Bandar Salakh). The results of these indicators in transects of Bandar Kong and Bandar Bostaneh in Bandar Lengeh area was indicated that T. O. C and bottom sturdiness indices had no significant difference (p>0. 05) and the whole of these transects had average priority. Bottom sturdiness, primary productions and macrobenthose communities indices had difference in Bandar Lengeh area (p<0. 05) and these indices had average priority in Bandar Kong transect and had good priority in transects of Bandar Bostaneh and Bandar Hasineh. Ichthyoplankton community had average priority for Bandar Bostaneh transect, and had good priority for transects of Bandar Kong and Bandar Hasineh. The good priority has obtained for transects of Bandar Charak, Bandar Gorzeh and Bandar Chiroeyah. Also Macrobenthose community, primary production, water physical factors and bottom sturdiness were known as good, good, average and weakness priority respectively for transects of Bandar Charak, Bandar Gorzeh, but primary production, bottom sturdiness, water physical factors and macrobenthose community were resulted as average, good, good and average priority respectively for Bandar Chiroeyah transect . T.O.C index was determined as average priority for transects of Bandar Gorzeh and Bandar Chiroeyah and good priority for Bandar Charak transect. Finally, excluded areas maps, suitability areas maps and feasibility areas maps were drawn by Arc GIS software. In this survey, layers between 10 to 20 meters depth were recognized as the best position for installation of artificial reefs

Ecological interaction between commercial fishes in the Persian Gulf

An ecosystem-based management fishery is a new way of looking at management of living resources. Trophic levels of basic food items, feeding habits, growth and mortality rate of 20 exploited fish species (including commercial and bycatch) are investigated in the Persian Gulf (from the provinces of Khuzestan, Bushehr and Hormozgan) from 2010 to 2012. The model considers trophic interactions among 12 functional group of the ecosystem involving Phytoplankton, Zeoplankton, Cephalopods, Shrimp, Infauna Benthos, Epifaunal Macrobenthos, Demersal Zoobenthos Feeders, Small Pelagic Planktivorous Fish, Benthoplagic Feeder, Piscivorous, Large Benthic Carnivores And Small Benthic Carnivores. In general 7452 of stomach contents samples were analyzed based on the weight and numerical method and were detected about 40 preys. The results demonstrated gaps in our knowledge on the food web structure. The mean trophic levels were varied from L. klunzingeri (2) to S. tumbil (4.64), while the total catch of some species were fluctuating widely. Result of our study showed that Total mortality varied between 0.45 per year (A. suppositus) to 9.5 per year (P. indicus) and food consumption rate also fluctuated by 1.9 (L. johni ) to 89 (L. lineolatus). The results indicated that some fish species including sardine, Anchovies, small carangids, S. stridens with high frequency in ecosystem, have been occupied in the food web as a wasp-waist. The model showed that most hunters groups live in middle levels in the food web such as N. japonicas, A. latus, P. kaakan, L. nebolusus, P. indicus and T. lepturus . Analysis the catch rate during 2001-2011 reveled that there is a clear trend of declining most of fish species catches in this research except for T. lepturus, P. kaakan and sparids which lead to upset the fundamental ecological balance of the Persian Gulf in future