Identification of marine ornamental fishes in northern part of the Persian Gulf, Iran

In the past decade, the investment in fisheries development has grown remarkably in the Persian Gulf region. A 1800 km of northern coastline of the Persian Gulf, the Oman Sea and more than 14 islands belong to Iran have provided great possibilities of economic activities. In-shore marine islands such as Kish, Farour, Hendurabi, Tonb made a good opportunity for fishing and harvesting of ornamental fishes living on coral reefs. The Kish island have a plenty of coral reefs in around. The study was conducted on the Kish islands to identify various species of reef fishes on October 1997 to November 1998. Experiment was carried out at 77 stations around the islands. Samples were collected by underwater purse_seining, scuba diving, and using anesthetizes by injection around the fish hiding area. Results conducted that overall 113 species belong to 47 families were identified of which Pomacentridae, Acanthuridae, Scaridae and Lutjanidae are the most important in terms of number of species represented. 4 species of Apogonidae, 6 species of Lutjanidae, 11 species of Pomacentridae, 6 species of Nemipteridae, 6 species of Serranidae, 3 species of Teraponidae, 3 species of Sparidae, 3 species of Scorpaenidae, 3species of Scaridae, 3 species of Lethrinidae, 4 species of Labridae, 4 species of Gobiidae, 4 species of Chaetodontidae, 4 species of Carangidae, 2 species of Belonidae, 2 species of Balistidae, 2 species of Acanthuridae, 2 species of Tetraodontidae, 2 species of Siganidae, 2 species of Ostraciidae, 1 species of Monacanthidae, 1 species of Leiognathidae, 1 species of Atherinidae are the species presented in coral reefs at Kish island

The reproduction biology of Abudefduf sexfasciatus in the Persian Gulf (Larak Island)

The reproduction biology of A. sexfasciatus, one of the main and important ornamental fishes in the Persian Gulf were studied during 1997-98. For sampling, Larak island sited on south-eastern of Bandar-Abbas was chosen. The main fishing gear was hook for collecting samples. During this investigation, weight, length (FL & T.L), GSI, HSI, Kf, sex ratio, LM50 and sexual overlap zone were measured or calculated. Also, the histological studies were done on gonads. The results showed that this species is a protogenous hermaphrodite. A. sexfasciatus has an allometric growth and the results of GSI, HSI and Kf indicated that the spawning season occured in spring as a total spawner species. The sex ratio was found M:F=1.00:1.24 without any significant difference. The overlap zone was recongnized 30mm (with a range of 125-155mm). The LM50 was calculated 130-140mm for females and 160-170mm for males. The size at first maturity for females and males were determined 105 and 120mm, respectively

Effect of 17- alpha- methyl testosterone on cichlid kaliko (Labeotropheous foellobroni) sex reversal

In this present study, Cichlid Kaliko (Labeotropheous foellobroni) fallowing was exposed to 17-alpha-methyl testosterone at 2 stages of development including prior to maturity (larvae) and after puberty (broodstock). The influence of sex hormone on the larvae was also explored. The first group was the larvae under the four treatments (0, 50,100, 250) mg per kg of food and hormones that broodstock group also included four treatments (0, 100, 250, 400) mg per kg food three replicates were performed in a period of 30 days. Hormone was added to fish food. Results showed that treatments had a significant difference in fish growth, which correlated with increased amounts of 17 alpha-methyl testosterone. In group I, food with 250mg/kg testerone resulted in an increase in growth indices (i.e.s, SGR=1.4, ADG= 6.5) with a mortality rate of 48.3 percent. In group II results showed that treatment of G (400mg testosterone per kg food) produced larvae with maximum growth indices (SGR=0.91, ADG= 3.6) and the least mortality rate of 31 percent; Research revealed that 17 alpha methyl testosterone could have an effect on Calico fish sex changes in both larval and stock stages

Feeding behaviour of blue swimmer crab (Potunus pelagicus) in Hormuzgan province waters

This research was carried out to study the feeding behaviour of blue swimmer crab (Portunus pelagicus) in Hormuzgan province waters from October 2001 to December 2002. Samplings were done in different methods by presence on research vessels, fishing vessels and dhows in addition to collect the samples from stake-nets. 490 stomach contents were observed under stereomicroscope in which among them the numbers of full, semi-full and empty stomachs were 136,197 and 157, respectively. The food contents were classified into 4 main groups namely; fish, mollusc, crustacean and plankton. The Index of C.V. was estimated 32.04. This figure shows that blue swimmer crab can be assumed as a gluttonous species

A study on growth parameters, blood factors and proximate composition of rainbow trout (Oncorhynchus mykiss) cultured in underground brackish and freshwater

In this research, growth rate, blood parameters and proximate composition of rainbow trout (Oncorhynchus mykiss) cultured in brackish and freshwater were evaluated. Two treatments (brackish and freshwater) in 3 replications were investigated. Six 1.5 m³ fiberglass tanks were used for this experiment, containing 180 rainbow trout specimens with average weight of 47.2±0.1g. Feeding rate in treatments was about 3% of body weight based on water temperature and fish biomass. Total length and weight of fish were measured in 15 days intervals. After 135 days of culture period, some fish samples were transferred to the Lab. Blood were directly collected from the heart. Muscle composition was analyzed for proximate composition. The results showed that the body weight of samples in brackish water was increased significantly after 45 days of culture period. Blood factors including WBC, RBC, Hb, Hct, MCV, MCH, MCHC, lymphocyte, thrombocyte and concentration of K+ ions in fish cultured in brackish water showed a significant increase (P<0.05). Muscle composition analysis showed a significant increasing (p<0.05) in fat and dry matter in freshwater treatment, while moisture was significantly higher in brackish water (P<0.01)

Effects of LHRH-A2 and chlorpromazine (dopamine antagonists) on inducing spawning in Caspian Kutum, Rutilus frisii kutum, from the southwest of the Caspian Sea

Caspian kutum, Rutilus frisii kutum, is one of the most commercially important fish species in the Caspian Sea, but there are few reports about the endocrinology of induced spawning in this fish. In the present study, 54 individuals of female broodstocks of Kutum were studied for quantity and quality of propagation index, during March and April 2007. Hormone treatments include: LHRH-A2 (1 µg kg-1bw;chlorpromazine (2.5 mg kg-1bw); LHRH-A2 + chlorpromazine (1µg kg-1bw+2.5 mg kg-1bw); CPE as a positive control (1 mg kg-1bw); Physiological saline as a negative control; and normal brood stocks without injection. For histological examinations, ovarian samples of non-ovulated females were fixed in bouin's fluid. The routine procedures of preparation of tissues were followed and the paraffin blocks were cut at 5-7 microns, stained with H&E and studied under light microscope. The results showed that the highest percentage of ovulated females belonged to group 1 without significant difference with positive control.There was a significant difference between ovulated females in the LHRH-A2, chlorpromazine and LHRH-A2 + chlorpromazine treatments (P0.05). Chlorpromazine could not be a potent dopamine antagonist and the microscopic observations of ovary in non- ovulated brood stocks showed that the oocytes in these treatments were in the final phase of IV stage

Heritability estimation for growth-related traits in juvenile wild common carp (Cyprinus carpio L.) in the south of Caspian Sea

Wild common carp of the Caspian Sea is one of the important fish in the north of Iran, which has been introduced to inland aquaculture. Its genetic characteristics are investigated to set up for breeding programs that are still unknown. Using wild common carp in aquaculture is limited for uncontrolled variation in performance of fish derived from undomesticated breeders. A 7×7 factorial mating design was employed to examine genetic effects of dam and sire on growth and heritability of growth-related traits based on dam half-sib and sire half-sib families. Breeders were obtained originally from the Caspian Sea. A total of 1470 offspring were raised in 49 separate fiberglass tanks with common conditions. Body weight and length were recorded at three different ages of rearing. Estimation of heritability of weights ranged from 0.23±0.05 to 0.30±0.07 for dams and ranged from 0.15±0.03 to 0.26±0.04 for sire. Similar results were obtained with length but with less variation (0.24±0.02 to 0.26±0.01 for dams and 0.20±0.02 to 0.22±0.03 for sire). The broad-sense of weight and length are 0.23±0.04 and 0.23±0.01 respectively. The dam and sire effect on growth were significant, indicating the presence of variations among the native fish of the Caspian Sea. Therefore, it is suggested to use a length for selection that is more reliable and less affected by environment than weight at any time of growth and in respect of high phenotypic correlation (0.87-0.95) observed between weight and length. In the present study we even used wild common carp and the heritability was not higher than the domesticated common carp. It means the genetic variation for quantitative traits, for common carp of the Caspian Sea are low or it may be under pressure of inbreeding which should be studied further

Some aspect of reproductive biology of Sillago sihama in Persian Gulf

This study was carried out to evaluate some biological reproductive aspects of Sillago sihama, a valuable gonochoristic species living in coastal areas of the Persian Gulf, from August 1997 to September 1998. Forty fish were caught each month, and their total length, standard length and total weight were measured. Fish were then diseeted and liver, stomach and gonads were weighted. A piece of gonad samples 01 different stages of maturity were taken and placed in bouins fixative. Minimum and maximum fish length were and 23.5 centimeters respectively. Length-weight relationship showed isometric growth in this species. Gonadosomatic index (GSI), gastrosomatic index (GI) and hepatosomatie index (HSI) were also measured. GSI was averaged 4.5 in March for females and 1.50 in April for males. Histological evidence showed that this fish has an ovary with free riped ova at the same time and spawn once a year in spring (synchronos). Sex ratio was measured (1 M:1.2 F (α=0.05,df=1, X^2=5), Size of maturity were 11.4 and 12.6cm for males and females respectively

Effect of replacement of fish meal by soybean meal in red pacu (Piaractus brachypomus) diet on growth performance and intestine morphology

An 8-week feeding trial was conducted to evaluate the effect of fish meal replacement by soybean meal on growth and intestine morphology in red pacu (Piaractus brachypomus). Five isonitrogenous and isocaloric diets formulated containing 32.04±0.46 crude protein and 17.26 ± 0.31 KJ gross energy g-1 diet. The control diet was formulated to contain 50% fish meal, whereas in the other four diets soybean meal was included at 16.5, 33, 49.5 and 66% to replace 25 (SMP25), 50 (SMP50), 75 (SMP75) and 100% (SMP100) of the fish meal protein. One hundred and ninety fish (with average weight 1.8±0.07g) were randomly distributed into five treatments (each treatment included 3 replicates). After 8 weeks of feeding, weight gain and specific growth rate in SMP25 and SMP50 diets were significantly higher than other treatments (P<0.05). Feed consumed in fish fed SMP50 diet were significantly higher than other treatments (P<0.05). Feed convention ratio in SMP100 diet was significantly higher than fish fed other treatments. No differences in inflammation and atrophy were observed among different treatments but villous length were significantly higher in SMP25 and SMP50 treatments (P<0.05). The results of the present study indicated that soybean meal can be replaced up to 50% of fish meal protein in red pacu diet and this may allow production an economical diet without negative effect in growth performance

Short communication: A comparative study on manganese accumulation in liver, kidney, fatty tissues including muscle of rainbow trout (Oncorhynchus mykiss) fed with different levels of manganese in the diet

Most minerals, occurring in aqueous environments, play a key role in the survival rate of aquatic living organisms. However, life situation of the living organisms would be under attack when the contents of these elements exceed than the specified limit because of various reasons. Bioaccumulation of the elements in living organisms and their excess concentration than standard limit would result in acute and chronic biological impacts in their tissues. ... The experiment was performed in fish farming center of Arab Kheil at the countryside of Amol city for 90 days from July to October 2010. Four diets were prepared for 204 rainbow trout samples. Experimental feeding diets included: the control treatment which contained 29 mg kg^-1 of manganese. This level of manganese occurs naturally in the principle composition of the feeding diets. Treatments 1, 2 and 3 contained 48, 78, and 98 mg of manganese sulphate per kg of food, respectively. ... According to the obtained results, it can be concluded that there is a significant relationship between manganese concentrations in liver, kidney, fatty tissues including muscle of rainbow trout. Manganese mean content is less than the standard limit of FAO which contradicts any interdict in the consumption of rainbow trout. Significant differences were observed among manganese contents in treated fish samples and the control. Manganese content in kidney tissues showed the highest level than other tissues