فصلنامه آبزیان و شیلات
پیاپی 10 (تابستان 1391)

Diplostomom Spathaceum cause serious economics losses especially in culture fishes. In this survey, infection of this parasite is studied in Mahabad dam in West Azarbayjan province with emphasis on epidemiologic aspect. From summer 2010 to spring2011, a total of 140 fishes were collected from Mahabad dam. Captured fish species (number of fish) were as follow: Hypophthalmichthys moltrix (43), Cyprinus carpio (39), sander lucioperca (29) and Abramis brama (29). Overall of infection was 51%. The highest infection rate was 93% in Hypophthalmichthys moltrix and follows by Cyprinus carpio (82%). No infection in sander lucioperca and Abramis brama was observed. Acording to the present study, the prevalence of parasites in fishes were influenced by season’s duration

This study was do in Mollusc Research Station, Bandar-e Lengeh and invitro condition in 2011. Four different treatments consisting of Sargassum powder with coral sand substrate, Sargassum powder with fine sand substrate, Padina powder with coral sand substrate and Padina powder with fine sand substrate and for each treatment, three replicates were considered. Initial length and weight of juvenile H.scabra species in all treatments was 14.2±1.72 mm and 2.394±0.112 gr and cultured for 30 days in polyethylene tanks. Finally length in treatments reaches to 23.78±3.52, 34.32±7.72, 19.94±7.71 and 21.41±5.92 mm, respectively. Weight in treatments reaches to 3.984±0.172, 4.014±0.382, 2.994±0.232 and 3.174±0.378 gr, respectively. Survival rate in all treatments was same and 100 percent. Highest average growth rate based on the length (mm per day) and weight (grams per day) observed in treatment Sargassum powder with fine sand substrate and lowest average growth rate was in treatment Padina powder with coral sand substrate. The one way ANOVA showed no significant difference in growth rate between substrate with same feed (P>0.01). But significant difference showed between Surgassum and Padina powder with same substrate (P>0.01).Finally use of Surgassum powder have great effect than Padina powder on growth of juvenile sea cucumber H.scabra in different substaret

In this study some biological and ecological (i.e. Age, growth and Reproduction) characteristics of Capoeta trutta in Alvand River in Kermanshah provience were studied from August 2008 to June 2009. During the study 225 specimens were caught by using cast net and gillnet from Alvand totally, six totally, six age group in this River identified. sex ratio of alvand population was 1.27♂: 1♀. In this study it was revealed that in Age, length and weight frequencies female was longer and heavier than males. Mean GSI of fish in Alvand River was 1.71 ± 0.14 also,mean condition factor of fishes in Alvand River was 1.13 ± 0.007,There was no significant differences between males and female fishes (p> 0.05). mean egg diameter was 0.8  0.06 mm. Absolute fecundity was 15233 ± 11058 eggs.

Due to small size of microalgae and low concentration in the culture medium, cost-efficient harvesting of microalgae is a major challenge. In the present study, the possibility of using electro-flocculation technique (direct current) for harvesting of microalga Nanochloropsis oculata biomass from the culture broth was investigated. The microalga biochemical composition and chlorophyll a content, and viability of N. oculata cells were determined on concentrated microalgal cells after 10 days of electro-flocculation. The results from the biochemical analysis and chlorophyll a measurements indicated that N. oculata flocculated cells showed no sign of degradation in biochemical composition and chlorophyll a from electroflocculation as compared to control. Moreover, the results clearly showed that, flocculation efficiency improved with increasing direct current. Between 3-10 V; the flocculation efficiency was as high as 85-97.0%. The highest flocculation efficiency, 97.0%, was obtained at 10 V, of 30 minutes and with short settling time of 2 hours. The cell viability obtained in flocculation with direct current (3-10 V) showed cells in good shape and indistinguishable from nonflocculated cells when viewed by light microscopy. This study demonstrated that electroflocculation is an effective method to flocculate N. oculata cells; therefore, it could be considered as a cost-effective alternative for preparing microalgal concentrates for the aquaculture industry and hatcheries.

Sea cucumber is one of the echinoderms belonging to the branch of (Echinodermata) and from the class of (Holothuroidea) that has appeared during the evolutionary period, 540 million years ago in the oceans. At this time 1400 species of sea cucumber have been identified and reported in the seas of the whole world Sea cucumbers have many important and useful properties known for human health. Although sea cucumber is commercially important, its biology, ecology and dynamic of population have not been known yet. With this respect and the lack of scientific knowledge about them, this study has been conducted in order to identify the species present in the Larak Island in the Persian Gulf .two species of sea cucumber (two family, two species belong to genus Holothuria and another one species of Stichopus) were collected on sub tidal zone of the Larak Island (Persian Gulf) via scuba diving on January 2011. The species identification was done through morphological keys and review of their ossicles.

For enrichment of adult Artemia, Artemia franciscana, Spari Selco emulsifier, prepared from Belgium, were used in 10 specimens per ml at different concentration of 0.5, 1 and 2 g/l during 3 hours. During the study all chemico- physical factors such as water temperature, salinity and light were constant. Significant differences (P<0.05). were observed in ihe amounts of the fatty acids linoleic(18:2n6), linolenic(16:1n-6), arachidonic (20:4n6), eicosapentaenoic (20:5n3) and docosahexaenoic (22:6n3) for enriched adult at 2 g/l concentration of Spari selco compared with enriched adult at 1 and 0.5 g/l concentration. On the other hand the results showed that more concentration with significant differences (P<0.05) of amount of total Fatty Acids ω3, Fatty Acids ω6 and unsaturated Fatty Acids(HUFAs) at 2 g/l, when compared with the other samples. The results also indicated that 2 g/l concentration is the optimum level for the unsaturated Fatty acids in the adult Artemia

This study was carried out in Shahid Maleki Warm Water Fish Culture Centre in Ahwas to investigate the effects of salinity levels (1>, 3, 6, 9 and 12 ppt) on moisture, crude protein and crude lipid in body composition of silver carp fingerlings (Hypophthalmichthys molitrix) (weight: 13.55±0.726 g and length: 11.04±0.093 cm) during 21 days. At 12 ppt all fishes died prior to 14 days. Findings of body composition at the end of the study revealed no significant variation in protein and lipid (p>0.05) but salinity produced a significant body dehydration (p<0.05).

The aim of this study was to assess protein, lipid, carbohydrate, fiber, ash, and moisture in Otolithes ruber, Scomberomorus guttatus and Scomberomorus commerson from Persian Gulf, 2011. Nine samples of fishes were prepared from any fish market in January of Ahvaz. The total length of the fish Otolithes ruber, Scomberomorus guttatus and Scomberomorus commerson, were 35.17±0.50, 49.33±0.57 and 53.38±4.5 cm respectively. Data were analyzed with SPSS17 software in terms of t-test.which determine exist or non-exist of the significant difference in level 95 precent (P=0.05). The highest of lipid and ash was 3.4±0.1 and 1.63±0.01 % in muscle of Scomberomorus commerson and the highest of protein and moisture 19.9±0.2 and 78.2±0.1 % in muscle of Scomberomorus guttatus and Otolithes ruber. Fiber and carbohydrate were not detected in samples. In this study between of lipid and ash in muscle of three species fish Scomberomorus commerson, Otolithes ruber and Scomberomorus guttatus significance different (P<0.05), but protein and moisture no significance different (P≥0.05).