• An investigation on the micropyle number in the ova of the strugeon species in Caspian Sea

      Hallajiyan, A.; Pourkazemi, M.; Kalbasi, M.; Amini, K. (1999)
      The micropyle number in the ova of sturgeon species from the South Caspian Sea was investigated. The study was conducted on female broodfishes of three species of sturgeon (Persian sturgeon Acipenser persicus, Stetates sturgeon A. stellatus and great sturgeon Huso huso) included 44 Persian sturgeon, 13 stellate sturgeon and 8 great sturgeon specimens. Fifty eggs were randomly collected from each broodfish and the micropyle number of totally 3250 eggs was determined. Out of 44 Persian sturgeon used, 14 specimens were collected from the south-east Caspian region (Golestan Province, Shaid Marjani Center) and 30 were from the south-west Caspian region (Guilan Province, Shahid Dr. Beheshti Center). The stellate sturgeon specimens were taken from the south-west and the great sturgeon specimens from the south-east Caspian region. The obtained result showed that the mean micropyle number in Persian sturgeon caught from the south-east Caspian region was 8 whereas in those caught from the south-west region was 9. There was no significant difference (p>0.95) in the micropyle number of Persian sturgeon collected from the south-east and south-west regions. The mean micropyle number determined for stellate and great sturgeon was 5. The outer diameter of the micropyle in the Persian, stellate, and great sturgeon were 22 μm, 17 μm and 19 μm respectively.
    • Distribution and biomass of macrobenthic fauna in the Chabahar Bay (North Eastern Sea of Oman)

      Nikouyan, N.; Saravi, A. (1999)
      Population density, distribution and biomass of macrobenthic fauna in Chabahar Bay were investigated from May 1995 to March 1996 on a bimonthly basis. The most abundant groups were Amphipods (21%), Polychaetes (19%), Gastropods (15.7%) and Bivalves (10.6%). Maximum (13000 individuals/m2) and minimum (4600 individuals/m2) were observed in May and July respectively. The changes in density were influenced by monsoon season of the Indian Ocean. Spatial and temporal variations in biomass were recorded for all groups separately. The lowest biomass was observed during monsoon period (July-September) with a mean of 51.5 g dry wt/m2 and the highest in permonsoon period (March-May) with an average of 164.8 g dry wt/m2. The results are discussed in terms of understanding secondary production of Chabahar Bay.
    • Myxosporean parasites from mesopotamian part of Iran

      Masoumian, M.; Pazooki, J. (1999)
      A survey on myxosporean parasites of freshwater fishes from Mesopotamian part of Iran (south western part of the country, Khuzestan Province) was carried out. Some 280 individuals belonging to 14 different species were examined the prevalence of myxosporean parasites, morphology of the spores, plasmodial development, the infective site, and characteristics of the cyst location using the histological approach. The collected parasites were as follows: Myxobolus presicus, M. karuni, M. bulbocordis, M. nodulointestinalis, M. iraanicus, M. mesopotamiae, M. shadgani, M. sharpeyi, M. molnari and M. mokayeri. Barbus sharpeyi and B. grypus, economically important fishe, were infected by six and four myxosporean parasites respectively. All of the studied cases of infection were observed in the natural waters.
    • Effect of chemical herbicides and insecticides on mortality and feeding of silver carp (Hypophthalmichthys molitrix)

      Piri, M.; Ördog, V. (1999)
      Fingerlings of Silver Carp (Hypophthalmichthys molitrix) were used in an ecotoxicological investigation. The fish were exposed to (0.3-10 mg/l) Machete, (3-5 mg/l) Saturn, (1.5-13 mg/l) Diazinon and (1-10 mg/l) Malathion to measure the toxicity effect of these chemicals on mortality, feeding and ingestion rate. Methods for investigation on mortality were according to TRC (1984) and feeding behavior, according to Gould Equation (1951). Porbit analysis was used for evaluation of obtained data. LC10 of these toxic compounds were 0.17-0.23, 2.85-3.73, 0.6-0.95, 0.87-1.34 mg/l for Machete, Saurn, Diazinon and Malathion respectively. Experiments showed that Machete and Diazinon in comparison with Saturn and Malathion were highly toxic for fingerlings of silver carp. At first fish showed to be disturbed, then moved rapidly and exhausted. A secretion of excess mucus was also noticed and eye-ball became expanded. There was also blanching of the skin. The fish surfaced sometimes on their side and became unbalanced which resulted in death. Abnormal behavior of fish became greater with the increase of pesticides concentration. In these exposures pH was decreased, in contrast with the amount of water hardness. LC10, LC50 and LC90 form 24 to 96 hours were mostly decreased. Feeding experiments showed that 8 hours exposure below the LC50 values reduced 50 percent of feeding and ingestion rates.
    • Comparative study of biochemical and hematological features in reared sturgeons

      Bahmani, M.; Kazemi, R.; Donskaya, P. (1999)
      Suitable physiological condition in fishes for the selection of broodfishes can be achieved through hematological studies. The present study aimed to examin the hematological indices in Juvenile Sturgeons at different stages of growth. Total albumin content in blood serum, hemoglobin concentration, the erythrocyte and leukocyte count of 54 sturgeon specimens (Persian sturgeon Acipenser persicus and Great sturgeon Huso huso) were determined at the age of 1, 2 and 6 years reared fish. In the Persian sturgeon specimens studied, total albumin concentration increased from 26.1 to 52.5 gL-1, hemoglobin from 42.2 to 65.8 gL-1, erythrocyte count from 240 to 452.5 thousand cells/ μL-1, and leukocyte count from 17.4 to 46.7 thousand cells/ μL-1. The total leukocyte was composed of 73.2-82.7% lymphocytes, 12.3 to 20% neutrophils, 2.2 to 6.5% eosinophils and 0.2 to 2.5% monocytes with the increase of age. In the great sturgeon specimens studied, total albumin concentrations in blood increased from 20 to 42.4 g L-1, hemoglobin from 46.3 to 78.6 g L-1, and erythrocyte count from 495 to 735 thousand cells μL-1. The total leukocyte was composed of 54.5 to 67.5% lymphocytes, 6.1 to 26.9 % neutrophils, 6.6 to 13.25% eosinophils and 0.6 to 2.5% monocytes with the increase of age. This research revealed the evolutionary trends of hematological features in the natural growth and development of sturgeons in the South Caspian Sea, reared in artificial conditions and shows that with the increase in age, the hematological indices also increased.
    • In Vivo oocyte maturation and ovulation in females and spermiation in males of hybrid sturgeon, bester

      Mojazi Amiri, B.; Maebayashi, M.; Omoto, N.; Adachi, S.; Yamauchi, K. (1999)
      Bester, a hybrid sturgeon (Huso huso L. females ´ Acipenser ruthenus L. males), neither spermiate nor ovulate in the captivity. Thirteen-year-old adult male and female bester were injected with LH-RHa (0.1-0.3 mg/kg B.W.) intramuscularly and spawning status of the treated fish was checked 24-48 hours later. Additionally, changes in serum levels of DHP in both the responded and the non-responded individuals were monitored 0, 1, 3, 6, 9, 12, 24, 48 and 72 hours after treatment. Between 70-100 percent of the LR-RHa injected males individuals, and 11-40 percent of the females spawned 24-48 hours after the treatment; the rest did not respond to the injection. In the responded males, 3-9 hours after the treatment, serum levels of DHP increased; while in the females it occurred first after 12-24 hours. In contrast, during the same period, serum levels of DHP remained low in all non-responded individuals. The present study indicated that using 0.1-1.3 mg/kg B. W. of LH-RHa can induce oocyte maturation and ovulation in the females and spermiation in the males cultured bester. The results suggested additionally DHP as an appropriated steroid that could be used in the final maturation stage of the gonads.
    • New records of trematode parasites (digenea) in the banded frog (Rana camerani) and marsh frog (Rana ridibunda ridibunda) (Anura: Ranidae), from southwest of Iran

      Masahaii, N. (1999)
      Fourteen adult frogs including six banded frog, Rana camerani and eight marsh frog, Rana ridibunda ridibunda were collected from two sites of Chahar Mahal-o-Bakhtiari province at the southwest of Iran and then were examined for helminth parasites. Only Dolichosaccus rastellus (50%) was found in R. camerani, Skrjabinoeces similis (50%) and metacercarian cysts of Codonocephalus urniger (12.5%) were found in R. ridibunda ridibunda. This is both the first report of Dolichosaccus rastellus in R. camerani as a new host for this parasite, and of Codonocephalus urniger in Iranian frogs; also a first report of Skrijabinoeces similis in south west of Iran.
    • Herbicides and insecticides effects on green algae and cyanobacteria strain

      Piri, M.; Ördog, V. (1999)
      The toxic effects of herbicides (Machete, Saturn) and pesticides (Diazinon and Malathion) on green algae, Scenedesmus obtusiusculus, and cyanobacteria, Anabaena flos aquae, were studied. The results indicated that Machete and Saturn, in comparison to Diazinon and Malathion, were more toxic. On the other hand it was revealed that green algae was more sensitive to the pesticides than the cyanobacteria. When we added 3.199 mg/l machete (EC50 of this toxicant for Anabaena flos aquae) to a mix algal culture, the growth rate of green algae after 6 days of treatment was reduced 0.95 times, while it was 4.5 for the cyanobacteria. Treating the culture with 10.53 mg/l of Saturn for the same period of time revealed that the growth rate for green algae and the cyanobacteria increased 1.19 and 7 times, respectively. Hence, we can conclude that pesticides are capable of decreasing the diversity of the phytoplankton species in an aquatic ecosystem that from the fisheries point of view could cause serious problems.
    • Age and growth of marbled sole Pleuronectes yokohamae in Kikonai Bay, Hokkaido, Japan

      Shafieipour, M.M.; Takahashi, T.; Ishino, K.; Takatsu, T.; Nakatani, T. (1999)
      Age and growth of marbled sole Pleuronectes yokohamae werer estimated from growth increments in otolith. The samples were collected with commercial set nets and an experimental bottom trawl net in Kikonai Bay and the nearby waters, southern coast of Hokkaido, from May 1994 to July 1995. Monthly changes in the percentage occurrence of oltoliths with translucent edge in one band and the marginal increments on the other hand verified that the translucent zone was formed once a year after their spawning season in May, indicating availability of outer margin of translucent zone as an annulus. The regression method as well as Fraser-Lee's method was used to estimate the back-calculated lengths. Growth of marbled sole was expressed by the von Bertalanffy asymptotic growth function: TLt=361.78[1-exp-0.390(t-0.098)) for males and TLt=438.15[1-exp-0.323(t-0.145)) for females using back-calculated lengths by the regression method and TLt=367.04[1-exp-0.388(t-0.114))] for males and TLt=436.05[1-exp-0.323(t-0.147)) for females by the Fraser-Lee's method, where TLt is total length (millimeters) at estimated age t.The theoretical lengths predicted by these two methods at all estimated ages were very similar. It was found that the growth rate of marbled sole in this study area was relatively high compared to those obtained in the Inland Sea of Japan as. However, the highest growth rate was observed with regard to the population off Fukushima Prefecture, although the bottom water temperatures were similar to those in Kikonai Bay. It is inferred that the geographical variation in the growth rates of marbled sole is influenced by the hydrographic and food conditions.
    • Polymerase Chain Reaction (PCR) and direct sequencing of mtDNA from the ND5/6 gene region in Persian sturgeon Acipenser persicus from the southern Caspian Sea

      Rezvani Gilkolaei, S.; Skibinski, D.O.F. (1999)
      A partial sequence of the mtDNA ND5 gene region was used for population study in Persian sturgeon (west and east areas of southern Caspian Sea). The result showed that although this approach was informative for phylogenetic study in sturgeon, it was less informative for population study in Persian sturgeon.
    • Gonadal changes and serum steroid levels during the annual reproductive cycle of the pearl oyster Pinctada fucata Gould

      Jamili, S.; Amini, G.; Oryan, S. (1999)
      The annual reproductive cycle of peal oyster Pinctada fucata was characteised by documenting gonadal development and changes in serum levels of estradiol-17b (E2), testosterone (T) and progesterone (P) in the wild bivalve caught in natural beds in the Persian Gulf throughout the year. Bivalve populations employed in this study spawn in June-July and November-December. The pearl oysters had group synchronous ovarian development with exogenous vitellogenesis during spring and summer for first spawning and during August-September for the second spawning. Serum E2 levels in the females increased rapidly from low values in May to peak in June and also in October coinciding with the time of spawning. Serum T levels in male and female exhibited a bimodal pattern. However in the male it increased during the early spermatogenesis. P was detected in both females and males. Its concentrations start to increase during the early gametogenesis and reaching to peak during the spawning season. The obtained results indicated that vitellogenesis and spermatogenesis in pearl oyster are not completed by the mi-summer and early winter.
    • A preliminary study on fecundity of fresh water crayfish (Astacus leptodactylus) in Arass water reservoir, I.R. Iran

      Hosseinpour, N.; Karimpour, M. (1999)
      A research study was conducted to investigate the number of ovarian eggs and estimate potential egg production of A. leptodactylus. In this study, mean number ovarian eggs 420.41±42.51 with the average total length to 121.93±4.27 mm (n=58). The mean pleopodal eggs were 322.04±29.61 with average total length of 119.14±3.94 mm (n=67). Comparison of the fecundity rate in different population of A. leptodactylus in different areas revealed that the Arass crayfish has a greater fecundity rate than others. The discrepancy between ovarian eggs and pleopodal eggs were 21% in Arass reservoir.
    • Evaluation of some haematological variables of Acipenser persicus and Acipenser stellatus at different water temperaures

      Pourgholam, R.; Saeidi, A. (2000)
      Some haematological variables including Red Blood Cells (RBC), White Blood Cells (WBC) differential counts, Haemoglobin (Hb), Haematorite (HCT), Mean Corpuscular Volume (MCV), Mean Corpuscular Haemoglobin (MCH) and Mean Corpuscular Haemoglobin Concentration (MCHC) were measured in 90 stellate sturgeon juveniles Acipenser stellatus (1-2 years old) and 90 Persian sturgeons Acipenser persicus (1-2 years old) at different water temperature 10-15C, 16-20?C and 21-25C. Also these parameters were evaluated in 84 adult including A. persicus (54 samples) and A. stellatus (30 samples) collected from Caspian Sea during spring and autumn 1997. The results have showed that WBC differential counts, Hb, HCT, MCV and MCH were identical for both species at the mentioned water temperatures. However, the values for RBC of A. persicus were generally less than those of A. stellatus. These haematological factors relatively increased with the water temperature increasing. Although RBC and WBC values of A. persicus were less than those of A. stellatus. The rates for HCT, MCV and MCH were higher in A. persicus.
    • A preliminary study on phylogenetic relationship between five sturgeon species in the Iranian Coastline of the Caspian Sea

      Pourkazemi, M.; Skibinski, D.O.F.; Beardmore, J.A. (2000)
      The phylogenetic relationship of five sturgeon species in the South Caspian Sea was investigated using mtDNA molecule. Sequence analysis of mtDNA D-loop region of five sturgeon species [Great sturgeon (Huso huso), Russian sturgeon (Acipenser gueldenstaedtii), Persian sturgeon (Acipenser persicus), Ship sturgeon (Acipenser nudiventris), Stellate sturgeon (Acipenser stellatus)] and DNA sequencing of two Escherichia coli cloned DNA fragments sized 758 bp and 922 bp was carried out. Sequence comparison of the mtDNA D-loop region between the five sturgeon species showed 100 % sequence identity. However comparison between a short (758 bp) and long (922bp) mtDNA D-loop region within Russian sturgeon showed a 5 bp differences. On the contrary a partial sequence of the mtDNA ND5 gene region showed high sequence and organic base variability in the five species. These results indicate that direct sequencing of ND5 gene provide more information for phylogenetic or population level studies in sturgeon species. The present study revealed a distinct classification among the five sturgeon species. On the basis of the phylogeny tree it is clear that a close evolutionary relationship exists between the great sturgeon and ship sturgeon that was verified in five phylogenetic trees. On the other hand a close resemblance was also seen between Persian and Russian sturgeon indicates that these two species have a closer evolutionary relationship. This study also showed a 2.2 % sequence divergence in sequence data for ND5 gene between Persian sturgeon and Russian sturgeon which indicated that these two species diverged from each other approximately one million years ago. However the verification of this calls for DNA sequencing of different genes.
    • Study on the changes of some physiological factors during osmoregulation of juvenile Persian sturgeons (Acipenser persicus)

      Jabbarzadeh Shiadeh, S.M.; Abtahi, B.; Mojazi Amiri, B.; Nazari, R.M. (2000)
      Experimental trials of acclimatization of juvenile Persian sturgeon, Acipenser persicus to different salinites of 0,5,10, 15ppt were studied. The juvenile Persian sturgeons in three weight classes (1.5, 3, 5g) have been transfered from freshwater to different concentrations of saline water. Na+, k+, Cl- concentrations of blood serum and the changes in the number and size of chloride cells were measured. Na+ concentration showed an imperceptible trend and K+ concentration had a decreasing one size of changed chloride cells in different salinities were 8.6-13±0.3 μm and their numbers were (25-65±3) in 5 pairs of fillaments. The results revealed that salinity tolerance was increased with the fish size. According to this study, there is a direct relation between the number and size of chloide cells and salinities and time exposure.
    • Determination of optimum feeding rate expressed as percent of body weight in Persian sturgeon, Acipenser persicus

      Yousefpour Pirbazari, H.; Aghtouman, V.; Mohseni, M. (2000)
      The present study was conducted to determine the best feeding rates expressed as percent of body weight in Persian sturgeon fingerlings at different body weights. Eighteen fiberglass tanks each holding 30 fingerlings with an average initial body weight of 19.45 ± 0.5 g were used in this experiment. Six different feeding trials (1, 2, 3, 4, 5 and 6 percent of body weight) were employed and each trial was run in three replicates through a period of 60 days (4 periods of 15 days). The results were analyzed using Statgragh software and compared using Duncan test. The optimum recommended feeding rate was 4 percent of body weight for an increase of body weight from 19.5 to 31g and 3 percent of body weight for an increase of body weight from 33 to 47g. For an increase in body weight from 47 to 90g the recommended feeding rate was 3 percent of body weight. The recommended doses are subject to alteration with variation in water temperature.
    • New records about helminth parasites of the marsh frog, Rana ridibunda ridibunda (Anura: Ranidae) from the north of Iran

      Mashaii, N.; Balouch, M.; Moubedi, I. (2000)
      A field trials were conducted to assess the helminth parasites of 12 marsh frogs (Rana ridibunda ridibunda) in the Anzali, Astara and Aghbaba regions in the north of Iran in May 1994. Experimental results showed that 83.8% of the Anzali marsh frogs were infected by one or two kinds of metacercarian cysts of digenetic trematodes. The helminth parasites were included Skrjabinoeces breviansa, S. smilis, Gorgodera dollfusi, Opisthioglyphe ranae, Prosotocus confusus, Encyclometra colubrimurorum and Codonocephalus urniger. Frogs collected from the Astara region was infected by the helminth parasites such as Diplodiscus subclavatus, P. confusus, C. urniger and Cosmocerca ornata. There were only one digenetic trematodes cysts such as Pleurogenoides medians in the Aghbaba region. In this paper, except the S. smilis, C. urniger and O. ranae we report 7 new helminth parasites in the north Iranian freshwater system for the first time.
    • Biology and control of reproduction of sturgeons in fish farm

      Billard, R. (2000)
      Over the last century the reproduction of sturgeon has been intensively studied par Russian scientists who established a technology for the ranching of alevins which included artificial fertilization of gametes taken from wild broodfish and larvae rearing. More recently, since 1970, major contributions originated from teams in the USA, the EU, Japan and Iran. A rather good knowledge of the reproductive physiology of sturgeon is now available: gametogenesis, reproductive cycle, ovulation, spermiation and fertilization. The complete life cycle was obtained in captive conditions allowing the production of juveniles and caviar.
    • The marine algae of the Sistan and Baluchestan Province, Iran

      Gharanjik, B.M. (2000)
      The identification of marine algae in the Sistan and Baluchestan Province were performed from December 1998 to November 1999 at the coastal area of Gwatr (25 10´ N; 61 30´ E) and Mydani (25 24´ N; 59 5´ E). Data on vegetation were gathered in subtidal and intertidal zones by seasonal and monthly sampling, respectively. Samples were transferred to the laboratory and fixed in 4% formalin. According to some references the marine algae were recognized. Also, the herbarium sheet and algal photos were obtained. To final approval, the prepared samples were send to scientific centers of America, Chana and Pakistan (Wynn; Tseng and Qari, 1999). There are a number of genera and species of main algae consisting of Ulvaceae in green algae, Gildiaceae, Gracilariacea and Hypneacea in Red algae and Sarggaceae in brown algae.
    • Ecophysiological indicators of stress in female Persian sturgeon, Acipenser persicus

      Bahmani, M.; Oryan, S.; Pourkazemi, M.; Vosoughi, G. (2000)
      The study on the ecophysiological impacts of stress in female Persian sturgeon broodfishes revealed that the average cortisol level varried in all broodfish caught at the Sefidrud River (163.38±21.2ng mL-1), Sefidrud River estuary (260.27±19.7ng mL-1) and Gorganrud River estuary (179.38±20.8ng mL-1). The variations in serum glucose levels were 140.65±12.05mg dL-1, 144.44±5.9mg dL-1 and 126.24±11mg dL-1, respectively. The maximum level of cortisol (781 ng mL-1) and serum glucose (281 mg dL-1) were observed during the transport of broodfish from the capture stations to the hatcheries and the minimum level of cortisol (25.2 ng mL-1) and serum glucose (33 mg dL-1) were observed during the confinement of broodfishes in the breeding ponds. The rhythmic and significant variations of cortisol level during capture, handling, transport and confinement of female Persian sturgeon broodfish in all three regions can be regarded as a valuable indicator of stress.