Persian Sturgeon Acipenser Persicus Research Articles

Marking fin spine of juvenile sturgeon (acipenseriformes: acipenseridae) using oxytetracycline and the comparing of growth performance

ABSTRACT This study aimed to describe and validate the formation of the rings in the spine of the pectoral fin and to determine the coherence of the OTC mark with the rings of three species of Caspian Sea sturgeon, the Persian sturgeon (Acipenser persicus), the Starry sturgeon (Acipenser stellatus) and Ship sturgeon (Acipenser nudiventris). Validation was achieved by comparing the total radius of the fin spine of fish of known age after one and two years of growth with the measured radius of the first and second rings in the zone. There was no overlap between the measured radius for the first year and the increase for the second. The Ship sturgeon showed the largest width of the second ring followed by the Persian sturgeon and Stellate sturgeon. The results indicate that the highest growth parameter belongs to the juvenile Ship sturgeon. This research showed that chemically marking the fin spines of juvenile Acipenseridae leads to unbiased estimates and contributes to the knowledge of the population dynamics of these species. The study found that the combination of the dial ring of the pectoral fin spine with growth validated the age estimation in juvenile sturgeon Ship, Persian, and Starry sturgeon.

Morphological analysis of pectoral fin spine for identifying ecophenotypic variation of Persian Sturgeon Acipenser persicus

AbstractOne goal of fisheries management is to identify stocks and ecophenotypics of individual specimens correctly. Discrimination of Persian sturgeon Acipenser persicus ecophenotypics due to geographic variation was attempted based on calcified anatomical structures. Morphological characteristics of the pectoral fin spine were analysed in stocks from the eastern and western parts of the south Caspian Sea to explore if polymorphism could be discerned between regions within the Caspian Sea using ten key features which were measured. These key features were measured and used for multivariate analysis. Principal component analysis (PCA), discriminant function analysis and cluster analysis were used to visualize differences between regions, to follow any shape differences in the spines and to classify into the groups. On the basis of morphometrics between spines, 82.9% of the individuals were correctly classified into one of the two regions. PCA showed the largest differences between the eastern and western regions were the density and arch of pectoral fin spine. Fish from the eastern region had a heavier and more curved pectoral fin spine when compared to those from the western part. The results from this study indicate that the morphological traits of pectoral fin spine of the Persian sturgeons can be used to discriminate between regions with a reliability rate of about 83%. Therefore, the morphological differences are discernible in spite of the volume of artificial rearing and release of fish in the south.

Influence of Insecticides Diazinon and Endosulfan on Taste Reception in Persian Sturgeon Acipenser persicus (Acipenseridae)

The present paper studies the effects of sublethal concentrations of two neurotoxic insecticides (diazinon and endosulfan, duration of exposure 48 h) on the taste attractiveness of L-histidine (0.1 M), L-cysteine (0.1 M), and L-asparagine acid (0.01 M) for juvenile Persian sturgeon Acipenser persicus. The study revealed different effects of diazinon and endosulfan on the extraoral and intraoral taste reception in fish. The taste responses determined by the extraoral taste system (frequency of grasping of 50 food pellets for 5 min of trial) following exposure to endosulfan are the same as in the intact specimens. The exposure to diazinon leads to two to fourfold increase in the number of grasping the pellets, while the amino acids become tasteattractive as opposed to the intact specimens. Both insecticides affect the taste responses controlled by the intraoral taste reception. The insecticide-related pathology is expressed either as a sharp (tens of times) decrease in the absolute and relative consumption of all types of pellets or as full rejection of the pellets after their grasping. Furthermore, the intraoral taste properties of amino acids remain the same as in the intact fish.

Skeletogenesis in the Persian sturgeon Acipenser persicus and its correlation with gene expression of vitamin K-dependent proteins during larval development.

The present study describes morphological development of the skeleton in the Persian sturgeon Acipenser persicus and discusses the hypothesis that expression of genes encoding vitamin K-dependent proteins (VKDP) might be correlated with the mineralization of skeletal tissues during early development in sturgeons. Results showed that development of cartilage started just after hatching (mean ± S.D., 10·9 ± 0·7mm in total length, LT ) in the head and notochord, whereas the first signs of mineralization occurred in the dentary and in the dermopalatine and palatopterygoid elements of the upper jaw, coinciding with the onset of exogenous feeding (20·1 ± 1·5mm LT ). All branchial arch elements developed between 19·3 and 22·3mm LT , whereas mineralization was only observed in tooth plates associated with the hypobranchial 1 and gill rakers at 20·8 ± 1·5mm LT and 48·4 ± 6·4mm LT , respectively. Quantitative real-time PCR showed that transcripts of VKDP genes including bone Gla protein (bgp), matrix Gla protein (mgp) and Gla rich protein (grp) genes were significantly up-regulated during the transition to exogenous feeding, supporting hypotheses about relevance of the above-mentioned genes in chondrogenesis at early developmental stages. The strong mineralization of skeletal elements from 21·5 to 27·3mm LT (20 days post hatch) was in accordance with the maximal levels of bgp, mgp and grp expression indicating a correlation between development of the skeleton and the expression of VKDP genes. These data are important for evaluating A. persicus larval quality, understanding the influence of rearing biotic and abiotic factors on skeletogenesis and recognizing the occurrence of skeletal deformities in this species.

Hydrology and water resources in Caspian Sea

Abstract. Precipitation is the main driver of the water balance variability of the water over space and time, and changes in precipitation have very important implications for hydrology and water resources. Variations in precipitation over daily, seasonal, annual, and decadal time scales influence hydrological variability over time in a catchment. Flood frequency is affected by changes in the year-to-year variability in precipitation and by changes in short-term rainfall properties. Desiccation of the Caspian Sea is one of the world's most serious ecosystem catastrophes. The Persian Sturgeon (Acipenser persicus) caught under 10 m depth using bottom trawl net by research vessel during winter 2012, summer and winter 2013 and spring 2014 in east, central and west of southern parts of Caspian Sea, then, their diets were investigated. During 136 trawling in the aimed seasons, Persian sturgeon with 1 to 2 years old and 179.67 × 0.2 g (body weight) and 29.97 ± 0.4 cm (Total length) captured. Examination of stomach contents in the sturgeon specimens revealed that the food spectrum was composed of bony fishes (Neogobius sp., Atherina sp. and Clupeonella delicatula), invertebrates belonging to the family Ampharetidae polychaeta worms including (Hypanai sp. and Nereis diversicolor), various crustaceans (Gammarus sp. and Paramysis sp.). Investigation on stomach contents of sturgeon Acipenser persicus caught under 10 m depth in 2012 to 2013 surveys showed that there is significant difference in the consumed food. The most food diversity have been observed in winter 2013, also Polychaeta is the primary consumed food and crustacean is the secondary one (P > 0.05), no new types of food (such as bony fishes or benthics) have been observed on food chain of Acipenser persicus and shows no significant difference (P > 0.05).

Study on the effect of climate change on feeding of Persian sturgeon (Acipenser persicus Bordin,1987) in coastal zone of Caspian Sea (Iranian water)

Abstract Ecosystems in the Caspian Sea region have been heavily modified by anthropogenic activities, mainly as a result of changes in the water flow and degradation of the water quality in the eco...

Salinity effects on osmoregulation and gill morphology in juvenile Persian sturgeon (Acipenser persicus).

The effect of abrupt and 5-day gradual salinity transfers from freshwater (FW) to 11‰ Caspian Sea brackish water (BW) was investigated in juvenile Persian sturgeon Acipenser persicus with three different weight groups: 1-2g (1.62±0.27g), 2-3g (2.55±0.41g) and 3-5g (4.28±0.76g). Mortality rates, blood osmotic pressure, gill morphology and branchial Na+, K+-ATPase (NKA) activity were measured 4 and 10days after abrupt transfer and 9 and 15days after the initial gradual transfer (i.e. 4 and 10days after reaching Caspian Sea salinity). Fish under 3g could not survive increased salinity, and the blood osmotic pressure of the remaining surviving fish increased and remained elevated. However, heavier fish were able to survive and successfully acclimate, even to rapid salinity change with osmotic pressure reduced to Caspian Sea osmolality levels. At the gill level, the developmental increase in chloride cell volume and a higher NKA content most probably allow juveniles weighing more than 2g to sharply increase NKA activity if the fish are transferred to BW. The rapid chloride cell proliferation occurring with increased salinity should strengthen this acclimation response. Therefore, a drastic physiological change occurs when fish weigh more than 2g that allows migration to higher salinities. The triggering signal on chloride cells must be further investigated in order to optimize this functional step.

Cryopreservation of Persian sturgeon (Acipenser persicus) sperm: effects of cryoprotectants, antioxidant, membrane stabilizer, equilibration time and dilution ratio on sperm motility and fertility

Three experiments were performed to develop protocols for cryopreservation of Persian sturgeon Acipenser persicus, sperm. In the first experiment, sperm from six males was individually split in three subsamples and cryopreserved using Modified Tsvetkova's extender (mT) supplemented with dimethyl sulfoxide (DMSO), methanol (MeOH), glycerol (Gly) and ethylene glycol (EG) at concentration of 5%, 10%, 15% and 20%. In the second set of experiments, the effects of six equilibration times (0, 5, 10, 20, 40 and 60 min) and dilution ratios (volume sperm: volume extender 1:0.5, 1:1, 1:2, 1:3, 1:5 and 1:10) and the additive advantage of bovine serum albumin (BSA; 0, 2.5, 5 and 10 mg mL−1) and ascorbic acid (0, 2.5, 5 and 10 U mL−1), on the post-thaw survival of sperm (triplicate set of six fish) were evaluated. Then, sperm was diluted in 1:1 mT extender with 10 mg mL−1 BSA with selected cryoprotectants (15% MeOH and 10% DMSO) for 5 min. After a month of storage in liquid nitrogen, post-thawed sperm motility; fertilization and hatching rate and viability of derived larvae were measured (Exp.3). Evaluation of cryoprotectants efficiency showed that MeOH 15% and DMSO 10% were suitable for cryopreservation of Persian sturgeon sperm. Gly and EG resulted in very low post-thaw motility rates even at lowest concentration. No significant difference was observed among the four different equilibration times (0, 5, 10, 20 min) (P > 0.05) although higher equilibration times than 20 min resulted low post-thaw motility (P < 0.05). The motility of frozen–thawed sperm did not significantly change when dilution ratio was increased from 1:0.5 to 1:3 (P > 0.05). However, higher dilution ratios (1:5 and 1:10) reduced the percentage of motile sperm. Supplementation of the cryoprotectant solution with 10 mg mL−1 BSA significantly improved post-thaw motility (P < 0.05), but ascorbic acid did not improve post-thaw motility (P > 0.05). The results of experiment 3 showed that the highest fertilization (30.2 ± 5.75) and hatching rates (28.2 ± 5.25) were observed when samples were frozen with 15% MeOH (P > 0.05). Our study indicates that the use of mT extender consisting of 10 mg mL−1 BSA in 15% MeOH diluted with sperm at 1:1 ratio for 5 min can be recommended cryopreservation method for Persian sturgeon sperm.

Production and Enrichment of Chironomid Larva with Different Levels of Vitamin C and Effects on Performance of Persian Sturgeon Larvae

AbstractChironomid larvae have a high reproduction capacity. Because of their excellent nutritional quality, they have great potential in larval fish nutrition, specially bottom feeders like sturgeons. In this study, indoor production of Chironomus riparius was performed by controlling the physicochemical factors and developing an appropriate condition for this insect to complete the life cycle. Enrichment of lava was conducted by adding 0 (C0), 100 (C100), or 1000 (C1000) mg of ascorbic acid to 1 kg of chicken manure (as substrate). Ascorbic acid analysis of chironomid larva showed significant differences among the groups: 74.2 μg/g for C0, 325.0 μg/g for C100, and 779.9 for C1000. In the second experiment, enriched chironomids were fed to larval Persian Sturgeon Acipenser persicus and were compared with sturgeons fed live cladocerans, Daphnia, which are regulary used in hatcheries. Length and weight measurements after 14 d of the experimental period showed no significant differences in growth performance. Analysis of ascorbic acid in Persian Sturgeon viscera also showed no significant differences between the groups. In conclusion, chironomids could be cultured indoors and can be enriched to meet the nutritional requirements of fish. We found ascorbic acid did not have a signifucant effect on Persian Sturgeon larval feeding, but longer feeding periods and implication of unfavorable physicochemical conditions or causing stress tests might demonstrate the beneficial effects of this vitamin.

Egg cortisol response to stress at early stages of development in Persian sturgeon Acipenser persicus

One of the most important periods in artificial breeding of sturgeon is incubation. In general, little is known about ontogeny of the stress response in early developmental stages of sturgeon. In this study, cortisol content was measured by radioimmunoassay for the first time in eggs of Persian sturgeon Acipenser persicus to elicit at which times during early developmental stages, that they were particularly sensitive to stressful events. In this study, fertilized eggs of mature Persian sturgeons were placed in special boxes (as replicates) that were put in incubation units of Yushchenko. To assess pre-stress samples (resting cortisol levels), 5 eggs were selected randomly from each box in 7 important stages of incubation (2-cell division, blastula, end of blastula, mid of gastrula, neurula, eyed stage and heart beaten). In another experiment, eggs were exposed to an acute stress (10 min out of water) in 7 developmental stages. For determination of post-stress cortisol, eggs were collected 2 and 6 h after the stress. The results indicated significant difference in various stages of incubation but cortisol levels revealed no differences in whole-body levels between stressed samples (2 and 6 h post-stress) and unstressed samples (P > 0.05). The highest percentage of hatching rate for post-stressed eggs was recorded in 2-cell division stage while this percentage declined steadily in the heart beaten stage when a statistically significant difference was revealed with regard to other stages (P = 0.000). These findings suggested that sturgeon eggs were not so much sensitive in their early developmental stages and relatively resistant to stress. However, significant decrease in survival rate in heart beaten stage showed a sensitivity of this stage to stress. Lack of an increase in cortisol after acute stress indicated that hypothalamus-pituitary-interrenal (HPI) axis for cortisol synthesis was not yet functional. However, further studies seem necessary to clarify when HPI axis is activated in this species.

Comparative enzymologic study of catalytical properties of liver monoamine oxidases of sturgeon fish

We carried out the comparative study of the substrate and inhibitory specificity of liver monoamine oxidases (MAO) of the giant sturgeon Huso huso, the starred sturgeon Acipenser stellatus, the Persian sturgeon Acipenser persicus, and the Russian sturgeon Acipenser gueldenstaedtii. Results of the substrate-inhibitor analysis with use of inhibitors chlorgilin and deprenil, as well as five specific substrates indicate homogeneity of these enzymes. All studied MAO have the several orders higher sensitivity to chlorgilin than to deprenil, with essential interspecies differences being observed. There are determined kinetic parameters of enzymatic deamination (KM and V) of tyramine, serotonin, noradrenalin, benzylamine, β-phenylethylamine, and N-methylhistamine. All studied enzymes have been established to have the higher activity toward serotonin and noradrenalin-substrates of the MAO A form as compared with benzylamine, β-phenylethylamine, and N-methylhistamine-substrate of the mammalian MAO B form, the maximal activity being characteristic of the giant sturgeon.

Effect of sperm pH and density on fertilization success in Persian sturgeon Acipenser persicus (Borodin, 1897)

The objectives of the present study were to determine the relationships between sperm characteristics (density and pH) and fertilization capacity (hatching rate) for Persian sturgeon during their reproductive season. Eleven males were used in this study. The luteinizing hormone releasing hormone analog was used to induce spermiation following which semen samples were stripped. Statistical analysis revealed positive correlations between hatching rate and sperm pH (P 0.01, r = −0.745). We suggest that understanding these correlations is critical in the evaluation of sperm quality and for the composition of media (extender) to be used in the dilution of semen to improve sperm motility/fertility parameters of Persian sturgeon.

Feasibility Studies on Vitrification of Persian Sturgeon (Acipenser persicus)Embryos

The feasibility of cryopreservation by vitrification of Persian sturgeon (Acipenser persicus) embryos at 48 h post-fertilization stage was investigated. Vitrification is considered the most promising option. Many factors are involved in the success of the process. The choice of a proper vitrificant solutions and temperature for thawing, were the parameters considered in the present study. Six vitrificant solutions (V1-V6) were tested using a stepwise incorporation protocol. The tested solutions contained acetamide as the main cryoprotectant +3 other permeable cryoprotectants +3 non-permeable cryoprotectants. Before loading the embryos into tubes, toxicity tested was affected with these solutions. The hatching rate of embryos that had been exposed to the vitrificant solutions was analyzed and the highest hatching rate was obtained with exposure to V1. After thawing (water bath, 0 or 20°C), embryos were incubated until hatched. The highest survival rate (69.69%) was observed in samples frozen with V1 and thawed at 20°C. These results establish that cryopreservation of Persian sturgeons embryos by vitrification is possible.

Genetic diversity of lactic acid bacteria in the intestine of Persian sturgeon fingerlings

Summary Lactic acid bacteria (LAB) are often found as sub-dominant microbial components in the gastrointestinal (GI) tract of fish and have positive effects on the host. They are generally promising candidates for probiotics and can act as substances to improving both native immune responses and growth performance of animals including fish. In the present study the Persian sturgeon Acipenser persicus autochthonous intestinal LAB were investigated. A total of 90 sturgeon fingerlings were sampled and LAB were isolated and enumerated on MRS agar. Initial identification of 47 LAB isolates using standard biochemical and phenotypic tests revealed five dominant phenotypes. Twenty-one isolates, representatives from each of these phenotypes, were subsequently identified by 16S rRNA sequence analysis. The results showed that cultivable authochthonous LAB ranged from log 2.93 to 5.61 CFU g−1 intestine, with a mean of 4.38 ± 0.58 CFU g−1. 16S rRNA sequence analysis revealed that the LAB community was dominated by Lactococcus spp., with Lactococcus garvieae and Lactococcus lactis accounting for 42.55 and 36.17% of the LAB population, respectively. Pediococcus pentosaceus (14.90%), Weissella cibaria (4.25%) and Enterococcus faecalis (2.13%) were identified as minor components of the LAB community. This is the first report of these LAB as members of the microbial community in the intestine of Acipenser persicus. The results show that both potentially pathogenic (i.e. Lactococcus garvieae) and probiotic (i.e. Lactococcus lactis and Weissella cibaria) LAB inhabit the Persian sturgeon GI tract. Future studies should seek to elucidate the relevance of these species to the host.

Evaluation of Artemia and formulated diets on performance of Persian sturgeonAcipenser persicuslarvae

Evaluation of Artemia and formulated diets on performance of Persian sturgeon Acipenser persicus larvae By B. Falahatkar, E. Sotoudeh and A. M. Lazur Fisheries Department, Faculty of Natural Resources, University of Guilan, Sowmeh Sara, Guilan, Iran; Fisheries Department, School of Natural Resources and Marine Sciences, Tarbiat Modarres University, Noor, Mazandaran, Iran; University of Maryland Extension, College Park, MD, USA

Primary and Secondary Responses of Juveniles of a Teleostean, Pikeperch Sander lucioperca, and a Chondrostean, Persian Sturgeon Acipenser persicus, to Handling during Transport

AbstractThe dynamics of stress responses in small, juvenile pikeperch Sander lucioperca (as a representative teleostean) and small, juvenile Persian sturgeon Acipenser persicus (as a chondrostean) were determined during capture and transportation for release into rivers. Blood samples were obtained from juveniles from a pond, channel, and loading basin and at 1.5 and 24 h after loading. Samples were analyzed for cortisol, glucose, and lactate concentrations, and mortality was recorded. Plasma cortisol concentrations increased, reaching a maximum in Persian sturgeon from the channel and pikeperch from the loading basin. Significant increases in plasma glucose concentrations were observed in samples from the channel and at 1.5 h after loading for Persian sturgeon and pikeperch, respectively. Similarly, significant decreases in lactate concentrations were observed 1.5 h after loading in both species. The results of this study show the sensitivity of these species to stress during transportation. They suggest a higher resistance to transportation stress by the sturgeon than the pikeperch, but it is highly recommended that transportation procedures and capture techniques be modified so that they are appropriate for the species.

Comparison of respiratory burst activity and ATP level of blood leukocyte in rain Persian sturgeon (Acipenser persicus) and common carp (Cyprinus carpio)

Comparison of respiratory burst activity and ATP level of blood leukocyte in rain Persian sturgeon (Acipenser persicus) and common carp (Cyprinus carpio)

Effects of ghrelin on some plasma hormonal changes in juvenile Persian sturgeon (Acipenser persicus)

The functions of ghrelin, a novel weight-regulatory peptide, have not been intensively investigated in primitive fish. This experiment was conducted to determine whether ghrelin has a specific effect on growth hormone (GH), prolactin and cortisol levels in Persian sturgeon (Acipenser persicus). Juvenile Persian sturgeons with a mean body weight of 320 ± 30 g were given a single injection of ghrelin at three doses of 0.1, 1 and 10 ng/g body weight. Control animals were injected with vehicle (sterile saline) only. Blood samples were collected at 0, 2, 4, 8, 24, 48 and 72 h after injection. The level of plasma hormones were determined by ELISA kit. As expected, ghrelin injection significantly elevated plasma GH (P 0.05). Plasma cortisol levels decreased in fish injected with high doses of ghrelin (P < 0.05). Ghrelin at 10 ng/g body weight had the most influence on GH release, and 1 ng/g ghrelin injection caused the lowest level of cortisol. These results show for the first time that ghrelin induces some plasma hormonal changes in sturgeon fish, as lower vertebrates, but more investigations are needed in this area.

Ultrastructure and osmoregulatory function of the kidney in larvae of the Persian sturgeon Acipenser persicus

The localization of Na(+) , K(+) -ATPase (NKA) and the ultrastructural features of kidney were examined in larvae of the Persian sturgeon Acipenser persicus (L 31-41 mm total length and 182·3-417·3 mg). Investigations were conducted through light and electron microscopy and through immunofluorescence for NKA detection. The kidney nephrons consisted of a large glomerulus and tubules (neck, proximal, distal and collecting), which connected to the ureters. Posteriorly, ureters extended and joined together into a thin-walled ureter terminal sac. Ultrastructurally, the glomerular cells (podocytes) possessed distinctive pedicels that extended to the basal membrane. The proximal tubule (PT) showed two different cells. The cells lining the anterior part of PT possessed apical tall microvilli (c. 2·7 µm), a sub-apical tubular system, a basal nucleus and dense granules. Posteriorly in the cells, the sub-apical tubular system and granules were absent and round mitochondria associated with basolateral infoldings were found; the apical microvilli were reduced. Distal and collecting tubular cells showed the typical features of osmoregulatory cells, i.e. well-developed basolateral infoldings associated with numerous mitochondria. No immunofluorescence of NKA was detected in the glomeruli. A weak immunostaining was observed at the basolateral side of the cells lining the neck and PT. A strong immunostaining of NKA was observed in the entire cells of the distal tubules, collecting tubules and in some isolated cells of the ureters. In all immunostained cells, the basolateral region showed a much higher fluorescence and nuclei were immunonegative. In conclusion, the epithelial cells of kidney tubules had morphological and enzymatic features of ionocytes, particularly in the distal and collecting tubules. Thus, the kidney of A. persicus larvae possesses active ion exchange capabilities and, beside its implication in excretion, participates in osmoregulation.

The transcription of l-gulono-gamma-lactone oxidase, a key enzyme for biosynthesis of ascorbate, during development of Persian sturgeon Acipenser persicus

l-Gulono-gamma-lactone oxidase (GULO) is a key enzyme for the biosynthesis of ascorbate, which is essential for several cellular functions. In the present study, mRNA expression of GULO gene was evaluated during the early development of Persian sturgeon. First, because there are no comparative studies that have established suitable quantitative real-time PCR reference genes in sturgeons for any physiological conditions, we evaluated six candidate reference genes (ACTB, RPL13, UBQ, RPL6, GAPDH and EF1A) during the early development of Persian sturgeon. The most stable mRNA expression was obtained with RPL6 and ACTB, whereas the least stable was RPL13. After normalization using RPL6, ACTB and RPL6/ACTB combination, the mRNA expression of GULO was highest at the embryonic stage (2days before hatching; P<0.05) and started to decline from hatching of larvae to the rest of the developmental time-points. This suggests that the vitamin C requirements are highest during early life stages, and it is likely that the changes in GULO mRNA expression are associated with changes in GULO enzyme activity.