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Antioxidant defense status was examined during early developmental stages of rainbow trout, Oncorhynchus mykiss, as affected by heat shock (HS) treatment to induce tetraploidy. Samples were collected at 3850 degree-min post-fertilization at 10 °C and at eyed, hatch, swim-up, in addition to fry stages to determine the activity of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GPx), and levels of vitamin C, A and E as well as malondialdehyde (MDA). HS treatment caused a significant reduction in survival, but not affected growth compared to the control. CAT and SOD activities peaked at hatch, whereas GPx activity reached a maximum at the swim-up stage, showing similar patterns, however, significantly higher activities in the HS group. Vitamin levels were at their minimum at the hatch in both groups, while significantly lower in the HS groups. Vitamin levels were at their highest at the fry stage, with the exception of low vitamin E in the HS group. The levels of MDA showed a steady increase during development, with consistently higher levels in the HS group. These results suggest that HS treatment and/or tetraploidy status cause high oxidative stress, as evidenced by higher activity of antioxidant enzymes and MDA levels, and lower levels of vitamins. [ABSTRACT FROM AUTHOR]

To compare body shape variations and meristic plasticity among four populations of Alburnoides idignensis fish from Aab-barik, Aab-Sardeh, Darband and Sarab-e Kayvareh rivers in Tigris River Drainage, Persian Gulf Basin of Iran. Geometric morphometric method was used to compare shape data extracted by recording 15 landmark points on 2-D pictures of 94 specimens collected from the rivers by electrofishing and a seine net. The principal component analysis, Canonical Variate analysis and MANOVA analysis were used to examine shape differences among the populations. Eight meristic traits including number of lateral line scales (LL), scales above and below LL to ventral fin, pre-dorsal scales, dorsal, anal, pectoral and pelvic branched rays were counted under a stereomicroscope and mean number of the data were compared by Kruskal--Wallis and ANOVA in SPSS software. Significant differences were found among the four populations in all meristic traits but the number of LL scales and in their body shape, separating them from each other. Results revealed that the studied populations have some differences in meristic characters and in the shape and size of the head, body, caudal peduncle and ventral and anal fin position. [ABSTRACT FROM AUTHOR]

The ontogeny of the gastrointestinal tract of the hybrid between female rainbow trout, RT (Oncorhynchus mykiss) and male Caspian brown trout, CBT (Salmo trutta caspius) was compared to the parental species. Larvae were collected for histology and enzymatic assays (amylase, lipase and trypsin) at 3, 6, 9, 12, 15, 18, 21, 26, 31, 35, 40 and 45 days post‐hatch (dph). The development of the gastrointestinal tract (GI‐tract) and the onset of digestive enzyme production was variable between groups. The GI‐tract post‐hatch was a relatively simple tubular structure, and a rudimentary oesophagus was differentiated from other regions at 3 dph in all studied groups. The pyloric caeca and the U‐shaped stomach were clearly visible at 26, 35 and 40 dph in RT, triploid hybrid and CBT, respectively. An abrupt increase in trypsin activity at 31, 35 and 45 dph was identified in CBT, RT and the triploid hybrid, respectively. The increasing activity of trypsin and decreasing activity of lipase during larval development suggests that the CBT, RT and triploid hybrid rely more on dietary proteins than lipids with increasing age. The hybrid grew better and had a faster GI‐tract development than CBT, while RT performed best overall. [ABSTRACT FROM AUTHOR]

Osteological structure of Alburnoides holciki Coad & Bogutskaya, 2012 from Hari River was described. Three specimens were cleared and stained for osteological examination and its detailed osteological characteristics and differences with available osteological data of other members of the family Cyprinidae, subfamily Leuciscinae, were provided. The genus Alburnoides had no unique osteological characteristics that can be used for genus identification. However, there are much variation in the osteological structures of the specimens, especially, the caudal skeleton. [ABSTRACT FROM AUTHOR]

Summary: The Caspian brown trout, Salmo trutta caspius is an endangered species of economic value and better knowledge of its biology will contribute to conservation measures. In the present study we characterized its early development to identify critical embryonic stages, by observing embryos and larvae from a broodstock maintained in captivity incubated at 9 ± 1°C. Morphological analysis of landmark stages of embryonic development revealed that first cleavage occurred at 189 degree‐h, a many‐celled blastoderm formed at 62 degree‐days (dd), a germ ring at 72 dd, the neural keel stage at 88 dd, the blastopore closed at 137 dd, the eye became pigmented at 188 dd and the larvae hatched at 373 dd. The detailed timing of these landmark features will help development of strategies aiming at increased aquaculture production of this species. [ABSTRACT FROM AUTHOR]

Population genetics of Petroleuciscus esfahani in Zayandeh Rood River, Iran were analysed using 120 samples of adult fish from four stations of the river Cheshmeh Dimeh (CHD), Khersoonak (KH), Chamgordan (CH) and Safaeye Bridge (SB) and 5 pairs of microsatellite primers. All loci showed polymorphism. A total number of 54 alleles were recorded across loci ranging from 6 at CnaB-030 to 17 at Ca3. The mean number of alleles per populations ranged from 9.6 in CHD to 8.6 in others. Mean observed heterozygosity at the five loci detected ranged from 0.92 to 1.00 which showed high level of genetic diversity in each population. Deviation from Hardy-Weinberg equilibrium was obvious in most combinations (locus × population), mainly due to heterozygosity excess. The lowest and highest genetic distances were calculated between CHD-KH and CHD-CH populations, respectively. The results showed low but significant FST values between each pair of the populations. This investigation represented at least four separate populations of P. esfahani in the river which showed the effects of river landscape fragmentation on population genetic structure of P. esfahani. [ABSTRACT FROM AUTHOR]

Genetic structure of two populations of Spirlin, Alburnoides eichwaldii from Karganroud and Chalous Rivers was investigated using six microsatellite molecular markers (CtoF-172, BL1-2b, CnaB-030, LleA-071, Ca3 and Z21908) on 30 fishes from each river. The mean of observed alleles at each locus was 6.5. Allele sizes at CtoF-172, BL1-2b, CnaB-030, LleA-071, Ca3 and Z21908 loci were ranged from 107-147, 147-184, 124-157, 332-387 300-347 and 147-183 bps respectively. Z21908 and Ca3 showed the lowest and the highest polymorphism respectively. All loci in both rivers showed deviations from Hardy-Weinberg equilibrium. The number of effective alleles, expected heterozygosity, observed heterozygosity and polymorphism information content (PIC) were 4.86, 0.81, 0.96 and 0.94 respectively cindicative of high level of genetic diversity in both populations. The mean FIS value for all loci in both station ranged from -0.23 to -0.30 indicating low possibility for inbreeding occurrence. The analysis of molecular variance (AMOVA) indicated that the percent of variance among and within populations were 6.31 and 93.69 %, respectively. The genetic distance was 0.363. Significant FST value (0.063) was observed between the two populations. The high level of genetic differentiation may reflect local segregation of two populations because of differences in ecological conditions of two rivers . [ABSTRACT FROM AUTHOR]

Objective: A study of the effects of triploidy on some haematological indices of rainbow trout. Materials and Methods: Haematological characteristics such as red blood cell (RBC) dimensions, area and volume, RBC and white blood cell counts (WBC), haematocrit (Hct%), hemoglobin (Hb), mean erythrocytic hemoglobin (MEH), mean erythrocytic volume (MEV), mean erythrocytic hemoglobin concentration (MEHC) and RBC abnormalities were measured in 14 and 15 ten month old rainbow trout, respectively. Results: Triploidy significantly increased all morphometric indices containing dimensions, nuclear area and volume of RBCs in compare to diploid fish (p<0.05). The triploid trout had lower numbers with larger RBC sizes. The decrease in RBCs was compensated by an increase in MEV. Thus, triploidy did not affect Hct% (p>0.05). A significant reduction in Hb was observed in triploids (7.4 g/dL) when compared to diploid fish (9.2 g/dL; p<0.05). The MEH values were 82.8 and 116.8 μg/cell in diploids and triploids, respectively (p<0.01). There were no significant differences in MEHC levels between diploids and triploids (p>0.05). Triploids had lower numbers of WBCs and showed higher erythrocytic abnormalities than diploids (p<0.01). Conclusion: Numerous haematological indices of rainbow trout were affected by the ploidy levels, therefore it is expected that optimum culture conditions should vary between diploid and triploid fish. [ABSTRACT FROM AUTHOR]

Abstract: Kutum, Rutilus frisii kutum (Kamenskii, 1901), Cyprinidae is an endemic fish of the Caspian Sea. The Iranian Fisheries Organization (Shilat) produces up to 200 million fry (1–2 g b.w.) to restock the Caspian Sea population annually. These fish are produced by artificial breeding using carp pituitary extract (CPE). The objective of this study was to assay the effectiveness of a gonadotropin releasing hormone analogue (D-Ala6, Pro9-NEt GnRH) alone or in combination with the dopamine antagonist domperidone (DOM) on spawning success, latency period, ovulation index (OI), weight of stripped egg mass/weight of stripped egg mass+remnant ovaries, and fertilization success in kutum. Ninety fish were divided into nine groups and injected intraperitoneally as follows: 2 mg kg−1 b.w. of CPE as positive control, 20 μg GnRHa kg−1 b.w. in single injection, 5 μg+2.5 mg, 10 μg+5 mg and 20 μg+10 mg kg−1 b.w. of GnRHa+DOM in single or double injection (10–90%) 24 h apart. Propylene glycol injected fish were used as negative controls. The results showed that the highest doses of GnRHa and DOM in single injection lead to higher spawning success and latency periods in comparison with positive control (P <0.05), while no significant differences in the OI and fertilization success were found (P >0.05). Only 2/10 fish were ovulated in the group which received GnRHa 20 μg kg−1 b.w. alone suggesting dopaminergic tone on gonadotropin (GtH) secretion in this fish at the preovulation stage. Therefore, it can be concluded that like many other cyprinids, dopamine inhibitory tone is active in kutum and it is necessary to combine GnRHa with a dopamine antagonist for spawning induction. [Copyright &y& Elsevier]