Dietary astaxanthin (Lucantin® Pink) mitigated oxidative stress induced by diazinon in rainbow trout (Oncorhynchus mykiss).

The potential of commercial astaxanthin on growth, biochemical factors, and antioxidant-related gene expression following a challenge with diazinon were studied in rainbow trout (Oncorhynchus mykiss). Fish (~ 20.70 g) were fed diets containing commercial astaxanthin (ASX) at 0.00 (CTR and ASX0), 0.50 (ASX1), 2.00 (ASX2), and 5.00 (ASX3) g kg-1 for 60 days. Afterwards, the treated fish (ASX1, ASX2, ASX3) as well as the fish in ASX0 group were challenged with diazinon (0.11 mg L-1) for 96 hr whereas fish in the CTR group was not challenged with diazinon. Results showed that growth pattern improved significantly with all enriched diets compared to the ASX0 group. Metabolic enzyme activities, including alanine aminotransferase and alkaline phosphatase decreased in ASX2 and ASX3 groups with respect to the ASX0 group. Serum antioxidant status also showed the same pattern with enhancement in the fish fed with the ASX2 and ASX3 supplemented diets. Feeding the fish with astaxanthin, particularly in the ASX3 group, up-regulated the expression of some antioxidant-relevant genes, including superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione S-transferase (GST), and nuclear factor erythroid-2 related factor 2 (Nrf2) in the kidney and liver. Besides, the histopathological damages in kidneys and liver induced by diazinon were less pronounced in the ASX2 and ASX3 groups compared to the ASX0 group. In conclusion, commercial astaxanthin, especially at 5.00 g kg-1, enhanced the growth performance and ameliorated the oxidative stress induced by diazinon in rainbow trout.

Cabdio occidentalis, a new species from Lake Mashkid basin and the Makran region (Teleostei: Danionidae).

Cabdio occidentalis, new species, is described from the Lake Mashkid basin and the Makran region of Iran. It is distinguished from other species of the genus by a combination of characters: 3842+12 total lateral-line scales, 1923 predorsal scales, 911 pectoral-fin rays, and the absence of a keel between the pelvic-fin base and the genital papilla. The cytochrome c oxidase subunit I (COI) sequence separates C. occidentalis from C. morar, its closest congener, by a p-distance of 5.5%.

Five new species of the sisorid catfish genus Glyptothorax from Iran (Teleostei: Sisoridae).

Five new species of Glyptothorax are described from Iran. Glyptothorax alidaeii, new species, from the Seimare in the Karkheh drainage, G. galaxias, new species, from the upper Karun drainage, G. hosseinpanahii, new species, from the Zohreh drainage, G. pallens, new species, from the Sirvan drainage, and G. shapuri, new species, from Shapur in the Helleh drainage. Glyptothorax silviae from the Jarrahi drainage is re-diagnosed. All six species are morphologically distinguishable by the structure of the thoracic adhesive apparatus, as well as morphometric characters and details in the colour pattern. They form distinct mitochondrial clades between 1.2% and 4.1% minimum K2P distance based on the mitochondrial DNA barcode region.

Paracobitis abrishamchiani, a new crested loach from the southern Caspian Sea basin (Teleostei: Nemacheilidae).

Paracobitis abrishamchiani, new species, is described from the southern Caspian Sea basin, where it is found in the Babol, Haraz, Siah, Tajan, Talar and Kashpal River drainages. It is distinguished from P. hircanica and P. atrakensis, the two other Paracobitis species known from the Caspian Sea basin, by having scales on the flank posterior to the dorsal-fin origin and from its congeners in the Middle East by the position of its dorsal-fin origin, having a roundish posterior narial opening, and a colour pattern consisting of many widely spaced brown spots and blotches. It is further characterized by six diagnostic nucleotide substitutions and a minimum K2P distance of 4.3% to P. persa and 4.6% to P. malapterura in the mtDNA COI barcode region.

Cobitis avicennae, a new species of spined loach from the Tigris River drainage (Teleostei: Cobitidae).

Cobitis avicennae, new species, from the Karkheh and Karun sub-drainages in the Tigris catchment is distinguished from other Cobitis species in the Persian Gulf, Kor and the southern Caspian Sea basins by having a single lamina circularis in males, a small comma-shaped black spot on the upper caudal-fin base, 5½ branched anal-fin rays, 5-6 rows of dark spots on the dorsal and caudal fins, scales below the dorsal-fin base with a small focal zone and pigmentation zone Z4 with 12-17 large, partly fused blotches. It is also distinguished from other Cobitis species in the comparison group by six fixed, diagnostic nucleotide substitutions in the mtDNA COI barcode region.

Morphometric variation of the endangered Caspian lamprey, Caspiomyzon wagneri (Pisces: Petromyzontidae), from migrating stocks of two rivers along the southern Caspian Sea.

BACKGROUND: Morphological studies on fishes are important from various viewpoints. Studies carried out on the Caspian Sea fishes show that many species possess speciation and population formation microprocess running. Morphologicalcharacteristics of the native endangered Caspian lamprey, Caspiomyzonwagneri Kessler1870, from migrating stocks of two major rivers in the southern Caspian Sea were analyzed to investigate the hypothesis population structure and morphologic sexual dimorphism. RESULTS: Univariate analysis of variance of 180 adult specimens showed significant differences between the means of the two studied groups for 15 standardized morphometric measurements out of 31 (P < 0.05). In morphometric trait linear discriminant function analysis, the overall assignments of individuals into their original groups in male and female specimens were 77.1 and 84.0 %, respectively. The discriminant analysis showed a morphological segregation of the studied populations based on the characters predorsal length, interdorsal, interorbital distance, tail length, and first dorsal fin length. The principal component analysis, scatter plot of individual component score between PC1 and PC2, showed the specimens grouped into two areas but with high and moderate overlap between two localities in males and females, respectively. CONCLUSIONS: The present study indicated that there are at least two types of morphological forms of Caspian lamprey that had high morphometric differentiation in the rivers across the southern Caspian Sea, which can be considered in conservational policy of this valuable species.