Population of sand goby (Neogobious fluviatilis pallasi) in southwest coasts of the Caspian Sea using morphological characteristics

Caspian sand goby, Neogobius fluviatilis pallasi belongs to Gobiidae family. Because of their abundance in Caspian Sea, they have important role in the sea food chain in this area. This study was conducted from October 2005 to September 2006 in southwest coasts of the Caspian Sea in Guilan province. Samples were collected monthly from four stations (Astara, Anzali, Chamkhaleh and Chaboksar coasts) from coastal areas to waters l5 meters deep using bottom trawl. Result of differential function analyses on corrected morphometric statistic showed three functions 51.3%, 28.4% and 20.3%, respectively, and sum of differentiative function percentage was 80% which proved difference among groups. The functions showed that samples in Astara station were completely different from other regions while they were similar to Anzali station only in some sampling points. Chamkhaleh and Astara stations were the same but Chaboksar station was a separated group. Analysis of differential functions for studied characteristics included on average 86.3% of the population with most of it belonging to Astara station (93.3%) and Anzali (90%). The minimum amount belonged to Chamkhaleh with 79.3%. The results showed that Neogobius fluviatilis pallasi probably has three different populations in Astara, Anzali, Chamkhaleh and Chaboksar populations

Effects of probiotic (Pediococcus acidilactici) on growth and survival of kutum (Rutilus kutum) fingerlings

In the present study effects of different levels of probiotic Pediococcus acidilactici, on growth performance and survival rate of Rutilus kutum fingerlings were investigated. Kutum fingerlings with a mean weight of 1±0.235 g were reared for 8 weeks in 500-l fiberglass tanks (15 fish per tank) with 4 diet treatments (3 replicates for each). Treatments included 1×10^9, 2:1×10^9, 3×10^9 CFU kg^-1 dry food and a control without probiotic. At the end of the study, specific growth rate (SGR) and survival rate (SR) were significantly higher in treatments supplemented with probiotic compared to the control (p<0.05), while the fish fed with probiotics showed lowest food conversion ratio (FCR) (p<0.05). The results indicated that the use of 3× 109 CFU kg^-1 dry food probiotics improved growth parameters and survival rate in R. kutum fingerlings