First record of karyotype analysis in anjak, Schizocypris altidorsalis (Bianco and Banarescu, 1982) from Hamoun Lake, Iran

The chromosomal spread and karyotype of Anjak (Schizocypris altidorsalis) from Hamoun Lake were determined using tissue squashing techniques with an injection of 1 mL/100 g body weight of 0.01% colchicines solution. Kidney and gill epithelia tissues were removed and used for karyotype analysis. The analysis of 145 chromosome spreads revealed the diploid chromosome number of this fish, 2n=48 and a fundamental arm number (FN) =88. The diploid complements comprised 12 metacentric pairs, 8 submetacentric pairs, 1 subtelocentric pair and 3 telocentric pairs (12m+8Sm+1St+3t). Total length of the haploid complement equaled 44µm with a range in the length of the shortest and longest chromosome between 0.76-2.78µm. The arm ratio and the centromeric index ranged between l.00-∞ and 0-50 respectively. This is the first report on the chromosome number and karyotype of S. altidorsalis from the Hamoun Lake in Iran

Biological assessment of the Tang Sorkh River (Iran) using benthic macroinvertebrates

A biological assessment of the Tang Sorkh River (Iran) was studied from July 2013 to August 2014 using benthic macroinvertebrate communities. Samples were gathered every two months, from five stations using a Surber sampler( 30×30cm), fixed in formalin (4%) and then separated and identified in the laboratory. Environmental conditions (current velocity, temperature, depth, width, dissolve oxygen, conductivity, pH, alkalinity, Total Suspended Solids (TSS) and grain size) were measured. In addition, diversity and biotic indices were used to determine the water quality of the river. Results showed that 5 classes, 9 orders and 20 families were identified in this river. The families Hydropsychidae (Trichoptera), Simuliidae (Diptera) and Baetidae (Ephemeroptera) were dominant. Shannon-wiener and Simpson indices showed the highest diversity at station 1 and the lowest diversity in station 4. According to the Hilsenhoff, ASPT and BMWP indices, station 1 had good water quality for aquaculture