Determination of bioaccumulation and microscopic survey of LAS pollutant effect on the liver, kidney and gill tissues of Rutilus frisii kutum in Caspian sea

Linear alkylbenzene sulfonate (LAS) are widely used in detergent industry. Due to contaminants entering the water, and the effects of their accumulation in fish, LAS, has a great importance in environmental pollution. In the present study, accumulation of LAS and its histological effects on gill tissue, liver and kidney of Caspian kutum (Rutilus frisii kutum) were studied. Caspian kutum is the most important and most valuable teleosts of the Caspian Sea. Due to releasing Caspian Kutum in rivers and Anzali Lagoon and unlimited entry of wastewater to the aquatic ecosystem, research on the impact of LAS on Caspian kutum is important. In the present study, fish exposed to sublethal concentrations of LAS (0.58, 1.16 and 2.32 mg/l) for 192 hours. Control treatments with three replicates at 0, 24, 48, 72, 96 and 192 hours were done. For assessments of the histological effects of LAS, tissue sections prepared and by using Hematoxylin - Eosin were stained, then the prepared sections, examined by light microscopy. For determination of the bio accumulation of LAS, the soxhlet extraction and solid phase extraction was performed to determine the amount of LAS using HPLC with fluorescence detector. According to results average of bioconcentration factor and LAS concentrations in fish had reached stable levels after approximately 72 h and thus represented steady state BCF values in this species. The value of steady-state bio-concentration factor of total LAS was 33.96 L.Kg- 1 and for each of the homologous C10-n-LAS, C11-n-LAS, C12-n-LAS and C13-n- LAS were 3.84, 6.15, 8.58 and 15.57 L.Kg-1 respectively. According to the results obtained in gills exposed to LAS, histopathological alteration include hypertrophy, lifting of lamella epithelium, edema, clubbing of lamellae hyperplasia, lamellar fusion and aneurysm were seen. In liver tissue exposed to three concentrations of LAS, congestion and dilation of sinusoids, irregular-shaped nuclei and degeneration in the hepatocyte, vacuolar degeneration and necrosis were observed. In kidney exposed to three concentrations of LAS, reduction of the interstitial haematopoietic tissue, degeneration in the epithelial cells of renal tubule, tubular degeneration, necrosis, shrinkage and luminal occlusion were observed. According to the results the most alteration due to exposure to LAS was seen in the gill tissue. None of the control samples showed histological effects of LAS.

Study on macroscopic, microscopic and hormonal changes in gonads of the crayfish Astacus leptodactylus in Aras Dam

This study was carried out to seasonal determination of some morphological characteristics, Seasonal fecundity, Seasonal fluctuations of vertebrate-type steroids and seasonal analysis of gonadal histology in both female and male sexes of freshwater crayfish (Astacus leptodactylus Eschscholtz 1823) in the area of Aras dam Lake. Crayfish were collected respectively in June, August, November (2011) and January (2012). The average length and weight of male crayfish was higher than that of females. %GSI of females fluctuated within an extended range (between 0.6 and 13.5% from June to January). Both of synchronous and asynchronous ovaries were seen in August sampled ovaries; however asynchronous form was higher than another. The annual reproductive cycle of male A. leptodactylus was surveyed by study on the seasonal changes of the external appearance of the testes and vasa deferentia, fluctuations in the gonadosomatic index (GSI%) and the histological analysis of the male reproductive system. Based on the histological differentiation of testis, spermatogenisis devided to 5 separated stages. The findings suggested asynchronous testis in the species A.leptodactylus. The presence of primary spermatophore layer may help keeping spermatozoa alive while the secondary spermatophore layer may produces spermatophore or synthesize of acellular material which forms spermatophre. Pleopodal fecundity was 37.3%lower than ovarian fecundity observed. The significantly higher number of eggs attached to 3rd and 4th pairs of pleopods. The egg number and gonadosomatic index increased with female size while egg weight and egg diameter didn’t increase with female size. Hemolymph levels of 17β-estradiol and progesterone followed a similar fluctuation pattern with % GSI in females, while testosterone didn’t follow the mentioned pattern. The testis of November sampled crayfish presented significantly higher gonadosomatic (%GSI) index (P < 0.05).The most observed gonadosomaticindices were 13.5%(forfemales) and 1.21% (for males, in autumn. Althogh the lowest GSI was (0.50%) formales in spring and (0.26%0 for spent females in January. Testosterone which followed a similar pattern with %GSI in males increased remarkably in November. 17β-estradiol increased strictly in January. The strictly enhancement of the three estroid hormones in January in both male and female sexes could bedue totheir stimulating role in in spermatophre and egg lying in the mating season (In January). Most of the ovaries followed the asynchoronous growth pattern. Also the testes presented asynchoronous growth pattern in autumn.