The effects of temperature, sexual stages and migration on non-specific immune system in the serum and mucus of the male Caspian kutum with emphasis on lysozyme



Non-specific immune system plays an important role infections and prevent pathogens from growing and multiplying of. In the present study, lysozyme and total protein non-specific immune variations in during developmental testis in the male Caspian kutum were investigated. The samples monthly collected from Jefrood coast (Anzali, Guilan province, 37º 27´ N; 49º 33´ E) from October 2011 to May 2012 The blooding and skin mucus were prepared in the laboratory. Lysozyme and total protein measurement performed by Turbidimetric and Bradford method. After identifying the various stages of the sperm development based on histological observations, the results showed that lysozyme levels had ascending trend during the sampling from October to January and after that, being descending up to march and finally, increased in May again. The concentration of mucus lysozyme showed significant ascending trend from October to December (P<0.05) and then simultaneously with lowering the Caspian Sea surface temperature until march, this trend became descending and finally lysozyme concentration increased after the fish migration to the river in May (P<0.05).Serum lysozyme levels from the early maturing of testis developmental stages to late maturing was ascendant and after that, in matured stage descended and after migrating to the river for spawning, lysozyme activity significantly increased. The changes in the mucosal lysozyme were similar to the serum (P<0.05).Total protein concentration showed significantly descending trend in the skin mucus from October to March (P<0.05). In May, it was increased significantly following the fish migration to river (P<0.05). The descendant trend was observed for total protein during the ovarian growth from early maturing to matured stages (P<0.05) but in the spawning stage, it was significantly increased (P<0.05). In conclusion, the results are showing the effects of temperature, testis development and migration on lysozyme variations of the Caspian kutum that between them, the temperature factor can be more highlighted.