Sexual reproduction cycle of the sea cucumber (Stichopus hermanni) in the coral reefs of Kish Island of Iran

Sea cucumber is commercially important in the world. Reproductive biology of Stichopus hermanni in the coral reefs of the Kish Island was investigated using 252 specimens. Morphology of the gonad of the sea cucumber species of the Kish Island was found to be similar to other species. We showed that the gonad color is an unreliable character for sex determination except in maturity stage. We reported the gametogenesis sequence of events and found a sex ratio of 1:1 for the species. The sequence begins late in winter and continues until summer. The active stage of gametogenesis coincides with increasing photoperiod and temperature. Very little spawning activity out of season was noticeable and the maximum spawning was seen in summer. Average body length at first maturity was found to be 310 mm and the diameter of mature oocytes was 200 um. Oocytes moved upward at a rate of 20-30mm per minute that confirms divers' reports of the abundance of developing S. hermanni embryos near the water surface

Hydrology and hydrobiology and environmental pollutions in lower than 10 meters depths of Caspian Sea

The present project in related to survey of factors and hydrology and hydrochemical features (water temperature, dissolve oxygen saturation, pH, clearance, salinity, nitrogen, phosphorus and silicon) hydrobiology (zooplankton, phytoplankton, macrobenthos) and survey of bio environment pollution (oil, heavy metal, detergent) executed in lower 10m in different water larger in southern Caspian Sea in 2002-2003. For sampling 8 lines number were vertical on coast that selected from Astra in west to Gomishan in east in southern Caspian Sea basin. The result indicated the average physical factors such as pH were 8.11 and salinity12.12 ppt ,and disolve oxygen6.7 mg/l. Average chemical factors such as NO_2 , NO_3 and NH_4 were 1.2 µg/l, 25.7 µg/l, 13 µg/l respectively.Total nitogen and organic nitrogen and inorganic nitrogen were 690.2 µg/l , 667.6 µg/l , 41.6 µg/l. Average silicat were recrded 266.35 µg/l . Total Phosphorus was observed 37.35 µg/l and average of organic Phosphorus concentration was and 20.25 µg/l .Average of Total organic matter (T.O.M) was 4.98% maximum amount were observed in Lisar and minimum in Nooshahr . Concentration of heavy metal during sampling were respectively ,Fe>Mn>Zn>Cr>Ph>Co>Cd>Cu. Maximum concentration of Fe were determined in winter in Nooshahr and Babolsar respectively 13/3 µg/l 17/1 µg/l. In many stations and different Season, the amount of heavy meta were lower standard of in marine water. The concentration of oil hydrocarborate (PAHs) in autumn was 0/13 ppb and in winter 0/12 ppb. The amount of (PAHs) in Southern Caspian Sea were Lower than other parts of Caspian Sea. The average of detergent concentration (LAS) was 0/036 µg/l that was two fold higher than determined in 2001. Total 107 species of phytoplankton belong to 5 phylum were identified. The numbers of species of phytoplankton groups were respectively, chrysophyta (42 species), cyanophyta (17 species), pyruphyta (17 species), chlorophyta (21 species) and euglenophyta (9 species). The maximum diversity of phytoplankton observed in summer and minimum in autumn. High diversity of chrysophta and cyanophyta observed in summer and phyrophyta and chrlophyta in spring. The composition of phytoplanhkton groups were respectively, chrysophyta (70%), phyrophyta (9%) and chlorophyta (7%) and euglonophyta (1%). Maximum density of phytoplankton was observed in autumn and minimum in winter. Total 19 species of Zooplankton were identified. Maximum diversity was observed in summer and minimum in winter. Zooplankton changes during sampling, showed amount of density of zooplankton in 5m were more than 10 m depths. Total (17 species macrobenthos were identified. The composition of macrobenthos groups were respectively , Annalida (92/7% ) , Bivalvia (2/7%) gumarida (108%) cumacea ( 1/5%) , Balanidae 103% . max . density were observed in Astara and min . in Sefied roud Average of density were 1218 0/851 ind /m^2 and biomass 14 15 g/m^2 High density were recorded in autumn and low density in winter . Correlation of phytoplankton and zooplankton with physicochemical parameter and also relation between total organic matter and sediment grain size were calculated.Ecological indicies (simpson diversity evenns diversity and shanoon-wiever diversity) were calculated for macrobenthos. Data were shown impact of cetenephora (Mnenemiopsis leidyi) on zooplankton and phytoplankton and macrobenthos density