Sexual diversity of red algae using isomorphic generations of Gracilaria corticata in the northern Persian Gulf and Oman Sea

In conformity with the sex determination of Gracilaria corticata in the Persian Gulf and Oman Sea, a total of 41 samples were collected from two stations of Bostaneh region (northern Persian Gulf, 54° 38´ E / 26° 30´ N) and Lipar regions (northern Oman Sea, 60° 49´ E / 25° 15´ N). The specimens were cultured in PES media for observing the different life stages. The anatomical structures of thallus were taken into consideration. The diploid tetrasporophytes and spermatangia in thallus of male’s gametophytes; and Carpospore and cystocarps of female were determined. Due to DNA extraction, the parasites and epiphytes were cleaned and then the under growing sections were sectioned using liquid nitrogen. After extraction of DNA, by using 20 different primers according to ISSR molecular indicator, the sex diversity and genetic diversity of populations were studied; and four primers were selected ultimately. The obtained results were analyzed by GenAlex and PopGen softwares. In total, 74 bands, all polymorphisms, were propagated. According to PIC index, polymorphism separation of primer C (0.33) was higher than other primers. The Marker Index was measured between 4.48 and 6.51 with mean Shannon’s index of 0.46. The genetic similarity amongst algae was 96%. The genetic diversity inter and intra populations had significant differences of which 83% of total diversity was related to the intra diversity and 17% was related to inter diversity populations. The highest genetic distance belonged to the specimens 5 (Bostaneh) and 35 (Lipar), and it indicated the inter populations diversity in addition to intra population. As an overall conclusion, these populations can be considered as broodstocks for hybrid production for further species breeding and also to attain the maximum heterosis in adaptation with environment. In Ward clustering analysis, the dendrograms showed 5 different clusters in genetic distance of 12.18 of isomorphic phases. The PCA analysis as a complementally method was used for attest the findings. In this research, the ISSR primers could determine the male and female gametophytes and diploid tetrasporophytes in which the primer A (bands of 1200 & 1700 bp) specific for diploid tetrasporophyte and band of 300 bp specific for male were produced. The primer C showed the bands of 820 & 900 bp for diploid tetrasporophyte, and 500 bp for female gametophyte. The primer AB (990 bp) for male, 520 bp for female and 1600 & 1900 bp for diploid tetrasporophyte were specified. The primer ABC showed the specific band of 1100 bp for male; 500 bp for female; and 1200 & 1500 bp for diploid tetrasporophytes

The effect of feeding algal species Isochrysis galbana and Pavlova lutheri as Substitution and combination with Chaetoceros mulleri on the growth and survival of white leg shrimp (Litopenaeus vannamei)

Nutrition and the use of valuable nutrients is one of the most important issues in the aquaculture industry. In this study, the algal species I. galbana and P. lutheri alone and in combination with C. mulleri were incorporated in the diet of white leg shrimp larvae (L.vannamei) and the survival and growth rate of shrimp were investigated. This research was carried out in Persian Gulf & Oman sea Ecological research institute in July 2016. The experiment was carried out from nauplii 6 stages to PL10 and the shrimp were fed six times a day over 16 days.  Six treatments including single species of I. galbana, P. lutheri, and in combination with C.mulleri (as control) were in 3 replicates. At the end of the feeding period, the results of the experiment indicated that C treatment had the highest survival (72%) and the lowest survival was observed in B treatment (47%). There were significant differences among treatments (P≥ 0/05). The maximum (8.02mm) and the minimum (7.23mm) length were observed in F and B treatments, respectively. However, there was no significant difference among treatments (P≤ 0/05). The highest survival rate in salinities 45 and 53 was observed at 98% in E treatment and 95% in F treatment.  No significant differences were observed in survival among treatments. Thus C.mulleri is an essential main species for feeding white leg shrimp larval stage and I.galbana can also be supplemented for increasing nutritional value that could be suitable to improve quality and growth factor of shrimp larvae