Effect of stocking density of Indian white shrimp (Penaeus indicus) on pond health indices in north Tiab (Hormuzgan Province)

Regarding to the role of shrimp culture on economy of southern region of Iran, investigation of disease agents seems to be very important. In this study the effects of stocking density of P. indicus (4 treatments) on health indices of pond in semi-intensive system was investigated. The investigated health indices were: bacterial, fungal and parasites agents. The obtained data from this study indicated that the vibrio spp., Aspergillus sp. and Epistylis sp. had the highest contamination rate of the pond. ANOVA showed significant difference between the increase of bacterial and parasitical contaminations respect to stocking density (p0.05). The liner regression showed relationship between the increase of bacterial and parasitical contaminations respect to stocking density. Also results showed that increasing of the shrimp density caused increase in all pathogen agents

PUFA content of silages prepared from tuna cannery wastes

Ensiling as one of the best methods for utilization of tuna wastes was investigated. docosahexaenoic acid [DHA C22:6(n-3)]- rich products were obtained from the wastes (viscera and dark meat) of four tuna species, namely longtail, skipjack, yellowfin and kawakawa by a procedure involving ensiling in organic acids followed by neutralization. Identification of fatty acids in the samples was performed by comparison with chromatograms of fatty acids standard. Total lipid content of silages varied from 10.41% in skipjack dark meat silage to 22.01% in kawakawa viscera silage, but all lipids contained high percentages of DHA and EPA [eicosapanteoneic acid C20:5(n-3)]. The highest DHA ratio (15% of total lipids) was found in the lipid of skipjack viscera silage and the highest ratio of EPA (11% of total lipids) belonged to the lipids of kawakawa dark meat silage. ANOVA test results indicated that DHA ratio was significantly high before silage preparation and linolenic acid [C18:3(n-3)] content significantly differed between the species (p<0.05)

Isolation and screening of antibacterial and enzyme producing marine actinobacteria to approach probiotics against some pathogenic vibrios in shrimp Litopenaeus vannamei

The application of new probiotics is a good strategy in the biological control of infectious diseases in aquaculture. Approximately 100 marine actinobacteria isolates were obtained from 10 sediment samples of shrimp farms. Heat treatment of sediment samples resulted in a selective reduction of the non actinobacterial heterotrophic microflora. Starch nitrate agar medium exhibited more efficacy than glycerol arginine agar medium for isolation. Twenty seven percent of actinobacterial isolates showed antagonistic activities against pathogenic Vibrio spp. All the antagonistic isolates showed the typical morphology of genus Streptomyces. Exoenzymatic activity screening showed that 44%, 26%, 37% of antagonistic isolates represented amylase, lipase and protease activities, respectively. MNM-1400 strain exhibited highest antagonistic and exoenzymatic activity. The pathogenicity experiment revealed that MNM-1400 strain did not cause disease in Litopenaeus vannamei larvae. Extraction of produced antibacterial compounds by MNM-1400 strain showed that the active constituent didn’t have non polar property. Morphological, physiological and biochemical identification confirmed that MNM-1400 strain belonged to the genus Streptomyces. Phylogenetic analysis by 16S rRNA gene sequencing showed a high similarity between MNM-1400 strain and Streptomyces californicus (similarity: 99%). These results suggest that the MNM-1400 strain can be considered as a potential probiotic in aquaculture

Population genetic study on two commercial shrimp species and determining of DNA-Barcoding of 6 – 8 species by partial sequencing of mtDNA using molecular method (PCR-Sequencing)

Barcodes are short segments of DNA that can be used to uniquely identify an unknown specimen to species, particularly when diagnostic morphological features are absent. These sequences could offer a new forensic tool in plant and animal conservation especially for endangered species. Ideally, barcodes could be used to positively identify illegally obtained material even in cases where diagnostic features have been purposefully removed or to release confiscated organisms into the proper breeding population. In the present study molecular data were used besides the morphological ones to introduce a specific barcode for six selected species of Shrimp. Based on the previous phylogenetics study, it has been proved that the mitochondrial COI gene in crustacean is a good discriminative marker at both inter- and intra-specific levels. In this regard, six species of shrimp (Fenoro penaeus indicus, Fenoro penaeus merguensis, penaeus semisulcatus, Metapenaeus affinis, Marsupenaeus japonicas, Fenoro penaeus penicillatus were collected from the Persian Gulf and Oman sea. After identification, the total DNA was extracted; COI gene was first amplified and then sequenced for each species. Finally the collected data were analyzed with the specific phylogenetic software. Molecular analysis revealed some degree of interpopulation differences but six good species were recognizable based on COI sequences. Also for population study molecular data of two species Penaeus semisulcatus and Metapenaeus affinis were analysed base on COI RFLP and 16SrRNA sequences respectively. The results would be helpful to protect shrimp species

Gracilaria corticata cultivation in fiberglass tanks and Agar extraction

In order to culture the G. corticata for further agar extraction, during one year study (2001), 3 treatments with 3 different densities of 500, 1000 and 2000 g/m^2 and 3 replicates were cultured in fiberglass tanks. During the culture period the parameters of temperature, pH and salinity were measured and 30-40 percent of water was exchanged once every two days. The aeration activity was constantly done and also 0.5g urea added into the water after exchanging the water. The biometric measurement of algae was carried out every week and ultimately end of the period culture, the daily growth and net production (wet weight) was calculated in proportion to g/m2. Also, amount of extracted agar (dry weight) estimated seasonally. In winter, the daily growth (%), net production and agar extracted (%) were estimated 1.46±0.11, 11.5±3.57 and 17.5%, in which these figures for three other seasons of spring, summer and autumn were: 3.74±0.31, 38.3±5.4, 19.3 and 1.5±0.28, 12.43±3.3, 14% and 3.11±0.04, 26.9±0.61 and 15%, respectively. Some epiphytes and grazers were recognized in algae cultivation tanks such as Navicula, Nitzschia, Oscillatoria, Peridinium, Chaetoceros, Enteromorpha, Ulva, and Isopoda, Nemertine and Nereis. Two seasons of spring and autumn showed the best daily growth and net production, and also the 500 g/m^2 treatment was recognized the best culture treatment

Gene bank preparation from the endemic shrimps and crustaceans of Persian Gulf and Oman Sea

Genetic knowledge and Gene bank preparation can help to protect biodiversity and detect , species identify , fishing offenses , genetic classification and also identification the faliure cross hybridizations of marine animals. In this study, sampling was performed from Jask, guatr and Hormuz areas, which is the most important habitats for the species studied using bottom trawl. Total DNA extraction was performed using phenol- chloroform method. After relevant studies on this gene primers were designed and in use. After editing the sequences, nucleotide BLAST (Basic Local Alignment Search Tool) was performed using NCBI blast main page. The sequences obtained from each sample were aligned and corrected from any ambiguities and assembled using Bio edit program. Trees were generated using maximum parsimony (MP), a character-based algorithm and neighbor joining (NJ) a distance-based algorithm for phenetic analysis. The distance matrix option of MEGA4 was used to calculate genetic distance according to the Kimura 2-parameter model of sequence evolution. Based on the results obtained, the optical density of 260 to 280 nm in the samples was recorded between 1/8 - 2, indicating good quality DNA samples. Optimized PCR reaction to 16SrRNA and COI gene amplification using the gradient between 48 - 60° C showed that the most suitable criteria for binding primers, 48 and 54 Celsius degrees respectively. The project objectives including the identification of the genetic structure of the species, and draw the phylogenetic trees using two genes 16SrRNA and COI, making identification and registration of specified computer storage and regulate the structure and management of mentioned species by focus on genetic resources 5 species of shrimp (P. semisulcatus، P. indicus، P. merguiensis ، P. monodon، M. affinis) in the Persia Gulf and Oman Sea through the creation of an integrated network of aquatic genetic resources in the region to try to identify genetic resources and aquatic gene bank. Molecular investigation of mitochondria DNA (mtDNA) using partial sequences of 16S rRNA gene showed relatively low genetic differences between the P. semisulcatus morphotypes. These sequences were able to distinguish between the two morphotypes, and separated them into two distinct clades. Also genetic divergence detected by COI gene analysis was consistently higher. High genetic divergence for COI was observed between the two morphotypes of P.semeisulcatus which emphesise that the gene bank preparation should be perform for this morphotype of this species. This type of analysis could be considered as an important tool to be used in broodstock selection in breeding programs. In this case, different management in broodstocking programs should be performed for two morphotypes of P. semisulcatus which were detected in Persian Gulf. The results of this study show that two Morphotype of P.semisulcatus can be considered as two separate species from genetic aspects. In this regard, it can be assumed that the genetic composition of the studied species is very close together and we've no seen a huge difference in the species except in the green tiger species

Studying molecular 2 species econimic shrimps (P. merguiensis, P. indicus) Northern coast of the Persian Gulf and Oman sea using microsatelitte markers to separating and identificating of their possible populations

This study focuses on molecular investigation of two commercial shrimp species of penaeus family namely as : P. merguiensis and P. indicus in order to find and introduce the genetic differentiations and also probable genotypes for monitoring and managing the genetic resources of populations in three major catch areas in the Persian Gulf and the Oman Sea. Only five out of the eight primers for P. merguiensis and four out of the eight primers for P. indicus produced good amplified PCR products with fixed annealing temperature. The rest of the primers were either not easily amplified or produced nonspecific bands. Seven and six alleles were found to be unique to each of the three populations in P.merguiensis and and two populations of P. indicus respectively. Occurrences of heterozygosity deficiency were found at most loci. These heterozygosity deficiencies in observed heterozygosity in compare to expected heterozygosity may be due to inbreeding, genetic drift and consequences of illegal overharvesting of P. merguiensis and P. indicus in the studied areas as well. Deviation from HWE in both studied species was significant in most microsatellite loci (P <0.001). We observed deviation from HWE in most loci with hetrozygosity deficits. The genetic variation results showed that the pairwise Fst values were significant between populations in both species. The assignment test for P. merguiensis revealed high gene flow between Hormoz and Jask and restricted genetic flow between Guatr and Hormoz populations .We observed high gene flow between Hormoz and Jask populations for P. indicus. It seems that the changes in immigration patterns of populations between Hormoz, Jask and Guatr areas in both species are depend on the influence of Persian Gulf currents or the life cycle of studied species. Alternatively, the presence of ecological barriers such as mangrove forests may result in restricted genetic flow between Guatr and both Hormoz and Jask populations