The fluctuations of physicochemical factors and phytoplankton populations of Urmia Lake, Iran

Urmia Lake is one of the two large hypersaline lakes in the world which have Artemia. It is located in northwest of Iran. Due to a decrease in water inflow and volume, the salinity of Urmia Lake has reached to more than 300 g.l-1 since 2001. The increased salinity has greatly influenced biological aspects of the lake, and caused the lake undergoes at critical conduction. The aim of the present study was to investigate the distribution fluctuations of phytoplanktons and selected physicochemical factors in relation to Artemia distribution in Urmia Lake during 8 months. Statistical analysis of mean values of ion concentrations and phytoplankton abundance indicated significant differences among sampling months. The minimum and maximum values for the selected factors were, as Cl- 176.2-201.3 g.l-1 , CO2 95-175mg.l-1 , dissolved oxygen (DO) 0.1-2.8 mg.l-1 , HCO3 - 144-496 mg.l-1 , PO42+ 104-875 mg.l-1, NO3- 330-4104 mg.l-1, NO2- 4-21.5 mg.l-1, SO42- 10490-29840 mg.l-1, Ca2+ 561-1606 mg.l-1, Mg2+ 3649-14587 mg.l-1 while water hardness was 21000- 62000 mg.l-1. Fourteen phytoplankton genera included Bacillariophyceae (10 genera),Chlorophyceae (2 genera) and Cyanophyceae (2 genera) were identified during sampling period. The smallest average density of phytoplankton 97249 L-1 was observed in December 2005 and the greatest average density 481983 L-1 in August 2005. Dunaliella sp. composed 92.1% of the lake's phytoplankton. Statistical analysis of phytoplanktons fluctuations showed a significant difference among different months (p< 0.05)

Effect of broodstocks numbers on cyst formation of bisexual and parthenogenetic strains of Artemia urmiana habitat

Artemia has important role as live food in aquaculture nutrition. There are bisexual and parthenogenetic strains of Artemia urmiana which are living around the Urmia Lake. Selection of suitable strain for culturing programe must be considered at aquaculture industry. In order to find suitable at both strains for, the evaluation of ovoviviparous and viviparously characteristics must be done. The objective of the present study was to introduce the suitable generation for both characteristics (cyst & nauplii production) in bisexual and parthenogenetic strains of Artemia urmiana at urmia lake, Iran. This research was carried out at laboratory under similar and fixed experimental condition for culture. Each artemia was fed with live Dunaliella tertiolecta species .Adults at each generation were assessed the number for frequency of cyst and nauplii production and mortality rate. Results with using one-way ANOVA &Duncan test by SPSS software were analyzed. The results showed that there is significant difference among 10 generation at bisexual strain of Artemia urmiana for cyst-production and mortality rate (P<0.05) and this variation was not significant for nauplii production.In addition that the seventh generation had high cyst-production and sixth generation had high nauplii-production in bisexual strain. The results showed that there is significant difference among 10 generation for at parthenogenetic strain of Artemia urmiana around urmia lake for cyst and nauplii production and mortality rate (P<0.05). In addition that the seventh generation had high cyst-production and tenth generation had high nauplii-production in parthenogenetic strain. Totally, adults of bisexual strain was suitable for cyst-production and parthenogenetic strain for nauplii-production was suitable. The mortality rate had high at bisexual strain compared to parthenogenetic strain .It can be concluded that the seventh generation for cyst-production were suitable in both strains and sixth generation for nauplii-production in bisexual strain and tenth generation for nauplii-production in parthenogenetic strain were suitable. It is recommended to select seventh generation for cyst-production at both strains and tenth generation for nauplii-production at parthenogenetic strain studied

Effect of broodstocks numbers on cyst formation of bisexual and parthenogenetic strains of Artemia urmiana habitat

Artemia has important role as live food in aquaculture nutrition. There are bisexual and parthenogenetic strains of Artemia urmiana which are living around the Urmia Lake. Selection of suitable strain for culturing programe must be considered at aquaculture industry. In order to find suitable at both strains for, the evaluation of ovoviviparous and viviparously characteristics must be done. The objective of the present study was to introduce the suitable generation for both characteristics (cyst & nauplii production) in bisexual and parthenogenetic strains of Artemia urmiana at urmia lake, Iran. This research was carried out at laboratory under similar and fixed experimental condition for culture. Each artemia was fed with live Dunaliella tertiolecta species .Adults at each generation were assessed the number for frequency of cyst and nauplii production and mortality rate. Results with using one-way ANOVA &Duncan test by SPSS software were analyzed. The results showed that there is significant difference among 10 generation at bisexual strain of Artemia urmiana for cyst-production and mortality rate (P<0.05) and this variation was not significant for nauplii production.In addition that the seventh generation had high cyst-production and sixth generation had high nauplii-production in bisexual strain. The results showed that there is significant difference among 10 generation for at parthenogenetic strain of Artemia urmiana around urmia lake for cyst and nauplii production and mortality rate (P<0.05). In addition that the seventh generation had high cyst-production and tenth generation had high nauplii-production in parthenogenetic strain. Totally, adults of bisexual strain was suitable for cyst-production and parthenogenetic strain for nauplii-production was suitable. The mortality rate had high at bisexual strain compared to parthenogenetic strain .It can be concluded that the seventh generation for cyst-production were suitable in both strains and sixth generation for nauplii-production in bisexual strain and tenth generation for nauplii-production in parthenogenetic strain were suitable. It is recommended to select seventh generation for cyst-production at both strains and tenth generation for nauplii-production at parthenogenetic strain studied

The study of genetical differentiation of bisexual and parthenogenetic strains of Artemia urmiana by RAPD s method

The brine shrimp Artemia consists of a number of bisexual species and a large number of parthenogenetic forms, which collectively, inhabiting a wide range of hypersaline habitats. This research was carried out in order to study the genetic differentiation of Artemia urmiana and two parthenogenetic populations originated from surrounding lagoons of the Lake Urmia (Fesendoz, Saray village) and also to find the phylogenetic relationships of some Iranian Artemia (Qom, Arak, Golestan, and Shiraz) with a comparison to some foreign Artemia species (A. sinica, A. franciscana, A. parthenogenetica (Russia and Turkmenistan) using a molecular technique (PCRRAPD`s). Of a total number of 56 random primers (10 bp) survey, 29 and 26 oligonucleotides showed polymorphic patterns with highly reproducible bands in Artemia urmiana groups and Iranian Artemia groups.The highest percentage of polymorphic loci were in Artemia urmiana (P= 78.89 %) and in comparison with the other parthenogenetic forms, in parthenogenetic Artemia from Saray village (P= 59.8 %). The highest values of Shannon index were estimated in Artemia urmiana (I= 0.41), and in comparison with other parthenogenetic forms, in parthenogenetic Artemia from Saray village (I= 0.3). Analysis of molecular variance indicated that most variation were within populations (A. urmiana with parthenogenetic forms, FST= 0.35) and among populations (Iranian Artemia with foreign species, FST= 0.76). Genetic pattern was not in accordance to geographical distribution, which indicated the wide range of Artemia samples at different regions in Iran. UPGMA showed two distinct clusters in group I including A. urmiana with two parthenogenetic forms and four clusters in group II including Iranian Artemia with some foreign species. It is understood that two parthenogenetic populations (Fesendoz and Saray village) had close genetic relationship together with high value of heterozygosity in parthenogenetic Artemia from Saray village. Iranian Artemia (Qom, Arak, and Golestan) indicated close genetic relationships with A. parthenogenetica (Russia and Turkmenistan) with low values of heterozygosity. A sister group was generated including Shiraz and USA Artemia samples which attests a possible contamination of local water with A. franciscana. FST value revealed high genetic structuring at all studied groups. Besides, it is suggested that gene flow was not strong enough to prevent substantial genetic differentiation. Result could lead to a management programmes to use suitable Artemia strains with high genetic diversity, for culturing and establishment of gene bank of Artemia stocks in Lake Urmia

Data from: Population genomics and morphometric assignment of western honey bees (Apis mellifera L.) in the Republic of South Africa

Backgrounds: Apis mellifera scutellata and A.m. capensis (the Cape honey bee) are western honey bee subspecies indigenous to the Republic of South Africa (RSA). Both bees are important for biological and economic reasons. First, A.m. scutellata is the invasive "African honey bee" of the Americas and exhibits a number of traits that beekeepers consider undesirable. They swarm excessively, are prone to absconding (vacating the nest entirely), usurp other honey bee colonies, and exhibit heightened defensiveness. Second, Cape honey bees are socially parasitic bees; the workers can reproduce thelytokously. Both bees are indistinguishable visually. Therefore, we employed Genotyping-by-Sequencing (GBS), wing geometry and standard morphometric approaches to assess the genetic diversity and population structure of these bees to search for diagnostic markers that can be employed to distinguish between the two subspecies. Results: Apis mellifera scutellata possessed the highest mean number of polymorphic SNPs (among 2,449 informative SNPs) with minor allele frequencies >0.05 (Np = 88%). The RSA honey bees generated a high level of expected heterozygosity (Hexp = 0.24). The mean genetic differentiation (FST; 6.5%) among the RSA honey bees revealed that approximately 93% of the genetic variation was accounted for within individuals of these subspecies. Two genetically distinct clusters (K = 2) corresponding to both subspecies were detected by Model-based Bayesian clustering and supported by Principal Coordinates Analysis (PCoA) inferences. Selected highly divergent loci (n = 83) further reinforced a distinctive clustering of two subspecies across geographical origins, accounting for approximately 83% of the total variation in the PCoA plot. The significant correlation of allele frequencies at divergent loci with environmental variables suggested that these populations are adapted to local conditions. Only 17 of 48 wing geometry and standard morphometric parameters were useful for clustering A.m. capensis, A.m. scutellata, and hybrid individuals. Conclusions: We produced a minimal set of 83 SNP loci and 17 wing geometry and standard morphometric parameters useful for identifying the two RSA honey bee subspecies by genotype and phenotype. We found that genes involved in neurology/behavior and development/growth are the most prominent heritable traits evolved in the functional evolution of honey bee populations in RSA

Population genomics and morphometric assignment of western honey bees (Apis mellifera L.) in the Republic of South Africa

Abstract Backgrounds Apis mellifera scutellata and A.m. capensis (the Cape honey bee) are western honey bee subspecies indigenous to the Republic of South Africa (RSA). Both bees are important for biological and economic reasons. First, A.m. scutellata is the invasive “African honey bee” of the Americas and exhibits a number of traits that beekeepers consider undesirable. They swarm excessively, are prone to absconding (vacating the nest entirely), usurp other honey bee colonies, and exhibit heightened defensiveness. Second, Cape honey bees are socially parasitic bees; the workers can reproduce thelytokously. Both bees are indistinguishable visually. Therefore, we employed Genotyping-by-Sequencing (GBS), wing geometry and standard morphometric approaches to assess the genetic diversity and population structure of these bees to search for diagnostic markers that can be employed to distinguish between the two subspecies. Results Apis mellifera scutellata possessed the highest mean number of polymorphic SNPs (among 2449 informative SNPs) with minor allele frequencies > 0.05 (Np = 88%). The RSA honey bees generated a high level of expected heterozygosity (H exp = 0.24). The mean genetic differentiation (F ST; 6.5%) among the RSA honey bees revealed that approximately 93% of the genetic variation was accounted for within individuals of these subspecies. Two genetically distinct clusters (K = 2) corresponding to both subspecies were detected by Model-based Bayesian clustering and supported by Principal Coordinates Analysis (PCoA) inferences. Selected highly divergent loci (n = 83) further reinforced a distinctive clustering of two subspecies across geographical origins, accounting for approximately 83% of the total variation in the PCoA plot. The significant correlation of allele frequencies at divergent loci with environmental variables suggested that these populations are adapted to local conditions. Only 17 of 48 wing geometry and standard morphometric parameters were useful for clustering A.m. capensis, A.m. scutellata, and hybrid individuals. Conclusions We produced a minimal set of 83 SNP loci and 17 wing geometry and standard morphometric parameters useful for identifying the two RSA honey bee subspecies by genotype and phenotype. We found that genes involved in neurology/behavior and development/growth are the most prominent heritable traits evolved in the functional evolution of honey bee populations in RSA. These findings provide a starting point for understanding the functional basis of morphological differentiations and ecological adaptations of the two honey bee subspecies in RSA