The Global Aquaculture Advocate is a four-color trade magazine focused on efficient and responsible aquaculture throughout the world. Written by and for professionals from all farmed seafood sectors, “The Global Magazine for Farmed Seafood” features a range of culture species in articles valued for both their technical content and informative perspectives.
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Glacial vicariance is regarded as one of the most prevalent drivers of phylogeographic structure and speciation among high-latitude organisms, but direct links between ice advances and range fragmentation have been more difficult to establish in marine than in terrestrial systems. Here we investigate the evolution of largely disjunct (and potentially reproductively isolated) phylogeographic lineages within the amphi-boreal kelp Saccharina latissima s. l. Using molecular data (COI, microsatellites) we confirm that S. latissima comprises also the NE Pacific S. cichorioides complex and is composed of divergent lineages with limited range overlap and genetic admixture. Only a few genetic hybrids were detected throughout a Canadian Arctic/NW Greenland contact zone. The degree of genetic differentiation and sympatric isolation of phylogroups suggest that S. latissima s. l. represents a complex of incipient species. Phylogroup distributions compared with paleo-environmental reconstructions of the cryosphere further suggest that diversification within S. latissima results from chronic glacial isolation in disjunct persistence areas intercalated with ephemeral interglacial poleward expansions and admixture at high-latitude (Arctic) contact zones. This study thus supports a role for glaciations not just in redistributing pre-existing marine lineages but also as a speciation pump across multi-glacial cycles for marine organisms otherwise exhibiting cosmopolite amphi-boreal distributions.
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The expansion of the global macroalgal aquaculture and climate change creates the need for germplasm preservation of valuable aquaculture strains and maintenance of natural biodiversity. Compared to the large number of studies in fish and shellfish species, relative few studies have been conducted on the macroalgal germplasm cryopreservation. The first cryopreservation of macroalgae to −75 °C was reported on Neopyropia tenera (formerly called Porphyra tenera) in 1964. To date, a total of 34 studies reported germplasm cryopreservation in 33 species, including Chlorophyta (7 species), Ochrophyta (14 species), and Rhodophyta (12 species). The goal of this review was to summarize the published studies on macroalgal germplasm cryopreservation, compare the reported protocols for the cryopreservation process, and identify the factors affecting post-thaw viability. Overall, macroalgal germplasm cryopreservation included haploid or diploid thalli, spores, and gametes. Cryotubes (1.5-ml or 2-ml) have been widely used to package germplasm samples for cooling and storage in most studies, and the 0.5-ml straws and 5-ml cryotubes have been used in several studies. Two approaches (programmable controlled cooling and vitrification) were employed for macroalgal germplasm cryopreservation. A two-step programmable controlled cooling (e.g., from initial culture temperature to a frozen temperature, such as −40 °C, and then directly plunging into liquid nitrogen at −196 °C) was determined to be an effective cooling strategy. Vitrification, a super rapid cooling for a sample to form non-crystalline amorphous solid, was applied on macroalgal germplasm cryopreservation with sample encapsulation and dehydration. Survival of post-thaw samples varied significantly in different studies. Based on research updates, recommendations are made for future research. It is expected that this review can serve as a foundation for future germplasm banking of macroalgae for aquaculture and biodiversity preservation.
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Ecological differentiation between strains of bacterial species is shaped by genomic and metabolic variability. However, connecting genotypes to ecological niches remains a major challenge. Here, we linked bacterial geno- and phenotypes by contextualizing pangenomic, exometabolomic and physiological evidence in twelve strains of the marine bacterium Alteromonas macleodii, illuminating adaptive strategies of carbon metabolism, microbial interactions, cellular communication and iron acquisition. In A. macleodii strain MIT1002, secretion of amino acids and the unique capacity for phenol degradation may promote associations with Prochlorococcus cyanobacteria. Strain 83-1 and three novel Pacific isolates, featuring clonal genomes despite originating from distant locations, have profound abilities for algal polysaccharide utilization but without detrimental implications for Ecklonia macroalgae. Degradation of toluene and xylene, mediated via a plasmid syntenic to terrestrial Pseudomonas, was unique to strain EZ55. Benzoate degradation by strain EC673 related to a chromosomal gene cluster shared with the plasmid of A. mediterranea EC615, underlining that mobile genetic elements drive adaptations. Furthermore, we revealed strain-specific production of siderophores and homoserine lactones, with implications for nutrient acquisition and cellular communication. Phenotypic variability corresponded to different competitiveness in co-culture and geographic distribution, indicating linkages between intraspecific diversity, microbial interactions and biogeography. The finding of “ecological microdiversity” helps understanding the widespread occurrence of A. macleodii and contributes to the interpretation of bacterial niche specialization, population ecology and biogeochemical roles.
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A Massachusetts company, Aquabounty Technologies, submitted an application to the U.S. Food and Drug Administration (FDA) in 1995 to grow a genetically modified AquAdvantage® Atlantic salmon to be marketed as a food product. Aquabounty proposed to raise the broodstock fish on Prince Edward Island, ship their eggs to a contained inland recirculating production system in Panama to grow, harvest and process the fish, and then ship food grade product back to the United States for sale. The fish for this physically secure production system would be at least 99 percent triploid and all-female, as an additional reproductive-containment measure.
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Thirteen asexually reproducing clones of Enteromorpha linza were found in samples collected from March to September 1982 in Long Island Sound, USA, based on variation at five enzyme loci. Significant differences in the relative frequency of each clone were observed among samples from 16 localities. There was a tendency for localities at the eastern end of the Sound to form a group genetically differentiated from localities at the western end, but in general there was no strong relationship between geographic distance and genetic distance. Areas separated by only a few hundred meters were genetically differentiated, despite the presence of a dispersing spore stage in this species. Samples from areas of low salinity were genetically similar but distinct from adjacent high salinity areas. One clone restricted to high salinity localities and one associated with low salinity localities were tested for growth under high and low salinity conditions in the laboratory. The clone from the high salinity habitat grew more slowly under low salinity conditions. However, there was no evidence for a detrimental effect of high salinity on the low salinity associated clone, Additional environmental factors, as well as biological factors such as limited recruitment and competitive interactions among clones, may also be important determinants of genetic differentiation among populations of E. linza. Temporal shifts in clone frequency were observed within some localities and may be due to seasonal-dependent regeneration from microscopic holdfasts for different clones or a seasonal recruitment of new clones from other areas. The pattern of differentiation among populations of E. linza in Long Island Sound appears to be maintained by factors operating on a microgeographic scale.
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Despite the abundance of seaweeds from Ulleungdo Island, genetic diversity and distribution of edible brown al-gae from the island remain unstudied. We analyzed mitochondrialcox3 sequences from 86 specimens collected in theisland and from the nearby Korean Peninsula. Ourcox3 phylogeny for the first time confirmed the occurrence of fivesspecies from Ulleungdo Island;Petalonia binghamiae,P. fascia,Planosiphon zosterifolius,and two cryptic species previ-ously identified asScytosiphon lomentaria.P. binghamiaewas relatively homogeneous withthree haplotypes.P.fasciacomprised four haplotypes, which were grouped into two genetic lineages.S.lomentariawas heterogeneous with ninehaplotypes and was divided into two cryptic species; one species clustered with taxa from cold waters while the otherclustered with taxa from temperate and cold waters. Low genetic diversity inP. binghamiaewhile high genetic diversityinS. lomentariafrom Ulleungdo Island arecomparable to patterns observed from other species from the Korean pen-insula. Ulleungdo Island, although small in size, is an ideal field laboratory to investigate genetic diversity and distribu-tions of economic marine algae
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Research conducted into the genetic make-up of a resilient red alga has taken scientists a step closer to breeding disease-resistant seaweed. Researchers at the Scottish Association for Marine Science (SAMS) in Oban, Scotland have established the genetic code for the Porphyra umbilicalis, a small, but tough intertidal species that can tolerate a range of conditions and is among the world’s most valuable commercial seaweeds.
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In this Special Issue of Asian Fisheries Science, we are pleased to present 21 papers that resulted from the 48 presentations and posters of the 3rd Global Symposium on Gender in Aquaculture and Fisheries (GAF3), 9th Asian Fisheries and Aquaculture Forum, April 2011. GAF3 was the fifth triennial women/gender Symposium organized by the Asian Fisheries Society.
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Ever pondered what humans will be eating 30 years from now? Food scientists believe that the diet of 2050 won’t be like the one we have today. There will be a decline in the red meat production and rise in the consumption of bugs.
From croissants to Doritos, from Oreo biscuits to Cinnamon Toast Crunch, the preferences for edibles has revolutionized and gotten weirder and wonderful at the same time. Dietary specialists anticipate that 30 years from now, our dietary horizon will be really enthralling and amazing. The predictions of what will we be eating after we emerge from our cryogenic slumber by 2050 ought to be fun!
Some of the interesting futuristic foods have been listed below:
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