The phylum Actinobacteria constitutes one of the largest and anciently divergent phyla within the Bacteria domain. Actinobacterial diversity has been thoroughly researched in various environments due to its unique biotechnological potential. Such studies have focused mostly on soil communities, but more recently marine and extreme environments have also been explored, finding rare taxa and demonstrating dispersal limitation and biogeographic patterns for Streptomyces. To test the distribution of Actinobacteria populations on a small scale, we chose the extremely oligotrophic and biodiverse Cuatro Cienegas Basin (CCB), an endangered oasis in the Chihuahuan desert to assess the diversity and uniqueness of Actinobacteria in the Churince System with a culture-dependent approach over a period of three years, using nine selective media. The 16S rDNA of putative Actinobacteria were sequenced using both bacteria universal and phylum-specific primer pairs. Phylogenetic reconstructions were performed to analyze OTUs clustering and taxonomic identification of the isolates in an evolutionary context, using validated type species of Streptomyces from previously phylogenies as a reference. Rarefaction analysis for total Actinobacteria and for Streptomyces isolates were performed to estimate species’ richness in the intermediate lagoon (IL) in the oligotrophic Churince system. A total of 350 morphologically and nutritionally diverse isolates were successfully cultured and characterized as members of the Phylum Actinobacteria. A total of 105 from the total isolates were successfully subcultured, processed for DNA extraction and 16S-rDNA sequenced. All strains belong to the order Actinomycetales, encompassing 11 genera of Actinobacteria; the genus Streptomyces was found to be the most abundant taxa in all the media tested throughout the 3-year sampling period. Phylogenetic analysis of our isolates and another 667 reference strains of the family Streptomycetaceae shows that our isolation effort produced 38 unique OTUs in six new monophyletic clades. This high biodiversity and uniqueness of Actinobacteria in an extreme oligotrophic environment, which has previously been reported for its diversity and endemicity, is a suggestive sign of microbial biogeography of Actinobacteria and it also represents an invaluable source of biological material for future ecological and bioprospecting studies.

A total of 168 bottom longline operations were carried out at depths between 72 and 1102 m during four cruises off Lanzarote and Fuerteventura, Canary Islands. One hundred and twenty-eight operations were successful, resulting in the capture of I167 fishes belonging to 55 species. Clear variations in fish total weight and number, species richness and diversity, and the relative abundance of single species occurred among five different depth zones between 100 and 1100 m. The particular platform topography of the Canary Islands may affect the density and diversity of slope-dwelling fishes. Whereas fish body length and weight showed an overall increase with depth, no such trends were found at the level of individual species. One species, Lepidopu.~ caudatus, even revealed a bigger-shallower trend. Among three species of trichiurids, depth distribution patterns were detected that may reflect vertical space partitioning. In October 1995, an unusually high number of Mora moro with advanced gonadal maturity were collected off eastern Fuerteventura at 997 m depth. At lesser depths and during other seasons, only a few individuals of this species were caught in the same area. This indicated a seasonal variability in local abundance that is most probably related to reproduction. Mora moro has an excellent flesh and may represent a valuable fisheries resource. Open problems requiring further research in the study area such as selectivity effects of the fishing gear and possible influences of ecological factors on geographical distribution of the deep-water ichthyofauna, as well as important aspects of the future demersal fisheries management in the Canarian archipelago are briefly outlined. $?) 1996 The Fisheries Society of the British Isles

The phylum Actinobacteria constitutes one of the largest and anciently divergent phyla within the Bacteria domain. Actinobacterial diversity has been thoroughly researched in various environments due to its unique biotechnological potential. Such studies have focused mostly on soil communities, but more recently marine and extreme environments have also been explored, finding rare taxa and demonstrating dispersal limitation and biogeographic patterns for Streptomyces. To test the distribution of Actinobacteria populations on a small scale, we chose the extremely oligotrophic and biodiverse Cuatro Cienegas Basin (CCB), an endangered oasis in the Chihuahuan desert to assess the diversity and uniqueness of Actinobacteria in the Churince System with a culturedependent approach over a period of three years, using nine selective media. The 16S rDNA of putative Actinobacteria were sequenced using both bacteria universal and phylum-specific primer pairs. Phylogenetic reconstructions were performed to analyze OTUs clustering and taxonomic identification of the isolates in an evolutionary context, using validated type species of Streptomyces from previously phylogenies as a reference.Rarefaction analysis for total Actinobacteria and for Streptomyces isolates were performed to estimate species´ richness in the intermediate lagoon (IL) in the oligotrophic Churince system. A total of 350 morphologically and nutritionally diverse isolates were successfully cultured and characterized as members of the Phylum Actinobacteria. 105 from the total isolates were successfully subcultured, processed for DNA extraction and 16S-rDNA sequenced. All strains belong to the order Actinomycetales, encompassing 11 genera of Actinobacteria; the genus Streptomyces was found to be the most abundant taxa in all the media tested throughout the 3-year sampling period.

A total of 1789 fish belonging to 38 families and 73 species were collected at depths between 18 and 1 102 m during 216 bottom longline operations off Lanzarote and Fuerteventura, Canary Islands, between February 1994 and December 1995. For each species the depth distribution is provided. Length-weight and depth-size relationships are reported for three shelf-dwelling species. The biggerdeeper relationship found in two of them contrasts with the bigger-shallower pattern of the deeper living trichiurid Lepidopus caudurus. In November 1997, nine additional bottom longline operations were carried out of€ eastern Fuerteventura at depths between 805 and 1217 m. In this area, after earlier studies in October 1995, a spawning aggregation of the morid Mom moro was encountered for the second time. The catches of 1997 revealed a strongly male-biased sex ratio. Also, the males showed a significantly lower gonadosomal index than two years earlier. These findings indicate slight interannual variations in reproductive timing and an earlier arrival of male Mora moro at the spawning grounds. Clear variations in the number of fish collected at adjacent sites possibly reflect a preference for distinct microhabitats. Preliminary evidence of local upwelling of cold water above the spawning grounds is provided by satellite imagery. ProblemThe Canary Islands region, situated in the northernmost part of the Eastern Central Atlantic, shows distinctive topographic and hydrographic conditions which may affect the spatial distribution of both shallow-and deep-water fishes to a considerable extent. The rather narrow shelf and the steep upper slope, typical for oceanic islands of volcanic origin, set spatial limits to the demersal fish assemblage. The hydrography of this region is characterized by countercurrents at different U. S.

The phylum Actinobacteria constitutes one of the largest and anciently divergent phyla within the Bacteria domain. Actinobacterial diversity has been thoroughly researched in various environments due to its unique biotechnological potential. Such studies have focused mostly on soil communities, but more recently marine and extreme environments have also been explored, finding rare taxa and demonstrating dispersal limitation and biogeographic patterns for Streptomyces. To test the distribution of Actinobacteria populations on a small scale, we chose the extremely oligotrophic and biodiverse Cuatro Cienegas Basin (CCB), an endangered oasis in the Chihuahuan desert to assess the diversity and uniqueness of Actinobacteria in the Churince System with a culturedependent approach over a period of three years, using nine selective media. The 16S rDNA of putative Actinobacteria were sequenced using both bacteria universal and phylum-specific primer pairs. Phylogenetic reconstructions were performed to analyze OTUs clustering and taxonomic identification of the isolates in an evolutionary context, using validated type species of Streptomyces from previously phylogenies as a reference.Rarefaction analysis for total Actinobacteria and for Streptomyces isolates were performed to estimate species´ richness in the intermediate lagoon (IL) in the oligotrophic Churince system. A total of 350 morphologically and nutritionally diverse isolates were successfully cultured and characterized as members of the Phylum Actinobacteria. 105 from the total isolates were successfully subcultured, processed for DNA extraction and 16S-rDNA sequenced. All strains belong to the order Actinomycetales, encompassing 11 genera of Actinobacteria; the genus Streptomyces was found to be the most abundant taxa in all the media tested throughout the 3-year sampling period. 88Actinobacterial diversity and community structure have been thoroughly investigated, not 89 only for their ecological importance, but also by virtue of their unique biotechnological potential 90 due to their robust secondary metabolism and incomparable ability to produce a plethora of 91 bioactive molecules with extensive medical, industrial and agricultural applications.92 Actinomycetes, are the source of most clinically relevant antibiotics in use today (Barka, Vatsa, 93 Sanchez 2016). Nevertheless, the growing emergence of antibiotic multirresistant pathogenic 94 strains, challenges the scientific community to overcome the problem of rediscovery of known 95 compounds. Recent studies have concluded that discovery of unkown bioactive molecules will 96 be facilitated by focusing heavily on "gifted" (secondary-metabolites-rich), readily culturable 97 microbes that have been isolated from untapped environments, such as marine ecosystems, 98 which enhance the isolation of large-genome (>8 Mb), thus, rare culturable bacteria (Tiwari &