Discover the most talked about and latest scientific content & concepts.

Concept: Chuuk


The taxonomy, biology, and population status of flying foxes (Pteropus spp.) remain little investigated in the Caroline Islands, Micronesia, where multiple endemic taxa occur. Our study evaluated the taxonomic relationships between the flying foxes of the Mortlock Islands (a subgroup of the Carolines) and two closely related taxa from elsewhere in the region, and involved the first ever field study of the Mortlock population. Through a review of historical literature, the name Pteropus pelagicus Kittlitz, 1836 is resurrected to replace the prevailing but younger name Pteropus phaeocephalus Thomas, 1882 for the flying fox of the Mortlocks. On the basis of cranial and external morphological comparisons, Pteropus pelagicus is united taxonomically with Pteropus insularis “Hombron and Jacquinot, 1842” (with authority herein emended to Jacquinot and Pucheran 1853), and the two formerly monotypic species are now treated as subspecies - Pteropus pelagicus pelagicus in the Mortlocks, and Pteropus phaeocephalus insularis on the islands of Chuuk Lagoon and Namonuito Atoll. The closest relative of Pteropus pelagicus is Pteropus tokudae Tate, 1934, of Guam, which is best regarded as a distinct species. Pteropus pelagicus pelagicus is the only known resident bat in the Mortlock Islands, a chain of more than 100 atoll islands with a total land area of <12 km(2). Based on field observations in 2004, we estimated a population size of 925-1,200 bats, most of which occurred on Satawan and Lukunor Atolls, the two largest and southernmost atolls in the chain. Bats were absent on Nama Island and possibly extirpated from Losap Atoll in the northern Mortlocks. Resident Mortlockese indicated bats were more common in the past, but that the population generally has remained stable in recent years. Most Pteropus phaeocephalus pelagicus roosted alone or in groups of 5-10 bats; a roost of 27 was the largest noted. Diet is comprised of at least eight plant species, with breadfruit (Artocarpus spp.) being a preferred food. Records of females with young (April, July) and pregnant females (July) suggest an extended breeding season. Pteropus pelagicus pelagicus appears most threatened by the prospect of sea level rise associated with global climate change, which has the potential to submerge or reduce the size of atolls in the Mortlocks. Occasional severe typhoons probably temporarily reduce populations on heavily damaged atolls, but hunting and ongoing habitat loss are not current problems for the subspecies.

Concepts: Caroline Islands, Atoll, Pteropus, Federated States of Micronesia, Chuuk, Namonuito Atoll, Yap, Pohnpei


Nine suvanine analogs including suvanine phenethylammonium salt and two new compounds were isolated from the marine sponge Coscinoderma sp., collected from Chuuk State, Federated States of Micronesia. The structures of the new compounds were elucidated by 2D NMR and HRMS analyses. Suvanine and a new analog exhibited weak but selective cytotoxicity against colon (HCT-15), lung (NCI-H23), stomach (NUGC-3), and prostate (PC-3) cancer cell lines.

Concepts: Cell, Cancer, Metastasis, Lung cancer, Prostate cancer, U.S. state, Federated States of Micronesia, Chuuk


The suvanines, a new suvanine salt, five new (2, 4-8) and two known sesterterpenes from the same structural class, and two new modified lipids (9 and 10) were isolated from a Coscinoderma sp. sponge collected from Chuuk Island, Micronesia. On the basis of the results of combined spectroscopic and chemical analyses, a new suvanine salt was determined to be the suvanine N,N-dimethyl-1,3-dimethylherbipoline salt (2) and suvanine-lactam derivatives (4-8) formed by condensations between an oxidized furan moiety and amino acids. The lipid metabolites were found to be new derivatives of the taurine-containing deacyl irciniasulfonic acid class. The suvanines exhibited moderate cytotoxicities against the K562 and A549 cell lines, while the new suvanine salt (2) had significant antibacterial activity.

Concepts: Protein, Alcohol, Amino acid, Acid, Amine, Ammonia, Metabolism, Chuuk


A Gram-reaction-negative, rod-shaped (1.2-2.1 m  0.8-0.9 m), flagellated and motile marine bacterium designated as MEBiC05461T was isolated from a marine sponge inhabited in Micronesia. Strain MEBiC05461T was oxidase negative and catalase positive. Growth was observed at 8.0-35.6OC (optimum 30.0OC), at pH 5.0-9.0 (optimum pH 7.0) and with 1.5-6.0% (optimum 2.0-2.5%) NaCl. The 16S rRNA gene sequence analysis revealed that strain MEBiC05461T showed high similarity with the members of the genus Amphritea (96.4-96.6%). The predominant cellular fatty acids were C16:0 (23.9%), summed feature 3 (C16:1ω7c and/or C16:1ω6c; 39.7%) and summed feature 8 (C18:1ω7c and/or C18:1ω6c; 22.0%). The DNA G+C contents is 48.5 mol%. The major respiratory quinone is Q-8. Phospatidylethanolamine, phosphatidylglycerol, one unidentified glycolipid, one unidentified aminolipid, one unidentified glycophospholipid, and two unidentified lipids were detected as major polar lipids. On the basis of this polyphasic taxonomic data, strain MEBiC05461T should be classified as a novel species in the genus Amphritea, and it is proposed as Amphritea spongicola sp. nov. The type strain is MEBiC05461T (=KCCM 42943T =JCM 16668T). Emendations of the genus Amphritea and species Amphritea atlantica Gärtner et al. 2008 and Amphritea balenae Miyazaki et al. 2008 were also given.

Concepts: DNA, Archaea, Fatty acid, Biology, Ribosomal RNA, 16S ribosomal RNA, Federated States of Micronesia, Chuuk


Two novel bacterial strains GH2-4T and GH2-5 were isolated from mangrove soil near the seashore of Weno Island in Chuuk state, Micronesia and were characterized by polyphasic approaches. The two strains were strictly aerobic, Gram-staining-positive, endospore-forming rods, motile, catalase and oxidase-positive. Colonies were circular, convex, stringy and transparent yellowish (GH2-4T) or opaque whitish (GH2-5). The two isolates were identical each other based on their 16S rRNA gene sequences. Their closest related strains were Bacillus kochii WCC 4582T, B. horneckiae 1P01SCT, B. azotoformans DSM 1046T, B.cohnii RSHT and B.halmapalus PN-118T (95.6, 95.4, 95.4, 95.2 and 95.2% sequence similarity, respectively). The partial sequence of groEL of strain GH2-4T showed 100% similarity with that of strain GH2-5 and < 85% similarity with those of the closest related strains. The isolates grew at pH 5-12 (optimal growth at pH 9) at 10-40 °C (optimum 30-35 °C) and at salinities of 0-9 % (w/v) NaCl (optimum 1-3 % NaCl). The cell wall peptidoglycan of strain GH2-4T and GH2-5 contained meso-diaminopimelic acid and the cell-wall hydrolysates contained ribose as a major sugar. The DNA G+C content is 36 mol% and the DNA-DNA relatedness values of the isolates to the five related reference strains were around 20-24%. Strain GH2-4T exhibited 81% DNA-DNA relatedness with strain GH2-5. The major cellular fatty acids of both strains were iso-C15:0, iso-C16:0, iso-C14:0 and anteiso-C15:0 and the predominant menaquinone was MK-7. On the basis of polyphasic evidence from this study, strains GH2-4T (= KCTC 33142T = JCM18994T = DSM27083T) and GH2-5 (= KCTC 33143 = JCM18995 = DSM27084) represent a novel species of the genus Bacillus, for which the name Bacillus solimangrovi sp. nov. is proposed; the type strain is GH2-4T.

Concepts: DNA, Archaea, Bacteria, Acid, Ribosomal RNA, 16S ribosomal RNA, Cell wall, Chuuk


The bacteria resident in sponges collected from Chuuk Lagoon and Kosrae Island of Micronesia were investigated using the 16S rRNA gene PCR-tagged pyrosequencing method. These sponges were clustered into 5 groups based on their bacterial composition. Diversity indexes and cumulative rank abundance curves showed the different compositions of bacterial communities in the various groups of sponges. Reads related to the phylum Chloroflexi were observed predominantly (9.7-68.2%) in 9 sponges of 3 groups and unobserved in the other 2 groups. The Chloroflexi-containing group had similar bacterial patterns at the phylum and lower taxonomic levels, for example, significant proportions of Acidobacteria, Gemmatimonadetes, SBR1093, and PAUC34f were observed in most members of this group. The three groups in the Chloroflexi-containing group, however, showed some minor differences in the composition and diversity. The other two groups contained high proportions of Proteobacteria (>87%) or Bacteroidetes (>61%) and different composition and diversity compared to the Chloroflexi-containing group and each other. Four pairs of specimens with the same species showed similar bacterial profiles, but, the bacteria in sponges were highly specific at the individual level.

Concepts: Bacteria, Microbiology, Ribosomal RNA, 16S ribosomal RNA, Phylum, Chloroflexi, Chuuk, Kosrae