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The infraorder Anomura is a species-rich clade of decapod crustaceans recognized by its remarkable disparity in terms of morphology, anatomy, ecology, physiology, and behavior. This study assembled and characterized the complete mitochondrial genomes of two anomuran species, the hermit crab Coenobita clypeatus and the mole crab Emerita talpoida. The AT-rich mitochondrial genomes of C. clypeatus and E. talpoida are 16,469 bp and 15,810 bp long, respectively, and are composed of 13 protein-coding genes (PCGs), two ribosomal RNA genes, and 22 transfer RNA genes. A 1,390 bp and 553 bp long intergenic space is assumed to be the D-loop in C. clypeatus and E. talpoida, respectively. Mitochondrial synteny in C. clypeatus is identical to that reported in other congeneric hermit crabs while synteny in E. talpoida is identical to that described for the confamilial mole crab Stemonopa insignis. No major differences occur between the studied species and their respective congeneric / cofamilial species in terms of nucleotide composition and codon usage profiles of PCGs. Selective pressure analysis in PCGs, rarely conducted in anomuran crabs, indicate that all these mitochondrial PCGs experience purifying selection and that this purifying selection is stronger in some (i.e., cox family genes and cob) compared to other PCGs (e.g., atp8). Most of the tRNA genes exhibited a typical 'cloverleaf' secondary structure with few exceptions in the two studied species. In C. clypeatus, tRNA-Ser1 lacks the thymine pseudouracil cytosine (TΨC) loop while tRNA-Phe and tRNA-Tyr each exhibit a deletion of the dihydroxyuridine (DHU) loop but not the arm. In turn, in E. talpoida, tRNA-Phe and tRNA-Arg exhibit a deletion of the DHU loop but not the arm while tRNA-Ser1 lacks the TΨC arm. A phylogenomic analysis based on translated PCGs confirms the monophyly of the infraorder Anomura and retrieves most/all relationships at the superfamily and family level previously reported for anomurans. The analysis supports the monophyletic status of the families Albuneidae, Lithodidae, Coenobitidae, and Porcellanidae. In turn, the superfamily Paguroidea, and the families Paguridae and Diogenidae are polyphyletic.

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Amendment tailing heaps with compost may deplete metal(loid)s concentration and improve the conditions for plant development. This research aimed to compare the Tecoma stans ability to grow on soil from the Sonora desert and mining waste (MW) after amendment with compost. Amendment the MW, with compost, decreased soluble As, Cd, Cu, Mn, Pb, and Zn up to 47, 33, 11, 34, 69, and 34%, respectively; increased ten times the leaves weight, and thirteen times the leaf area of the plants. Arsenic, Cd, Pb, Cu, and Zn in plants tissues decreased 27, 28, 27, 12, and 11%, respectively. The bioaccumulation and translocation factors were lower than one, so T. stans do not accumulate these elements. Polyunsaturated fatty acids 18:2ω6 and 18:3ω3 were increased, suggesting lower alteration of thylakoidal membrane integrity due to compost treatment. But, the amendment to the tailing was not enough to deplete the abiotic stress.

Amendment mine tailing with vermicompost depletes changes in polyunsaturated fatty acid of Tecoma stans.

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Triterpenoid biosynthesis is generally anaerobic in bacteria and aerobic in Eukarya. The major class of triterpenoids in bacteria, the hopanoids, is different to that in Eukarya, the lanostanoids, and their 4,4,14-demethylated derivatives, sterols. In the deep sea, the prokaryotic contribution to primary productivity has been suggested to be higher because local environmental conditions prevent classic photosynthetic processes from occurring. Sterols have been used as trophic biomarkers because primary producers have different compositions, and they are incorporated in primary consumer tissues. In the present study, we inferred food supply to deep sea, sponges, cnidarians, mollusks, crustaceans, and echinoderms from euphotic zone production which is driven by phytoplankton eukaryotic autotrophy. Sterol composition was obtained by gas chromatography and mass spectrometry. Moreover, we compared the sterol composition of three phyla (i.e., Porifera, Cnidaria, and Echinodermata) collected between a deep and cold-water region and a shallow tropical area. We hypothesized that the sterol composition of shallow tropical benthic organisms would better reflect their photoautotrophic sources independently of the taxonomy. Shallow tropical sponges and cnidarians from environments showed plant and zooxanthellae sterols in their tissues, while their deep-sea counterparts showed phytoplankton and zooplankton sterols. In contrast, echinoids, a class of echinoderms, the most complex phylum along with hemichordates and chordates (deuterostomes), did not show significant differences in their sterol profile, suggesting that cholesterol synthesis is present in deuterostomes other than chordates.

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Nutritional quality of suspended particulate matter (SPM) and the degree of human fecal pollution in the largest coral reef system in the southwest Gulf of Mexico were evaluated using lipid classes, fatty acids (FA) and sterols in the dry and rainy seasons. High proportions of triacylglycerols and saturated and monounsaturated FA were detected in the SPM however it was considered poor quality because it had low proportions of highly unsaturated FA which can be used to determine production of marine biogenic material of dietary value to pelagic and benthic organisms. Urban sewage organic carbon was traced with coprostanol. The reference value of coprostanol from the point source of pollution was set using two samples from a sewage treatment plant processing waste from >140,000 people near the coral reef system, and it was contrasted with one river station and nine marine stations including six coral reefs. The concentration of coprostanol in the SPM was 3621 ± 98 ng L-1 comprising 26% of total sterols. During the dry season, the river was contaminated upstream with human feces as evidenced by coprostanol at 1823 ng L-1, the 5ß-coprostanol: cholesterol ratio at 0.5, and 5ß-coprostanol: [5α-cholestanol+5ß-coprostanol] at 0.7. In contrast, marine stations had concentrations of coprostanol lower than a suggested regulation limit for tropical marine coastal waters (30 ng L-1), ranging between 6 and 28 ng L-1. During the rainy season a dilution effect was detected in the river, however significantly higher concentrations of coprostanol in the marine stations were detected ranging between 15 and 215 ng L-1, higher than the tentative tropical regulation range (30-100 ng L-1). Among the reefs, the nearshore one, 14.3 km from the treatment plant, was more exposed to human-fecal pollution, and offshore reefs, >17.3 km from the plant, had a lower degree of contamination. Finally, only three stations were clearly uncontaminated during both seasons including two reefs in the south located 21.8 and 35.6 km from the plant, with no presence of coprostanol. Contamination in the rainy season likely comes from a village with untreated sewage located 9.3-32 km from the reefs, and from the second largest Mexican river flowing into the Gulf of Mexico which has a watershed covering three states with lower than average sewage treatment. Inclusion of coprostanol monitoring could be a key factor in the management of this coral reef system.

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