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Army ant invasion of leatherback nests in Gabon

Egg mortality is one of the main factors affecting life history and conservation of oviparous species. A massive and cryptic colonisation of many leatherback turtle (Dermochelys coriacea) eggs is presented in the most important rookery for the species in Gabon. A total of 163 nests were exhumed at Kingere beach, revealing that only 16.7% of eggs produced hatchlings. In the 59% of the nests, more than half of the eggs were dead and attacked by invertebrates and 94% had at least one egg affected by invertebrates. The rate of eggs and SAGs (yolkless eggs) affected by invertebrates within a clutch ranged from 0% to 100%, with an average proportion of 39% and 52%, respectively. The most common invertebrates interacting with the eggs were ghost crabs and insects that affected 51% and 82% of the nests, respectively. Crab and insect co-occurred in 33% of the affected nests. Ants, identified as Dorylus spininodis (Emery 1901) were found in 56% of the excavated nests. However, it was not possible to determine if the ants predated alive eggs or scavenged dead eggs. Very often, hundreds of ants were found drowned within dead eggs. Termites and other invertebrates were associated with the clutch environment and identified as opportunistic feeders, being this is the first record of interaction between termites and sea turtle eggs. An unusual ecological interaction within the leatherback clutches between termites and ants was found in 11% of the nests. The abrupt transition between the soil forest and the beach might be favouring a thriving microbial and invertebrate activity in the sand profile that colonises the nests. informacion[at] Ikaran et al (2020) Cryptic massive nest colonisation by ants and termites in the world's largest leatherback turtle rookery Ethol Ecol Evol 2020. Doi 10.1080/03949370.2020.1715487
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LC-MS determination of catecholamines and related metabolites in red deer urine and hair

LC-MS determination of catecholamines and related metabolites in red deer urine and hair

A novel analytical methodology for the determination and extraction of catecholamines (dopamine, epinephrine and norepinephrine) and their metabolites DL-3,4-dihydroxyphenyl glycol and DL-3,4-dihydroxymandelic acid by LC-MS is here developed and validated for application to human and animal urine and hair samples. The method is based on the preliminary extraction of analytes by a magnetic multi-walled carbon nanotube poly(styrene-co-divinylbenzene) composite. This is followed by a < 9 min chromatographic separation of the target compounds in an Onyx Monolithic C18 column using a mixture of 0.01% (v/v) heptafluorobutyric acid in water and methanol at 500 µL min-1 flow rate. Detection limits within range from 0.055 to 0.093 µg mL-1, and precision values of the response and retention times of analytes were > 90%. Accuracy values comprised the range 79.5–109.5% when the analytes were extracted from deer urine samples using the selected MMWCNT-poly(STY-DVB) sorbent. This methodology was applied to real red deer urine and hair samples, the resulting concentrations within range from 0.05 to 0.5 µg mL-1for norepinephrine and from 1.0 to 44.5 µg mL-1 for its metabolite 3,4-dihydroxyphenyl glycol. Analyses of red deer hair resulted in high amounts of 3,4-dihydroxyphenyl. informacion[at] Murtada et al (2019) LC-MS determination of catecholamines and related metabolites in red deer urine and hair extracted using magnetic multi-walled carbon nanotube poly(styrene-co-divinylbenzene) composite. J Chromatogr B