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Fishes of the order Gymnotiformes have high diversity of oral and head morphology, which suggests trophic specializations within each clade. The aim of this study was to describe resource use patterns by two fish species (Gymnorhamphichthys rondoni and Gymnotus coropinae) in the National Forest Saracá-Taquera, Oriximiná -Pará, analyzing microhabitat use, diet composition, feeding strategies, niche breadth and niche overlap. Stomach contents of 101 individuals (41 G. rondoni and 60 G. coropinae), sampled in 23 headwater streams were analyzed and volume of food items was quantified to characterize their feeding ecology. Gymnorhamphichthys rondoni was captured mainly on sandy bottoms, whereas G. coropinae in crevices. Both species had a zoobenthivorous diet and consumed predominantly Sediment/Detritus and Diptera larvae, but also included allochthonous prey in their diet. These species had high niche overlap, with small variations related to the higher consumption of Ceratopogonidae larvae by G. rondoni and of Chironomidae larvae by G. coropinae. Both species had a generalist feeding strategy, but G. coropinae had a broader niche breadth. Our results demonstrate that G. rondoni and G. coropinae occupy different microhabitats but rely on similar food resources.Keywords: Amazon, Diet overlap, Feeding, Microhabitat, Streams.Peixes da ordem Gymnotiformes apresentam alta diversidade morfológica, o que sugere a existência de especializações tróficas dentro dos clados. O objetivo deste estudo foi analisar o uso de recursos por duas espécies de peixes elétricos (Gymnorhamphichthys rondoni e Gymnotus coropinae) na Floresta Nacional Saracá-Taquera, Oriximiná -Pará, analisando o uso de microhabitats, composição da dieta, estratégias alimentares, amplitude de nicho e sobreposição de nicho. Conteúdos estomacais de 101 indivíduos (41 G. rondoni e 60 G. coropinae), capturados em 23 igarapés de cabeceira, foram analisados e quantificados volumetricamente para a caracterização da ecologia trófica. Gymnorhamphichthys rondoni foi registrada principalmente em bancos de areia, enquanto G. coropinae em fendas. Ambas as espécies apresentaram dieta zoobentívora e consumiram predominantemente sedimento/detritos e larvas de Diptera, mas também consumiram presas alóctones. Foi observada alta sobreposição de nicho trófico e a baixa variação encontrada foi relacionada à maior utilização de larvas de Chironomidae por G. rondoni e de larvas de Ceratopogonidae por G. coropinae. Ambas as espécies apresentaram estratégia alimentar generalista, porém G. coropinae apresentou maior amplitude de nicho. Nossos resultados demonstram que G. rondoni e G. coropinae ocupam microhabitats diferentes, mas dependem de recursos alimentares similares.Palavras-chave: Alimentação, Amazônia, Microhabitat, Riachos, Sobreposição de nicho.

In the title compound, C18H19N3O5, the 3,6-dihydro-2H-pyran ring adopts a half-chair, distorted towards a half-boat, conformation with Q T = 0.5276(14) Å. The benzene ring is twisted out of the place of the triazole ring [dihedral angle = 23.54 (8)°]. In the crystal, supra­molecular layers in the ac plane are formed through C—H⋯O and C—H⋯π(triazole) inter­actions. These stack along the b axis being connected by C—H⋯N contacts.

5‐Substituted derivatives are obtained via treatment of the substrates with BuLi followed by trapping the lithium intermediate with various electrophiles.

Synthesis of 1,2,3-Triazolylpyranosides Through Click Chemistry Reaction. -The 1,3-dipolar cycloaddition between protected C-alkynyl-glycosides and organic azides is promoted by CuI. The triazolyl pyranosides (III) thus obtained can be easily deprotected under mild conditions. -(STEFANI*, H. A.; SILVA, N. C. S.; MANARIN, F.; LUEDTKE, D. S.; ZUKERMAN-SCHPECTOR, J.; MADUREIRA, L. S.; TIEKINK, E. R. T.; Tetrahedron Lett. 53 (2012) 14, 1742-1747, http://dx.

Functionalization of 2-(S)-Isopropyl-5-iodo-pyrimidin-4-ones Through Cu(I)-Mediated 1,3-Dipolar Azide-AlkyneCycloadditions. -(STEFANI*, H. A.; AMARAL, M. F. Z. J.; MANARIN, F.; ANDO, R. A.; SILVA, N. C. S.; JUARISTI, E.; Tetrahedron Lett. 52 (2011) 51, 6883-6886, http://dx.