Apomixis evolves from a sexual background and usually is linked to polyploidization. Pseudogamous gametophytic apomicts, which require a fertilization to initiate seed development, of various ploidy levels frequently co-occur with their lower-ploid sexual ancestors, but the stability of such mixed populations is affected by reproductive interferences mediated by cross-pollination. Thereby, repr...

Os estuários são ecossistemas altamente produtivos e dinâmicos, sendo o fitoplâncton principal produtor primário, as diatomáceas cêntricas grupo mais abundante observado no marinho estuarino. Nesse contexto, objetivo deste estudo foi realizar levantamento taxonômico das planctônicas(Coscinodiscophyceae Mediophyceae) de dois tropicais localizados Nordeste do Brasil. O realizado antes maior impac...

The western Palaearctic species of the hawkmoth genus Hyles (Lepidoptera: Sphingidae) have long been subject molecular phylogenetic research. However, much less attention has paid to taxa inhabiting central and eastern Palaearctic, particularly Central Asia, where almost 50% diversity occurs. Yet, many taxonomic conundrums hinder a proper assessment true in these moths. One still unresolved gro...

The evaluation of abiotic and biotic variables can provide information for understanding the structure and function of lotic systems. To obtain this information, measurements of 15 chemical and physical variables and of phytoplankton were conducted at two sampling stations. The present study aims to evaluate the temporal and spatial variation of planktonic diatoms in terms of abiotic variables ...

In order to elaborate a planorbid chart of the State of Rio de Janeiro a survey of freshwater gastropods in the Metropolitan Mesoregion of this State was performed and revealed the occurrence of 20 species: Antillorbis nordestensis (Lucena, 1954); Biomphalaria glabrata (Say, 1818); Biomphalaria schrammi (Crosse, 1864); Biomphalaria straminea (Dunker, 1848); Biomphalaria tenagophila (Orbigny, 18...