A fauna do Novo Mundo e o dealbar da alimenta����o cient��fica na Europa

As preocupa����es m��dicas com o equil��brio alimentar remontam �� Antiguidade, mas apenas a partir do s��culo XVII o assunto come��ou a ser questionado de modo mais cient��fico e preciso. Dois m��dicos holandeses de renome, Lu��s Nunes (1553-1645) e Willem Piso (1611-1678), estudaram esta quest��o e legaram-nos tratados de inquestion��vel relev��ncia historiogr��fica. Destacamos, em particular, Ichtyophagia sive de piscium esu commentarius (���Ictiofagia ou coment��rio sobre uma alimenta����o pisc��vora���, Antu��rpia, 1616) e De Indiae utriusque re naturali et medica. Libri quatuordecim (���Sobre a ��ndia e sua hist��ria natural e m��dica���, Amesterd��o, 1658). A defesa de uma dieta que inclua o consumo de peixe �� transversal aos dois textos, pois ambos fundam um discurso inaugural em defesa de h��bitos alimentares equilibrados numa ��poca de profundas mudan��as hist��ricas e culturais impostas pelo contacto com as realidades do ex��tico Novo Mundo. Esta influ��ncia �� sobretudo evidente na obra de Piso, especialmente nas suas descri����es de esp��cies de peixes end��micas do Brasil.

Do the crabs Goniopsis cruentata and Ucides cordatus compete for mangrove propagules? A field-based experimental approach

Mangroves are under threat worldwide by deforestation, overexploitation and climate change. The availability and consumption rates of propagules influence mangrove recruitment and can play a major role in their viability and restoration potential. We assess the potential trophic competition between Goniopsis cruentata and Ucides cordatus, two dominant crab species in the New World, by experimentally comparing herbivory levels between forest stands with varying crab abundance. We hypothesize that herbivory rates (HR) of G. cruentata will be lower in mangroves where it coexists with U. cordatus than in mangroves where U. cordatus is absent. The removal of Rhizophora mangle propagules was very rapid, and HR were overall high and increased through time. However, HR did not differ significantly between mangroves with and without the potential trophic competitor U. cordatus. Our study did not support previous literature indications of food competition between these two crab species, which seem to have developed strategies for competition avoidance.