Gonadal steroids and energy availability during ovarian maturation stages of the Amazonian pirarucu Arapaima gigas (Teleostei: Osteoglossidae) in the wild.

The Amazonian pirarucu, Arapaima gigas, belongs to a phylogenetically basal group of teleosts (family Osteoglossidae). The commercial importance and the overexploited status of natural stocks of A. gigas brought the interest to rear it in the Amazon region, but rearing techniques are not fully understood to obtain reproduction success.

Capillostrongyloides arapaimae sp. n. (Nematoda: Capillariidae), a new intestinal parasite of the arapaima Arapaima gigas from the Brazilian Amazon.

A new nematode species, Capillostrongyloides arapaimae sp. n., is described from the intestine and pyloric caeca of the arapaima, Arapaima gigas (Schinz), from the Mexiana Island, Amazon river delta, Brazil.