Caracterização do desenvolvimento inicial do Cachara, Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889)

• Autor(a) principal: Andrade, Fernanda Freitas
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações do UNIOESTE
• Texto Completo: http://tede.unioeste.br:8080/tede/handle/tede/1933
• topic: Pseudoplatystoma reticulatum; Ontogenia; Morfologia; Crescimento alométrico; Ontogeny; Morphology; Allometric growth; CNPQ::CIENCIAS AGRARIAS::RECURSOS PESQUEIROS E ENGENHARIA DE PESCA

This study aimed to describe the embryonic, larval and juvenile development of the cachara Pseudoplatystoma reticulatum, as well as changes in growth patterns, as well as changes in patterns of growth, in view test the hypothesis of occurrence of differential growth during ontogeny initial of the species. A total of 70 eggs, 220 larvae and 20 juveniles from induced breeding were analyzed for morphometric and meristic variables, besides the allometric growth coefficient during the larval and juvenile. The eggs presented 1,79mm of mean diameter, ample vitelline space (23,41%) with 0,42mm of mean size and the average diameter of the yolk was 0,95mm. The standard length (SL) of the larvae ranged from 2.98 to 19.47 mm, and the total number of myomeres ranged from 45 to 50 (= 13-16 Anal pre-and post-anal = 30-35). The initial pigmentation is scarce, restricted only a few chromatophores on the ventral region of the body and so concentrated in the anterior and posterior extremits of the yolk sac. From the flexion stage it intensifies in the upper region the swimbladder, in the head and along the dorsum, forming a longitudinal band in the lateral face of the head that extends from the snout to operculum and two in body, a dorsal and another ventral, who unite on the caudal peduncle. Initially there is a differential growth especially of the head and tail, with subsequent accentuated growth of the trunk, which shows changes in ontogenetic priorities for eating, swimming and breathing capabilities. Thus, the information obtained in this work are of great importance to the ecology, systematics, and production of the species, particularly in aspects related to ontogenetic variation in morphology, growth, feeding behavior and mortality.