Efeito da diversidade de habitats sobre o desenvolvimento populacional do camarão-da-amazônia

• Ano de defesa: 2014
• Autor(a) principal: Santos, Michélle Roberta dos [UNESP]
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual Paulista (Unesp)
• Palavras-chave em Português: Camarão; Macrobrachium; Substratos; Habitat (Ecologia); Ecologia; Heterogeneidade ecológica; Ecology
• Link de acesso: http://hdl.handle.net/11449/108933

The objective of this study was to test the hypothesis in which the development of the population structure of amazonian prawn, Macrobrachium amazonicum, is affected by the heterogeneity of habitats from the bottoms of bodies of water. Twelve mesocosms of natural background were used, where each mesocosm had an area of ~0.01 ha and a depth of ~1 m, and with an approximate volume of 100 m3. The mesocosms were stocked with 22/m2 juveniles of amazonian prawn and 1.1/m2 of juvenile tilapia (which composed the nektonic extract) in three different treatments: mesocosm with substrate made of geotextile blanket (MG), mesocosm with substrate made from bamboo (BB), and then mesocosm without substrate (SS). The prawn were collected monthly and at the end of the experiment in order to assess population structure, ovarian stage, body mass and length, sex-ratio, and survival. The presence of the substrates in the mesocosms increased the frequency of the CC morphotypes, accelerated the appearance of the GC1 and GC2 morphotypes, decreased the frequency of the TC morphotype at the end of the experiment, increased the size of males and females, and increased the frequency of ovarian stages IV and V. The effect was more pronounced with the presence of the MG substrate. On the other hand, the survival rate was significantly higher in the mesocosms without substrates even though the values were quite similar. The sex-ratio did not differ significantly between treatments with or without the addition of substrate. Therefore, the presence and the type of substrate added to the bottoms of water systems present an effect on the population growth of M. amazonicum, confirming the initial hypothesis which stated that population structure is dependent on the heterogeneity of habitats