Vulnerabilidade nutricional dos primeiros estágios larvais do camarão Lysmata vittata(crustácea : decapoda)

• Autor(a) principal: Almeida, Andrea Santos e
• Data de Publicação: 2017
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UFS
• Texto Completo: http://ri.ufs.br/jspui/handle/riufs/8826
• topic: Biologia; Ensino de biologia; Lysmatidae; Alimentação do camarão; Camarão; Criação de camarão; Crustáceo; CIENCIAS BIOLOGICAS::ZOOLOGIA

Feeding is one of the main factors that influence the larval development of decapod crustaceans. Two points can estimate the nutritional vulnerability of larvae: the “point-of-reserve-saturation” (PRS) and the “point-of-no-return” (PNR). The objective of this study was to evaluate starvation influence on mortality, duration of stages and on larvae size through PRS and PNR values of the first and second (ZI and ZII) larval stages of the peppermint shrimp Lysmata vittata. Ovigerous females were obtained, and two experiments (PRS and PNR) were initiated right after hatching. PSR presented seven different periods of initial feeding (1, 2, 3, 4, 5, 6 and 7 days, named A1, A2, A3, A4, A5, A6 and A7) followed by continuous starvation, while PNR presented different periods of initial starvation (1, 2, 3, 4, 5, 6 and 7 days, named I1, I2, I3, I4, I5, I6 and I7) followed by continuous feeding, plus two control groups (AC and IC). Daily, it was analyzed mortality and larval development, and in the end, it was measured the cephalothorax length (CL). Nonparametric statistical tests (Kruskal-Wallis) were used to make comparisons between treatments. Also, PRS50 and PNR50 (time in which at least 50% of larvae reach PRS and PNR points, respectively) was calculated, and from the quotient of these points the Nutritional Vulnerability Index (NVI) was obtained. In PSR experiment, between 66,6% (A3) and 100% (A4) molted to ZII stage, and between 66,6% (A5) and 100% (A7) molted to ZIII. In PNR experiments, 66,6% (I3, I4 e I5) to 91,6% (I1) advanced to ZII while only treatments I1 (90,9%), I2 (90%) and I3 (50%) molted to ZIII. Total mortality varied between 25% (A4 and A7) and 80% (IC), while in PNR varied from 16,6% (I1) to 100% (I5). The carapace length (CL) of ZIII varied between 0,51±0,03mm (A1) and 0,60±0,02mm (A7) in PSR, and 0,56±0,03 (I2) and 0,58±0,05 (I1) in PNR. The low PRS50 (0,934) and high PNR50 resulted in a low NVI, which means low nutritional vulnerability. Larvae of the experiments presented Facultative Primary Lecithotrophy (FPL), a common feature among some Lysmata group species. Some characteristics also was observed, such as a delayed development in ZII larval stage due to the lack of food and some differences between larval sizes (CL). Thereby, these results can either contribute to some biological aspects of the early phase of L. vittata or provide essential information for aquaculture protocols of the species.