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| Author(s): |
Natália Bosco Talamonte
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Bauru. 2020-05-18. |
| Institution: | Universidade Estadual Paulista (Unesp). Faculdade de Ciências. Bauru |
| Defense date: | 2020-03-11 |
| Advisor: | Rogério Caetano da Costa |
| Abstract | |
The relative growth, morphological and functional sexual maturity, fertility, reproductive investment and sex ratio of Processa hemphilli were investigated. It was also tested, a relation of reproductive aspects with abiotic factors like temperature and salinity of the bottom water, content of organic matter and phi. Shrimps were collected seasonally, from autumn 2016 to autumn 2019 in the Ubatuba Bay, north of São Paulo, in trawls with a “mini otter-trawl” net. To analyze abiotic factors, the bottom water was collected using a Van-Dorn bottle and sediment, with a Van-Veen tracker. The individuals were identified according to sex and for the analysis of relative growth, the following structures were measured (mm): carapace length (CL), length of the propodus (Pl), carpus (Cl) and mere (Ml) of the first (1 ) and the second (2) pair of pereopods, width of the second abdominal pleura (2Pl), length of the internal appendage (IA) in males and females, and as for the length of the male appendix (MA) in males. The relationships that best evidenced changes in the growth rate between young population and adults, pointing to the morphological sexual maturity were: CC x Cp2 in males CC x 2Pl in females, with sexual maturity estimated at 3.2 and 3.6 mm CC for males and females respectively. The functional sexual maturity found was 3.3 mm CL. The estimated average fertility was 256.22 ± 134.62 with a positive correlation between the number of eggs and the length of the carapace, indicating a proportional increase between the number of eggs and the size of the females. On average, reproductive investment was 52.43% ± 20.20% and there was no significant difference in IR between seasons. There was no significant difference in sex ratio (M: F), however, there was a significant predominance of males in the smallest size classes. This fact is probably related to the “pure search” mating system, in which the smallest males benefit from being more agile in the search for receptive females and also to the r-strategism hypothesis, in which larger females would benefit from being able to incubate a greater number of eggs. There was no correlation between environmental factors and the abundance of individuals, both male and female, ovigerous and nonovigerous, nor with fertility. All the information contained here is of great importance as it provides the first biological information on the life history of P. hemphilli. (AU) | |
| FAPESP's process: | 18/24949-3 - Population aspects of Processa hemphilli shrimp Manning & Chace, 1971 (Caridea: Processidae) in Ubatuba bay, SP, Brazil |
| Grantee: | Natália Bosco Talamonte |
| Support Opportunities: | Scholarships in Brazil - Master |