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| Author(s): |
Geslaine Rafaela Lemos Gonçalves
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Botucatu. 2016-08-23. |
| Institution: | Universidade Estadual Paulista (Unesp). Instituto de Biociências. Botucatu |
| Defense date: | 2016-07-18 |
| Advisor: | Antonio Leão Castilho; Maria Lucia Negreiros Fransozo |
| Abstract | |
The spider crab Libinia ferreirae is a poorly studied species, even being an important component of the trophic web in its habitat, and presenting symbiotic relationships with several organisms as well. The aim of this research is to describe the population parameters (reproductive periodicity, juvenile recruitment and ecological distribution) of this species, for both benthic and pelagic (symbiotic) life stages. Sampling was carried out in the Cananéia region (São Paulo state, Brazil) from June 2012 through May 2014, using a shrimp fishing boat outfitted with double-rig nets. In total, 921 crabs were collected, 564 adults (benthic) and 357 juveniles (pelagic), living in symbiosis to medusas of Lychnorhiza lucerna. The abundance of ovigerous (carrying embryos) females showed a positive association to salinity and grain size values (CANONICA, r=0.44; p=0.000052). The presence of such ovigerous females throughout the whole sampling period characterizes a continuous reproduction pattern, once they presented a positive relation to symbiotic juveniles at time lag “+2” (Cross-correlation, p<0.05). It can also evidence an effective spawning, since two months after reproductive peaks it is possible to observe peaks in juvenile recruitment. The periods with increased primary productivity (high in chlorophyll concentration) also preceded periods of juvenile recruitment, in agreement to the match-mismatch theory. Therefore, we propose that this species presents an adjustment in the spawning periods to the ones with higher primary productivity, in which the planktotrophic larval stages will be provided with a high source of food, increasing its subsequent larval success. This study showed an ecological strategy of habitat segregation among juvenile and adult individuals, thus avoiding the competition for food resources. (AU) | |
| FAPESP's process: | 14/13770-1 - Population ecology of Libinia ferreirae (Brachyura: Majoidea) in Southeastern coast of Brazil |
| Grantee: | Geslaine Rafaela Lemos Gonçalves |
| Support Opportunities: | Scholarships in Brazil - Master |