| dc.contributor | Gonzaga, Marcelo de Oliveira | |
| dc.contributor | http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4796456E4 | |
| dc.contributor | Leiner, Natalia Oliveira | |
| dc.contributor | http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4762287Z8 | |
| dc.contributor | Santos, Adalberto José dos | |
| dc.contributor | http://buscatextual.cnpq.br/buscatextual/visualizacv.do?id=K4796461D1 | |
| dc.creator | Cardoso, João Custódio Fernandes | |
| dc.date | 2016-06-22T18:34:59Z | |
| dc.date | 2015-12-22 | |
| dc.date | 2016-06-22T18:34:59Z | |
| dc.date | 2015-02-26 | |
| dc.date.accessioned | 2023-09-28T20:39:23Z | |
| dc.date.available | 2023-09-28T20:39:23Z | |
| dc.identifier | CARDOSO, João Custódio Fernandes. Segregação espacial horizontal em pequena escala entre duas
espécies da família Theridiidae (Araneae). 2015. 105 f. Dissertação (Mestrado em Ciências Biológicas) - Universidade Federal de Uberlândia, Uberlândia, 2015. Disponível em: https://doi.org/10.14393/ufu.di.2015.132 | |
| dc.identifier | https://repositorio.ufu.br/handle/123456789/13421 | |
| dc.identifier | https://doi.org/10.14393/ufu.di.2015.132 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/9055704 | |
| dc.description | Mestre em Ecologia e Conservação de Recursos Naturais | |
| dc.description | Niche theory predicts that coexistence between related species occurring simpatrically is
unlikely. Due to the shared phylogenetically conserved ecological attributes, the stronger
competitor may exclude competitively the related heterospecific. However, coexistence
mechanisms may allow similar species to persist together. In this study, we investigated the
coexistence between two related theridiid spider species: Helvivis longicauda and Chrysso
intervales. Along riparian habitats of a tropical forest, H. longicauda occurs close to river
margins, while C. intervales occurs in higher abundance in further regions, after the zone
occupied by H. longicauda, but always in shaded, humid regions. In this sense, this study aimed
to investigate this fine-scale horizontal segregation pattern, exploring the relative contribution
of different factors in generating the arrangement. Our results confirmed spatial segregation
between spider species in both summer and winter, with H. longicauda populations being
restricted to river margins and C. intervales to contiguous regions. These species were positively
related to the abundance of suitable sites used for web-building and negatively to the relative
abundance of fern leaves, which seem to be unsuitable sites. Apparently, spiders also present
niche differentiation in the height they build webs, with C. intervales occurring at lower average
heights. Helvibis longicauda was the only one infested by fungi and the mortality rates were
higher during winter. At this time, we found more C. intervales individuals occupying areas close
to the river than we did in summer. Helvibis longicauda trophic niche breadth was wider than
that of the heterospecific. However, we did not found differences in prey abundance across
distinct distances from the river. Only the temperature was different, increasing away from the
river. There were no differences in establishment rates between species in both environments.
However, it is still possible that H. longicauda success far from the margins is lower during
summer, once transplant experiments were performed during winter, in which temperature did not differ between species zones. Helvibis longicauda was the most common species colonizing
potential web-building sites at marginal regions, while C. intervales colonizers were found
mainly in areas further away. Agonistic interactions demonstrated that resident spiders present
advantage in both intra and interspecific contests, once they remained alone in the web in most
contests. Resident spiders effectively defended the web even against larger intruders. However,
much larger intruders presented an increase in the probability of remaining in the alien web,
sometimes taking it over. Although C. intervales average body mass is higher than that of H.
longicauda, this difference seems to represent no effect in C. intervales reaching marginal
regions. We hypothesized that capture rates of H. longicauda at further distances is
compromised due to high temperature acting on the smaller viscid droplets, reducing
adhesiveness. This abiotic factor restricts this species to cooler places. In the vertical axis, both
species may potentially occupy the lower sites of the river margins. However, H. longicauda
apparently displace C. intervales through asymmetric exploitation competition. The fact that
fungi reduced H. longicauda populations functioned as a natural removal experiment and
resulted in a competitive release for C. intervales individuals to reach margins, even with H.
longicauda still being more abundant at this place. | |
| dc.format | application/pdf | |
| dc.format | application/pdf | |
| dc.language | eng | |
| dc.publisher | Universidade Federal de Uberlândia | |
| dc.publisher | BR | |
| dc.publisher | Programa de Pós-graduação em Ecologia e Conservação de Recursos Naturais | |
| dc.publisher | Ciências Biológicas | |
| dc.publisher | UFU | |
| dc.rights | Acesso Aberto | |
| dc.subject | Ecological niche | |
| dc.subject | Coexistence | |
| dc.subject | Interspecific competition | |
| dc.subject | Agonistic interactions | |
| dc.subject | Theridiidae | |
| dc.subject | Nicho (Ecologia) | |
| dc.subject | Aranhas | |
| dc.subject | CNPQ::CIENCIAS BIOLOGICAS::ECOLOGIA | |
| dc.title | Segregação espacial horizontal em pequena escala entre duas
espécies da família Theridiidae (Araneae) | |
| dc.type | Dissertação | |
