Aranhas sinantrópicas em três bairros da cidade de Salvador, Bahia, Brasil (Arachnida, Araneae)

Abstract

In order to evaluate which are the synanthropic spiders of Salvador and also to know if there exists any relationship between spider composition and time of urban occupation, this study analized 677 spiders, captured in three city neighbourhoods with different urbanization times: Santo Antonio Além do Carmo (300-400 years), Itapuã (100-300 years) and Pituba (less than 50 years). Sample size inside and outside of residences was calculated based on 10% district census and collections were carried out always by six collectors, who were also responsible for the interviews, totalling a sampling effort of 30 minutes/residence (n=71), from November/2002 to June/2003. Of a total of 329 adults, 13 species and 17 morfospecies distributed in 10 families, were recognized. Pholcidae (n=256), Oecobiidae (n=184) and Uloboridae (n=59) were the most abundant families. Oecobius concinnus, the only one Oecobiidae, appeared restricted to recent districts. Its unexpected absence in the oldest district suggests the existence of some limiting factor, that shows the need of more investigation on this poorly known species. In contrast, Smeringopus pallidus was more frequent in the oldest district and Physocyclus globosus (Pholcidae) occured in all three. There was significant differences in species abundance and structural organization of residences between the more ancient and the more recent districts. Thus, we suggest that the fact that the buildings structure remained untouched throughout the years is as a factor that favours the permanence of these species. Key words: synanthropic, spiders, residences, Salvador. ResumoPara avaliar quais as aranhas sinantrópicas de Salvador e relacionar a sua distribuição com a estrutura física das residências, e a composição das espécies com o tempo de ocupação urbana, investigou-se 3 bairros escolhidos segundo sua idade aproximada: Santo Antônio Além do Carmo (300-400 anos), Itapuã (100-300) e Pituba (menos de 50). A base amostral para residências correspondeu a 10% do setor censitário, com 6 capturadores realizando entrevistas concomitantes às capturas, nos domicílios e peridomicílios. Foram coletados 677 aranhas, 329 adultos, identificados em 13 espécies e 17 morfoespécies, distribuídas em 10 famílias, de novembro 2002 a junho 2003, num esforço amostral de 30 minutos/domicílio (n=71) ou peridomicílio. Pholcidae (n=256), Oecobiidae (n=184) e Uloboridae (n=59) foram as três famílias mais abundantes. Oecobius concinnus, única espécie de Oecobiidae registrada, esteve restrita aos bairros recentes e a sua ausência inesperada no bairro mais antigo sugere a existência de algum fator restritivo à sua permanência, havendo necessidade de continuar a investigação. Smeringopus pallidus foi mais freqüente no bairro mais antigo e Physocyclus globosus (Pholcidae) ocorreu nos três bairros. Houve diferença significativa tanto na abundância das espécies como na estrutura física dos domicílios entre os bairros mais antigo e mais recente, indicando que as características coloniais do primeiro devem favorece...

Ants (Formicidae) and Spiders (Araneae) listed from the Metropolitan Region of Salvador, Brazil

“…In our survey, it is to be noted that the exotic ant Monomorium pharaonis Linnaeus, 1958 was not recorded, nor either the spider Physocyclus globosus Taczanowski, 1874. We know that these species are frequent in the state of Bahia (M. pharaonis) and at Salvador (P. globosus), where they are easily found in house interiors (Delabie 1993, Delabie et al 1995, Brazil et al 2005, however, these sites were not sampled in this study. Despite the high incidence of exotic and synanthropic ants and spiders recorded, these species only represented 6% of the total species collected in the MRS (362 ant and spider species).…”

Spider species richness and sampling effort at Cracraft´S Belém Area of Endemism

“…However, many spider species present a wide distribution and some species are capable to occupy synanthropic habitats (e.g. Brazil et al 2005). In the current study, 27 synanthropic species were recorded.…”

Contextual analysis and epidemiology of spider bite in southern Santa Catarina State, Brazil

“…Some studies have shown that spiders in urban areas have synanthropic habits, living in peridomiciliary and intradomiciliary regions. 23,27 According to Diaz, 28 spider bites can usually be prevented by simple personal and domestic measures. Another possible reason for these results may be underreporting from rural areas, where the population has poor access to health services and information.…”