Data/hora: 23/06/2024 20:55:20

Biblioteca(s): | Embrapa Florestas.
Data corrente: | 16/09/2008
Data da última atualização: | 16/09/2008
Autoria: | SOKOLOWICZ, C. C.; ARAUJO, P. B. de.
Título: | Population biology of a species of terrestrial isopod, Benthana sp. (Crustacea, Isopoda, Oniscidea).
Ano de publicação: | 2008
Fonte/Imprenta: | In: INTERNATIONAL COLLOQUIUM ON SOIL ZOOLOGY, 15; INTERNATIONAL COLLOQUIUM ON APTERYGOTA, 12., 2008, Curitiba. Biodiversity, conservation and sustainabele management of soil animal: abstracts. Colombo: Embrapa Florestas. Editors: George Gardner Brown; Klaus Dieter Sautter; Renato Marques; Amarildo Pasini. 1 CD-ROM.
Idioma: | Inglês

Conteúdo:

Terrestrial isopods are crustaceans adapted to live on land. They play an important role on
terrestrial habitats, participating on soil formation, nutrient recycling and also as a source of
food to several organisms. The aim of this study was to provide information on the population
biology of a new species of the genus Benthana. Sampling was done in Taquara, Rio Grande
do Sul, Brazil (29°46?S, 50°50? W). Samples of leaf litter were taken randomly monthly from
March/2006 to August/2007. Animals were separated by sex and sex-differentiation stages
(adult and mancas) and had the cephalothorax width (CW) measured. To identify the existence
of significant differences in sex ratio a ÷2 test was performed (á=0.05). Three types of ovigerous
females were recognized: females bearing eggs, those with embryos and with mancas inside
de marsupium and were used in the analysis of fecundity correlating with CW. After eighteen
months of sampling, 2.016 individuals of Benthana sp. were found, 881 males, 1034 females
(90 ovigerous and 32 post-ovigerous) and 101 mancas. Reproductive females (ovigerous and
post-ovigerous) were present in all months, except June/2006, January and July/2007. Mancas
were present from March/2006-May/2006, September/2006 and from November/2006 to April/
2007. The mean cephalothorax width of males varied from 0.55 to 1.59mm (mean=1.18;
SD=0.19), females from 0.57 to 2.02mm (mean=1.24; SD=0.34), reproductive females from
1.32 to 2.02mm (mean=1.68; SD=0.18) and mancas from 0.57 to 0.71 (mean=0.64; SD=0.03).
The sex ratio favored significantly females with the proportion 1:1.17 (p<0.05). The correlation
of fecundity with CW were significantly positive (r=0.60, p<0.001) and mean fecundity was 10,
SD=2.3. The results found in this study follow a certain pattern among the species of terrestrial
isopods studied on tropical and subtropical regions: sex ratio favoring one sex, ovigerous females
absent during winter and a correlation in number of eggs and female size. As for other neotropical
philosciid, Atlantoscia floridana, mean fecundity is about 10-11 eggs. The minimum number of
eggs is five for both species, while the maximum is 23 for A. floridana and only 18 for Benthana
sp., a species that in comparison, reaches larger sizes.

Categoria do assunto: | --
Registro original: | Embrapa Florestas (CNPF)
Exemplares: | CNPF - (43577-1) - UPE - PL - -- - CD0305 -  -  - DIS