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541.
J. I. TÚNEZ M. L. GUICHÓN D. CENTRÓN† A. P. HENDERSON‡ C. CALLAHAN‡ M. H. CASSINI 《Molecular ecology》2009,18(1):147-155
Behavioural and trapping studies of the social organization of coypus have suggested the occurrence of kin groups and a polygynous mating system. We used 16 microsatellite markers to analyse parentage and relatedness relationships in two populations (Jáuregui and Villa Ruiz) in the Argentinean Pampas. At Jáuregui, a dominant male monopolized most paternities, leading to a high variance in reproductive success between males and a high level of polygyny. At Villa Ruiz, variance in reproductive success was low among resident males and males were the fathers of zero to four offspring each. For females, no significant differences were found. Two different social groups in each study site were used to assess genetic relatedness within and between groups. These groups were neighbouring at Jáuregui but not at Villa Ruiz. At Villa Ruiz, coypus were significantly more related within than between groups, suggesting that behavioural groups were also genetic ones, and adult females were more related within than between groups, as should be expected for kin groups. This relationship was not found at Jáuregui. Our results provide support to previous studies based on behavioural and trapping data, which indicate that coypus form social groups and have a polygynous mating system. However, we found differences in social organization between the two populations. This is the first study to determine parentage and/or relatedness in coypus. 相似文献
542.
M. M. MartÍnez-Romero A. E. Castro-RamÍrez P. Macario J. C. FernÁndez 《Economic botany》2004,58(1):83-97
Eleven species of vine, used in the elaboration of utensils and crafts, were identified and their populations were evaluated. The most demanded species arePlukenetia penninervia Muell. Arg.,Cydista aequinoctialis Miers andMonstera deliciosa Liebm. In mature rainforest and in the different successional sites, the availability of usable vine was evaluated; problems of excessive harvest were disregarded. The preferred areas of harvest were the medium and late successional sites. Four types of producers were identified: collectors, collector-artisans, artisans and those who make utensils for personal use. Two basic models of resource destination were distinguished: self-consumption and commercialization. Market value was identified in the elaboration of ornamental crafts that usually represents an economic activity, while the making of utensils reflects the cultural and social value. The main elements of the commercial chain were identified, as well as the problems in order to achieve a fair commercialization. 相似文献
543.
DIEGO C. GARCÍA‐BELLIDO JOHN R. PATERSON GREGORY D. EDGECOMBE JAMES B. JAGO JAMES G. GEHLING MICHAEL S. Y. LEE 《Palaeontology》2009,52(6):1221-1241
Abstract: Abundant material from a new quarry excavated in the lower Cambrian Emu Bay Shale (Kangaroo Island, South Australia) and, particularly, the preservation of soft‐bodied features previously unknown from this Burgess Shale‐type locality, permit the revision of two bivalved arthropod taxa described in the late 1970s, Isoxys communis and Tuzoia australis. The collections have also produced fossils belonging to two new species: Isoxys glaessneri and Tuzoia sp. Among the soft parts preserved in these taxa are stalked eyes, digestive structures and cephalic and trunk appendages, rivalling in quality and quantity those described from better‐known Lagerstätten, notably the lower Cambrian Chengjiang fauna of China and the middle Cambrian Burgess Shale of Canada. 相似文献
544.
Pejibaye (Bactris gasipaes) was domesticated and widely used in the lowland humid neotropics during pre-Colombian times. Several research programs are underway to study and improve the species for use by farmers in ecologically suitable regions. Five breeding programs are outlined, each for a use to which the pejibaye may be put: (1) palmito (heart of palm), (2) whole fruit for human consumption, (3) flour and meal production, (4) oil production, and (5) animal ration from residues or purposefully bred varieties. Yield estimates and breeding problems are discussed. It is certain that the pejibaye can again become an important crop for the humid tropics. 相似文献
545.