共查询到20条相似文献,搜索用时 15 毫秒
1.
J. Peter Brosius 《Human ecology: an interdisciplinary journal》1991,19(2):123-150
Bailey et al. (1989) and Headland (1987) have recently proposed hypotheses stating that human foragers are unable to live in undisturbed tropical rain forests without some reliance on cultivated foods. The present discussion considers these hypotheses, as well as some of the evidence by which they have been tested. Four conceptual problems in the way these hypotheses have been formulated are identified: (1) assumptions about the relationship between key features of tropical forest ecosystems and human subsistence potential, (2) in-consistencies in the definition of pure foraging, (3) adherence to a dichotomy between foraging and agriculture, the result being that conscious and unconscious effects of exploitation on the demographic parameters of key resources is ignored, and (4) problems in defining the significance of ecotones. I consider the case of Penan hunter-gatherers of Borneo, a population which, by virtue of their reliance on the sago palm Eugeissona utilis, contradicts the conclusions of Bailey et al. and Headland. I consider salient aspects of Penan reliance on Eugeissona, and describe how Penan exploitation of this resource may positively effect its availability. This case is seen to provide a challenge to the hypotheses of Bailey et al. and Headland, not only in the extent to which it contradicts their conclusions but, more significantly, in what it reveals about the assumptions upon which their hypotheses are based. This points to the need for greater precision in the definition of future hypotheses about foraging in tropical forests. 相似文献
2.
CHEKSUM SUPIAH TAWAN 《Botanical journal of the Linnean Society. Linnean Society of London》1999,130(1):65-68
A new species, Gonystylus othmanii Tawan (Thymelaeaceae) from Sarawak (Borneo) is described and illustrated. It is considered to be endemic to Sarawak. The morphological differences between the new species and related taxa are included. 相似文献
3.
CHARLES LIENHARD 《Zoologica scripta》1985,14(4):313-318
Both sexes of Ophiodopelma glyptocephalum sp.n. are described and illustrated. The species is unique in the Psocoptera by its specialized head morphology in the male. The female entirely lacks the unusual morphological structures on the head. These structures of hypothetically sensory and/or secretory function may prove to be correlated with particular behavioral elements and to play an important role in sexual life. With regard to general morphology the new species is similar to the previously known species of the genus Ophiodopelma Enderlein, 1908. 相似文献
4.
The spleen of Agama stellio is composed mainly of red pulp; the white pulp is poorly developed, and its clusters are scattered throughout the organ and contain lymphocytes, reticular cells, and some plasma cells. The red pulp consists of clear reticular cells intermingled with blood cells, sinusoids, and pigment cells. The spleen of Chalcides ocellatus is encapsulated by connective tissue and is composed of white and red pulp. The white pulp consists of lymphoid tissue that surrounds the central arterioles, forming the periarteriolar lymphocyte sheath (PALS). The red pulp is composed of a system of venous sinuses and cords. The results of various histochemical procedures designed to demonstrate mucosubstances, proteins, and nucleic acids indicate that the spleen in these species resembles the mammalian spleen. © 1993 Wiley-Liss, Inc. 相似文献
5.
Based on morphological and genetic evidence we evaluated the taxonomic status of a newly discovered forest-dwelling population of skink(genus Scincella)from the Keo Seima Wildlife Sanctuary, Mondulkiri Province, Cambodia. From phylogenetic analysis of a668-bp fragment of the mt DNA COI and diagnostic morphological characters we allocate the newly discovered population to the Scincella reevesii–S.rufocaudata species complex and describe it as Scincella nigrofasciata sp. nov. The new skink species can be distinguished from all other Southeast Asian congeners by the following combination of morphological characters: snout-vent length(SVL)40.0–52.6 mm; relative tail length(TaL/SVL ratio)1.25–1.94; prefrontals in broad contact; infralabials 6;primary temporals 2; relative forelimb length(FIL/SVL ratio) 0.20–0.22; relative hindlimb length(HIL/SVL ratio) 0.30–0.33; relative forearm length(FoL/SVL ratio) 0.14–0.16; adpressed forelimbs and hind limbs either overlapping(0.4–2.2 mm) or separated(1.9–2.3 mm); midbody scale rows 32–33, paravertebral scales69–74, vertebral scales 65–69; dorsal scales between dorsolateral stripes 8; comparatively slender fingers and toes, subdigital lamellae under fourth toe 15–17;dark discontinuous regular dorsal stripes 5–7; distinct black dorsolateral stripes, narrowing to lateral sides and extending to 52%–86% of total tail length. We provide additional information on the holotype of Scincella rufocaudata(Darevsky Nguyen, 1983), and provide evidence for the species status of Scincella rupicola. Our discovery brings the number of Scincella species in Cambodia to five and emphasizes the incompleteness of knowledge on the herpetofaunal diversity of this country. 相似文献
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Lalita Tuksitha Yi-Lin Sophia Chen Yi-Ling Chen Kie-Yiong Wong Chi-Chung Peng 《Journal of Asia》2018,21(2):563-570
Stingless honey bees form a large group of bees that lack of a sting and are found among Meliponinae species indigenous to various tropical and subtropical regions. They are able to produce “stingless bee honey” that contains divergent categories of phenolic and flavonoid compounds and have been associated with antioxidant and antibacterial activity. This study examines the physicochemical properties, antioxidant-activity and anti-microbial activity of stingless bee honey from Malaysia that was produced by Geniotrigona thoracica, Heterotrigona itama and Heterotrigona erythrogastra. The results show that G. thoracica honey has the highest concentration of the total phenolic context (99.04?±?5.14?mg/ml) and the greatest reducing power (19.05?±?0.79%), while flavonoids (17.67?±?0.75?mg/ml), reducing power (18.10?±?0.35%), DPPH (47.40?±?3.18%) and FRAP (50.66?±?5.77?mM of Fe2+/100?g) of H. itama honey is significantly higher than those of the other honeys. In addition, G. thoracica honey has the highest antibacterial activity against Staphylococcus xylosus (2.10?±?0.10?cm), which is Gram-positive bacterium, and against Pseudomonas aeruginosa (1.60?±?0.10?cm) and Vibrio parahaemolyticus (2.03?±?0.06?cm), which are Gram-negative bacteria. These results suggest that stingless bee honeys possess useful amounts of phenolic and flavonoid compounds that are able to act as natural anti-oxidants and also have significant anti-microbial activity. 相似文献
8.
Phylogenetic relationships of the Oriental semiaquatic lygosomine skinks of the genus Tropidophorus were inferred from 1219 base positions of mitochondrial 12S and 16S rRNA genes. Results of the phylogenetic analyses incorporating data for representatives of other lygosomine genera indicated that the basal phylogenetic split within Tropidophorus separated a clade of continental Indochinese species exclusive of T. cocincinensis and T. microlepis from one comprising T. cocincinensis , T. microlepis and species from Borneo, Sulawesi and the Philippines. Of the latter group, the two continental species form the sister taxon to a clade comprising the island species. Diversification among species in Indochina and among Borneo, the Philippines and Sulawesi was likely concentrated in the Miocene, with no apparent dispersal among these regions during the Pleistocene. The body depression recognized in several Indochinese species is likely to have occurred twice in parallel as an adaptation to saxicolous habitats. 相似文献
9.
Poulakakis N Lymberakis P Tsigenopoulos CS Magoulas A Mylonas M 《Molecular phylogenetics and evolution》2005,34(2):245-256
Sequence data derived from two mitochondrial markers, 16S rRNA and cytochrome b genes, were used to infer the phylogenetic relationships of 38 populations of the snake-eyed skinks of the genus Ablepharus with emphasis on A. kitaibelii from Greece and Turkey. The partition-homogeneity tests indicated that the combined data set was homogeneous, and maximum-parsimony, maximum-likelihood, and Bayesian analyses produced topologically identical trees that revealed a well-resolved phylogeny. All species except A. kitaibelii form monophyletic units. The latter species appears paraphyletic with respect to A. budaki and A. chernovi with populations clustering into two distinct clades. A. chernovi and A. budaki, which have recently been raised to species status, were confirmed as genetically distinct forms. We used sequence divergence and paleogeographic history of the Aegean region to reconstruct a biogeographic evolutionary scenario for A. kitaibelii. 相似文献
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Aurélien Miralles Raquel Vasconcelos Ana Perera David J. Harris Salvador Carranza 《Zoologica scripta》2011,40(1):16-44
Miralles, A., Vasconcelos, R., Perera, A., Harris, D. J. & Carranza, S. (2010). An integrative taxonomic revision of the Cape Verdean skinks (Squamata, Scincidae). —Zoologica Scripta, 40, 16–44. A comprehensive taxonomic revision of the Cape Verdean skinks is proposed based on an integrative approach combining (i) a phylogenetic study pooling all the previously published molecular data, (ii) new population genetic analyses using mitochondrial and nuclear data resulting from additional sampling, together with (iii) a morphological study based on an extensive examination of the scalation and colour patterns of 516 live and museum specimens, including most of the types. All Cape Verdean species of skinks presently recognised, formerly regarded as members of the genera Mabuya Fitzinger, 1826 and Macroscincus Bocage, 1873 are considered as members of the Cape Verdean endemic genus Chioninia Gray, 1845. The new phylogeny and networks obtained are congruent with the previously published phylogenetic studies, although suggesting older colonization events (between 11.6 and 0.8 Myr old), and indicate the need for taxonomic changes. Intraspecific diversity has been analysed and points to a very recent expansion of Chioninia delalandii on the southern islands and its introduction on Maio, to a close connection between Chioninia stangeri island populations due to Pleistocene sea‐level falls and to a generally low haplotypic diversity due to the ecological and geological characteristics of the archipelago. Three new consistent morphological synapomorphies supporting two of the four main clades of the genus have been identified. The complex taxonomic status of Euprepes fogoensis O’Shaughnessy, 1874 has been resolved and a lectotype has been designated for this species; Chioninia fogoensis nicolauensis (Schleich, 1987) is elevated to species rank, whereas Chioninia fogoensis antaoensis (Schleich, 1987) is now regarded as a junior subjective synonym of C. fogoensis. Additionally, one new subspecies of Chioninia vaillanti and two of Chioninia spinalis are described (Chioninia vaillanti xanthotis ssp. n., Chioninia spinalis santiagoensis ssp. n. and Chioninia spinalis boavistensis ssp. n.) and a lectotype has been designated for Mabuia spinalis Boulenger, 1906. Finally, an identification key for the Chioninia species is presented. 相似文献
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Chris T. McAllister Donald W. Duszynski Robert N. Fisher Christopher C. Austin 《Systematic parasitology》2013,86(1):53-57
A new species of Eimeria Schneider, 1875 from rainbow skinks, Carlia ailanpalai Zug and Carlia eothen Zug is described from specimens collected in Papua New Guinea (PNG). Oöcysts of Eimeria zugi n. sp. from one of one (100%) C. eothen are ellipsoidal to cylindroidal, with a smooth, colourless, bi-layered wall, measure 25.1 × 15.5 μm and have a length/width ratio of 1.6. The micropyle and the oöcyst residuum are absent, but a polar granule is present. The sporocysts are ovoidal to ellipsoidal and 10.3 × 7.1 μm in size and do not contain Stieda, sub-Stieda or para-Stieda bodies; and the sporocyst residuum is composed of a compact mass of large globules. The sporozoites are elongate, 12.8 × 2.9 μm in size, and contain anterior and posterior refractile bodies with a nucleus between them. This is the ninth species of coccidium described from skinks from PNG, and the new species described herein is apparently endemic to the skink genus Carlia (Gray). 相似文献
14.
《亚洲两栖爬行动物研究(英文版)》2015,(3)
A new species of the agamid genus Japalura is described based on 15 specimens from the upper Lancang(Mekong) Valley of eastern Tibet, PR China. Populations of the new species, Japalura vela sp. nov., were previously recognized as J. flaviceps. The new species is morphologically most similar to J. batangensis, J. micangshanensis, J. variegata, and J. zhaoermii, but is distinguished from the four species and all remaining congeners by the following combination of morphological characters: 1) small adult size(SVL 56–69 mm in males, 59–66 mm in females); 2) ratio of tail TAL/SVL 1.85–2.06; 3) ratio of hind limb HLL/SVL 0.72–0.81; 4) T4 S 24 or 25; 5) concealed tympanum; 6) transverse gular fold present; 7) gular pouch present; 8) axillary fold present; 9) a pronounced, continuous, sail-like vertebral crest along length of body in males; 10) ground dorsal coloration black in males; 11) distinct gray transverse streaks on dorsal surface of head; 12) black radiated streaks around eyes; 13) distinct, black vermiculate stripes on ventral surface of head in both sexes; 14) a strongly jagged dorsolateral stripe from neck to base of tail on each side of vertebral crest in males; and 15) absence of gular spots in both sexes. General distribution patterns of the genus in the Hengduan Mountains region are also discussed. 相似文献
15.
During the wet season of 1999–2000, we studied the effects of the hydroperiod and other physical and chemical variables on planktonic copepod communities from six stations in Everglades National Park. Two stations were located in a slough (Taylor Slough 1, Taylor Slough 2) and four stations in the marl prairies of the Rocky Glades (Long Pine Key 7, Long Pine Key 8, Pa-hay-okee, Chekika). During the period of investigation, Taylor Slough sites had the longest hydroperiods, together with Pa-hay-okee, which is located near the eastern edge of Shark River Slough. Long Pine Key 7 and Long Pine Key 8 had the shortest hydroperiods, and Chekika had an intermediate hydroperiod. The pineland edge sites in the southern Rocky Glades (Long Pine Key) had higher numbers of individuals, and high percentages of larval stages, especially at the end of the wet season. The pineland ecotone is morphologically very heterogeneous, with solution holes in the limestone bedrock that provide below-ground refugia when there is no water on the marsh surface. The slough stations had the lowest numbers of individuals, as well as Chekika in the Rocky Glades, probably as a consequence of the altered water quality and hydropatterns caused by water management structures and operations We collected two species of calanoids, 18 cyclopoids, and three harpacticoids. The most abundant species were Acanthocyclops robustus, Tropocyclops prasinus mexicanus, Arctodiaptomus floridanus, Mesocyclops americanus, Macrocyclops albidus, Osphranticum labronectum, Microcyclops varicans, Microcyclops rubellus, Eucyclops conrowae, and Mesocyclops edax. Of these species, T. prasinus mexicanus and A. floridanus seemed to be adapted to short-hydroperiod habitats, M. rubellus and M. varicans to longer hydroperiod habitats, and E. conrowae to high conductivity habitats. Acanthocyclops robustus, M. albidus, and O. labronectum were dominant regardless of hydroperiod. As regards the temporal distribution, A. robustus was abundant throughout the entire wet season, M. edax, M. rubellus, M. americanus and M. varicans were most abundant in mid-wet season, in September–October, and T. prasinus mexicanus, M. albidus, and E. conrowae were abundant late in the wet season, in winter. The two calanoids only slightly overlapped in time: A. floridanus was abundant at the beginning of the wet season, in July–August, and O. labronectum was abundant at the end of the wet season, in December. 相似文献
16.
Bo CAI Xiang JI Yingyong WANG Dingqi RAO Song HUANG Yuezhao WANG Zhaobin SONG Xianguang GUO Jianping JIANG 《亚洲两栖爬行动物研究(英文版)》2022,(1):64-74,后插1-后插34,封3
From the perspectives of biodiversity conservation and management,there is an urgent need to have at hand current synopses of classification and distributions o... 相似文献
17.
Raillietnema nanus n. sp. from the intestines of the skink Carlia mysi (Scincidae) from Morobe Province, Paupa New Guinea, is described and illustrated. It is the 23rd species assigned to the genus and first species of Raillietnema to be reported from the Australian biogeographical realm. It is the ninth species with a lizard type host and is distinguished from other species by its short body length, small egg size, and number of caudal papillae in the male. An initial parasite list of R. nanus and the nematode Physalopteroides milnensis is established for C. mysi. 相似文献
18.
Jörn Köhler Miguel Vences Martina Erbacher Frank Glaw 《Organisms Diversity & Evolution》2010,10(2):147-159
We report on the rediscovery of two limbless scincid species, Paracontias rothschildi Mocquard, 1905 and Paracontias minimus (Mocquard, 1906), after more than a century. The two species were found in syntopy in sandy soils of Forêt d’Orangea, Antsiranana
Province, northern Madagascar, which probably constitutes the respective type locality and confirms the species’ Malagasy
origin. Both taxa are redescribed based on newly collected material, and compared to other Malagasy species. In addition,
Paracontias fasika n. sp. is described from the same locality and habitat. We discuss the taxonomy and origin of all three species and provide
preliminary data on their natural history. Molecular relationships among seven Paracontias species are compared to external morphological characters formerly used in skink systematics. Our results indicate that morphology
in fossorial skinks is well suited to distinguish species, but is of rather limited value to elucidate phylogenetic relationships.
Similarities between these skinks in external characters apparently are the result of convergent evolution due to parallel
selective pressures. 相似文献
19.
Skinks are the largest family of lizards and are found worldwide in a diversity of habitats. One of the larger and more poorly studied groups of skinks includes members of the subfamily Scincinae distributed in sub-Saharan Africa. Sub-Saharan African scincines are one of the many groups of lizards that show limb reduction and loss, and the genus Scelotes offers an excellent opportunity to look at limb loss in a phylogenetic context. Phylogenetic relationships were reconstructed for a total of 52 taxa representing all subfamilies of skinks as well as other Autarchoglossan families using sequence from six gene regions including; 12S, 16S, and cytochrome b (mitochondrial), as well as alpha-Enolase, 18S, and C-mos (nuclear). The family Scincidae is recovered as monophyletic and is the sister taxon to a (Cordylidae+Xantusiidae) clade. Within skinks the subfamily Acontinae is monophyletic and sister group to all remaining skinks. There is no support for the monophyly of the subfamilies Lygosominae and Scincinae, but sub-Saharan African scincines+Feylinia form a well supported monophyletic group. The monophyly of Scelotes is confirmed, and support is found for two geographic groups within the genus. Reconstructions of ancestral states for limb and digital characters show limited support for the reversal or gain of both digits and limbs, but conservative interpretation of the results suggest that limb loss is common, occurring multiple times throughout evolutionary history, and is most likely not reversible. 相似文献
20.
In the scincid lizard Chalcides chalcides, females ovulate small ova and supply most of the nutrients for development by placental means. The yolk is enveloped precocially by extraembryonic ectoderm and endoderm during the gastrula stage, establishing a simple bilaminar yolk sac placenta. The shell membrane begins to degenerate at this time, resulting in apposition of extraembryonic and maternal tissues. A true chorioplacenta has developed by the early pharyngula stage, as has a choriovitelline placenta and the first stages of an omphaloplacenta. Although the choriovitelline membrane disappears rapidly, the omphaloplacenta spreads to occupy the entire abembryonic pole. The yolk cleft is not confluent with the exocoelom, and no omphalallantoic placenta develops. By the limb-bud stage, an allantoplacenta has been established, with a mesometrial placentome composed of interdigitating ridges of chorioallantois and uterine mucosa. The discovery of five distinct placental arrangements in this species, three of which are transitory and two of which have not previously been recorded in reptiles, emphasizes the need for accounts that specify ontogenetic stages and the precise identity and composition of squamate placental membranes. Contrary to previous interpretations, the pattern of extraembryonic membrane development in C. chalcides is evolutionarily conservative, despite the presence of a reduced yolk mass and cytological specializations for nutrient transfer. Our observations indicate that substantial placentotrophy can evolve in squamates without major modifications of morphogenetic patterns. J Morphol 232:35–55, 1997. © 1997 Wiley-Liss, Inc. 相似文献