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1.
We provide the first report on the herpetological biodiversity (amphibians and reptiles) of the northern Sierra Madre Mountain Range (Cagayan and Isabela provinces), northeast Luzon Island, Philippines. New data from extensive previously unpublished surveys in the Municipalities of Gonzaga, Gattaran, Lasam, Santa Ana, and Baggao (Cagayan Province), as well as fieldwork in the Municipalities of Cabagan, San Mariano, and Palanan (Isabela Province), combined with all available historical museum records, suggest this region is quite diverse. Our new data indicate that at least 101 species are present (29 amphibians, 30 lizards, 35 snakes, two freshwater turtles, three marine turtles, and two crocodilians) and now represented with well-documented records and/or voucher specimens, confirmed in institutional biodiversity repositories. A high percentage of Philippine endemic species constitute the local fauna (approximately 70%). The results of this and other recent studies signify that the herpetological diversity of the northern Philippines is far more diverse than previously imagined. Thirty-eight percent of our recorded species are associated with unresolved taxonomic issues (suspected new species or species complexes in need of taxonomic partitioning). This suggests that despite past and present efforts to comprehensively characterize the fauna, the herpetological biodiversity of the northern Philippines is still substantially underestimated and warranting of further study.  相似文献   

2.
Larval (5th-final instar) drift patterns of five species of black flies (Prosimulium mixtum, Stegopterna mutata, Simulium tuberosum FG, S. vittatum IIIL-1, and S. vittatum IS-7) were analyzed. The diel drift patterns were not species-specific, but consistently exhibited a marked increase after sunset, preceded by a period of minimal drift. The drift minimum generally occurred during or shortly after the period of maximum water temperature. Larvae showed significantly more nocturnal than diurnal drift. Pupal drift was attributed to accidental detachment from the substrate. Adult drift was over 90% diurnal and usually composed primarily of teneral individuals. Upstream larval movements of the S. vittatum and S. tuberosum complexes were each less than 6.5% of the total upstream and downstream larval movements. The proportion of parasitized larvae of the S. vittatum and S. tuberosum complexes was generally higher in the benthos than in the drift. Based in part on data included in a thesis submitted by the senior author to The Pennsylvania State University in partial fulfillment of the requirements for the Ph. D. degree.  相似文献   

3.
We explored macroinvertebrate size-differential drift in the lower Mississippi River (a 9th order system). Because this river system is highly turbid, we hypothesized that visually-dependent vertebrate predators feeding on drifting organisms would be at a disadvantage. Thus, size-differential drift should not occur. For one 24-hour period in both January and April, six drift nets were used to sample surface drift. Nets were emptied once every four hours. Individual intra-ocular distances of three macroinvertebrate species (Hydropsyche orris: Trichoptera, Hexagenia limbata: Ephemeroptera, Macrobrachium ohione: Crustacea) were measured. Percentages of size classes in the drift were determined. In both months, large individuals of H. orris and H. limbata were prevalent in the nocturnal but scarce in the diurnal drift. In January, large M. ohione drifted regardless of time. In April, large M. ohione predominated the nocturnal drift. Our results could not be attributed solely to vertebrate predator avoidance. Other mechanisms such as diel microhabitat migration and current velocity may have accounted for the results.  相似文献   

4.
Abstract

Desired family size and contraceptive behavior of 986 ever‐married women aged 15–54 from Northern Mindanao, the Philippines, are described. Using the Dow and Werner typology of demographic and contraceptive patterns, it was found that a majority of the women were traditional in their demographic attitude and contraceptive behavior. A substantial proportion of the women desired medium to large families. Inconsistency in attitude and behavior was also manifested by women who desired small families but have never used efficient family planning methods. Sociodemographic characteristics of these women are described. A majority of the women who have never used efficient contraception also never practiced family planning. Rhythm was the primary method of birth control among demographic innovators and traditionals who have ever used inefficient methods; the pill was popular among contraceptive innovators and the moderns. A considerable proportion of the demographic innovators and the traditionals were not currently using any family planning method; a lesser proportion of contraceptive innovators and moderns were also not using birth control methods. Relevance of the findings to family planning programs is pointed out. Recommendations are given.  相似文献   

5.
The present paper studies the evolutionary process operating on prehistoric groups from the Azapa valley and coast (northern Chile). The sample consists of 237 crania from the Archaic Late, Early Intermediate, Middle, Late Intermediate, and Late periods. Six metric variables were used, which were transformed to eliminate the special environmental component and to increase the proportion of genetic variance. Population structure was assessed using a method based on quantitative genetic theory, which predicts a lineal relationship between average within-group phenotypic variance and group distance to the population centroid. Results indicate that 17.5% of the total variance accounts for special environmental variance. An excess in extraregional genetic flow is observed in the population corresponding to the Early Intermediate period in the valley. A reduced differentiation is observed between Archaic and Early Intermediate coastal groups, as well as between the latter and the inhabitants of the valley in the same period. Genetic differences between both areas increased substantially since the Middle period. Evidence indicates that long-range gene flow was lower on the coast than in the valley, the lowest estimated Fst being 0.0199 for the total population (coast and valley), 0.0111 for the coastal population, and 0.0057 for the valley. Results are discussed in terms of regional archeological and ethnohistorical evidence, and a microevolutionary model is presented to account for the biological history of the population.  相似文献   

6.
C E Tan  J A Ballweg 《Social biology》1984,31(3-4):232-242
Desired family size and contraceptive behavior of 986 ever-married women aged 15-54 from Northern Mindanao, the Philippines, are described. Using the Dow and Werner typology of demographic and contraceptive patterns, it was found that a majority of the women were traditional in their demographic attitude and contraceptive behavior. A substantial proportion of the women desired medium to large families. In consistency in attitude and behavior was also manifested by women who desired small families but have never used efficient family planning methods. Sociodemographic characteristics of these women are described. A majority of the women who have never used efficient contraception also never practiced family planning. Rhythm was the primary method of birth control among demographic innovators and traditionals who have ever used inefficient methods; the pill was popular among contraceptive innovators and moderns. A considerable proportion of the demographic innovators and the traditionals were not currently using any family planning method; a lesser proportion of contraceptive innovators and moderns were also not using birth control methods. Relevance of the findings to family planning programs is pointed out. Recommendations are given. Motivation for a small family is a prerequisite for a successful family planning program. Without motivation, what family planning programs do is reduce the number of unwanted births. Family planning programs should reach out to those who are sufficiently motivated to have small families but have never used efficient family planning methods. A major finding of this research is that a majority of the women who never used efficient contraception also never used inefficient or traditional methods. Efforts should be made to change this. Additionally, efforts should be made to bring those modern and contraceptive innovators who had stopped using any family planning method to practice contraception again.  相似文献   

7.
Sixty-one species of grassflies (Diptera, Chloropidae) have been found in the meadows in the middle Lena valley, Central Yakutia. Differences between the grassfly taxocenoses of different parts of the valley depend on specific features of a particular plant community. The dominant and subdominant chloropid species are distinguished. The differences of the riparian fauna from the complexes inhabiting the alases in Yakutia are shown. Six species of grassflies are recorded for Yakutia for the first time, all of them belonging to the subfamily Oscinellinae: Polyodaspis ruficornis Macquart, Tricimba cincta Meigen, Aphanotrigonum trilineatum Meigen, Trachysiphonella scutellata v. Roser, Rhopalopterum anthracinum Meigen, and Rh. fasciolum Meigen  相似文献   

8.
Although invertebrate drift is an important ecological process in lotic ecosystems, very little is known about it in Kenyan rivers. The primary aim of this study was to investigate the effect of driftnet mesh size and exposure duration on drift density in 2017. Drift samples were dominated by Chironomidae, Baetidae, Simuliidae, Caenidae and Culicidae. The 100 µm mesh driftnet had the highest mean invertebrate density, followed by the 250 µm and 500 µm nets. Invertebrate drift densities decreased with increased exposure time. This study demonstrates that sampler mesh size and exposure time should be taken into account when characterising invertebrate drift in streams. Future studies should consider sampling different biotopes and during different seasons.  相似文献   

9.
Insect drift on shore of lakes and seas is a relatively common phenomenon although apparently not frequently reported in the literature. Here we review the worldwide occurrence of insect drift with emphasis on Heteroptera, and speculate on possible causes to explain such phenomenon. The dramatic drift of millions of specimens of the pentatomid Mayrinia curvidens (Mayr) on the shore of the southern coast of the Atlantic ocean in Brazil is reported for the first time. This drift, previously observed to occur in the mid 70s on the coast of Paraná state with minor intensity (A.R. Panizzi, unpublished) was again observed on January 2006 along the Atlantic coast of Paraná (latitude 25 masculine 45 S), where an estimated population of 16 to 18 million of dead specimens of the bug were observed forming a windrow for at least 15 km along the ocean shore. The circumstances of such event are analyzed in detail considering meteorological data and the possible build up of populations of the bug on cultivated and non-cultivated host plants along the coast of the states of Paraná and Santa Catarina.  相似文献   

10.
In 2004 and 2005, we conducted a survey of the small mammals on Mt. Tapulao (=Mt. High Peak, 2037 m) in the Zambales Mountains, Luzon Island, Philippines in order to obtain the first information on the mammals of this newly discovered center of endemism. We also tested two hypotheses regarding the relationship of species richness with elevation and the impact of alien species on native mammals. The survey covered five localities representing habitats from regenerating lowland rain forest at 860 m to mossy rain forest near the peak at 2024 m. We recorded 11 species, including 1 native shrew, 1 alien shrew, 8 native rodents, and 1 alien rodent. Two species of Apomys and one species of Rhynchomys are endemic to Zambales; this establishes the Zambales Mountains as a significant center of mammalian endemism. Species richness of native small mammals increased with elevation, from five species in the lowlands at 925 m to seven species in mossy forest at 2024 m; total relative abundance of native small mammals increased from 925 to 1690 m, then declined at 2024 m. Alien small mammals were restricted to highly disturbed areas. Our results support the prediction that maximum species richness of small mammals would occur in lower mossy forest near the peak, not near the center of the gradient. Our results also support the hypothesis that when a diverse community of native Philippine small mammals is present in either old-growth or disturbed forest habitat, “invasive” alien species are unable to penetrate and maintain significant populations in forest.  相似文献   

11.
Finston T 《Molecular ecology》2002,11(10):1931-1946
Samples from 83 populations of salt lake Ostracods belonging to the genus Mytilocypris were collected from 74 saline lakes and ponds in the semi-arid regions of Australia. These populations were examined for variation at six polymorphic enzyme loci to diagnose breeding systems and to measure population structure, to investigate relative levels of gene flow in species with differing distributions and hence different presumed dispersal capabilities. Despite the occurrence of some populations in disjunct, peripheral, and recent ephemeral habitats, all populations of each species were found to reproduce sexually. Gene flow does occur on a local basis and appears to be facilitated by occupation in the same drainage basin for some species. There was considerable gene pool fragmentation among peripheral populations of four of the five species. Only one species, M. mytiloides, was relatively homogeneous across its range. It may be that gene flow is non-existent into peripheral populations because of poor dispersal abilities, or it may not be frequent enough to overcome local selective pressures. Regardless of these possibilities, the observed gene pool fragmentation has implications for allopatric speciation.  相似文献   

12.
Five species of the subgenus Galumna (Galumna) (Acari, Oribatida, Galumnidae) are registered in the Philippine oribatid mite fauna. A new species, Galumna (Galumna) makilingensis sp. n., is described; it is most similar morphologically to Galumna (Galumna) tokyoensis Aoki, 1966, but differs from the latter by the morphology of porose areas Aa and Ap, rostral setae, and length of interlamellar setae. Three species, Galumna (Galumna) crenata Deb & Raychaudhuri, 1975, Galumna (Galumna) cf. exigua Sellnick, 1925 and Galumna (Galumna) khoii Mahunka, 1989, are recorded in the Philippines for the first time. The species Galumna (Galumna) crenata is redescribed. An identification key to the Philippine species of Galumna (Galumna) is given.  相似文献   

13.
The mariculture of eucheumatoids (species of Kappaphycus and Eucheuma) in the Philippines has had a long history, dating back to the 1970s. Over this period, a number of varieties have been brought into domestication; some are now widely distributed and farmed in various regions of the country, but a significant number appear to have a more restricted distribution and are farmed only in certain areas. The taxonomy of many of these seaweed cultivars and their phylogenetic relationships still remain to be resolved at the specific and subspecific levels. In this study, two mitochondrial DNA markers, COI-5P region and cox2-3 intergenic spacer, were used to assess the genetic diversity of the farmed varieties and a few specimens collected from the wild. Analysis using haplotype networks revealed several new haplotypes for K. alvarezii, K. malesianus and K. striatus, mainly from specimens collected from eastern and southwestern regions of the Philippines. The inferred phylogenetic relationships based on both mtDNA markers resolved the identity of all the materials used in the study at the species level. We present molecular evidence that K. malesianus, in addition to K. alvarezii, K. cottonii, K. inermis, K. procrusteanus and K. striatus (and, hence, all currently recognized species of Kappaphycus) occurs in the Philippines. Collectively, these observations suggest that the Philippine archipelago has richer genetic diversity of farmed and wild Kappaphycus than do the other geographic regions, consistent with the hypothesis that the Philippines is, or is part of, the centre of Kappaphycus biodiversity in the world. These findings also reveal an untapped diversity that can potentially be exploited for improving the commercial production of these carrageenophytes.  相似文献   

14.
Background and AimsHybridization is an important evolutionary process that can have a significant impact on natural plant populations. Eucalyptus species are well known for weak reproductive barriers and extensive hybridization within subgenera, but there is little knowledge of whether patterns of hybridization differ among subgenera. Here, we examine eucalypts of Western Australia’s Stirling Range to investigate how patterns of hybridization are associated with landscape and taxon age between the two largest Eucalyptus subgenera: Eucalyptus and Symphyomyrtus. In doing so, we tested a hypothesis of OCBIL (old, climatically buffered, infertile landscape) theory that predicts reduced hybridization on older landscapes.MethodsSingle nucleotide polymorphism markers were applied to confirm the hybrid status, parentage and genetic structure of five suspected hybrid combinations for subg. Eucalyptus and three combinations for subg. Symphyomyrtus.Key ResultsEvidence of hybridization was found in all combinations, and parental taxa were identified for most combinations. The older parental taxa assessed within subg. Eucalyptus, which are widespread on old landscapes, were identified as well-defined genetic entities and all hybrids were exclusively F1 hybrids. In addition, many combinations showed evidence of clonality, suggesting that the large number of hybrids recorded from some combinations is the result of long-term clonal spread following a few hybridization events rather than frequent hybridization. In contrast, the species in subg. Symphyomyrtus, which typically occur on younger landscapes and are more recently evolved, showed less distinction among parental taxa, and where hybridization was detected, there were high levels of introgression.ConclusionsReduced hybridization in subg. Eucalyptus relative to extensive hybridization in subg. Symphyomyrtus affirmed the hypothesis of reduced hybridization on OCBILs and demonstrate that clade divergence times, landscape age and clonality are important drivers of differing patterns of speciation and hybridization in Eucalyptus.  相似文献   

15.
Despite accumulating data on microbial biogeographic patterns in terrestrial and aquatic environments, we still lack a comprehensive understanding of how these patterns establish, in particular in ocean basins. Here we show the relative significance of the ecological mechanisms selection, dispersal and drift for shaping the composition of microbial communities in the Pacific Ocean over a transect of 12,400 km between subantarctic and subarctic regions. In the epipelagic, homogeneous selection contributes 50–60% and drift least to the three mechanism for the assembly of prokaryotic communities whereas in the upper mesopelagic, drift is relatively most important for the particle-associated subcommunities. Temperature is important for the relative significance of homogeneous selection and dispersal limitation for community assembly. The relative significance of both mechanisms was inverted with increasing temperature difference along the transect. For eukaryotes >8 µm, homogeneous selection is also the most important mechanisms at two epipelagic depths whereas at all other depths drift is predominant. As species interactions are essential for structuring microbial communities we further analyzed co-occurrence-based community metrics to assess biogeographic patterns over the transect. These interaction-adjusted indices explained much better variations in microbial community composition as a function of abiotic and biotic variables than compositional or phylogenetic distance measures like Bray–Curtis or UniFrac. Our analyses are important to better understand assembly processes of microbial communities in the upper layers of the largest ocean and how they adapt to effectively perform in global biogeochemical processes. Similar principles presumably act upon microbial community assembly in other ocean basins.Subject terms: Microbial ecology, Microbiology  相似文献   

16.
? Premise of the Study: Studies of the geographic patterns of genetic variation can give important insights into the past population structure of species. Our study species, Taxodium distichum L. (bald-cypress), prefers riparian and wetland habitats and is widely distributed in southeastern North America and Mexico. We compared the genetic variation of T. distichum with that of its close relative, Cryptomeria japonica, which is endemic to Japan. ? Methods: Nucleotide polymorphisms of T. distichum in the lower Mississippi River alluvial valley, USA, were examined at 10 nuclear loci. ? Key Results: The average nucleotide diversity at silent sites, π(sil), across the 10 loci in T. distichum was higher than that of C. japonica (π(sil) = 0.00732 and 0.00322, respectively). In T. distichum, Tajima's D values were each negative at 9 out of 10 loci, which suggests a recent population expansion. Maximum-likelihood and Bayesian estimations of the exponential population growth rate (g) of T. distichum populations indicated that this species had expanded approximately at the rate of 1.7-1.0 × 10(-6) per year in the past. ? Conclusions: Taxodium distichum had significantly higher nucleotide variation than C. japonica, and its patterns of polymorphism contrasted strikingly with those of the latter, which previously has been inferred to have experienced a reduction in population size.  相似文献   

17.
18.
Pyropia acanthophora is a foliose Bangiales with widely known endemic populations in Indo-Pacific region. This alga has expanded its range recently as a consequence of introduction. In an attempt to explore the genetic diversity of Py. acanthophora within the Philippines and the impact of the introduction of the species from elsewhere, an examination of molecular differentiation and distribution was undertaken using the mitochondrial COI-5P and plastid rbcL gene sequences. The results revealed that the populations of Py. acanthophora in the Philippines exhibited high haplotypic and genetic diversities, and were found to be distinct from those previously reported as conspecific populations found in Taiwan, India, Japan, Hawaii, and from those introduced populations from Brazil. The network analyses as inferred from rbcL and from the combined COI-5P and rbcL genes showed evidence that the Philippine populations of Py. acanthophora exhibited a chaotic patchiness pattern characterized by a population with highly site-exclusive haplotypes, wide genetic variability and lack of local geographic patterns. The distribution of Py. acanthophora within the Philippines was also found to be greater than what was previously known, ranging from the extreme northwest to extreme northeast mainland Luzon coasts, including Camiguin Is., Cagayan. Understanding the genetic diversity and distribution of Py. acanthophora in the Philippines provides valuable information in relation to the conservation and effective resource management of native populations of Py. acanthophora in the tropical Asian region.  相似文献   

19.
Two separate 1?m2 plots were cleared of algal cover every 3 or 4 wk for 1 yr and each time, one was filled with cleaned, sun-dried coralline rocks. These plots were closely monitored in subsequent months for any sign of Sargassum regrowth. Control plots were also monitored during the same period. New growth was first detected in December in cleared and control plots, 3 months after the start of the reproductive season for Sargassum spp. in the area. New growth was observed in the plots with coralline rocks in January, and only on rocks placed at least 3 months earlier. No new growth was observed in cleared and control plots after June, nor throughout the rest of the experimental period on rocks placed after October. Pre-conditioning of the coralline rocks appeared to be a prerequisite for settling of Sargassum germlings and the importance of timing in laying these rocks for successful colonization of Sargassum spp. is discussed.  相似文献   

20.
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