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1.
I examined seasonal, sex, and interspecific differences in activity time budgest and diets of patas (Erythrocebus patas) and sympatric tantalus monkeys (Cercopithecus aethiops tantalus) on the basis of 5-day data sets collected in three and two different seasons, respectively, by the method of focal animal sampling. The seasons included species-specific mating and birth seasons. As compared with not only the birth season but also conspecific females, both patas resident male and tantalus male spent less time feeding and more time resting, day and night, in their respective mating seasons. Given that day-resting time includes time for vigilance for non-resident males and receptive females, this may reflect that males should minimize time spent feeding to allow maximum participation in other fitness-increasing activities such as mating-relating activities asSchoener (1971) predicted. In both species, the males consumed fruits containing less protein but more calories and showed a high feeding rate to compensate for the shorter time spent feeding in the mating season. In contrast, females consumed protein-rich food types (i.e. animals, protein-rich seeds, leaves, and flowers) in the birth season to meet the high demand for protein due to pregnancy and lactation. Given that the season for males was considered to be not a calendar but a reproductive “season” (i.e. mating or birth season), both sexes of patas spent more time moving and less time day- and night-resting than did the tantalus counterparts irrespective of the “season”. Patas subsisted on fruits, gums, and supplementarily lipid-rich seeds as an energy source and animal matters and protein-rich seeds as a protein source. In contrast, tantalus subsisted on fruits and lipid-rich seeds as energy and flowers and leaves as protein.  相似文献   

2.
Den sharing by conspecific spiny lobsters (aggregation) is modulated by chemical attraction but may confer several, not necessarily mutually exclusive, antipredator byproduct benefits: a “guide effect”, which only benefits the individual attracted to a sheltered conspecific; a “dilution effect”, which reduces per-capita risk of predation simply through aggregation; or active “group defense”. Each potential benefit has a different set of predictors (relationships between aggregation and conspecific or predator densities), but conflicting results could suggest the simultaneous operation of more than one benefit. These predictions were tested for coexisting Panulirus guttatus (a reef-obligate) and Panulirus argus (a temporary reef-dweller) using data collected during 11 surveys on fixed sites over a coral reef in Mexico. P. guttatus greatly outnumbered P. argus, but P. argus showed a greater tendency to aggregate. All three benefits of den sharing operated for the more social P. argus, with “group defense” being of the most benefit for larger individuals, and the “guide” and “dilution” effects for smaller individuals recently immigrating into the reef habitat and sharing dens with larger conspecifics. P. guttatus did not display “group defense” and its aggregations appeared to be modulated by the interplay between attraction and aggressive behaviors. This species relied more on solitary crypticity, especially at larger sizes, but appeared to benefit from a “guide effect” at high conspecific densities. In experimental tanks, each species tended to aggregate when tested separately, but when tested jointly, aggregation among P. guttatus was significantly reduced. The experimental results reflect the differential patterns of aggregation between the fore-reef, where P. guttatus dominated, and the back-reef, where coexistence of both species was greater.  相似文献   

3.
We describe short-term changes in foraging behavior by wild Yakushima macaques (Macaca fuscata yakui),which inhabit a warm-temperate broad—leaved forest on Yakushima Island (30°N, 131°E), Japan. Rapid changes of dietary composition, activity budget, and range use by the monkeys occurred from May to June, apparently associated with changes in the availability of the fruit of Myrica rubraBefore the fruit ripened, monkeys spent less time moving and more time feeding on many species of leaves, which accounted for 40% of feeding time. However, when M. rubrabegan to ripen, they fed intensively on the fruit, which accounted for three-fourths of feeding time,though the activity budget remained unaffected As fiuit of M. rubradecreased,the monkeys fed more on the fruit of other species and on insects, and spent more time moving at higher speeds. There marked shifts in foraging pattern occurred within only two months. In terms of moving cost and dietary quality,Yakushima macaques shifted their foraging pattern according to the availability of M. rubrafrom a “low-cost, low-yield” strategy to a “low-cost, high-yield” strategy, and then to a more costly strategy. The ability to make such rapid shifts in foraging pattern may allow the macaques to effectively use the highly variable food supply within their small range.  相似文献   

4.
Zornia subsessilis, a new species from Serra do Cabral, Minas Gerais State, Brazil, is described and illustrated on the basis of field and herbarium studies. It belongs to Zornia section Zornia of subgenus Zornia and it appears to be restricted to “campo rupestre” (rocky fields) within the “cerrado” biome. This new species is characterized by its sessile to subsessile leaves, fruits with articles 4 to 5 mm long and with bristles up to 3.5 mm long.  相似文献   

5.
Traditional Knowledge and Management of Feijoa (Acca sellowiana) in Southern Brazil. This paper investigates traditional knowledge of the use and management of Acca sellowiana in southern Brazil. Fifty-six informants from three rural communities were assigned to one of four subgroups (“maintainers,” “managers,” “cultivators,” or “users”) based on their responses regarding management and use of A. sellowiana. Traditional knowledge related to use of this species is widespread among rural residents, but traditional knowledge related to management is fragmented depending on whether one uses, manages, or cultivates the species. Knowledge held in rural communities suggests that A. sellowiana could play an expanded role in local economies as well as biodiversity conservation. We suggest that participatory research could stimulate greater local use as well as on-farm conservation of A. sellowiana.  相似文献   

6.
The osteological development of the feeding apparatus was examined in early stage larvae of laboratory-reared seabass,Lates calcarifer. At initial mouth openings 40 hours after hatching, the larvae were equipped with the fundamental elements forming the oral cavity, such as the trabecular roof, the lower branchial and hyoid arches forming the floor, the quadrate and symplectic-hyomandibular cartilages making up the sides, and the maxilla and Meckel's cartilage bordering the jaws. The cleithrum appeared almost simultaneously. The mechanics of creating a negative pressure in the oral cavity, which results in a “sucking” mode of feeding, were elucidated from these elements. During a period from 50–60 to 100–110 hours after initial mouth opening (HAMO), new elements such as the premaxilla and jaw teeth appeared, and the ossification of existing elements started. The new elements apparently enabled the larvae to “grasp” food organisms, in addition to the already existing and increasing sucking ability, from 100–110 HAMO.  相似文献   

7.
Summary This paper examines competition between three VA endophytes places respectively as “inoculant” fungus in an inner compartment (300 ml) below the germinating seed, and as “indigenous” fungus in an outer compartment (900 ml). Previously prepared infested soil was used as source of the endophytes. Inner and outer compartment roots were harvested separately and percentage infection determined for each fungus, using diagnostic anatomical features of each fungus. Changes in colonisation patterns were followed up to 4 and 5 months. Treatments with non-infested soil in the outer compartment were used to compare infectivity and spread of the different endophytes. All three endophytes were able to invade soil already colonised by either of the other two, butGlomus fasciculatum (E3) was more invasive thanGlomus tenue. This pattern appeared to be related to rates of spread of the fungi in the non-infested soil. The pattern was not affected by host, clover or sorghum, or by position, immediately below the seed or in the outer compartment. It seemed that the endophyte in the inner compartment had overriding and persistent effects on plant growth, unrelated to its dominance pattern or share of overall root infection at the later harvests.  相似文献   

8.
The epistatic interaction of alleles at the VRN-H1 and VRN-H2 loci determines vernalization sensitivity in barley. To validate the current molecular model for the two-locus epistasis, we crossed homozygous vernalization-insensitive plants harboring a predicted “winter type” allele at either VRN-H1 (Dicktoo) or VRN-H2 (Oregon Wolfe Barley Dominant), or at both VRN-H (Calicuchima-sib) loci and measured the flowering time of unvernalized F2 progeny under long-day photoperiod. We assessed whether the spring growth habit of Calicuchima-sib is an exception to the two-locus epistatic model or contains novel “spring” alleles at VRN-H1 (HvBM5A) and/or VRN-H2 (ZCCT-H) by determining allele sequence variants at these loci and their effects relative to growth habit. We found that (a) progeny with predicted “winter type” alleles at both VRN-H1 and VRN-H2 alleles exhibited an extremely delayed flowering (i.e. vernalization-sensitive) phenotype in two out of the three F2 populations, (b) sequence flanking the vernalization critical region of HvBM5A intron 1 likely influences degree of vernalization sensitivity, (c) a winter habit is retained when ZCCT-Ha has been deleted, and (d) the ZCCT-H genes have higher levels of allelic polymorphism than other winterhardiness regulatory genes. Our results validate the model explaining the epistatic interaction of VRN-H2 and VRN-H1 under long-day conditions, demonstrate recovery of vernalization-sensitive progeny from crosses of vernalization-insensitive genotypes, show that intron length variation in VRN-H1 may account for a continuum of vernalization sensitivity, and provide molecular markers that are accurate predictors of “winter vs spring type” alleles at the VRN-H loci.  相似文献   

9.
Four flattened Gracilaria species have been reported from Taiwan: G. spinulosa, G. vieillardii, G. textorii and G. punctata, identified based on branching pattern, the presence or absence of spines, and characters that often vary seasonally. Gracilaria spinulosa was originally described from the type locality, Tainan. Species with toothed margins are usually referred to G. “vieillardii”; those with smooth margins to G. “textorii”, and those with smooth margins and dark spots scattered over the blade to G. “punctata”. Molecular analyses show that specimens with marginal teeth cluster in three different groups: a G. “vieillardii” clade, a G. spinulosa clade, and a clade sister to G. spinulosa. An undescribed species comprises the third clade, which is distinguished by its relatively large gonimoblast cells and weakly developed tubular nutritive cells. The three clades can be separated by the character of the tubular nutritive cells, the size of gonimoblast cells and certain vegetative features. Plants with entire margins form a single clade characterized by cystocarps with basal tubular nutritive cells and their absence in the cystocarp cavity. They are nested in the Hydropuntia complex and are referred to as Gracilaria “punctata” here. The records of G. textorii and G. punctata from Taiwan require reinvestigation in comparison with the Japanese species.  相似文献   

10.
R. M. Beach  J. W. Todd 《BioControl》1986,31(3):237-242
Field grown foliage from the resistant soybean [Glycine max (L.) Merrill] breeding line GAT “81–327” and the susceptible cultivar “Ransom” was used to rear unparasitized larvae of the soybean looper (SBL),Pseudoplusia includens (Walker), and larvae parasitized byCopidosoma truncatellum (Dalman). SBL larvae, whether parasitized or not, consumed more foliage when fed “Ransom”. Unparasitized larvae reared on “81–327” had longer developmental times and suffered greater mortality than unparasitized larvae reared on “Ransom”. Parasitization of SBL larvae byC. truncatellum increased total foliage consumption of both soybean lines. Parasitized larvae reared on the resistant “81–327” weighed less and yielded fewer parasitoid adults.
Résumé Des larves dePseudoplusia includens (Walker) parasitées ou non parCopidosoma truncatellum (Dalman) ont été nourries des feuilles de deux lignées de soja [Glycine max (L.) Merrill] l'une, GAT “81–327” résistante et l'autre, “Ransom” sensible. Les larves deP. includens qu'elles soient parasitées ou non consommaient plus de feuillage lorsqu'elles étaient nourries de la lignée “Ransom”. Les larves non parasitées élevées sur “81–327” avaient un cycle de développement beaucoup plus long et un taux de mortalité beaucoup plus élevé que les larves non parasitées élevées comparativement sur feuilles de “Ransom”. Par contre, les larves parasitées manifestaient une consommation accrue du feuillage des deux lignées de soja. Les larves parasitées élevées sur les feuilles de la variété résistante GAT “81–327” pesaient moins et produisaient moins également de parasites adultes.
  相似文献   

11.
A first case of subsociality is reported for the genus Latrodectus. Individuals were found sharing the same web and feeding together. In captivity they showed mutual tolerance and communal feeding. This finding is remarkable for two reasons. First, widow spiders, even compared with other spiders, are famously aggressive and cannibalistic so that social behavior in the genus was unexpected. Second, the genus nests outside the “Anelosimus + lost colulus” clade where all the other social theridiids are found.  相似文献   

12.
Predatory behaviors of Neoseiulus californicus (McGregor) and Galendromus helveolus (Chant) attacking Oligonychus perseae Tuttle, Baker and Abbatiello on avocado leaves were videotaped and analyzed. Behaviors were recorded for “fresh” predators that were used ≤ 48 hr post receipt from a commercial insectary and “cold stored” predators that were maintained at 12°C for ≈ 14 days. Fresh and cold stored G. helveolus were observed to attack O. perseae only after invading webbed nests. Conversely, fresh and cold stored N. californicus employed three different modes of predatory attack: (1) intercepting and attacking migrant O. perseae outside of web nests; (2) attacking prey through nest webbing; or (3) invading and attacking O. perseae inside nests. Predatory efficacy of both N. californicus and G. helveolus was reduced following cold storage, as both species engaged in certain predatory behaviors less frequently in comparison to predators that were not stored at low temperatures. Our observed results for N. californicus and G. helveolus attacking O. perseae are interpreted in relation to the chaetotaxy hypothesis, which proposes that phytoseiid invasion efficiency and propensity of webbed nests is facilitated by dorsal setal lengths. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

13.
Genetic variation within, and divergence among, populations of the liverwortConocephalum conicum were estimated from the study of 17 populations and 23 putative gene loci. Two additional multilocus genotypes (“T” and “FS”) were detected in Japan, along with the previously reported “J” type. These three multilocus genotypes differed both morphologically and ecologically. All eight populations from western Japan included only the J-type and exhibited low genetic variation within populations: Nei's (1973) average gene diversity (Ĥ)=0.080±0.029. In contrast, co-occurrence of several multilocus genotypes in each population from the Kanto District resulted in much higher levels of genetic variation (Ĥ=0.218±0.037). If the three genotypes are distinguished,Ĥ values are 0.113±0.030 for T-type, 0.107±0.033 for FS-type, and 0.083±0.018 for J-type. UsingC. japonicum, which showed low genetic variation (0.014±0.010) as an outgroup, each genotype formed a monophyletic clade, and the J- and FS-types were more closely related to each other than to the T-type. Populations of western Japan and the Kanto District also differed in the degree of gene diversity among populations, but the reasons for these differences are obscure.  相似文献   

14.
The future status of sharks is an issue of widespread conservation concern due to declines in many species in the face of high levels of exploitation to satisfy market demands for products, especially fins. Substantial declines in the large-bodied hammerhead sharks, Sphyrna lewini, S. mokarran and S. zygaena, even in regions where some management occurs, indicate that informed conservation measures are warranted for these circumglobally distributed species. Despite the importance of assessing shark catch and trade on a species-specific basis to detect potential overexploitation of individual species, achieving this goal for hammerheads has proven elusive due to difficulties in identification of their products. Here, we present the development and application of a diagnostic, streamlined, five-primer multiplex polymerase chain reaction assay utilizing species-specific primers based on nuclear ribosomal ITS2 for the three hammerhead species throughout their global distribution. Application of this assay to investigations of the fin market confirmed the presence of hammerhead fins in the international trade. A study of the world’s largest fin market in Hong Kong revealed a high concordance between specific Chinese-name trade categories and fins from these three species (“Bai Chun” with S. lewini, “Gui Chun” with S. zygaena and “Gu Pian” with S.␣mokarran), and clear species preferences. This concordance information allows the use of market records for monitoring species-specific trends in trade and exploitation rates. The assay is also proving useful for identification of shark body parts in U.S. fisheries law-enforcement activities. Screening of morphologically identified “ S. lewini” from globally distributed areas using this assay with subsequent whole ITS2 sequencing suggests a cryptic species closely related to S. lewini occurs off the SE USA coast.  相似文献   

15.
Three cassava clones (SOM-1, “05”, and “50”) were cultured in vitro on MS medium plus sucrose (30 g L−1) and myo-inositol (100 mg L−1) without plant growth regulators and with additions of 0 (control), 0.5, 1, 1.5, 2, 2.5, and 3 g L−1 NaCl to test their salt tolerance. The same cassava clones were cultivated in greenhouse conditions on a sandy soil substratum and irrigated with 20% strength Hoagland solution, and additions of 0, 4, and 8 g L−1 of NaCl. Salinity negatively affected the survival, development, leaf water content, and mineral composition (mainly by accumulation of Cl and Na) of both in vitro and ex vitro plants, but with different intensity in each clone. In both conditions of culture (in vitro and ex vitro) clone SOM-1, from a desert arid saline zone of Somalia, was the most tolerant and clone “05”, from a rainy region of Ivory Coast, the most sensitive. Clone “50” tolerance to in vitro salt treatments, although lower, was not significantly different from that of SOM-1 but the ex vitro response was similar to “05”. In general, there was a correlation between in vitro and ex vitro behavior of the cassava plant regarding salt tolerance, which would allow the in vitro culture method to be used for selection of salt-tolerant plants of this crop.  相似文献   

16.
Tao N  Hu Z  Liu Q  Xu J  Cheng Y  Guo L  Guo W  Deng X 《Plant cell reports》2007,26(6):837-843
Citrus is an important fruit crop as regards accumulation of carotenoids. In plant carotenoid biosynthesis, phytoene synthase gene (Psy) plays a key role in catalyzing the head-to-head condensation of geranylgeranyl diphosphate molecules to produce colorless phytoene. In the present paper, we reported the phytoene contents determination and characterization of Psy during fruit ripening of “Washington” navel orange and its red-fleshed mutant “Cara Cara”. Results showed that phytoene was exclusively accumulated in peel and pulp of “Cara Cara”. Although phytoene was observed accumulating with fruit ripening of “Cara Cara”, the contents in pulp were 10 times higher than those in peel. The isolated two Psy cDNAs were both 1520 bp in full length, containing 436 deduced amino acid residues, with a different amino acid at 412th. Genomic hybridization results showed that one or two copies might be present in “Cara Cara” and “Washington” genomes. During “Cara Cara” and “Washington” fruit coloration, expression of Psy was observed to be up-regulated, as revealed by tissue specific profiles in the flavedo, albedo, segment membrane and juice sacs. However, Psy expression in albedo of “Cara Cara” was higher than that in “Washington”, as evidenced by phytoene accumulation in the peel.  相似文献   

17.
The chlorinated insecticide γ-hexachlorocyclohexane (γ-HCH) is sequentially metabolized by the products of linA, linB, linC, linD, linE, and linF genes to β-ketoadipate, which is subsequently mineralized. Two or more copies of these genes are present in the bacterium Pseudomonas aeruginosa ITRC-5 that was isolated earlier by selective enrichment on technical-HCH. At least one copy of linA, linB, linC, linD, and possibly linE is lost from ITRC-5 upon its growth on γ-HCH. All the lin genes, however, are lost when the bacterium was grown in Luria–Bertani (LB) medium. The loss of lin genes is accompanied with the loss/rearrangement of insertion sequence IS6100 genes. Concomitant to the loss of lin genes, the degradation of HCH-isomers by “γ-HCH grown cells” is slower, when compared with “technical-HCH grown cells”, and is completely lost by “LB-grown cells”. The selective loss of lin genes during different growth conditions has not been reported before and is expected to help in understanding the dynamism of degradative genes.  相似文献   

18.
The efficiency of food exploitation correlates positively with the extent of dietary specialization. Neotropical nectar-feeding bats (Glossophaginae) have one of the most specialized diets among mammals, as floral nectar constitutes a sugar-rich and highly digestible but protein and fiber depleted food source. However, dietary constraints, such as a temporary scarcity of nectar, or protein demands may sometimes require the uptake of alternative food items. We investigated the influence of a diet switch from nectar to fruit on intestinal morphology, body mass, and energy budget in the nectar-feeding bat Glossophaga commissarisi and quantified feeding efficiency. We hypothesized that these nectar specialists depend on a constant supply of nectar, if they were lacking the ability for morphological and physiological plasticity in response to a fiber-rich diet. Although capable of harvesting infructescences of Piper hispidum, G. commissarisi was less efficient in extracting energy from fruits (48% digestive efficiency of total fruit energy content) than from nectar (c. 99% digestive efficiency). The intestinal morphology and organ masses did not change after bats were switched from nectar to fruits. Captive bats exhibited lower daily energy expenditures and flight activity when feeding on fruits than during nectarivory. Possibly, this may have been a deliberate regulation to balance reduced feeding efficiency, or simply the consequence of extended digestive pauses. The low digestibility of Piper, in combination with slow digestion and the bats’ inability for morphological and physiological plasticity may cause nectar-feeders to reduce their maximum energy expenditure when feeding on fruits. We argue that although fruits may substitute for nectar, they may cause restricted maximum energy assimilation compared with nectar.  相似文献   

19.
A seaweed with the local name “endong” is a rare eucheumoid variety that has recently been farmed in Tawi-Tawi, southern Philippines. Local farmers describe it as “eel-like” because of its long, slender and smooth thalli. Being somewhat similar in appearance to the dominantly farmed seaweed “tambalang” (Kappaphycus alvarezii var. tambalangii), farmers mix their harvests of “endong” with those of “tambalang”. We analyzed the hydrocolloid extract from “endong” using spectroscopic and chemical techniques. The extract’s infrared and nuclear magnetic resonance (1H and 13C) spectra, and sulfate and 3,6-anhydrogalactose contents revealed carrageenan of the iota-type, similar to extracts from another farmed species, Eucheuma denticulatum. This result implies that “endong” carrageenan exhibits physico-chemical properties different from those of kappa-carrageenan of “tambalang”. The findings of this study are of significance to the seaweed industry, as carrageenan quality problems could potentially arise from a mixed harvest. Seaweed farmers are advised to separate their harvests of “endong” and “tambalang”. Presented at the 19th International Seaweed Symposium, Kobe, Japan  相似文献   

20.
The systematics and taxonomy of Kappaphycus and Eucheuma (Solieriaceae) is confused and difficult due to morphological plasticity, lack of adequate characters to identify species and commercial names of convenience. These taxa are geographically widely dispersed through cultivation. Commercial, wild and herbarium sources were analysed; molecular markers provided insights into taxonomy and genetic variation, and where sources of genetic variation may be located. The mitochondrial cox2-3 and plastidal RuBisCo spacers were sequenced. There is a clear genetic distinction between K. alvarezii (“cottonii”) and K. striatum (“sacol”) samples. Kappaphycus alvarezii from Hawaii and some samples from Africa are also genetically distinct. Our data also show that all currently cultivated K. alvarezii from all over the world have a similar mitochondrial haplotype. Within Eucheuma denticulatum (“spinosum”) most African samples are again genetically distinct. Our data also suggest that currently cultivated E. denticulatum may have been “domesticated” several times, whereas this is not evident for the cultivated K. alvarezii. The present markers used do not distinguish all the morpho-types known in cultivation (e.g. var. tambalang, “giant” type) but do suggest that these markers may be useful to assess introductions and species identification in samples.  相似文献   

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