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1.
Photo-identification and conventional tagging were used to estimate population size and structure of the whale shark Rhincodon typus near Holbox Island, Mexico. From 2005 to 2008, photographs of spot patterns behind the last gill slit and in a lateral view on the left side of each animal were used to identify individuals. Additionally, 578 R. typus were tagged using conventional marker tags. Of these and the 350 R. typus that were identified from 1184 photographs, 65% were male; 27%, female and 8%, indeterminate sex. Photographed R. typus ranged in size from 2·5 to 9·5 m total length. Size was bimodal with a large peak at 6 m and a smaller peak at 7 m. Photo-identification showed that there was considerable loss of marker tags. Few of these remained on the animals for more than a year, so that interannual re-sights using tagging could not be used in population modelling. Forty six interannual re-sightings were found in the photographic library; the interval between these re-sightings was typically 1 year. It was estimated that the R. typus aggregation near Holbox Island ranged from 521 to 809 individuals, based on mark-recapture models. From 13 to 33% of R. typus photographed had scars that were attributable to boat strikes. This study provides a baseline for assessing the status of R. typus near Holbox Island. This information is useful to understand drivers of local population size and distribution and potential concerns about increasing effects of tourism on R. typus in this area and for designing better management programmes for R. typus conservation.  相似文献   

2.
This study gives an account of spatial and temporal distribution of whale shark Rhincodon typus catch events in China on the basis of historical records and information obtained from interviews with fishing industry stakeholders. A total of 186 R. typus were recorded with key harvest areas identified as in Hainan and Zhejiang, and the peak catching seasons were May to June and September to October. Aspects of the R. typus trade are discussed, including products, markets and the process. The results suggest that R. typus is increasingly becoming a targeted resource in China as a consequence of fierce competition for large shark fins and an emerging local market for consumption of all body parts. Current obstacles and potential measures for sustainable exploitation and trade of R. typus are discussed.  相似文献   

3.
A phylogenetic analysis of Taiwanese fanged dicroglossine frog, Limnonectes fujianensis (Anura, Ranidae), was conducted to examine its genetic diversification using sequence data from a portion of the mitochondrial DNA (mtDNA) cytochrome b sequences. We collected genetic data from 200 individuals at 23 localities in Taiwan and three localities in China. A neighbor-joining tree of 39 haplotypes revealed two clades in Taiwan and a clade in China, each showing restricted geographical distribution. The pattern of geographical divergence suggests a single invasion into Taiwan. Divergence times between clades were inferred using molecular clock tests. The population relationship of L. fujianensis between Taiwan and mainland China, and the phylogenetic relationships with its congeners, e.g., L. bannaensis, L. fragilis and L. kuhlii, were obtained and discussed.  相似文献   

4.
The 72 most important commercial fish species as well as nine unidentified fish groups representing hundreds of fish species as the major and minor target species caught in waters off Taiwan and the East China Sea were selected from the ‘Fisheries Yearbook Taiwan Area.’ All available published and grey literature as well as the Fish Database of Taiwan and Fishbase websites were thoroughly reviewed for a total of 108 fish species, including 51 out of 72 major and 57 minor target fish species, on their reproductive periods in waters off Taiwan and the East China Sea. The spawning periods from these commercial fish species were then summarized. An imperative adjustment was recommended for the established fishing season closure, i.e. for an earlier start, from April to June, in the southern East China Sea. This suggested correction corresponded with the spawning period of most fishes so as to maximize the protection of spawning cohorts for at least 68 major and minor target fish species, which would account for over 53% of the total fish yield in Taiwanese offshore fisheries.  相似文献   

5.
云南新平哀牢山夜间捕获鸟类的多样性   总被引:1,自引:0,他引:1  
2007-09-05—2007-11-05和2008-09-03—2008-11-07期间,在云南省新平县哀牢山金山丫口用灯光诱捕对秋季夜间迁徙鸟类组成进行了调查。共捕获鸟类129种,7943只,分属于14目23科。雀形目鸟类为网捕主要鸟类,占总网捕数量的58.9%。其中红尾伯劳(Lanius cristatus)、小杜鹃(Cuculus poliocephalus)和红喉歌鸲(Luscinia calliope)3种是该地夜间网捕优势种鸟类,三者数量皆超过网捕鸟类总数的5%。每天夜间20:00—22:00和次日凌晨04:00—06:00是捕获鸟类数量的高峰时段。网捕期间,早期Shannon-Wiener指数和Pielou指数最低,优势指数C最高;中期Shannon-Wiener指数和Pielou指数最高,优势度指数C最低。2008与2007年相比, 优势指数C和G-F指数较低, 但Shannon-Wiener指数和Pielou指数较高。云南省不同“打雀山”夜间捕获鸟类的种类和数量存在差异。地理和气候可能是造成这些差异的主要因素。  相似文献   

6.
Taiwanese aborigines have been deemed the ancestors of Austronesian speakers which are currently distributed throughout two‐thirds of the globe. As such, understanding their genetic distribution and diversity as well as their relationship to mainland Asian groups is important to consolidating the numerous models that have been proposed to explain the dispersal of Austronesian speaking peoples into Oceania. To better understand the role played by the aboriginal Taiwanese in this diaspora, we have analyzed a total of 451 individuals belonging to nine of the tribes currently residing in Taiwan, namely the Ami, Atayal, Bunun, Paiwan, Puyuma, Rukai, Saisiyat, Tsou, and the Yami from Orchid Island off the coast of Taiwan across 15 autosomal short tandem repeat loci. In addition, we have compared the genetic profiles of these tribes to populations from mainland China as well as to collections at key points throughout the Austronesian domain. While our results suggest that Daic populations from Southern China are the likely forefathers of the Taiwanese aborigines, populations within Taiwan show a greater genetic impact on groups at the extremes of the current domain than populations from Indonesia, Mainland, or Southeast Asia lending support to the “Out of Taiwan” hypothesis. We have also observed that specific Taiwanese aboriginal groups (Paiwan, Puyuma, and Saisiyat), and not all tribal populations, have highly influenced genetic distributions of Austronesian populations in the pacific and Madagascar suggesting either an asymmetric migration out of Taiwan or the loss of certain genetic signatures in some of the Taiwanese tribes due to endogamy, isolation, and/or drift. Am J Phys Anthropol 150:551–564, 2013. © 2013 Wiley Periodicals, Inc.  相似文献   

7.
Pathogenic mutations in leucine-rich repeat kinase 2 (LRRK2) cause autosomal-dominant familial Parkinson’s disease (PD). We performed clinical, imaging, and molecular functional studies in one family with the R1441H and six families with the G2385R variants of Lrrk2. To determine the contribution of these variants to familial PD in Taiwanese, we screened 32 Taiwanese or ethnic Chinese patients with familial PD for four pathogenic substitutions (R1441H, I2012T, I2020T, and G2019S) and one susceptibility polymorphism (G2385R). The frequencies of R1441H and G2385R were 3.7% and 22.2%, respectively. G2019S, I2012T, and I2020T were not detected. The clinical phenotypes and [18F]-dopa PET findings for subjects with R1441H or G2385R resembled those of patients with idiopathic PD; however, their lymphoblastoid cell lines showed increased apoptosis following exposure to a proteosome inhibitor. Thus, LRRK2 mutations are rare in Taiwanese with familial PD. Further study is needed to identify causative genes or unique biomarkers for familial PD.  相似文献   

8.
Length–weight relationships are described for four marine teleost fish species caught in the South China Sea. A total of 625 individuals were collected from April to August 2007 and November 2012 using a bottom trawl (mesh size, 3.9 cm) and longline fishing. The values of parameters a and b ranged from 0.004612 to 0.02137 and 3.019 to 3.371, respectively. The high r2 values (all >.950) indicate that these relationships are robust and will be appropriate for use in fisheries management of these species.  相似文献   

9.
In late November 1990 salmon parr, Salmo salar L., from the Girnock Burn in northern Scotland were either caught on their feeding territories (n=25) or trapped during downstream migration (n= 18). They were then housed in a laboratory rearing tank and their food intake and growth rates were tracked, until their smolting status was ascertained in the following May. Female fish were predominant in both groups; although the range of ages was the same, the total age of migrants was 2+ while that of residents was 1+. In November, compared to resident fish of the same year class, migrants were larger, heavier and in better condition. Although growth rates dropped during the winter in both groups before increasing in spring, migrants ate more and consistently grew faster than residents. In seawater tolerance tests conducted in May, more residents than migrants failed to adapt. These results confirm the suggestion that autumn migrants smolt in the following spring and suggest that they represent the faster-growing component of their cohort.  相似文献   

10.
Although the whale shark Rhincodon typus is the largest extant fish, it was not described until 1828 and by 1986 there were only 320 records of this species. Since then, growth in tourism and marine recreation globally has lead to a significant increase in the number of sightings and several areas with annual occurrences have been identified, spurring a surge of research on the species. Simultaneously, there was a great expansion in targeted R. typus fisheries to supply the Asian restaurant trade, as well as a largely un-quantified by-catch of the species in purse-seine tuna fisheries. Currently R. typus is listed by the IUCN as vulnerable, due mainly to the effects of targeted fishing in two areas. Photo-identification has shown that R. typus form seasonal size and sex segregated feeding aggregations and that a large proportion of fish in these aggregations are philopatric in the broadest sense, tending to return to, or remain near, a particular site. Somewhat conversely, satellite tracking studies have shown that fish from these aggregations can migrate at ocean-basin scales and genetic studies have, to date, found little graphic differentiation globally. Conservation approaches are now informed by observational and environmental studies that have provided insight into the feeding habits of the species and its preferred habitats. Notwithstanding these advances, there remain notable gaps in the knowledge of this species particularly with respect to the life history of neonates and adults who are not found in the feeding aggregations.  相似文献   

11.
Estimated age, hatching date and sexual maturation were investigated for the loliginid squids Loligo duvauceli and L. chinensis, the commercially important neritic species in the Andaman Sea of Thailand. The specimens caught by commercial bottom-trawl in Phang-nga Bay and southern area off Phuket Island were obtained monthly from Phuket fish landing between April and August 2005. Age was estimated based on the counting of statolith increments from a total of 329 individuals of L. duvauceli (ML ranges from 41 to 224 mm) and 116 individuals of L. chinensis (ML ranges from 42 to 186 mm). The estimated age ranged from 41 to 161 and 67 to 158 days old for L. duvauceli and L. chinensis, respectively. The length–weight relationships differed among sexes and the sexual dimorphism was expressed as mature females having a greater body weight than males of the same length. Males showed a wide range of maturity size possibly because of the seasonal change in size at maturity. The results of the back calculation for the hatching date of individuals fell between November 2004 and June 2005 which suggests that L. duvauceli and L. chinensis hatch continuously and recruit to the fishing ground for a relatively short period with a shorter lifespan than expected.  相似文献   

12.
Abstract. The orientation of adults of the myiasis species Wohlfahrtia magnified and Lucilia sericata to artificial visual stimuli (cloth targets) and olfactory stimuli ('swormlure-4', a potent screwworm attractant), was studied in sheep pastures near to Sarbogard in Hungary. Experiments with odour-baited cloth targets, enclosed in electrocuting grids, demonstrated that colour was an important factor influencing catches on targets: a black target caught most flies of both species, with other colours in the following order of effectiveness, blue > white > yellow. Wohlfahrtia magnified did not respond to swormlure-4 in the strong manner that L. sericata did. The sex ratios of W. magnifica caught on targets (67.2% males) and hand-netted from fence posts (68.8% males) were similar and biased towards males, whereas that of L. sericata on targets was strongly biased towards females (15.6% males), indicating a fundamental difference in the response of these two myiasis species towards the swormlure-baited targets. The orientation of these two species towards hosts was also recorded together with that of a third species, Phormia regina . Electric nets placed beside infested sheep caught significantly more flies of all three species than those placed beside uninfested sheep or in the absence of sheep. The sex ratio of W. magnified caught around infested sheep was the reverse of that on targets, with 68.5% females. Wohlfahrtia magnifica responded more strongly to healthy, uninfested sheep than did L. sericata and P. regina . The potential for use of targets both for population monitoring and control is discussed.  相似文献   

13.
Studies in Argentina and Chile during 2010–2011 evaluated a new trap (Ajar) for monitoring the oriental fruit moth, Grapholita molesta (Busck). The Ajar trap was delta‐shaped with a jar filled with a terpinyl acetate plus brown sugar bait attached to the bottom centre of the trap. The screened lid of the jar was inserted inside the trap, and moths were caught on a sticky insert surrounding the lid. The Ajar trap was evaluated with and without the addition of a sex pheromone lure and compared with delta traps left unbaited or baited with a sex pheromone lure and a bucket trap filled with the same liquid bait. Studies were conducted in a sex pheromone‐treated orchard in Argentina and an untreated orchard in Chile. In Chile, the Ajar trap without the sex pheromone lure caught significantly fewer males, females and total moths than the bucket trap, and fewer males and more females than the sex pheromone‐baited delta trap. Total moth catch did not differ between the Ajar trap without a sex pheromone lure and the sex pheromone‐baited trap. Adding a sex pheromone lure to the Ajar trap significantly increased total moth catches to levels not different from those in the bucket trap. However, the Ajar trap with the sex pheromone lure caught significantly more males and fewer females than the bucket trap. In Argentina, the Ajar trap with or without the addition of a sex pheromone lure caught similar numbers of both sexes and total moths as the bucket trap. The sex pheromone‐baited delta trap caught <4% of the number of moths as these three traps. The bucket trap in both studies caught significantly more non‐targets than the delta and Ajar traps. Moth catches in the Ajar trap declined significantly after 2–3 weeks when the bait was not replaced.  相似文献   

14.
Macrobrachium amazonicum is considered a favorite Brazilian species of freshwater prawn for cultivation as a result of its quick development and because it is easy to maintain in captivity. The aim of this work is to describe the sexual cycle stages and determine maturation age of the female M. amazonicum, which was collected monthly from June, 2002 to May, 2003 in the Jaguaribe River, Itai?aba, Ceará. A monthly sample of water was also collected to determine the following parameters: temperature, dissolved oxygen, pH and salinity. A monthly sample of females was selected among the individuals caught, to determine the total weight (W(T)), carapace length (L( C)) and abdomen+telson length (L(A+T)) and to register the number of non-ovigerous females (NOF) and ovigerous females (OF). Determining ovarian maturation stages of M. amazonicum was done in a laboratory by observing macroscopic characters such as coloring, size, location and appearance of ovarians examined by transparent carapace. The first maturation age was determined from the relative frequency of the total length (L(T)) of young and adult females. The environmental parameters of the Jaguaribe River did not hold any influence in the number of individuals collected. A total of 1,337 prawns were sampled, 513 males (38.4%) and 824 females (61.6%). The proportion between males and females in the studied population was of 1:1.6. Among the collected females, 492 (50.7%) did not carry eggs in their abdomens (NOF) and 332 (40.3%) carried eggs in their abdomens (OF). There was no record of intact females. Non-ovigerous females with mature ovaries were recorded throughout all the months of collection. The female ovaries were classified as immature (IM), rudimentary (RU), intermediary (IN) and mature (M). M. amazonicum females reach their first sexual maturity between 4.5 and 5.5 cm of total length.  相似文献   

15.
Aims Tropical forest plays a key role in global C cycle; however, there are few studies on the C budget in the tropical rainforests in Asia. This study aims to (i) reveal the seasonal patterns of total soil respiration (R T), litter respiration (R L) and soil respiration without surface organic litter (R NL) in the primary and secondary Asian tropical mountain rainforests and (ii) quantify the effects of soil temperature, soil moisture and substrate availability on soil respiration.Methods The seasonal dynamics of soil CO2 efflux was measured by an automatic chamber system (Li-8100), within the primary and secondary tropical mountain rainforests located at the Jianfengling National Reserve in Hainan Island, China. The litter removal treatment was used to assess the contribution of litter to belowground CO2 production.Important findings The annual R T was higher in the primary forest (16.73±0.87 Mg C ha-1) than in the secondary forest (15.10±0.26 Mg C ha-1). The rates of R T, R NL and R L were all significantly higher in the hot and wet season (May–October) than those in the cool and dry season (November–April). Soil temperature at 5cm depth could explain 55–61% of the seasonal variation in R T, and the temperature sensitivity index (Q 10) ranked by R L (Q 10 = 3.39)> R T (2.17)> R NL (1.76) in the primary forest and by R L (4.31)> R T (1.86)> R NL (1.58) in the secondary forest. The contribution of R L to R T was 22–23%, while litter input and R T had 1 month time lag. In addition, the seasonal variation of R T was mainly determined by soil temperature and substrate availability. Our findings suggested that global warming and increased substrate availability are likely to cause considerable losses of soil C in the tropical forests.  相似文献   

16.
The performance of clear delta traps baited with 3.0 mg of pear ester, ethyl (E,Z)-2,4-decadienoate, and 5.0 ml of acetic acid in separate lures was compared with orange delta traps baited with a single lure containing 3.0 mg of both pear ester and the sex pheromone, (E,E)-8,10-dodecadien-1-ol (codlemone) for codling moth, Cydia pomonella (L.), in apple, Malus domestica (Borkhausen). Residual analyses and field tests demonstrated that both the pear ester and acetic acid lures were effective for at least 8 wk. The two trap-lure combinations caught a similar number of total moths in an orchard treated with sex pheromone dispensers during short-term trials in 2008. However, the mean catch of female moths was significantly higher and male moths significantly lower in clear traps baited with pear ester and acetic acid versus orange traps baited with pear ester and codlemone. Season-long studies were conducted with these two trap-lure combinations in orchards treated with (n = 6) and without (n = 7) sex pheromone dispensers during 2009. The two trap-lure combinations caught similar numbers of moths in dispenser-treated orchards. In contrast, total catch was significantly higher (>2-fold) in the orange compared with the clear traps in untreated orchards. The clear caught >6-fold more females than the orange trap in both types of orchards. These studies suggest that deploying clear delta traps baited with pear ester and acetic acid can be an effective monitoring tool for female codling moth and an alternative to codlemone-baited traps in sex pheromone-treated orchards.  相似文献   

17.
《Endocrine practice》2016,22(11):1303-1309
Objective: There are conflicting studies in euthyroid males and females regarding associations between thyroidrelated hormones and parameters of the metabolic syndrome (MetS). We investigated the association between serum thyroid hormones and thyroid-stimulating hormone (TSH) concentrations and MetS in euthyroid men and women.Methods: Taiwanese subjects aged 20 to 65 years who had undergone a voluntary health examination at a preventive examination agency in Taipei were enrolled in this cross-sectional study. The definition of MetS was suggested by the Bureau of Health Promotion, Department of Health, Taiwan. Euthyroidism was defined as TSH and free thyroxine (FT4) levels within the normal reference ranges while not taking any thyroid medication. We conducted multiple logistic regression to identify the ability of serum triiodothyronine (T3), FT4, and TSH concentrations to identify the relative risk for the presence of MetS and components of the MetS in euthyroid Taiwanese individuals.Results: A total of 8,207 Taiwanese subjects (mean age: men, 45.3 ± 9.9 years; women, 43.5 ± 9.3 years) were enrolled in this study. A total of 1,672 subjects (20.4%) were defined as having MetS; these subjects had significantly higher (P<.0001) mean age (48.4 ± 9.1 years vs. 43.6 ± 10.7 years), prevalence of men (78.7% vs. 53.4%), and smoking (16.8% vs. 11.6%) than those without MetS. The median TSH, FT4, and T3 levels in all subjects were 1.70 mIU/L, 1.41 ng/dL, and 1.20 ng/mL, respectively. Higher T3 and lower FT4 values rather than TSH increased the odds ratio for MetS in men and women after adjusting for smoking and age, particularly for the association of T3 and MetS in women (uppermost quartile versus lowermost quartile: odds ratio, 2.4; 95% confidence interval, 1.6 to 3.5; P for trend <.0001).Conclusion: In euthyroid Taiwanese men and women, relatively high serum T3 concentrations was most strongly associated with the presence of the MetS; relatively low serum T4 was less strongly related, and serum TSH levels were not associated with the MetS. It is not known if the relationship of serum T3 and T4 to the MetS is causal.Abbreviations:BMI = body mass indexFT4 = free thyroxineMetS = metabolic syndromeOR = odds ratioT3 = triiodothyronineTSH = thyroid-stimulating hormoneWC = waist circumference  相似文献   

18.
1. Emergence and inland dispersal of adult stoneflies (Plecoptera) and caddisflies (Trichoptera) from Broadstone Stream, an acidic and iron-rich stream in southern England, were studied over 10 months in 1996–1997. Fifteen pyramidal emergence traps were placed randomly in a 200-m stretch. Three Malaise traps were placed above the stream and six more on each side (one wooded, one open) along a transect at distances of 1, 15, 30, 45, 60 and 75 m from the channel. 2. More than 16 000 stoneflies, belonging to 11 species, and just under 400 caddisflies (22 species) were caught. Four dominant stoneflies (Leuctra fusca, Leuctra nigra, Leuctra hippopus and Nemurella pictetii) accounted for 96% and 95% of the catches in the emergence and Malaise traps, respectively. Two caddisflies (Plectrocnemia conspersa and Potamophylax cingulatus) accounted for 63% of the catch in the Malaise traps. Few caddisflies were taken in emergence traps. 3. The emergence periods of L. fusca, L. nigra and L. hippopus were well-defined and unimodal, whereas that of N. pictetii was prolonged and erratic. Overall, more females (1285) emerged than males (740). 4. Female stoneflies and caddisflies were in the majority in the Malaise traps above the stream. On land, significantly more females than males of L. fusca, L. nigra and P. cingulatus were caught. The sex ratio of the remaining species did not deviate significantly from 1:1. 5. The three Malaise traps placed above the stream caught most of the stoneflies though there was also dispersal away from the channel, the numbers caught declining with distance. Exponential models explained between 67% and 99% of the variation in numbers of individuals with distance from the channel in the four common stoneflies. Half the individuals went less than 11–16 m from the stream, while 90% travelled less than 51 m. Significantly more L. nigra and N. pictetii were caught in the woodland than on the open side, whereas L. hippopus showed no overall preference for either side.  相似文献   

19.
将从荆芥Nepeta cataria L.中提取的纯度为96%的荆芥内酯和通过二异丁基铝还原提取的荆芥内酯得到的纯度为67%荆芥醇,配成浓度为5%的不同比例的己烷溶液,于1995年10月19~28日在北京大兴县南郊农场的桃园进行了引诱蚜虫的试验。各种比例的性信息素诱捕器均能引诱到桃蚜Myzus persicae (Sulzer)雄蚜、桃粉大尾蚜Hyaloptera amygdali Blanchard雄蚜以及少量的桃蚜产雌性母;荆芥醇和荆芥内酯的比例为1∶1时引诱桃蚜雄蚜的效果最好;单一组分的荆芥醇引诱桃粉大尾蚜雄蚜的效果最好。  相似文献   

20.
Kim HJ  Han JH  Yoo JH  Cho HJ  Kim BD 《Molecules and cells》2008,25(2):205-210
To develop molecular markers linked to the L4 locus conferring resistance to tobamovirus pathotypes in pepper plants, we performed AFLP with 512 primer combinations for susceptible (S pool) and resistant (R pool) DNA bulks against pathotype 1.2 of pepper mild mottle virus. Each bulk was made by pooling the DNA of five homozygous individuals from a T10 population, which was a near-isogenic BC4F2 generation for the L4 locus. A total of 19 primer pairs produced scorable bands in the R pool. Further screening with these primer pairs was done on DNA bulks from T102, a BC10F2 derived from T10 by back crossing. Three AFLP markers were finally selected and designated L4-a, L4-b and L4-c. L4-a and L4-c each underwent one recombination event, whereas no recombination for L4-b was seen in 20 individuals of each DNA bulk. Linkage analysis of these markers in 112 F2 T102 individuals showed that they were each within 2.5 cM of the L4 locus. L4-b was successfully converted into a simple 340-bp SCAR marker, designated L4SC340, which mapped 1.8 cM from the L4 locus in T102 and 0.9 cM in another BC10F2 population, T101. We believe that this newly characterized marker will improve selection of tobamovirus resistance in pepper plants by reducing breeding cost and time.  相似文献   

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