Top PDF Differences in size and growth rates of male and female migrating Japanese eels in Pearl River, China.

Differences in size and growth rates of male and female migrating Japanese eels in Pearl River, China.

Differences in size and growth rates of male and female migrating Japanese eels in Pearl River, China.

(Sun Yet-Sen) University, Guangzhou 510275, PROC (Received 13 January 2000, Accepted 21 June 2000) The Sr/Ca ratios in otoliths of silver Japanese eels Anguilla japonica in Pearl River, China, indicated that both sexes did not stay in brackish water and grew in fresh water from the glass eel stage until spawning migration. This did not support the hypothesis that females tended to distribute upstream and males might be restricted to estuaries. The back-calculated total length of males at glass eel stage was not significantly different from that of females, indicating that the hypothesis that small glass eels became males and larger ones became females may not be true.
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Differences in size and growth rates of male and female migrating Japanese eels in Pearl River, China

Differences in size and growth rates of male and female migrating Japanese eels in Pearl River, China

(Sun Yet-Sen) University, Guangzhou 510275, PROC (Received 13 January 2000, Accepted 21 June 2000) The Sr/Ca ratios in otoliths of silver Japanese eels Anguilla japonica in Pearl River, China, indicated that both sexes did not stay in brackish water and grew in fresh water from the glass eel stage until spawning migration. This did not support the hypothesis that females tended to distribute upstream and males might be restricted to estuaries. The back-calculated total length of males at glass eel stage was not significantly different from that of females, indicating that the hypothesis that small glass eels became males and larger ones became females may not be true.
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Growth and habitat residence history of migrating silver American eels transplanted to Taiwan.

Growth and habitat residence history of migrating silver American eels transplanted to Taiwan.

growth rates of emigrants in North America. This was consistent with the observation that size of male American eels is not correlated with latitude (Oliveira 1999). As expected, female silver American eels in Taiwan also migrated at sizes more comparable to those in the southern United States, confirming the negative correlations between latitude, length at migration, and growth rate. These results are consistent with Oliveira’s (1999) conclusion that the panmictic life cycle of the American eel prevents long-term selection of growth rates in different habitats and that growth rates result from environmental con- ditions in a habitat. American eels in Taiwan were older at migration and grew much more slowly than did native Japanese eels, suggest- ing between-species differences in biological characteristics or reduced adaptability to en- vironmental conditions substantially different from those of streams, even in the southern United States.
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The swimbladder parasite Anguillicola crassus in native Japanese eels and exotic American eels in Taiwan

The swimbladder parasite Anguillicola crassus in native Japanese eels and exotic American eels in Taiwan

(Accepted April 30, 2008) Yu-San Han, Ya-Ting Chang, Horst Taraschewski, Su-Ling Chang, Che-Chun Chen, and Wann-Nian Tzeng (2008) The swimbladder parasite Anguillicola crassus in native Japanese eels and exotic American eels in Taiwan. Zoological Studies 47(6): 667-675. To understand differences in infection patterns of the swimbladder parasite Anguillicola crassus between habitats and eel species in Taiwan, the prevalence and intensity of the parasite were examined based on specimens collected from wild and cultured Japanese eel Anguilla japonica and from exotic cultured American eel A. rostrata in the Kaoping River and culture ponds in southwestern Taiwan in 2006-2007. The prevalence of Aco. crassus in wild Japanese eels was lower in winter compared with summer/autumn, varying 33%-58%, with a mean intensity of 1.5-4.4. The prevalence and intensity were size- dependent and increased with eel size. In cultured Japanese eels, the prevalence and mean intensity varied greatly at 3%-68% and 1.0-29.0, respectively. In cultured American eels, the prevalence and intensity were very high in ponds without drug treatment. In contrast to wild eels, the mean intensity of larval and adult worms showed a size-dependent decreasing trend in cultured eels. The mean body mass of Aco. crassus in American eels was significantly larger than that in Japanese eels. The external morphology, condition factor, and hepatosomatic index showed no significant differences between infected and uninfected groups, indicating a low pathogenic effect of Aco. crassus on these 2 eel hosts. Our results showed that both native Japanese eels and naive American eels are highly susceptible to Aco. crassus, but it causes little pathogenicity under good pond management. http://zoolstud.sinica.edu.tw/Journals/47.6/667.pdf
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The sex ratios and growth strategies of wild and captive Japanese eels Anguilla japonica

The sex ratios and growth strategies of wild and captive Japanese eels Anguilla japonica

The role of gender and sexual differences in the growth histories of Japanese eel Anguilla japonica were linked with respect to the sex ratio and growth rate of wild eels collected from Taiwanese rivers. The sex ratio of wild eels was compared with that of eels semi-intensively cultured in a pond and intensively cultured in an aquarium. The sex ratio of wild eels from a low-density river habitat was dominated by females (86.4% of sex-determined eels), slightly dominated by males (57.1%) in a cultured pond, and dominated by males (90.0%) in an aquarium. This evidence supported the hypothesis that the sex of eels is determined by population density. The parameters of the von Bertalanffy growth equation demonstrated that males grew faster to reach a smaller asymptotic length than did females. We propose that the variation in eel sex ratio interacts with sex-linked differences in growth strategy to play an important role in density-dependent population regulation.
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Occurrence of Anguillicola crassus (Nematoda: Dracunculoidea) in Japanese eels Anguilla japonica from a river and an aquaculture unit in SW Taiwan

Occurrence of Anguillicola crassus (Nematoda: Dracunculoidea) in Japanese eels Anguilla japonica from a river and an aquaculture unit in SW Taiwan

Similar intensity values (1.3 to 2.8) were recorded for the larvae. In cultured eels, prevalence as well as mean intensities were higher. In the cultured hosts, mean larval intensities exceeded those of adult worms 2-fold, and maximum larval intensities were 4- to 5-fold higher than in eels from the river. In cultured eels, dead larvae were also more abundant than in wild eels. We conclude that infrapopula- tions of A. crassus in Japanese eels are regulated by the defense system of this host, intraspecific den- sity-dependent regulation being less likely as the major regulatory mechanism. No influence of the parasite on eel condition was found in either wild or cultured eels, indicating a low or moderate path- ogenic effect of A. crassus on this host. This study shows that A. crassus is moderately common in cul- tured and wild Japanese eels in Taiwan, where the parasite is endemic.
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Differences in growth rates among cohorts of Encrasicholina punctifer and Engraulis japonicus larvae in the coastal waters off Tanshui River Estuary, Taiwan, as indicated by otolith microstructure analysis

Differences in growth rates among cohorts of Encrasicholina punctifer and Engraulis japonicus larvae in the coastal waters off Tanshui River Estuary, Taiwan, as indicated by otolith microstructure analysis

The hatching dates of Encrasicholina punctifer and Engraulis japonicus larvae collected in the coastal waters o ff Tanshui River Estuary during the fishing seasons of 1992 and 1993 indicated that these two anchovies had protracted spawning seasons, which resulted in multiple recruitment cohorts. Encrasicholina punctifer larvae recruited to the estuary from October to March, while the majority of E. japonicus larvae came in March–May and to a lesser extent in October and November. The E. punctifer larvae on arrival to the estuary were 17·4–35·6 mm in length, 16–89 days old and had growth rates of 0·4–1·0 mm day 1 , E. japonicus larvae were 12·1–32·7 mm in length, 19–62 days old and had growth rates of 0·7–0·9 mm day 1 . Growth rates were significantly di fferent among cohorts and positively correlated to water temperature.
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HKUST Works with China to Check Pollution in Pearl River Estuary

HKUST Works with China to Check Pollution in Pearl River Estuary

A cross-border project on environmental pollution in the Pearl River Estuary is to be conducted by the Hong Kong University of Science and Technology in collaboration with research institutes and government agencies on the Chinese Mainland, and with academic institutions in France and Hong Kong.

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Comparison of Recapture Rates and Estimates of Fishing and Natural Mortality Rates of Japanese Eel Anguilla japonica between Different Origins and Marking Methods in a Mark-Recapture Experiment in the Kaoping River, Southern Taiwan

Comparison of Recapture Rates and Estimates of Fishing and Natural Mortality Rates of Japanese Eel Anguilla japonica between Different Origins and Marking Methods in a Mark-Recapture Experiment in the Kaoping River, Southern Taiwan

Recapture rates of marked wild eels did not significantly differ between individuals marked by microchips and pectoral fin clipping (p = 0.51), but did differ between cultured eels marked by microchips and caudal fin clipping (p = 0.01). For wild and cultured eels marked by microchips, cultured eels had a significantly higher recapture rate than wild eels (p < 0.001), and eel length at release did not affect the recapture rates (p = 0.38). According to the Akaike information criterion corrected for the sample size, estimates of fishing and natural mortality rates differed between pectoral fin clipping and microchips in wild eels. However, neither rate differed between pectoral fin clipping and microchip in cultured eels. Both eel origin and marking method might influence the recapture rate and mortality rate estimates. Different behaviors of cultured eels in the wild and reaction to the marking process are possible reasons. Higher mortality rates of wild eels marked by pectoral fin clipping were unexpected, probably due to a size-related mortality rate, behavioral changes, or mortality associated with pectoral fin clipping. http://zoolstud.sinica.edu.tw/Journals/49.5/616.pdf
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The sex-ratio reversal of the Japanese eel Anguilla japonica in the Kaoping River of Taiwan: The effect of cultured eels and its implication

The sex-ratio reversal of the Japanese eel Anguilla japonica in the Kaoping River of Taiwan: The effect of cultured eels and its implication

The sex ratio of wild Japanese eels in the Kaoping River of southwestern Taiwan has been extremely skewed towards females in the recent years. However, the sex ratio skewed towards males after Typhoon Mindulle, July 2, 2004 then recovered to the previous female-dominated status in the following year. To determine why the sex ratio drastically changed, eels captured in the river were examined by both morphologic characteristics and otolith elemental signatures by solution-based inductively coupled plasma mass spectrometry (SB-ICPMS) and laser-ablation ICPMS (LA-ICPMS). Most of the eels collected in the river after the typhoon had a blue-gray colored back, with morphology and sex ratio similar to that of cultured eels, which differed from wild yellow eels which had a green colored back. The chemical signature in otoliths of eels with a blue-gray colored back was similar to that of cultured eels, with significantly lower Sr/Ca ratios but slightly higher Mn/Ca ratios than for wild eels. This confirmed that the reversal in eel sex ratio in the Kaoping River estuary resulted from cultured eels that had escaped from eel farms. Eel farmers estimated that about 30,000 eels escaped during the typhoon, sufficient to reverse the sex ratio of the eels in the river. Furthermore, silver eels caught in the estuary in the winter 2004 were also mostly males. The chemical signature in otoliths of these silver eels was similar to that of escaped cultured eels. Their morphology and mean GSIs, however, were comparable to wild silver eels. Thus, cultured eels that have escaped from eel farms can silver normally in the wild. Consequently, cultured eels may help to balance the sex ratio of the wild eel population and may contribute to the spawning stock of Japanese eel.
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Personality Disorders in Female and Male College Students with Internet Addiction

Personality Disorders in Female and Male College Students with Internet Addiction

Chinese version of the Modified Schedule of Affective Disorders and Schizophrenia-Lifetime Short form (CMSADS-L) Interviews were conducted by trained graduate-level examiners using the CMSADS-L short form, a semi-structured diagnostic interview based on SADS-L, and personality disorders were incorporated in reference to Structured Clinical Interviews for DSM-IV (SCID II). The inter-rater reliability of the CMSADS-L was good (Huang et al., 2004). Familiarity of the CMSADS-L was a requirement by each interviewers. Each trainee had to view a minimum of 6 CMSADS-L training videos of case vignettes, which was followed by consensus ratings. To be certified, the trainee had to achieve good to excellent agreement with the consensus diagnosis, and inter-rater reliability was good. During the actual diagnostic interview, in order to confirm a PD diagnosis, participants were asked a series of PD core symptoms. Questions were asked pertaining to how they behaved, felt or thought most of the time throughout their lifetime.
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Identification and growth rates comparison of divergent migratory contingents of Japanese eel (Anguilla japonica)

Identification and growth rates comparison of divergent migratory contingents of Japanese eel (Anguilla japonica)

Advantages include such aspects as increased food supply, avoidance of potentially harmful environmental conditions and/or a movement to more favorable ones, the occupation of habitats that have specific or specialized habitat requirement, and the availability of more living space. Costs of migration include mortalities resulting from migration itself, changed environmental conditions that may be intolerable (in diadromous fishes, specifically osmoregulatory stress) (McDowll, 1988). Gross (1987) proposed that diadromy occurs when the gain in fitness from using a second habitat minus the migration costs of moving between habitats exceeds the fitness from staying in only one habitat. When the elvers migrate from offshore seawater to upstream freshwater for living habitat and feeding, they have to overcome the osmotic pressure of salinity gradient environment. If they stayed in estuary their osmoregulatory cost would be lower than those in both freshwater and sea water. Meanwhile, the stability of water volume, living space and food abundance for the eel is generally superior in the estuary than the upper stream of the river in the island countries, such as Japan and Taiwan. The estuary functions as a nursery and feeding ground for the juveniles of many inshore fish and offers commercially important fish (Wallace et al., 1984;
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Effects of long-term ethanol consumption on jejunal lipase and disaccharidase activities in male and female rats

Effects of long-term ethanol consumption on jejunal lipase and disaccharidase activities in male and female rats

Abstract AIM: To study the effect of long-term ethanol consumption on jejunal lipase and disaccharidase (sucrase, maltase, and lactase) activities in rats and its gender difference. METHODS: Age-matched male and female Wistar rats were fed control or ethanol-containing liquid diets for 12 wk following the Lieber-DeCarli model.

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Effects of long-term ethanol consumption on jejunal lipase and disaccharidase activities in male and female rats

Effects of long-term ethanol consumption on jejunal lipase and disaccharidase activities in male and female rats

Age-matched male and female Wistar rats were fed control or ethanol-containing liquid diets for 12 wk following the Lieber-DeCarli model. According to both the plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, 40 rats were divided into four groups as follows: male control group (MC), male ethanol group (ME), female control group (FC), and female ethanol group (FE). RESULTS: After ethanol feeding for 12 wk, the results revealed that plasma AST and ALT activities of group ME were significantly increased by 58%
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Plasma levels of matrix metalloproteinase-2 and -9 in male and female patients with cirrhosis of different aetiologies

Plasma levels of matrix metalloproteinase-2 and -9 in male and female patients with cirrhosis of different aetiologies

disease aetiology and gender, than among the healthy controls. This suggests that plasma MMP-2 levels may be useful diagnostic markers for monitoring hepatic fibrogenesis in patients with disease of different aetiologies. More studies with larger patient cohorts can identify clinically relevant cut-off values with reliable confidence limits. Our study appears to show that MMP-9 has little value in differentiation between cirrhosis and healthy individuals. The plasma mean MMP-9 levels in cirrhotic patients were generally comparable to those in the healthy controls. They were significantly lower only in patients, female patients and male patients with low- grade cirrhosis, compared with healthy controls, female controls and male controls, respectively. Although the mechanism of evolution to HCC from cirrhosis differs in disease of different aetiologies and the prevalence of cirrhosis and HCC differs in men and women, our study results showed that the plasma levels of MMP-2 and MMP-9 in patients with cirrhosis were not significantly different between men and women and among patients with different disease aetiologies.
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Workshop on Air Pollution in the Pearl River Delta

Workshop on Air Pollution in the Pearl River Delta

For release 7 December 1999 W ORKSHOP ON A IR P OLLUTION IN THE P EARL R IVER D ELTA Experts and decision-makers in air pollution in the Pearl River Delta will share research findings and experiences in a two-day workshop to be held at the Hong Kong University of Science and Technology (HKUST).

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Temperature dependence of bacterial specific growth rates on the continental shelf of the East China Sea and its potential application in estimating bacterial production

Temperature dependence of bacterial specific growth rates on the continental shelf of the East China Sea and its potential application in estimating bacterial production

INTRODUCTION Heterotrophic bacterioplankton are the major organ- isms responsible for the decomposition of dissolved organic carbon (DOC; Fuhrman 1992 and citations therein), which constitutes > 90% of the organic carbon pool in the ocean. Bacterial production and specific growth rates play a key role in determining what is ac- tually left over or available for DOC export (Carlson et al.

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Role of prostatic size in the pathogenesis of male LUTS

Role of prostatic size in the pathogenesis of male LUTS

 BPH is characterized by an increased number of epithelial and stromal cells in the periurethral area of the prostate.  new epithelial gland formation[r]

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19 of the participants were female and 15 were male

19 of the participants were female and 15 were male

numbers originally. They were then converted into integers or a whole number with decimals. For instance, 3/4 was converted into 75, and 7/8, 87.5 (see Appendix 12 for the raw scores and Appendix 13 for the converted scores). In the current study, data collected from the vocabulary tests mentioned above was analyzed by means of four tools. Descriptive statistics were computed to compare the effect of different treatments. Independent samples t-test was used to detect if there were statistically significant differences between groups. Effect sizes (ES) were further used to assess the magnitude of a difference between means of two groups 1 . Besides, a two-way ANOVA (analysis of variance) was employed to detect if there were significant group-by-proficiency level interaction. Data collected from learners’ response to the questionnaire were analyzed by means of percentage and frequency.
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Comparing Cultural Differences in Trading Website Management between Mainland China and Taiwan

Comparing Cultural Differences in Trading Website Management between Mainland China and Taiwan

a buyer can share his/her perceptions towards this transaction. In this study, we randomly sampled appraisals of the sellers whose sales ranked first respectively in eight industry fields covering food, clothing, housing, transportation, education, entertainment, beauty, and 3C (computer, communication, and consumer electronics). The deadline for data collection was on April 30 th 2010. The historical database of Taobao.com allows only the latest 200 positive appraisals to appear on each website. Therefore, a total of 1,600 positive appraisals were collected from Taobao.com. Likewise, we collected 1,286 negative appraisals. We kept 669 positive and 712 negative appraisals after deleting repetitive and non-informative ones, such as “Good,” “I liked it,” “Great,” etc. For the purpose of balancing the number of appraisals on Yahoo!
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