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101.
Synopsis The spawning patterns of four Hawaiian reef fishes with similar reproductive habits, but different biogeographic distributions were studied from September 1980 to October 1981. Two species are Hawaiian endemics [Centropyge potteri (Pomacanthidae) and Chaetodon multicinctus (Chaetodontidae)] and the other two have pan-tropical Pacific distributions [Ctenochaetus strigosus and Zebrasoma flavescens (Acanthuridae)]. All showed increased spawning activity from January to July, the prevalent pattern among a majority of coastal marine fishes in Hawaii. Environmental correlatives to the period of peak reproduction include cycles of (a) daylight length and temperature which probably function as proximate cues and (b) seasonal variations in ocean current patterns which may ultimately affect survival of larvae and dispersal. Peak reproduction takes place during months when (1) mesoscale eddies most likely occur, and (2) the probability is greatest of drifting objects remaining near the islands.  相似文献   
102.
Synopsis Fish reproduction in floodplain ecosystems, based on relative abundance and total biomass of 0+ juveniles, was studied using the synchronic approach to typological analysis in conjunction with Point Abundance Sampling by modified electrofishing. In 3 different flood plains of the Upper Rhône River, 1015 point samples yielding 4573 juveniles (0+) from 21 species were collected from 48 ecosystems of various geomorphological origin. The results demonstrate the lotic-to-lentic succession of floodplain ecosystems to be a series of non-sequential reproductive zones, with spawning conditions being reflected by the specific composition and guild structure of the YOY fish assemblages. The habitat diversity and the fish reproductive potential of floodplain ecosystems are strongly influenced by geomorphological origin and by past and present hydrological conditions. The YOY assemblages of autogenically driven ecosystems (usually of anastomose or meander origin) tend to differ both in composition and in quantity from those found in allogenically driven ecosystems (generally of braided origin). Ecosystems of intermediate character, and fish reproduction thereof, occur as the result of either ecosystem rejuvenation or senescence: autogenically driven ecosystems by allogenic mechanisms, or allogenically driven ecosystems by anthropic and/or autogenic mechanisms, respectively. Because of co-occurrence of ecosystems at similar and at different successional status, the flood plain as an entity is seen as stable with respect to fish reproduction.  相似文献   
103.
Synopsis A number of factors can influence the accuracy and precision of underwater visual transect techniques. Among these are observer swimming speed and, during multispecies surveys, the effect of counting all fishes on estimates of particular species. This paper examines the effect of these factors on population estimates of inconspicuous fishes (defined as Type 1) in a temperate reef fish assemblage near Sydney, Australia. Counting Type 1 fishes with all others yielded significantly lower estimates of species richness and abundance than when counted alone. This suggests that multispecies surveys should be split into 2 or more counts, using a census procedure that is appropriate to the group of species cencused. Further, the effect of counting all other fishes on estimates of Type 1 fishes varied according to the relative abundance of the former: their effect was lowest when abundance of other fishes was lowest. There was a negative relationship between observer speed and estimated abundance for Type 1 fishes. Survey precision of Type 1 fishes was generally improved by surveying at slower observer speeds.  相似文献   
104.
杯叶科是食鱼的爬行类、鸟类、哺乳类寄生的吸虫。本文修订了以往在福建报道的虫种,叙述了一个新属三个新种,取消了前此所定的一个属及种[Tangiella parovipara(Faust and Tang,1938)],认为是存疑的种。本文还报道了盖前冠吸虫 Prosostephanus Tubangu,1922的终末宿主河獭,从而作者(Tang,1941)完成了其生活史的研究。本文比较了从河獭所得的标本与从描、犬所获标本各器官的测量数据,发现由最佳的终末宿住所得标本,其个体及各器官和卵子的测量数据均较大。  相似文献   
105.
云南西部狭臀蚤属四新种记述:蚤目:多毛蚤科   总被引:2,自引:1,他引:1  
本文报告云南西部狭臀蚤属Steni(?)chia 4新种:1)金氏狭臀蚤,新种 S.chini sp.nov.与锐额狭臀蚤 S.angustifrontalis Xie et Gong接近;2)李氏狭臀蚤,新种 S.liae sp.nov.与金氏狭臀蚤新种和锐额狭臀蚤接近;3)柳氏狭臀蚤,新种 S.liui sp.nov.与李氏狭臀蚤新种和高山狭臀蚤S.montanis xie et Gong接近。4)吴氏狭臀蚤,新种 S.wui sp.nov.与卢氏狭臀蚤 S.lewis Smit接近。本文认论了李氏狭臀蚤新种与金氏狭臀蚤新种的形态分类及本属蚤类的宿主等生态问題,并编制本属14种的检索表。  相似文献   
106.
本文描述1个珠恙螨属 Doloisia一新种,采自广东省罗定县社鼠 Rattus confucianus 鼻内,其感器双角状,盾板后侧毛的分枝长密,前侧毛光裸;足指数795。  相似文献   
107.
Eighteen graded non-metric characters and 30 measurements of the mandible and lower dentition were used to investigate the grouping of African species of the genera Crocidura, Suncus and Sylvisorex. Seventy-seven taxa (species, subspecies and synonyms), including four European species, were represented by one to nine mandibles (147 mandibles in all), and the means of four Pleistocene African species were also included. The metric data were subjected to principal component and canonical variate analyses, and the non-metric data to principal component analysis. Grouping was detected by comparing the results of the three analyses. Six groups are recognized within the genus Crocidura , typified by C. fumosa, C. turba, C. russula, C. fuscomurina, C. hirta and C. flavescens. Sylvisorex is divisible into two groups, typified by S. lunaris and S. granti. The African species of Suncus (but not the introduced species, S. murinus ) form a single group, which is linked to the Sylvisorex granti group. Suncus is closely related to, or convergent with, the Crocidura fuscomurina group. The first non-metric principal component, the second metric principal component and the second canonical variate are significantly correlated. It is considered that these together represent a general trend of evolutionary advance. Phylogenetic relations are discussed in the light of this; Crocidura may be diphylefic.  相似文献   
108.
Using a bacterial speciesPseudomonas PG-1, evidence has been obtained which indicates that uptake ofn-pentane ton-octane by microbial cells takes place primarily from the gas phase either directly orvia the aqueous phase. Specific growth rate increased along with the increase in substrate concentration but above the alkane concentration of 0.3% by volume, specific growth rate decreased indicating substrate inhibition of growth. In the case of less volatile alkanes,n-nonane andn-decane, substrate transfer is predominantly through substrate solubilization system elaborated by the cells. EDTA, a strong inhibitor of hydrocarbon solubilization by the cells, inhibited growth on these two alkanes but had negligible effect on growth onn-pentane ton-octane.  相似文献   
109.
农业生态系统中新物种引进的初步探讨   总被引:5,自引:0,他引:5  
在现有的农业生态系统中,引进某些新物种,往往可以使整个系统的功能发生变化。如果新物种引进得当,则可产生良好的效果,系统功能得以改善,效益提高;反之,则会造成人力、物力、财力的损失,削弱系统的功能,甚至可能遗患无穷。因此,对农业生态系统中  相似文献   
110.
Aphidius staryi Chen & Luhman n. sp. is described. The species was collected and introduced into California from Israel and Turkey byD. González. The new species is morphologically most similar toAphidius smithi, and keys toEady's urticae group.  相似文献   
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