马鞍列岛岩礁生境鱼类群落生态学.Ⅰ.种类组成和多样性

为了解潮下带岩礁生境的鱼类区系特征,于2009年对马鞍列岛岩礁生境进行了12个月的多网目组合刺网采样,从分类学和生态型组成等方面,结合多样性和相对重要性指数,对该生境的鱼类组成和多样性特征进行了分析。全年共采集鱼类87种,隶属2纲14目50科73属。其中鲈形目鱼类51种,占58.6%;趋礁性鱼类49种,占56.3%;放流鱼类7种,占8%。所有鱼类个体中,幼鱼的总比例为67.4%。暖水种、暖温种和冷温种分别为50、36和1种;底层、近底层和中上层鱼类各为19、46和22种,其中褐菖鲉(Sebasti scus marmoratus)、黄姑鱼(Nibea albiflora)和赤鼻棱鳀(Thryssa kammalensis)分别为各水层的绝对优势种;定居种、季节性洄游种和偶见种各为32、55和11种。岩礁生境鱼类多样性呈现明显的季节变化特征,2月份最低,9月份最高。研究结果表明,马鞍列岛岩礁生境是以趋礁鱼类为特征群体、暖水性和暖温性鱼类共同主导、各个类型的幼鱼在夏秋季集群出现、同时也分布了一定量放流种的高鱼类多样性栖息地,它为各种鱼类提供了优良的摄食、避敌和繁殖场所,是近岸海洋生态系统中相当重要的生境。然而相比过去,该生境的鱼类多样性已经大大降低,因此需对其保护工作予以更多关注。     

Life cycles of the trematode species Azygia hwangtsiytii and A. robusta (Azygiidae) in Primorsky Territory

As a result of experimental and faunistic investigations it is established that the development of the trematode species Azygia hwangtsiytii Tsin, 1933 in Primorsky Territory is realized in the first intermediate host, snail Cipangopaludina ussuriensis, and in second hosts, fishes Perccottus glehni and Channa argus warpachowskii, which can serve as transit, as well as final hosts. For Azygia robusta Odhner, 1911 terms of the development in the first intermediate host, snail Anisus centrifugus are established.     

Diversity of fishes and structure of ichthyocenoses in mountain catchment areas of the Amur Basin

Taxonomic characteristics of the diversity of fishes in the mountain areas of the Russian part of the Amur Basin are provided and based on the author’s investigations; data are given on the distribution of fishes and on the structure and dynamics of ichthyocenoses in different parts of the studied mountain catchment areas.     

洞庭湖渔业资源现状及其变化

1990－1999年资源监测表明,洞庭湖鱼的种类与70年代基本相同,但其组成结构发生较大变化,明显以鲤,鲫,鲶,黄颡鱼等湖泊定居性鱼类为主,最高达86．1％,“四大家鱼”在渔获物中所占比较不足10％,刀鲚等洄游性鱼类已极为罕见;90年代渔获量平均为3．97万t,渔业产量增加,但多以1－2龄鱼为主,补充群体严重不足,水利工程的兴建,泥沙淤积,围垦,污染加剧以及过度捕捞是造成洞庭湖渔业资源衰退的主要原因。     

Isolation-by-time population structure in potamodromous Dourado <Emphasis Type="Italic">Salminus brasiliensis</Emphasis> in southern Brazil

Isolation-by-distance is recognized as a useful model for describing the spatial distribution of gene frequencies depending on dispersal characteristics of the species under study. However, some species may have populations that occupy the same geographic distribution during the breeding season yet reproduce at different time periods resulting in isolation-by-time (IBT). IBT may complicate investigations of spatial population structure if samples are obtained from multiple discrete time periods or may remain undiscovered if surveys are conducted with limited temporal scope. IBT has been observed in several studies of anadromous fishes (primarily salmon) as well as a few examples in taxa such as frogs, plants, birds and insects, but has not been rigorously tested in freshwater fishes. In this study, we assessed spatial and temporal genetic variation and tested for IBT in Dourado (Salminus brasiliensis), a large and commercially-important potamodromous fish species found in multiple river basins of South America. Using 11 polymorphic microsatellite loci, we estimated genetic differentiation of 317 adult Dourado collected monthly during the breeding season at three locations along the Uruguay River in southern Brazil. Analyses identified three populations that were clustered in time (i.e. early, middle and late), suggesting an IBT pattern of population structure with no significant spatial structure. Our results contribute to the mounting evidence across a wide range of taxa that suggests IBT may be more common that currently considered, even for species with very high dispersal capabilities such as potamodromous fishes.     

The diet and infection of fishes in Cavendish Dock, Barrow-in-Furness

Some 934 fishes belonging to ten species were examined in Cavendish Dock, Walney Channel and in the River Duddon in order to study their diet and infection.
Because of the limited number of food species occurring in Cavendish Dock, the diet of fishes examined is similar and composed of twelve different species.
The diet of the flounders in Walney Channel differs markedly from those in the dock.
The infection with parasitic worms of fishes in Cavendish Dock is lower than in other localities.
Fifteen different species of parasitic worms belonging to Trematoda, Cestoda, Nematoda and Acanthocephala were recorded in fishes examined.
Salinity of the dock water influences the composition of the diet and infection of fishes in Cavendish Dock. Raised temperature and salinity are artificially introduced by human activities, and beiig controllable, could serve for experimental ecological investigations in     

The cytoskeleton of the Mauthner neurons in the guppy after returning from an orbital flight]

The ultrastructural investigations of the Mauthner neurons (M-cells) of P. reticulata were performed on the return of the fishes after a two weeks orbital flight, the M-cells of fishes from different control groups being simultaneously examined. The structure of M-cells from the experimental fishes was shown to be severely damaged. The changes involved the synaptic apparatus, postsynaptic areas, mitochondria and other organelles of the cytoplasm and the nucleus. Particular changes were seen in the neuronal cytoskeleton. While in the M-cells of intact fishes these were seen as evenly distributed microfilaments and neurofilaments, in the M-cells of experimental fishes the cytoskeleton looked as alternating bundles of condensed filaments. The first indications of cytoskeleton damage appeared in M-cells of the guppy from transport control group and strengthened in fishes from the group of synchronous control. Thus, the data obtained give us a possibility to suggest that the return on the Earth and following readaptation after a prolonged flight at conditions of microgravity and consequent disfunction of vestibular apparatus may result in the damage of central neurons receiving vestibular afferentation (such as M-cells). That, in turn, may be a cause of functional disorders of the central nervous system, including the nerve centres maintaining the organs of motion. These facts are necessary to take into consideration when more prolonged cosmic flights are planned.     

Genomic Organization of Repetitive DNA Elements and Its Implications for the Chromosomal Evolution of Channid Fishes (Actinopterygii,Perciformes)

Channid fishes, commonly referred to as “snakeheads”, are currently very important in Asian fishery and aquaculture due to the substantial decline in natural populations because of overexploitation. A large degree of chromosomal variation has been found in this family, mainly through the use of conventional cytogenetic investigations. In this study, we analyzed the karyotype structure and the distribution of 7 repetitive DNA sequences in several Channa species from different Thailand river basins. The aim of this study was to investigate the chromosomal differentiation among species and populations to improve upon the knowledge of its biodiversity and evolutionary history. Rearrangements, such as pericentric inversions, fusions and polyploidization, appear to be important events during the karyotypic evolution of this genus, resulting in the chromosomal diversity observed among the distinct species and even among populations of the same species. In addition, such variability is also increased by the genomic dynamism of repetitive elements, particularly by the differential distribution and accumulation of rDNA sequences on chromosomes. This marked diversity is likely linked to the lifestyle of the snakehead fishes and their population fragmentation, as already identified for other fish species. The karyotypic features highlight the biodiversity of the channid fishes and justify a taxonomic revision of the genus Channa, as well as of the Channidae family as a whole, as some nominal species may actually constitute species complexes.     

麻塘湖水库鱼类种群及其饵料生物现状的初步研究

通过对怀宁县麻塘湖水库的鱼类种群及饵料生物组成进行的调查,鉴定出水生维管束植物的四个优势种,底栖动物２２种,浮游动物三大优势类群和鱼类３２种。结果表明该水库的鱼类年龄组成趋于低龄化。在此基础上,作者提出了恢复该水库鱼类资源和提高水库生态效益的初步意见     

中国三叠纪鱼类综述

三叠纪鱼类在中国分布广泛。与当时“南海北陆”的古地理格局一致,淡水鱼类主要分布于北方大陆的河湖相盆地,但也见于扬子板块与北方大陆碰撞后的四川盆地;海生鱼类则主要分布于华南和喜马拉雅地区。值得注意的是,鄂尔多斯盆地已知的三叠纪鱼类中,多数为海生类型或与海生鱼类密切相关。中国的淡水三叠纪鱼群主要由原始辐鳍鱼类组成,它们与西伯利亚和中亚的鱼群最为相近,但也有与劳业大陆其他地区及冈瓦纳大陆的鱼类相似的属种。海生鱼群则以“亚全骨鱼类”为主,并包含鲱亚部的进步类群和真骨鱼类的基干类型。华南扬子区拉丁至卡尼早期的鱼群远较早三叠世的鱼群丰富,且这一时期的鱼群与西特提斯同期的鱼群关系已极为密切,约有1/3的种类可归入相同的属。华南中下扬子区很可能是部分后来繁盛于特提斯区的三叠纪鱼类的发源地,如龙鱼类。中国的三叠纪鱼类虽然十分丰富,但大多已知鱼类仅限于零星发现和初步报道,因而仍有待全面深入的调查研究。     

Communication and camouflage with the same 'bright' colours in reef fishes

Reef fishes present the observer with the most diverse and stunning assemblage of animal colours anywhere on earth. The functions of some of these colours and their combinations are examined using new non-subjective spectrophotometric measurements of the colours of fishes and their habitat. Conclusions reached are as follows: (i) the spectra of colours in high spatial frequency patterns are often well designed to be very conspicuous to a colour vision system at close range but well camouflaged at a distance; (ii) blue and yellow, the most frequently used colours in reef fishes, may be good for camouflage or communication depending on the background they are viewed against; and (iii) reef fishes use a combination of colour and behaviour to regulate their conspicuousness and crypsis.     

The nucleotypic effects of cellular DNA content in cartilaginous and ray-finned fishes.

Cytological and organismal characteristics associated with cellular DNA content underpin most adaptionist interpretations of genome size variation. Since fishes are the only group of vertebrate for which relationships between genome size and key cellular parameters are uncertain, the cytological correlates of genome size were examined in this group. The cell and nuclear areas of erythrocytes showed a highly significant positive correlation with each other and with genome size across 22 cartilaginous and 201 ray-finned fishes. Regressions remained significant at all taxonomic levels, as well as among different fish lineages. However, the results revealed that cartilaginous fishes possess higher cytogenomic ratios than ray-finned fishes, as do cold-water fishes relative to their warm-water counterparts. Increases in genome size owing to ploidy shifts were found to influence cell and nucleus size in an immediate and causative manner, an effect that persists in ancient polyploid lineages. These correlations with cytological parameters known to have important influences on organismal phenotypes support an adaptive interpretation for genome size variation in fishes.     

Fungi associated with the diseases of freshwater fishes

During the course of present investigations 43 isolates representing 5 genera of Saprolegniaceous fungi were isolated from 19 different species of freshwater fishes. The parasitic abilities of these isolates have been demonstrated by conducting artificial inoculation experiments under laboratory conditions using the species of Puntius and Colisa as test fishes.     

鱼类杂交不亲和性的研究

本文分析研究了鲮鱼属间杂交和亲本自交的胚胎发育时序和热量要求、胚后发育的形态特征、以及胚胎染色体组等方面的差异;并讨论了这些差异与各种杂交不亲和表现之间的相关性。明确地指出,决定鱼类杂交不亲和性的主要因素是亲本间核型的差异和核质间的矛盾程度。双亲的核型差异较大时,杂交胚胎往往在发育中途夭亡而成活率极低,甚至完全得不到仔鱼。核型相同或相似的亲本,其杂交子代的成活率一般甚高;但也可能与核型著异较大的组合一样,因核、质基因组表达的模式或调控机制等存在着差异,以及它们对外界环境条件的要求有矛盾,乃使胚后发育的速率与顺序失调而出现各种畸形胚;畸形的出现标志着一些特定细胞分化的专一性代谢作用停滞,而胚后幼体必然趋向死亡。     

Ecological relevance of temporal stability in regional fish catches

The concept of habitat selection based on 'Ideal Free Distribution' theory suggests that areas of high suitability may attract larger quantities of fishes than less suitable or unsuitable areas. Catch data were used from groundfish surveys to identify areas of consistently high densities of whiting Merlangius merlangus , cod Gadus morhua and haddock Melanogrammus aeglefinus in the Irish Sea and plaice Pleuronectes platessa , sole Solea solea , lemon sole Microstomus kitt in the English Channel over a period of 10 and 9 years respectively. A method was introduced to delineate areas of the seabed that held consistently high numbers of fishes objectively from large datasets. These areas may constitute important habitat characteristics which may merit further scientific investigations in respect to 'Essential Fish Habitats'(EFH). In addition, the number of stations with consistently high abundances of fishes and the number of stations where no fishes were caught gave an indication of the site specificity of the fish species analysed. For the gadoids, whiting was found to be less site specific than cod and haddock, while for the flatfishes, plaice and sole were less site specific than lemon sole. The findings are discussed in the context of previously published studies on dietary specializm. The site specificity of demersal fishes has implications for the siting process for marine protected areas as fish species with a strong habitat affinity can be expected to benefit more from such management schemes.     

Annual fishes of the genus Nothobranchius as a model system for aging research

Aging research in vertebrates is hampered by the lack of short-lived models. Annual fishes of the genus Nothobranchius live in East African seasonal ponds. Their life expectancy in the wild is limited by the duration of the wet season and their lifespan in captivity is also short. Nothobranchius are popular aquarium fishes and many different species are kept as captive strains, providing rich material for comparative studies. The present paper aims at reviving the interest in these fishes by reporting that: (1) Nothobranchius can be cultured, and their eggs stored dry at room temperature for months or years, offering inexpensive methods of embryo storage; (2) Nothobranchius show accelerated growth and expression of aging biomarkers at the level of histology and behaviour; (3) the species Nothobranchius furzeri has a maximum lifespan of only 3 months and offers the possibility to perform investigations thus far unthinkable in a vertebrate, such as drug screening with life-long pharmacological treatments and experimental evolution; (4) when the lifespan of different species is compared, a general correlation is found between wet season duration in their natural habitat and longevity in captivity; and (5) vertebrate aging-related genes, such as p66Shc and MTP, can be easily isolated in Nothobranchius by homology cloning. These fishes can become excellent models for aging studies. They can be employed to test the effects of experimental manipulation on aging at a pace comparable with that of Drosophila and to probe the effects of natural selection on the evolution of aging-related genes.     

Recording the Motor Activity of Aquatic Animals by Ultrasound

An ultrasonic technique based on the Doppler effect is presented to allow the registration of aquatic animal movements. The method was tested on crucians (Carassius carassius) in an aquarium as part of chronobiological investigations. Comparison with light barrier measurements shows that the Doppler technique is suitable for detecting typical circadian and seasonal changes in the motor activity of the fishes. The features of the ultrasonic method are discussed.     

Volumetric imaging of fish locomotion

Fishes use multiple flexible fins in order to move and maintain stability in a complex fluid environment. We used a new approach, a volumetric velocimetry imaging system, to provide the first instantaneous three-dimensional views of wake structures as they are produced by freely swimming fishes. This new technology allowed us to demonstrate conclusively the linked ring vortex wake pattern that is produced by the symmetrical (homocercal) tail of fishes, and to visualize for the first time the three-dimensional vortex wake interaction between the dorsal and anal fins and the tail. We found that the dorsal and anal fin wakes were rapidly (within one tail beat) assimilated into the caudal fin vortex wake. These results show that volumetric imaging of biologically generated flow patterns can reveal new features of locomotor dynamics, and provides an avenue for future investigations of the diversity of fish swimming patterns and their hydrodynamic consequences.