Record of cestode parasites from Penaeid prawns of Ratnagiri

Studies on the cestode parasites of commercially important prawns are few. So far only four species of larval cestodes have been recorded from penaeid prawns of Florida (Woodburn et al., 1957, Sparks and Mackin, 1957, Hutton et al, 1959 and Kruse, 1959). So far there are no records of larval cestodes from prawns of India. For the first time the authors have been able to collect six forms of larval cestodes from penaeid prawns of Ratnagiri.

Comparative electrophoretic patterns of lactase dehydrogenase and malate dehydrogenase in five Lake Victoria cichlid species

Biochemical techniques designed to compare species on the basis of protein differences were started by NUTTALL (1904) who used immunological methods to compare the serum of humans with that of other primates. Since then more refined techniques have led to better results at the protein level in taxonomy, The analyses of proteins are considered to be the simplest indirect approach to understanding the structure and function of the genetic material, deoxyribonucleic acid (DNA). Interest in these analyses arises because of the close relationship between protein structure and gene structure. Thus by comparing the properties of homologous proteins from different taxa one is in essence comparins their genes (GORMAN er al., 1971). It is now an established fact that genetic information coded in molecules of DNA is translated through a series of reactions in the structure of proteins which form the principal morphological units of the animal body at the molecular level of organization (SIBLEY, 1952). A convenient method of comparing molecular differences between species is to measure the electrophoretic mobility of proteins in a starch gel medium (ASPINWALL and TSUYUKI, 1968) or acrylamide gel (RAYMOND and WEINTRAUB, 1959; BOUCK and BALL, 1968). Proteins with enzymatic properties can be compared on the basis of catalytic activity in the presence or absence of inhibitors (KAPLAN et al., 1959); BAILEY et al., t 1970). A combination of gel electrophoresis and histochemical enzyme detection techniques (HUNTER and MARKERT, 1957) makes it possible to combine electrophoretic mobility anti catalytic activity comparison, Enzyme patterns exhibited in starch gel or acrylamide gel have been used to classify different species. BOUCK and BALL (1968)working with lactate dehydrogenase in species of Trout found that each Trout species had LDH pattern characterbtic of that species. ASPINIWALL and TSUYUKI (1968) used muscle protein electrophoretic patterns to identify hybrid fishes. TSUYUKI and ROBERTS (1963) and TSUYUKI et al. (1964-65) found that myogen protein patterns in fishes were species specific. The myogen patterns within one family were remarkably parallel with the existing morphometric classification and these patterns constituted a single criterion by which the fishes could be identified. The fish used in these investigations were collected from shallow waters (10 metres) of Lake Victoria in two areas, Jinja and Kisumu, using gillnets and beach-seines. The study included ten specimens of each of the following specIes: (l) Haplochromis michaeli (2) Haploehromis obems (3) Astatoreochromis ulluaudi (4) Tilapia zillii and (5) Tilapia nilotica.

黑龙江的白鲢

<正> 白鲢,东北地区又称胖头,在黑龙江流域内分布很广。黑龙江中下游、松花江、嫩江等干流中都很丰盛,黑龙江上游呼玛以上的水体中,则尚未见其棲息。本文是根据1957—1958两年内,黑龙江流域渔业考察队在上述地区所采的标本和野外观察的新鲜材料共约70多尾,而整理分析的。白鲢是一种闻名的淡水饲养鱼,生长迅速,市上常见的大小多为2—7市斤,黑龙江中10斤和10斤以上的个体也十分多,下面是1958年4—8月从黑龙江、松花江、嫩江等地所采到的40尾白鲢的体重记录:

黑龙江流域水产资源的现状和黑龙江中上游泾流调节后的渔业利用

<正> 一、野外工作概况及成果为了配合黑龙江流域规划和水产资源的开发以及制订发展渔业的远景规划,黑龙江综合考察队渔业小队在1957—1958两年内,在黑龙江流域的我国境内进行了两年野外调查工作。1957年的工作,从4月下旬开始,至10月上旬结束,先后分小组在第一松花江、黑龙江中游进行了流动考察,在黑龙江上游的黑河、呼玛、漠河和嫩江的江桥、齐齐哈尔、

黑龙江的浮游动物及未来水库中浮游动物的可能组成

<正> 一、前言黑龙江是我国四大河流之一,位于我国东北边境,上游有额尔古纳河和石勒喀河,汇合后从西北向东南蛇行,是中苏两国的天然分界线。与乌苏里江汇合后,下游全部流经苏联境内,注入鄂霍次克海。为了开发黑龙江的水力资源,中苏两国于1956年开始,进行综合考察。浮游动物的调查研究是渔业小队工作的一个组成部分。工作共进行两年,1957年工作着重于黑龙江流域各个水体中浮游动物普查,工作地区包括黑龙江、松花江、嫩江、达赖湖、镜泊湖、兴凯湖及五大连池。在各个水体中采集了定性标本,并在7月和8月在黑河和哈尔滨两地做

梁子湖鳜鱼的生物学

<正> 1956年1月至1957年3月,作者在梁子湖进行了鳜鱼[Siniperca chuatsi(Basilew-sky)]生态学的调查。材料主要取自梁子镇鲜鱼收购站。每月取材的次数自3次至10次不等,一般5次以上。在生殖季节,有时直接从渔船取得材料。材料取得后,除记录体长、体重外,还进行了性腺发育情形、胃内食物等观察,然后取下鳃盖骨,以作测定年龄之用。先后共解剖了360尾鳜鱼。

梁子湖湖沼学资料

<正> 梁子湖是湖北省境内的大型湖泊之一。本所鱼类学组曾选择它来作为研究鱼类生物学的场所(1955—1957)。同时,为了了解与鱼类生活活动有关的若干环境因素,我们也对梁子湖区的周围环境和自然条件以及湖水和湖泥的各种性质等进行了调查。一、调查概况1955年2月,我们就在湖中央的一个小岛——梁子镇——上设立了工作站(镇位于东经114°33′34″,北纬30°15′18″)。在岛的东面湖滨设置了水文气象的观测点,每日有专人测定并记录气温、水温、日照时间、水位、风向与天气的情况等。此外,并从东沟水文

Ultrastructure of the bloodstream forms of the fish trypanosome Trypanosoma pseudobagri dogiel et achmerov, 1959

The ultrastructure of the bloodstream forms of Trypanosoma pseudobagri from its natural host, yellow catfish (Pseudobagrus fulvidraco), a freshwater fish, is described in the present work. The pellicle, consisting of a unit membrane with a superimposed surface coat, the structure and attachment of the flagellum and the subpellicular microtubules show the usual structural and organizational features. Cell organelles and cytoplasmic inclusions such as kinetoplast, mitochondria, nucleus and vacuoles, which occur in trypanosomidae, are observed and described in detail. The ultrastructure of T. pseudobagri has been compared with that of bloodstream forms of other species and culture forms of fish trypanosomes, and similarities and divergences are discussed. The Golgi-complex and endoplasmic reticulum could not be observed and need further investigation.

First description of the male and redescription of the female of Philometra clavaeceps Dogiel and Akhmerov, 1959 (Nematoda : Philometridae), a parasite of east Asian cyprinid fish

The first description of the male and a redescription of the female of the nematode Philometra clavaeceps Dogiel and Akhmerov, 1959, a parasite of east Asian cyprinids, are presented on the basis of specimens collected from Culter erythropterus Basilewsky and Culler dabryi Bleeker from Liangzi Lake (the Yangtze River basin), Hubei Province, central China. Gravid females from the fish abdominal cavity, penetrating often into ovaries, occurred in May-June, whereas conspecific males and young mature females on the swimbladder were recorded in January. Philometra clavaeceps seems to have a pronounced annual maturation cycle in the locality. The finding of P. clavaeceps in C. dabryi represents a new host record.

Redescription of Camallanus hypophthalmichthys Dogel and Akhmerov, 1959 (Nematoda : Camallanidae) and its first record from fishes in China

The nematode Camallanus hypophthalmichthys Dogel and Akhmerov, 1959 is redescribed from specimens collected from the intestine of the bighead carp Aristichthys nobilis, from Liangzihu Lake (Yangtze River basin), Hubei Province, central China. The light and scanning electron microscopical examination made it possible to study in detail the morphology of this so far little-known species and to confirm its validity. The main specific features of C. hypophthalmichthys distinguishing it from the most similar Camallanus spp. is the presence of 3 small caudal processes on the male tail tip, 13-16 longitudinal ridges on the inner surface of the valve of the buccal capsule, and the arrangement of preanal and postanal genital papillae in the male. This finding represents a new host record, the first record of this parasite in the Yangtze River basin, and the first documented record of C. hypophthalmichthys from China. Camallanus hypophthalmichthys is considered a specific intestinal parasite of fishes of the cyprinid Hypophthalmichthyinae.

Long-term changes of Copepoda community (1957-1996) in a subtropical Chinese lake stocked densely with planktivorous filter-feeding silver and bighead carp

In contrast to the relatively well documented impact of particulate-feeding fish on zooplankton communities, little attention has been devoted to the impact of filter-feeding fish. Filter-feeding silver and bighead carp are the most intensively cultured fish species in Asia and comprise much of the production of Chinese aquaculture. However, little information is known about the impact of either fish on the zooplankton community. Long-term changes in the Copepoda community (1957-1996) were studied at two sampling stations of a subtropical Chinese lake (Lake Donghu) dominated by silver and bighead carp. For both calanoids and cyclopoids, the littoral station (I) was much more resource profitable than the pelagic station (II). There has been a tremendous increase in the annual fish catch over the past 30 years due to the increased stocking with fingerlings of the two carp species. There was a notably higher fish density at Station I than at Station II. Cyclopoid abundance was notably higher at Station I than at Station II during the 1950s to the 1980s, while the reverse became true in the 1990s. This is probably because when fish abundance increased to an extremely high level, the impact of fish predation on the cyclopoids became more important than that of food resources at the littoral station. At both stations, cyclopoid abundance was relatively low in spite of the presence of abundant prey. Similarly, calanoid density did not differ significantly between the two stations in the 1950s and 1960s, but was significantly lower at Station I than at Station II during the 1980s and 1990s. Such changes are attributed to the gradient of fish predation between the stations and an increasing predation pressure by the fish. The increased fish predation also correlated with a shift in summer-dominant calanoids from larger species to smaller ones. In conclusion, the predaceous cyclopoids are affected by fish predation to a much lesser extent than the herbivorous calanoids, and therefore increased predation by filter-feeding fish results in a definite increase in the cyclopoid/calanoid ratio. Predation by filter-feeding fish has been a driving force in shaping the copepod community structure of Lake Donghu during the past decades.

Changes of Leptodora kindti abundance (1957-1996) in a planktivorous fishes-dominated subtropical Chinese lake (Lake Donghu)

The changes of L. kindti density from 1957 to 1996 were studied in a shallow, eutrophic Chinese lake, Lake Donghu. Despite the fact that the fish yield of planktivorous fish (silver carp and bighead carp) has increased steadily, the population density of L. kindti has also increased since 1957 and peaked in 1982/1983, The increase of both fish and L. kindti densities during this period may have benefitted from a considerable increase in the densities of their zooplankton prey. and fish predation on L. kindti might have been minor. As the fish yield increased further, their predation began to suppress most zooplankton prey including L. kindti. The largely increased fish predation on L. kindti is also evidenced by the remarkable decline of their body length after 1984. The density of L. kindti was significantly higher at the pelagic station (II) than at the littoral station (I), although for L. kindti, the littoral zone was significantly more resource profitable than the pelagic zone. The gradient of fish predation (more fish in the littoral zone) is the most likely explanation, since L. kindti is reported to be a preferred prey for many planktivorous fishes. The maximum density of L. kindti was 1.78 ind./I (on Aug. 17, 1984) at Station I and 1.55 ind./I (on Sep. 13, 1985) at Station II, respectively, which are close to those in several other eutrophic lakes.

中国海砂海星科（棘皮动物门：海星纲）系统分类学研究

　　本文根据中国科学院海洋生物标本馆（MBMCAS）所收藏的砂海星科标本对中国海砂海星科进行了系统分类学研究。研究材料包括中国科学院海洋研究所等单位进行的北黄海西部和渤海综合调查（1957-1958），全国海洋综合调查（1958-1960），中越北部湾海洋综合调查（1959-1960，1962）等获得的大量标本。文中以传统的形态分类学方法为主，结合现代分类学的手段和方法准确鉴定了中国海砂海星科的疑难种类，搞清了中国海砂海星科的种类组成及分类上存在的问题，并进行了地理分布和分类区系研究。 　　文中共记述中国海砂海星科1属9种，包括2新种，详细描述了各种的形态特征、地理分布，并讨论了它们在分类学研究中存在的问题，提供了各种的形态结构图、地理分布图和中国海砂海星科种的分类检索表。地理分布和分类区系研究结果表明，中国海砂海星科有3种广布于印度－西太平洋海域，有4种仅发现于中国海域，5种在日本近海也有分布，区系分布与日本近海有着较大的相似性。 　　该研究对中国海砂海星科作了全面的系统分类学研究，改变了中国海砂海星科研究的混乱局面，为中国动物志编写，生物多样性监测、评估与保护，砂海星科资源的综合研究和利用积累了有用资料。