Models for comparing average first-year growth in length of freshwater fish

Abstract  Logistic curves of the average growth in length were elaborated for young-of-the-year perch, Perca fluviatilis L., zander. Stizostedion lucioperca (L.), ruffe, Gymnocephalus cernua (L.), bream, Abramis brama (L.), and roach, Rutilus rutilus (L.), using data from 62 localities. Mean relative deviation from this average growth (MRDAG) is proposed as a simple and reliable indicator of growth rate. The MRDAG for perch, zander, bream and roach showed a significant negative linear relationship with the geographical latitude.     

Ancient and modern mitochondrial haplotypes of common bream (Abramis brama L.) in Poland

Abstract –  Genetic data on archaeological specimens provide complementary information for addressing questions on distribution and migration of fishes over long time scales. In this study DNA was extracted from common bream bones ( N  = 4), dated c. 6000–1000  bp , and a 172 bp fragment of mitochondrial cytochrome b gene has been sequenced. The obtained sequences differed from homologous sequences of breams living contemporarily ( N  = 4), inhabiting the same geographical areas as 'ancient' fish. None of ancient mitochondrial haplotype was found in fish living at present. Our results suggest that fish vicariance could be affected also by other than glacial retreat historical events, and the mechanisms that influenced present distribution of freshwater fishes are still unclear.     

蛤蟆通水库东方欧鳊移殖试验

蛤蟆通水库东方欧鳊移殖试验ＴＥＳＴＯＮＴＨＥＴＲＡＮＳＰＬＡＮＴＡＴＩＯＮＯＦＡＢＲＡＭＩＳＢＲＡＭＡＯＲＩＥＮＴＡＬＩＳＴＯＨＡＭＡＴＯＮＧＲＥＳＥＲＶＯＩＲ夏重志姜作发董崇智赵春刚（黑龙江水产研究所，哈尔滨１５００７０）ＸｉａＺｈｏｎｇｚｈｉ，Ｊ...     

额尔齐斯河东方欧鳊(Abramis brama orientalis Berg)寄生虫调查研究

按照鱼类寄生虫调查及研究方法,对额尔齐斯河(中国段)东方欧鳊(Abramis brama orientalis Berg)寄生虫种类及感染情况进行了调查研究。结果检出寄生虫8种:对盲囊线虫、复口吸虫、温氏指环虫、宽头鲤蠢绦虫、奇怪双身虫、复殖吸虫幼虫、泡吻棘头虫和毛细线虫。感染率分别达43.75%,37.5%,18.75%,18.75%,14.58%,12.5%,8.33%,2.08%。奇怪双身虫经检索鉴定,为我国单殖吸虫纲铗钩虫目双身虫科的一属、种新记录。     

Genetic comparison of Iranian and Azeri populations of the oriental bream Abramis brama orientalis (Berg) using microsatellites

The aim of this study was to compare, levels of genetic polymorphism between Iranian and Azeri bream (Abramis brama orientalis) populations using five microsatellite loci. The reduced number of alleles in the Iranian populations compared with the Azeri population led us to infer that the genetic variability of the Iranian stocks has been reduced due to inbreeding and genetic drift. Significant population differentiation (F_st) was observed between the Azeri and the Iranian populations, which could be explained by the higher number of alleles in the Azeri population. Significant deviations from Hardy–Weinberg equilibrium were found at more loci in the Iranian populations than the Azeri population. Beyond the hypothesis of null alleles, the heterozygote deficiency may have arisen due to breeding between related individuals in the Iranian populations. This investigation represents the first approach to the knowledge of the genetic variability of Iranian and Azeri bream populations using microsatellite markers, and the reported results could be of interest for management and conservation programmes of this species in Iran.     

Mast cells in the gills and intestines of naturally infected fish: evidence of migration and degranulation

Immunopathological and ultrastructural studies were carried out on the gills of bream, Abramis brama, naturally infected with the copepod Ergasilus sieboldi and on the intestine of brown trout, Salmo trutta, infected with the acanthocephalan Echinorhynchus truttae. Infected gills showed extensive tissue damage due to copepod attachment, including hyperplasia, as well as proliferation of mast cells, rodlet cells and mucous cells. In parasitized gills of bream, mast cells were more abundant than in uninfected gills. They were free within the lacunae, as well as outside and inside the blood vessels of the primary lamellae, and made intimate contact with vascular endothelial cells and with neutrophils. In some infected gills, degranulation of mast cells was common. Infected intestines of brown trout had more mast cells than uninfected intestines, and these cells were often in close proximity to, and inside, the capillaries and lying close to fibroblasts of the muscularis layer and stratum granulosum. Intense degranulation of mast cells was encountered in all intestinal layers, especially near the E. truttae body.     

东方欧鳊染色体组型分析及其亚科分类地位的探讨

本文报导了东方欧鳊的染色体组型分析结果,其染色体数目为2n=50,由9对中部、11对亚中部、3对亚端部和2对端部着丝点染色体组成,核型公式为:18M+22SM+6ST+4T,NF=96。通过比较发现,东方欧鳊和鳊亚科鱼类的染色体组型差别较大,而与雅罗鱼亚科的某些鱼类有相似之处,这表明东方欧鳊在分类上归入雅罗鱼亚科更为妥当。     

额尔齐斯河温氏指环虫的种群生态学研究

2009年4月至2010年1月对额尔齐斯河(中国段)东方欧鳊(Abramis brama orientalis Berg)鳃部寄生的温氏指环虫(Dactylogyrus wunderi Bychowsky)进行了取样调查,以期了解温氏指环虫的种群生态学特点。结果表明,温氏指环虫的总感染率为12.92%,平均感染强度为5.70(1～19)。感染率、感染强度在不同体长组的宿主中表现出不同的变化趋势,随着宿主体长(L)的增大,温氏指环虫的感染率在35cm以上的宿主中达到最大,为50%,而平均感染强度在20≤L<25的体长范围内最小,为1.75;温氏指环虫种群在不同体长组宿主中的分布类型主要为聚集分布,且各体长段宿主之间的感染强度差异不显著(P>0.05)。     

额尔齐斯河东方欧鳊寄生奇异双身虫的种群生态学研究

通过2009年4月至2010年1月在额尔齐斯河(中国段)野外取样调查,研究寄生于东方欧鳊(Abramis brama orientalis)鳃部的奇异双身虫(Diplozoon paradoxum)的种群生态学特点。结果表明,东方欧鳊感染奇异双身虫的总感染率为24.16%,平均感染强度为4.19,在宿主体长L≤30 cm时,感染率随体长增大有升高的趋势;在体长25 cmL≤30 cm时,感染率达到最大,为42.11%;而体长L30 cm的宿主,没有感染奇异双身虫。奇异双身虫在东方欧鳊各体长段均呈聚集分布。