基因工程技术在我国淡水鱼类育种上的应用

近20年来,随着转基因工程技术的兴起和应用,我国在淡水鱼类的抗病育种上取得了可喜的研究成果,为进一步用转基因工程技术培育优良鱼种奠定了良好的学术基础。     

淡水鱼类寄生线虫三未定种

本文报道在湖北省武汉市(30°30′N,114°12′E)采到的嗜子宫科线虫三个未定种:嗜子宫线虫未定种1,寄生于乌鳢的肾;嗜子宫线虫未定种2,寄生于黄鳝的腹腔;布氏线虫未定种,寄生于蒙古红鲌的腹腔。后两种因只采到雌虫且不完全成熟而不宜鉴定种名。三未定种在国内均未曾有文献报道,本文给出了它们的简单描述、形态图和简单讨论,供进一步研究参考。     

Feeding tactics and body condition of two introduced populations of pumpkinseed Lepomis gibbosus: taking advantages of human disturbances?

Abstract –  Feeding tactics, body condition and size structure of two populations of pumpkinseed Lepomis gibbosus from Cabañeros National Park (Guadiana River basin, central Spain) were compared to provide insight into the ecological requirements favouring levels of success/failure in relation to human intervention. Habitat, benthic macroinvertebrates and pumpkinseed were quantified in Bullaque (regulated flow, affected by agricultural activities) and Estena (natural conditions) rivers, from May to September of 2005 and 2006. Significant differences were found in the limnological characteristics between the two rivers. Spatial and temporal variations in diet composition were likely related to opportunistic feeding and high foraging plasticity. Diet diversity was higher in Bullaque River. Electivity of benthic prey showed variation between sized individuals and populations. The body condition of pumpkinseed was better in Bullaque River. Current results show that this invasive species is favoured by human intervention in Bullaque River.     

The spectre of past spectral conditions: colour plasticity,crypsis and predation risk in freshwater sculpin from newly deglaciated streams

Whiteley AR, Bergstrom CA, Linderoth T, Tallmon DA. The spectre of past spectral conditions: colour plasticity, crypsis, and predation risk in freshwater sculpin from newly deglaciated streams. Ecology of Freshwater Fish 2011: 20: 80–91. © 2010 John Wiley & Sons A/S Abstract – Coastrange sculpin (Cottus aleuticus) have colonised recently deglaciated streams of Glacier Bay National Park, Alaska, USA, within the last 200 years. Highly cryptic colouration across a marked gradient of stream substrate colours within Glacier Bay could result from physiological (rapid) or morphological (slower) colour change. Laboratory experiments revealed that physiological colour plasticity occurred on the order of minutes, with significant variation in the degree of colour change among individuals and between populations. In contrast, morphological colour plasticity occurred on the order of weeks to months. Experimentally manipulated spectral conditions influenced the magnitude and variance of subsequent physiological colour plasticity. In‐stream predation trials revealed significantly more predation attempts on higher background contrast sculpin models, providing evidence that background colour matching has strong fitness consequences. Colour plasticity with apparent fitness consequences occurs at multiple interacting time scales in coastrange sculpin and may play an important role in the colonisation of recently deglaciated streams.     

Trophic structure of fish assemblages from Mamoré River floodplain lakes (Bolivia)

Abstract –  The fish assemblage of the floodplain of the Mamoré River (Bolivia) was estimated in eight lakes, corresponding to four habitat types, situated on an environmental gradient related to the river distance: lakes situated near the river, in the forested floodplain, at the floodplain edge and lakes isolated in the savanna. This paper documents the diet of 71 fish species (among the 140 recorded) and compares the taxonomic and trophic structure of fish assemblages between four lake types. The diet analysis was conducted to determine five trophic guilds: algivores/iliophages, herbivores, zooplanktivores, invertivores and piscivores. The taxonomic and trophic structures of the fish assemblages were not similar in the different lake types of the Mamoré River. The trophic structure of assemblages showed a coarse pattern of dominance of algivores/iliophages and invertivores, but different situations were observed in relative abundance of the trophic groups in relation to the spatial position of the lakes (except for piscivores). Lakes close to the river appeared more favourable to the microphages (algivores/iliophages, zooplanktivores) although remote lakes appeared more favourable to the macrophages (invertivores, herbivores). These results support the general idea that fish distribution follows a pattern linked to the ecology of the species, and related to environmental characteristics of the lakes.     

Life history trait diversity of native freshwater fishes in North America

Mims MC, Olden JD, Shattuck ZR, Poff NL. Life history trait diversity of native freshwater fishes in North America.
Ecology of Freshwater Fish 2010: 19: 390–400. © 2010 John Wiley & Sons A/S Abstract – Freshwater fish diversity is shaped by phylogenetic constraints acting on related taxa and biogeographic constraints operating on regional species pools. In the present study, we use a trait‐based approach to examine taxonomic and biogeographic patterns of life history diversity of freshwater fishes in North America (exclusive of Mexico). Multivariate analysis revealed strong support for a tri‐lateral continuum model with three end‐point strategies defining the equilibrium (low fecundity, high juvenile survivorship), opportunistic (early maturation, low juvenile survivorship), and periodic (late maturation, high fecundity, low juvenile survivorship) life histories. Trait composition and diversity varied greatly between and within major families. Finally, we used occurrence data for large watersheds (n = 350) throughout the United States and Canada to examine geographic patterns of life history variation. Distinct patterns of life history strategies were discernible and deemed congruent with biogeographic processes and selection pressures acting on life history strategies of freshwater fishes throughout North America.     

水温对淡水温水性鱼类生命活动的影响

水温是影响鱼类生命活动的重要生态学因子。综述水温对淡水温水性鱼类的影响,为鱼类资源的增殖和水体生物多样性保护提供参考。从繁殖、摄食生长、代谢速率、临界游泳能力、免疫功能5方面的鱼类生命活动进行综述,其中,水温对鱼类的繁殖和生长影响最大,当水温适宜时,多数淡水温水性鱼类的各项生理活动都能正常进行;但当水温超过临界温度时会导致机体内代谢紊乱、活动能力降低、甚至造成鱼类死亡,最终引起鱼类种群结构和数量分布的显著变化。鱼类的临界游泳能力和高强度运动之后的重复运动能力也会受到水温的影响;鱼类免疫应答受水温影响较大,水温严重不适会导致免疫防御机制紊乱。水温只是影响鱼类生存的生态因子之一,但在航道建设、河流生态修复、鱼类资源评估以及水生态系统保护过程中均占据不容忽视的地位。在河流开发以及水文调节过程中,要最大限度降低其对水温生态因子的影响。     

Impacts of introducing Nile tilapia on the fisheries of a tropical reservoir in North‐eastern Brazil

Abstract Nile tilapia, Oreochromis niloticus (L.), has been introduced in most tropical and subtropical regions of the world to improve inland fisheries and aquaculture. This species is generally viewed as beneficial where introduced, but the environmental impacts of its widespread introductions are uncertain and not well understood. In this study, a 30‐year time series of fisheries records from a tropical reservoir was divided into five equal periods of 6 years and compared. The introduction of Nile tilapia did not increase the total catch‐per‐unit‐of‐effort (CPUE), the number of fishers actively fishing or their per capita income. Conversely, a significant reduction in the CPUE of other commercially important species was observed after the introduction of Nile tilapia in the reservoir. Although other factors cannot be rule out as possible explanations of the observed changes in the reservoir fisheries, the results are consistent with the hypothesis that these changes may have been caused, at least partially, by the introduction of the Nile tilapia.     

Seasonal changes in abundance and age structure of burbot Lota lota (L.) and stone loach Barbatula barbatula (L.) in the littoral zone of a large pre-alpine lake

Abstract – Seasonal changes in the abundance and age structure of the stone loach and burbot populations in the littoral of Lake Constance, Germany were examined. The abundance of both species was lowest during the summer months and highest during autumn. The stone loach population in the littoral comprised age classes 1 to 3 plus, in autumn, age class 0. The burbot population showed distinct seasonal changes in both length and age composition. During spring and summer, only age class 1 was present in the littoral whereas, in autumn, only age class 0 was caught. This remarkably strict habitat segregation of two age classes by season is discussed with respect to a possible mechanism for avoiding conspecific predator risk in a cannibalistic species.     

淡水养殖鱼类细菌出血性败血病药物防治研究↑（*）

通过对防治淡水养殖鱼类细菌出血性败血病的口服药物败血宁的系列实验研究表明：败血宁主药（ＢＬ）对嗜水气单胞菌（Ａｅｒｏｍｏｎａｓｈｙｄｒｏｐｈｉｌａ）的ＭＩＣ为４μｇ／ｍｌ,在剂量１０～３０ｍｇ／ｋｇ范围内进行鱼体内抗菌试验,对鲢、银鲫的预防和治疗性给药有效率皆在８０％以上,其ＬＤ５０为６１５．２ｍｇ／ｋｇ,属低毒,对鱼类较为安全;以３０、６０ｍｇ／ｋｇ的剂量口灌银鲫进行微核试验证实ＢＬ诱发红细胞微核率不明显,无潜在致突变作用。用ＨＰＬＣ法测定ＢＬ在鱼体内治疗浓度维持时间为８～９ｈ,消除半衰期ｔ（１／２β）为２．５ｈ,连续灌药３ｄ后停药５ｄ在银鲫血浆中未检测到ＢＬ的含量。以３０ｍｇ／ｋｇ的剂量进行了四年的池塘应用试验,统计有效率为９２．９％,疗效肯定。     

The Palaeozoic, Mesozoic and Early Cenozoic fishes of Africa

Africa has provided many fossil fishes from sediments laid down over a 400 million year period. The large array of fossil fishes come from diverse localities throughout the continent, representing a variety of environments. The marine fossil fishes of Africa have not been reviewed as a whole, while the freshwater Cenozoic fishes of Africa were last reviewed over 25 years ago. Since that time, many new finds have increased our knowledge of the history of African fishes. This paper summarizes the known fish fossils, excluding otoliths, from marine and freshwater deposits throughout Africa from the Palaeozoic, Mesozoic and first part of the Cenozoic (Palaeogene). Much new work is ongoing, in areas such as Mali and South Africa, from which more information on the ichthyofaunas should come to light. New information presented here includes the Eocene site of Mahenge, Tanzania, from which have come the oldest known members of the family Cichlidae.