新疆伊犁河不同河段鱼类的物种多样性和优势种

为了了解伊犁河鱼类群落结构和多样性特征, 于2012—2014年连续3年对我国境内新疆伊犁河上、中和下游不同河段进行鱼类资源调查。获得27种鱼类样本, 隶属于6目9科23属。伊犁河中、上游河段主要以斯氏高原鳅、新疆裸重唇鱼、新疆高原鳅和伊犁裂腹鱼等土著鱼类为优势种, 下游河段的优势种主要有鲤、草鱼和鲫等外来种。伊犁河中、上游河段鱼类种类稀少, 大中型鱼类资源稀少, 鱼类群落多样性低。梯级水电站的开发、过度捕捞以及外来种入侵对伊犁河鱼类鱼类群落造成了很大的影响。     

颈斑尖猪鱼——中国南海隆头鱼科新纪录种

本文根据采自海南岛的标本描述了中国南海一新记录种:颈斑尖猪鱼(Leptojulis lambdastigma)。本种的主要形态特征为:体长形,体长为体高的3.7~4.0倍,为头长的3.1~3.6倍;头长为吻长的2.7~3.3倍,为胸鳍长的1.45~1.65倍;头裸露无鳞;两颌前端各具2对大犬齿,外侧1对犬齿弯向外后方;背鳍Ⅸ-12,臀鳍Ⅲ-12,胸鳍i(不分支)+11-12(分支);侧线完整,侧线鳞27;颈部具一个"V"形大黑斑,胸鳍后部的上方、侧线的下方具一小黑斑。新鲜标本头部具2条黄色纵带,沿体侧分别经眼和胸鳍基部向后达尾鳍基部;体侧背部具1条浅棕黄色条带;胸鳍基部棕红色,后部浅色;臀鳍浅蓝色;尾鳍下部淡蓝色,上部橙色。本种与尾斑尖猪鱼(L.urostigma)形态较为相似,主要差别在于颈斑尖猪鱼的颈部具有一显著的"V"形黑斑,尾鳍基部无黑斑(尾斑尖猪鱼具此黑斑)。     

生长激素及其基因转移对鱼类生长和渗透压的调节作用

生长激素及其基因转移对鱼类生长和渗透压的调节起着重要作用。转生长激素基因鱼表现出明显的快速生长效应。生长激素促进了鲑科鱼类对海水的适应能力。本文对此进行了综述,并讨论了生长激素及其基因转移对鱼类生长和渗透压调节作用的生理机制、生长激素与胰岛素样生长因子以及甲状腺激素的关系。     

Winter spatial distribution of fish larvae assemblages relative to the hydrography of the waters surrounding Taiwan

The aim of this study was to investigate the species composition and distribution of fish larvae in relation to hydrographic conditions in the waters surrounding Taiwan Island (TI) in February 2003. In total, 242 kinds of fish larvae belonging to 127 genera and 75 families were recognized. Among these, 109 taxa were identified to the family or genus level, others to the species level. The 12 predominant types, which constituted 71% of the total fish larvae, were Engraulis japonica, Scomber sp., Diaphus spp., Benthosema pterotum, Carangoides ferdau, Embolichthys mitsukurii, Maurolicus sp., unidentified Myctophidae, Gonostoma gracile, Trichiurus lepturus, unidentified Gobiidae, and Myctophum asperum. The distribution of fish larvae showed a clear association with water masses around TI, with higher abundances and lower species richness northwest of TI where the China Coastal Current prevails, and lower abundances and higher species diversity east of TI where the Kuroshio Current dominates. Cluster analysis distinguished three station groups and four species groups, and the distribution patterns of fish larvae also corresponded to hydrographic conditions. The total abundances of fish larvae and eight of the 12 predominant taxa showed significant and positive correlations with zooplankton abundance, which suggests that food source might be a key factor determining the abundance and distribution of fish larvae during the winter.     

Biological Control of Culex pipiens pattens (Diptera, Culicidae) by the Release of Fish Muddy Loach, Misgurnus mizolepis in Natural Ponds, Korea

ABSTRACT An assessment on the biological control potential with the fish muddy loaches (Misgurnus mizolepis) was conducted against naturally bred Culex pipiens pollens larvae in four ponds (A, B, C and D) in Busan from July through September, 2001. Predation of the fish at 3 different release rates of 4,5, and 6 fish/m² resulted in mostly over 90% mosquito control from the first week after treatment through the end of the survey period for 11 weeks. There were no significant difference among the release rates of fish at the 5% level of probability. However, substantial controls of 43.0% and 25.9% were obtained from pond C during the 3rd and 7th weeks after the fish introduction, respectively. The results of those two weeks showed a lower biological control by the introduced larvivorous fishes. This might be due to the presence of heavy organic matters including aquatic weeds and/or severely polluted water from sewage in pond C. The aquatic weeds covered the pond's water surface which may have affected the deterioration of mosquito preying in favor of aquatic weeds. Also, the fishes were observed to avoid severely contaminated sewage water in some parts of ponds A and C where more mosquito larvae were found.     

Spawning tactics of paired males of the dark chub,Zacco temmincki,reflect potential fitness costs of satellites

Synopsis Paired males of the dark chub, Zacco temmincki, buried released eggs by vibrating their anal fin, but this behavior was prevented and eggs were cannibalized when many satellites (males and females) were present. A number of satellite males also caused a loss to paired males in sperm competition on spawning grounds far from shelters. Paired males followed repeating tactics, which were defined as successive spawning acts at the same redd, in most cases, but occasionally did shifting tactics which refer to spawning acts conducted successively at different redds. The proportion of the shifting tactic was not correlated with the dominance status of paired males. The shifting tactic was not advantageous in performing spawnings frequently. The calculation of the total advantage of both tactics indicated that the shifting tactic itself was not more beneficial than the repeating tactic at any density of satellites. Since a number of satellites stayed around the redd when no spawning pair was present, or pursued a pair or a single dominant male moving between spawning grounds, the occasional shifting tactics of paired males functioned to confuse and disperse satellites. The spawning tactics of paired males apparently reflected potential fitness costs of satellites. Paired males mainly spawned at the redds near shelters, despite the fact that more satellites were present to devour eggs, presumably because they could obtain many females and monopolize fertilizations.     

鱼类趋化因子的研究进展

趋化因子(Chemokine)是由多种细胞在致病因子刺激后分泌的一类低分子量的细胞因子,它们都具有激活和趋化白细胞的作用。趋化因子从结构上可分为四类:CC型、CXC型、CX3C型和C型;从功能上可分为两种类型:一类主要诱导白细胞到炎症部位;另一类主要是对肌体起免疫监控作用。目前,有关鱼类趋化因子的研究主要集中于CXC型和CC型两类,以及其在非特异性免疫中的作用。     

Rapid changes in fish utilization of mangrove habitat in Western Madagascar

Fish use of a mangrove habitat was studied in a small mangrove forest on the West coast of Madagascar. A sand bar near the inlet retains water in parts of the channel (pools) at low tide. Fishes in four of these pools were examined daily at all phases of the tidal cycle for 3 weeks using underwater visual census. During week 1, fishes were diverse and abundant in all pools: the dominant species were cardinalfish (related to Apogon lateralis); monos, Monodactylus argenteus; black spotted snappers, Lutjanus ehrenbergi; double bar bream, Acanthopagrus bifasciatus; emperors, Lethrinus lentjan and L. sp., surgeon fish, Acanthurus nigricauda; red-lined sweetlips, Plectorhinchus plagiodesmis; and butterflyfish, Chaetodon kleini. Some species were more abundant in shaded pools; others in more open pools. During week 2 a dramatic difference was noted: the only fishes found were schools of cardinalfish and one moray eel. This week had neap tides, with high tides in the morning and low tides in the afternoon. As the week progressed and during week 3 (spring tides), fishes slowly repopulated the habitat and diversity increased. Monos, absent in week 2, now had increasing numbers of small individuals. While large emperors were scarce, small individuals appeared. The larger butterflyfish and surgeonfish seen in week 1 were replaced by small ones during week 3. Species that had been rare in week 1 were more abundant, including pipefish and small barracudas. While species richness increased during week 3, the community was strikingly different from that seen 2 weeks earlier. Only Pool 1, closest to the entrance, recovered its original species richness. Abundance was much lower than in week 1. Our snapshot study apparently captured a time when older juveniles left the mangrove forest and smaller fishes recruited into it. Utilization of this habitat will likely vary throughout the year depending on the reproductive cycle of the different species whose juveniles utilize it. Longer studies are needed to learn about cycles in fish use of the mangroves.