淡水白鲳的形态习性观察

淡水白鲳Colossoma brachypomum,学名为短盖巨脂鲤，隶属于鲤形目、脂鲤科、巨脂鲤属。原产于南美洲的亚马逊河，是典型的热带和亚热带鱼类。1982年台湾引进养殖，1985年中国水产科学研究院长江水产研究所、珠江水产研究所分别引进。至今，已在我国繁衍后代。1986年我所引进少量饲养。     

淡水白鲳越冬技术措施的改进

淡水白鲳，也称淡水鲳，学名为短盖巨脂鲤，属脂鲤目、脂鲤科，巨脂鲤属，是热带和亚热带食用与观赏兼备的大型经济鱼类。淡水白鲳被我国引进后，因其具有肉质好、体型大，生长快、食性广、病害少、耐低氧、易起捕、好垂钓等优点，受到各地消费者和养殖户的欢迎，其养殖面积正在不断扩大。     

生物工程应用技术：鲤科鱼类的全雌鱼生产

鲤科(或包括鲤亚目、泥鳅等)鱼类的染色体试验的比较早,已能制成各式各样的倍数体和雌性发生二倍体等。一般地说,鲤科、鱼类等,不象鲑科鱼类随着成熟期出现的弊病(生长、成活率、商品价值低等)显著,致使养殖界对生产三倍体不育鱼的兴趣不大。反而积极发展雌核生殖的全雌(种苗)生产和确立早期纯系的研究。这里,概要介绍东京水产大学水产养殖学教研组和水产厅养殖研究所育种研究室共同进行的“关于通过染色体操作的鲤科鱼类全雌性生产的研究的技术。     

南美鲱鱼池塘养殖初试

南美鲱鱼又称巴西鲷 ,学名小口脂鲤 ,属脂鲤目无齿脂鲤科鱼类 ,原产于南美洲 ,是巴西等国家的一种主要淡水经济鱼类 ,适温范围９～３６℃。１９９６年首次引进我国 ,系国内最新引进的淡水养殖鱼类新品种。为了探讨该鱼的经济性能及生长规律 ,为推广养殖提供科学依据 ,１９９９年我们进行了南美鲱鱼池塘养殖试验，经过近１２０ｄ的养殖 ,取得了较好的效果。现将试验情况总结如下。１材料与方法１．１试验塘试验塘１个 ,面积１３３４ ,为本县高湖水库坝下渔场的鱼种培育池。池底为沙质 ,保水性差 ,池塘深度２ｍ ,池水深度受水库蓄水大小的影…     

巴西鲷养殖技术

巴西鲷（Prochilodusscrofa）,学名小口脂鲤,属鲤科,脂鲤属,是我国1998年从巴西引进的一个淡水养殖新品种。它适应性强,生长速度快,食性广泛,抗病力强,易起捕,肉质细嫩,经济价值高,为一般养殖鱼类价格的2－3倍,具有很大的推广前景。从1999年开始,我们进行了巴西鳃的引种养殖,效果较好,现将有关养殖技术介绍如下。1生物学特性巴西绸原产于南美洲的巴西、巴拉圭、阿根廷等国的湖泊、河湾、水库中,也是巴西的主要淡水经济鱼类之一。巴西绸属热水性鱼类,生活在水体的底层。它体侧扁,体型与鲤。鲫鱼相似,体色银白,尾叉型,…     

镜鲤养殖密度的初步探讨与效益分析

根据市场需要和养殖品种的不断调整 ,勃利县水产技术推广站从 2 0 0 1年开始从哈尔滨市呼兰镇渔场引进大量镜鲤春片鱼种 ,在全县范围内推广养殖。该品种具有生长速度快、抗病力强、体型好等优良的经济性状。该镜鲤是利用德国镜鲤母本与散鳞镜鲤父本杂交获得的杂交一代 ,在形态特征上具有德国镜鲤与散鳞镜鲤的共同特征 ,属于杂食性鱼类 ,食性广 ,容易饲养 ,具有饵料利用率高及容易游钓等特点。但是镜鲤做为杂交品种具有遗传上的不稳定性 ,生产上仅利用做为养殖商品鱼对象 ,不宜做为亲鱼保留。经过几年的饲养 ,全县各个渔场的亩产量有高有低 ,…     

淡水白鲳养殖技术

淡水白鲳，学名为短盖巨脂鲤，隶属脂鲤目，脂鲤科，巨脂鲤属。原产于南美洲亚马逊河，为热带鱼类，正常生长温度为21～32℃．最适温度为25～30℃。此鱼与罗非鱼一样不能在自然水温条件下越冬。2003年5月中旬．我县从湘南引进8cm左右的鲳鱼苗3000尾，在同欢水库渔场的0．33hm^2鱼池试养，养殖3个月，尾重达到0．5kg以上，最大个体0．75kg，被钓、购一空，市场前景较好。     

名贵优质鱼类养殖技术系列（之十一）：淡水白鲳

淡水白鲳学名为短盖巨脂鲤，属于腮鲤目、脂鲤科、巨脂鲤属。原产南美亚马逊河流域。1982年我国台湾省最先从南美引进饲养，成为一种食用鱼。1985年长江水产研究所从台湾引入广东省东莞市试养，并于1988年人工繁殖成功．经有关科研、生产等单位试养．认为淡水白鲳具有肉质好、体形大、生长快、     

鲤科25种鱼类线粒体COⅡ基因序列差异及其系统进化关系

采用PCR技术获得了23种鲤科鱼类线粒体DNA细胞色素氧化酶（COⅡ）基因部分序列，将所得的COⅡ基因序列与2种取自GenBank的鲤科鱼类同一基因序列采用CLUSTAL X排序后，序列间未见插入和缺失，在实际分析的600 bp序列中，共有变异位点250个。以台湾缨口鳅作为外类群，用PAUP 4.0软件对序列结果进行统计和分支分析，分别用邻接法和最大似然法构建分子系统树。Kimura双因素模型计算25种鲤科鱼类遗传距离范围为0.018 5～0.237 5，其中，遗传距离值最小是与似（0.018 5），最大是似刺鳊与大鳍（0.237 5）。分子系统树显示鲤科雅罗鱼亚科、亚科、鲤亚科、亚科和亚科均没有各自形成单系群。雅罗鱼亚科被分为北方类群和东亚类群，北方类群是一单系类群，东亚类群与亚科、鲴亚科、鲢亚科形成另一个单系群。丁与贝加尔雅罗鱼、东方欧鳊、湖拟鲤等聚成一单系群，支持将丁保留在雅罗鱼亚科中的传统分类法。     

我国引进鱼类的种类及其生产效益的调查研究

本文记述我国引进鱼类55种;在生产中效益较好的种类有虹鳟、短盖巨脂鲤、露斯塔野鲮、日本白鲫、革胡子鲶、斑点叉尾鮰、尼罗丽鲷、奥利亚丽鲷、大口黑鲈以及德国镜鲤等10多个种,约占引进鱼类的20％;引进鱼类的年产量约占全国养殖鱼类产量的10％,数量虽少,却对我国渔业生产起着积极作用;此外,对我国鱼类引种工作提出需注意的问题和建议。     

Habitat differentiation between sei (Balaenoptera borealis) and Bryde's whales (B. brydei) in the western North Pacific

Two closely related baleen whale species, sei and Bryde's whales, in the western North Pacific were studied to identify differences in habitat use. Data were obtained from May to August 2004 and 2005. This study examined the relationship between oceanographic features derived from satellite data and the distribution of sei and Bryde's whales using basic statistics. We investigated oceanographic features including sea surface temperature (SST), sea surface chlorophyll a (Chl‐a), sea surface height anomalies (SSHAs), and depth of the habitat. These two whale species used habitats with different SST, Chl‐a, and SSHA ranges. The 0.25 mg m^?3 Chl‐a contour (similar to the definition of the Transition Zone Chlorophyll Front) was a good indicator that separated the habitats of sei and Bryde's whales. Then generalized linear models were used to model the probabilities that the whale species would be present in a habitat and to estimate their habitat distribution throughout the study area as a function of environmental variables. The potential habitats of the two species were clearly divided, and the boundary moved north with seasonal progression. The habitat partitioning results indicated that SST contributed to the patterns of habitat‐use and might reflect differences in prey species between the two whales. This study showed that the habitats of the sei and Bryde's whales were clearly divided and their potential habitat‐use changed seasonally.     

关于公鱼属鱼类分类的讨论

本文回顾了公鱼属鱼类的分类历史,讨论了分类存在的问题,提出了赞同把该属分成形态特征和生态习性明显不同的两个种的意见:淡水产卵的定为池沼公鱼(H.olidus(Pallas),海水产卵的定为海公鱼(H.pretiosus(Girard)。     

On the ecology of brackish water lagoons in Great Britain

1. Recent data on habitat characteristics and the animal and plant communities from 166 brackish lagoons in Great Britain have been analysed to interpret their community stucture and the environmental features important to maintaining the diversity of specialist lagoonal species. 2. Lagoons supporting a diverse community of specialist species of restricted distribution are considered to be the most valuable in conservation terms. 3. Lagoons are concentrated in the south and east of the country, are predominantly shallow with fine sand and mud sediments and cover a range of sea-inlet types, areas and salinities (from zero to hyperhaline). 4. The environmental characteristics of lagoons show more variability than those of ambient sea-or estuarine water. 5. Six suites of species are identified: freshwater species, stenohaline marine lagoonal specialists, euryhaline lagoonal specialists, estuarine species tolerant of lagoons, estuarine species incidental in lagoons and underrecorded species. 6. The lagoons are categorized as freshwater sites and groups of saline sites of a range of conservation value in terms of their community, from high value sites dominated by stenohaline specialist species to sites supporting no specialist lagoonal community. 7. The higher value sites are bar-built or sluiced lagoons with a channel inlet, with salinities close to 35%₀, a heterogeneous sediment, predominantly shallow and with larger area if narrow. Spatial density of lagoons may be important in recruitment of stenohaline specialist species, and frequent exchange of a proportion of the lagoon water with adjacent estuary or sea-water may be important in maintaining requisite salinity. 8. Aspects worthy of further study are identified.     

Fishpathogens.eu/noda: a free and handy online platform for Betanodavirus targeted research and data sharing

Viral nervous necrosis (VNN) is a severe neuropathological disease affecting a broad variety of finfish species worldwide. The causative agents of VNN are small viruses with a bi‐segmented RNA genome known as betanodaviruses. At least four species with distinct but yet insufficiently characterized epidemiological features are recognized. The spread of VNN to an increasing number of host species, its wide geographic extent and its economical and ecological impacts justify the importance of collating as much molecular data as possible for tracing the origin of viral isolates and highlight the need for a freely accessible tool for epidemiological and molecular data sharing and consultation. For this purpose, we established a web‐based specific database using the www.fishpathogens.eu platform, with the aim of collecting molecular and epidemiological information on VNN viruses, with relevance to their control, management and research studies.     

Immunohistochemical detection of gonadotropin-like material in the hagfish pituitary, correlated with their gonadal conditions

In the present study, immunoreactive gonadotropin (GTH)-like material was examined in the hagfish pituitary, in correlation with their gonadal conditions. For this purpose, three species of hagfish, Myxine glutinosa, Eptatretus burgeri and Paramyxine atami, were used. In all species, GTH-like cells were observed in the adenohypophysis. They were stained with several antibodies to LH-related GTHs, such as ovine LHβ, human LHβ, bullfrog LH, and salmon GTHIIβ. In the subsequent study, the relationship between the amount of GTH-like material and gonadal conditions was examined in Paramyxine atami. The adenohypophysis of adult animals exhibited well-developing features, and about half of the adenohypophysial cells were stained intensely with anti-ovine LHβ. On the other hand, the adenohypophysis of juveniles exhibited less developed features with few or no cells stained with anti-ovine LHβ. These results suggest that a GTH-gonadal system is truly present in the hagfish.     

Molecular species diagnosis confirmed the occurrence of Kumamoto oyster <Emphasis Type="Italic">Crassostrea sikamea</Emphasis> in Korean waters

In order to develop an appropriate natural resource management policy, it is important to elucidate the cryptic habitats of species. Oyster species are likely to have such unrecognized habitats owing to the difficulty involved in morphological species identification. In this study, we discovered a novel cryptic habitat of the Kumamoto oyster Crassostrea sikamea, a sibling species of the Pacific oyster C. gigas, in Korean waters. We collected 50 oyster samples from Suncheon Bay, located in the southern Korean Peninsula, among which 20 individuals of C. sikamea, 29 of C. gigas, and one C. sikamea/C. gigas hybrid were identified based on mitochondrial and nuclear DNA markers. There were no significant differences in shell morphology between the two species, which is consistent with how difficult it is to delineate them based on their shell features. Our identification of this novel C. sikamea habitat should help to improve the resource management of East Asian oysters.     

Identification of shark and ray fins using DNA barcoding

Fisheries managers and scientists worldwide are struggling with a lack of basic information for many shark and ray species. One factor hampering the data collection is inaccurate identification of many chondrichthyan species and their body parts. Morphologically similar species, and specimens which are poorly preserved or have had key diagnostic features removed, can be difficult to identify. This study examined DNA barcoding as a method to identify shark species from dried fins, confiscated from a vessel fishing illegally in Australian waters. 211 left pectoral fins were examined. 18 either did not provide a sequenceable product or yielded a microbial sequence, while 193 fins (91.5%) provided a chondrichthyan sequence. All of these could be matched to reference specimens in a DNA barcode database, and so were able to be identified. 27 species were detected, 20 species of sharks and seven species of rays The most abundant species (22% of fins) was Carcharhinus dussumieri. Many of these species are listed on the World Conservation Union (IUCN) Red List and include one, Anoyxpristis cuspidata (3%), rated as critically endangered. Fishing authorities can use DNA barcoding to gather data on which chondrichthyan species are targeted by illegal fishers, information that will greatly assist in management and conservation.     

Topographic preferences and habitat partitioning by pelagic fishes off southern Western Australia

Pelagic fishes are typically considered mobile and wide-ranging open ocean foragers. However, many species have also been recorded in association with nearshore topographic structures. The relative abundance of four pelagic species at and away from topographic features on the continental shelf, as inferred from fine-scale catch data collected over a 7-year period, was examined for southern Western Australia. A total of 1056 captures were recorded from 890 h of trolling over 102 days: the top four species accounted for 97.5% of all captures. Eight distinct topographic features received 13.7% of the total trolling effort and produced 43.8% of captures. The percentage of all captures within 1 km of these features were 80% for yellowtail kingfish (Seriola lalandi, YTK), 50% for bonito (Sarda australia, BON), 27% for southern bluefin tuna (Thunnus maccoyii, SBT), and less than 5% for skipjack tuna (Katsuwonus pelamis, SKJ). Catch rates were 26, 6.59, and 2.47 times higher than catch rates away from the topographic features for YTK, BON, and SBT, respectively. In contrast, SKJ catch rates were 1/3rd lower at topographic features, indicating avoidance rather than preference. The mean distance at which species were captured from the center of each feature differed significantly, with YTK closest (303 m), followed by SBT (442 m), BON (493 m), and SKJ (539 m). These findings indicate habitat partitioning in pelagic fishes at topographic features and offer a way to increase catch of a targeted species, or reduce the capture of unwanted or quota-limited species.     

Using remote sensing indicators to investigate the association of landings with fronts: Application to the Alboran Sea (western Mediterranean Sea)

This study examined links between the variability of coastal front features and composition of fishery landings. Satellite‐derived sea surface temperature data allowed the detection of thermal fronts and calculation of front metrics that account for gradient, persistency, and vicinity. Landings data were clustered by functional group (according to habitat use, size, morphology), and trophic level (TL). Three independent time series analyses, based on two different classes of statistical methodologies, were carried out: (i) correlation analysis performed on species aggregated by functional groups, and (ii) compositional analysis performed on the top five species landed and on species aggregated by trophic level. Analyses were carried out for the Moroccan coast of the Alboran Sea (western Mediterranean Sea). Results of the proposed type of application were discussed with respect to their potential for improving scientific knowledge and management of fisheries in data‐poor areas. Pelagic landings were associated with front indicators in two‐thirds of tested cases. The results demonstrated a markedly different association between landings and front features in the Nador fishing zone, relative to M'diq and Al Hoceima. Improved performance of the front gradient and persistence indicator was detected, with respect to the front gradient only for flatfish and demersal landings. Compositional data regression outlined a different role for Sardina pilchardus and Trachurus trachurus in the Al Hoceima and M'diq landings, and in the latter case the dominance of these two species in the landings seemed to respond to the front density indicator. A decreasing trend in TL > 3.5 landings was detected with increasing front distance.