鱼类食欲调控研究进展

寻找鱼粉替代物已成为肉食性鱼类养殖可持续发展的必然要求,如何提高鱼类对鱼粉替代物的利用率成为了鱼粉替代研究的瓶颈。食欲是影响鱼粉替代的重要因素,而食欲调控网络通过各种食欲调节因子(包括促进食欲因子和抑制食欲因子)的信号传递作用和中枢信号通路,对摄食进行综合调节。本文综述了常见食欲调节因子和中枢信号通路对食欲的调控,以期为鱼类食欲调控研究提供参考。     

观赏鱼与观赏鱼饲料

观赏鱼既有淡水品种,又有海水品种,尤以金鱼、锦鲤、热带鱼为主。饲养观赏鱼在我国有着悠久的历史。我国是金鱼的原产地,自宋朝初年开始驯化和家养,距今已有1200多年。16世纪初传入日本,300年前传入欧洲,100年前传入美国,现已成为世界性品种。     

中西医结合治疗牛黑斑病甘薯中毒

笔者从事兽医工作32年来,采用中西医结合治疗牛黑斑病甘薯中毒76例,除3例因就诊过晚造成死亡外,其余73例均治愈,疗效达96.1%,现将治疗方法报告于后,供同行参考。1发病原因甘薯黑斑病菌侵害表皮受损的甘薯并产生毒素,这种毒素高温处理也不致丧失毒性,牛吃病甘薯后即可中毒。中毒     

Genetics of Melanomas in Xiphophorus Fishes

Abstract

Data are presented from studies on heritable melanoma formation in certain hybrids of Xiphophorus fishes. In the best investigated case, benign and malignant melanomas were caused primarily by hemizygous and homozygous loss, respectively, of a tumor suppressor gene that promoted final pigment cell differentiation, although additional genetic events may be of importance. In other melanoma cases, different genes, most of them presumably also tumor suppressor genes, have been implicated in the development of melanomas and may interact at other levels of pigment cell development, such as commitment, migration, or homing of pigment cell precursors. Importantly, genetic factors have been identified that do not allow melanoma formation despite the loss of tumor suppressor genes. Taken together, these findings stress the complexity of tumorigenesis and the heterogeneity of pathways that lead to cancers of the same histological type.     

Distribution of Myxobolus cerebralis in Salmonid Fishes in Montana

Abstract

Over an approximately 2-year period, 20,974 fish (trout and other salmonid species) from 230 separate waters (creeks, rivers, lakes, reservoirs, ponds, hatcheries, and irrigation ditches) within 21 of the 22 major drainages in Montana were examined for Myxobolus cerebralis. Nine of the major river drainages have waters containing infected fish: Beaverhead, Big Hole, Blackfoot, Clark Fork above the Bitterroot River, Flathead below the south fork of the Flathead River, Jefferson, Madison, Missouri above the Marias River, and Yellowstone above the Bighorn River. The Beaverhead, Clark Fork above the Bitterroot River, Jefferson, Madison, and Missouri above the Marias River have the greatest number of waters containing fish infected with M. cerebralis. Comparisons of infection levels (number of pooled samples that contain fish infected with M. cerebralis) between species among these drainages show significantly lower levels of infection in brown trout Salmo trutta and rainbow trout Oncorhynchus mykiss in the Missouri above the Marias River drainage and significantly higher levels of infection of rainbow trout in the Jefferson. Comparisons of differences in infection levels between drainages among species show that, in the Beaverhead, Clark Fork above the Bitterroot River, and Madison, infection levels in brown trout are significantly higher than in rainbow trout. This is partially attributed to losses of juvenile rainbow trout because of M. cerebralis infection, leading to biased samples. Histopathologic studies showed lesions were consistently less severe in brown trout than other species and occurred in a different location (gill arches versus ventral calvarium). In six of the nine affected drainages (Beaverhead, Blackfoot, Clark Fork above the Bitterroot River, Flathead below the South Fork, Jefferson, and Madison), infected fish were found at or near the time that intensive sampling was initiated in the spring of 1995. In the three remaining affected drainages (Missouri above the Marias River, Yellowstone above the Bighorn River, and the Big Hole), infected fish were not identified until at least 15 months after the initiation of widespread testing. This indicates that in the first six drainages listed above, the infection was well established prior to 1995 but spread into the last three drainages in the ensuing months. Methods of transmission and the sources of infection are unknown, although the absence of infected fish in state, private, and federal hatcheries in Montana indicates hatchery fish from these sources are not likely to be responsible.     

Recreational Angler Perspectives of Nonnative Fishes

Although fish invasions have implications for conservation and resource management, research on public attitudes toward nonnative fishes is lacking. We surveyed boat and canal bank recreational anglers in the Everglades to assess their awareness, preferences, and perspectives of native versus nonnative fishes. Our findings showed that 79% of anglers were aware of the presence of nonnative fishes, and overall awareness was positively affected by the frequency of fishing, and years of angler experience at study sites. Frequency of fishing had a stronger effect on canal bank anglers. Boat anglers had higher awareness of nonnatives, higher familiarity with “nonnative” terminology, and expressed greater preferences for native fish. Most anglers favored native species (72% preference), and targeted native fishes, particularly Florida Largemouth Bass (66%). Overall, findings show that despite the prevalence of nonnative species, anglers favored native fishes and supported native fish conservation.     

淡水鱼在贮存过程中次黄嘌呤含量的变化

淡水鱼4种(鲤、鲫、鲢、鳙),每种30尾,每尾250g左右,于4℃保存共264h,其间按不同时间间隔,同时测定鱼体次黄嘌呤(Hx)和总挥发性盐基氮(TVBN)的含量.结果表明,4种鱼Hx含量的变化,在接近鱼腐败时均有一明显的高峰值.故利用Hx指标能较早地判断淡水鱼的新鲜度,与TVBN方法相比实用价值较高.     

中国淡水鱼类种质资源的保护和利用

本文简要介绍了目前世界鱼类资源概况、我国鱼类资源现状，以及鱼类生物多样性的极丰富程度与易被破坏性，还介绍了造成鱼类种类减少或区系组成变化的主要原因以及造成鱼类遗传多样性减少的内在原因和外部原因；比较详细的提出了鱼类种质资源保护的目的、策略及措施。并就我国鲤科鱼类繁育群体的大小、鱼类种质的鉴定与评价及利用前景作了分析。     

鳖鱼混养技术

鳖鱼混养是指精养中华鳖池塘中套养服务性鱼类的养殖模式,是实行中华鳖健康养殖的重要措施,它的优点和好处是：①可以充分利用水体,增加池塘的单位放养量,从而提高鳖鱼产量,降低成本,增加效益。鳖是水陆两栖爬得动物,靠肺呼吸,不存在与鱼争氧,增加水体负债。②发挥鱼鳖之间的互利关系,增加池水溶解氧,优化水体生活环境。鳖在水中不断活动,经常浮出水面进行呼吸,这样来回往返活动,可使表层水与底层水得到交换,防止浮游植物旺盛的光合作用产生的过饱和氧逸出,又可弥补深层水的“氧债”,且有利于淤肥中营养盐的释放,有利浮游…     

中国淡水鱼类种质资源的保护和利用

本文简要介绍了目前世界鱼类资源概况、我国鱼类资源现状,以及鱼类生物多样性的极丰富程度与易被破坏性,还介绍了造成鱼类种类减少或区系组成变化的主要原因以及造成鱼类遗传多样性减少的内在原因和外部原因;比较详细的提出了鱼类种质资源保护的目的、策略及措施.并就我国鲤科鱼类繁育群体的大小、鱼类种质的鉴定与评价及利用前景作了分析.     

营养物质对鱼类食欲的影响

寻找理想鱼粉替代物是近20年动物营养学的研究热点之一,尽管在肉食性鱼类中鱼粉替代物因适口性差、消化率低、氨基酸不平衡和存在抗营养因子等原因导致其替代比例较低,然而,随着鱼粉供求关系的进一步不平衡,替代鱼粉已成为肉食性鱼类养殖可持续发展的必然要求。因此,如何提高肉食性鱼类对鱼粉替代物的利用率成为了鱼粉替代研究的瓶颈。本文从食欲的角度,综述各种营养物质对食欲的影响,以便利用营养措施来人为调控鱼类的食欲,从而提高饲料利用率。     

观赏鱼全价营养饲料的研制

观赏鱼指金鱼、热带鱼和锦锂等一些可供人们欣赏的鱼类。它不仅可美化环境 ,丰富人们的业余生活 ,而且从中也可陶冶人的精神情操。随着我国国际贸易的发展 ,这些鱼早就作为一种观赏动物出口 ,远销日本、东南亚和欧美等国家 ,换取外汇 ,为祖国四个现代化建设筹集资金 ,也增进了同世界各国人民之间的友谊。同时 ,在科学研究中观赏鱼也是进行遗传、发育、生态、癌症和毒性试验等材料。长期以来 ,国际上测定各种药物对鱼类的毒性指标都以金鱼为试验动物。因此 ,发展观赏鱼养殖业在经济、科研方面都有重要的意义。然而 ,在城市和农村伴随市政和农…     

危情救赎当长江沦为“没有生命的死水”

我们赞美长江,你是无穷的源泉……长久以来,长江哺育和支撑着一代代的中华儿女,这支气势磅礴的《长江之歌》也留存在了人们的记忆之中.可如今,这位曾经无私奉献的母亲似乎已然年老色衰,风光不再了.作为长江多年的原住民,多种鱼类正在前赴后继地与死神会面,曾拥有的其他河流难以匹敌的渔业资源已经被永远地尘封进了泛黄的历史.目前,长江全流域每年鱼类的天然捕捞量已经减少到年10万吨左右,资源量已不足以支撑长江流域14多万渔民的基本生活——这个数字绝望到令人癫狂.     

黄姑鱼、海鲶鱼和白鱼的营养成分测定

对水貂、狐养殖中常用的海杂鱼(黄姑鱼、海鲶鱼、小白鱼)进行实验室概略养分分析,并测定其中氨基酸组成,以便为科学地制定水貂、狐饲料配方提供依据。结果表明,在测定的3种鱼中,海鲶鱼的品质最好,氨基酸平衡,水分含量低,粗蛋白含量为14.24%,略高于海杂鱼的平均粗蛋白水平13.8%,按氨基酸总量计接近平均值;而白鱼、黄姑鱼的粗蛋白质含量和氨基酸总量分别为13.32%、13.78%和12.19%、11.84%,其粗蛋白含量均低于海杂鱼平均值13.8%。     

Survey of Salmonid Pathogens in Ocean-Caught Fishes in British Columbia,Canada

Abstract

A survey of wild fishes captured around marine net-pen salmon farms and from open waters for certain salmonid pathogens was conducted in the coastal waters of British Columbia. Viral hemorrhagic septicemia virus was detected in Pacific herring Clupea pallasi, shiner perch Cymatogaster aggregata, and threespine sticklebacks Gasterosteus aculeatus. Infectious hematopoietic necrosis (IHN) virus was detected in one Pacific herring (collected well away from the farms) and in tube-snouts Aulorhynchus flavidus and shiner perch collected from a farm experiencing an IHN outbreak. Renibacterium salmoninarum was observed in moribund Pacific hakes Merluccius productus collected from within a net-pen and was also detected in several ocean-caught salmon. Aeromonas salmonicida subsp. salmonicida (typical strain) was isolated from a juvenile chinook salmon Oncorhynchus tshawytscha, whereas the atypical strain of this organism was isolated from a lingcod Ophiodon elongatus. Loma salmonae (Microsporea) was observed in chinook salmon, chum salmon Oncorhynchus keta, coho salmon O. kisutch, sockeye salmon O. nerka, and pink salmon O. gorbuscha, all of which were captured well away from net-pens. Loma spp. (Microsporea) were observed in the gills of shiner perch, lingcod, Pacific tomcod Microgadus proximus, Pacific cod Gadus macrocephalus, walleye pollock Theragra chalcogramma, and sablefish Anoplopoma fimbria; all but the first species represent new hosts for Loma. Epitheliocystis, caused by a chlamydia-like organism, was detected in the gills of chinook salmon, chum salmon, coho salmon, pink salmon, lingcod, Pacific cod, Pacific hakes, Pacific tomcod, walleye pollock, sablefish, shiner perch, Dover soles Microstomus pacificus, Pacific sanddabs Citharichthys sordidus, and various species of rockfish Sebastes spp., most of which represent new host records for this infection.     

Distribution of Fishes in the Mhlanga Estuary in Relation to Food Resources

Food resources play an important role in determining the distribution offish species in the Mhlanga estuary. Standing crops of detritus and associated micro-organisms, zoobenthos, zooplankton, epiphytic flora and fauna were measured in the upper, middle and lower reaches of the estuary, and the distribution of 20 fish species related to these resources. The distribution of the majority of species correlated with the abundance of preferred food items, except for the Mugilidae where substrate particle sizes influenced the composition offish in an area.     

鳚亚目(Blennioidei)鱼类的线粒体COI基因序列比较

应用生物信息学方法对12种鳚亚目鱼类线粒体COI基因序列片段进行了比较分析。结果表明:COI基因碱基组成偏倚明显,A+T含量(54.40%)明显高于G+C含量(45.60%)。转换和颠换位点数分别为59和42个。应用Kimura双参数法计算鳚亚目鱼类COI基因序列的种间遗传距离,结果表明:种间平均遗传距离为0.232 4,是种内遗传距离的9.62倍。应用MP和NJ法构建了分子系统发生树,结果显示,方氏云鳚、云鳚和六线鳚聚在一起,然后与颈鳍脂鳚聚在一起,再与巴西拟隆胎鳚、巴哈马拟隆胎鳚聚类,最后与疣眼吉氏指鰧聚类;粗头岩游鳚、环项副鳚和横带斯氏脂胎鳚聚为另一分支;背叉触角鳚并没有聚成一个单系分支,而是与旗鳚科和三鳍鳚科的鱼类交叉。此外,分子系统发生树的构建结果大部分与形态学分类结果相一致,相比之下,NJ法较MP法构建的分子系统发生树与鳚亚目鱼类形态学分类结果更接近。     

鱼类致病性气单胞菌诊断试剂盒的研制

在 Dot-ELISA检测胞外蛋白酶 ( ECPase)的基础上 ,研制了鱼类致病性气单胞菌诊断试剂盒。该试剂盒可检出气单胞菌培养上清中的 ECPase,检出的最低水平为 78μg/L;气单胞菌属的细菌均呈现阳性反应 ,与迟缓爱德华菌、鳗弧菌、鲁氏耶氏菌、荧光假单胞菌等 4种常见鱼类致病菌不发生交叉反应 ,仅与大肠杆菌有轻微交叉反应。反应试剂盒和脱脂奶平板法检测 2 3株参考株和 1 2 4株样本 ,两者符合率分别为 73.9%和87.2 %。以上试验批内、批外重复 3次结果一致。试剂盒可在 2 4 h内报告结果 ,保存期达 1 a,具有敏感、特异、实用的优点 ,可用于鱼类致病性气单胞菌的诊断     

Contributions to the Functional Morphology of Fishes Part VI

Some anatomical, adult shell and larval features of Unto coffer Krauss are described and compared to those reported in previous accounts of this and other species. The findings necessitate the removal of U. caffer from the nominal genus Cafferia Simpson, for which it is the type species, and its return to the genus Unio Pbilipsson, in the Unionidae: Unioninae. Cafferia consequently becomes a junior subjective synonym of Unto.

Unio caffer is characterized in part by zigzag beak sculpture, dimorphic septal spacing between the marsupial, outer (comparatively dense) and the non-marsupial, inner (more distant) demibranchs and also within the marsupial demibranchs, the presence of perforated marsupial septa and imperforate non-marsupial septa, the occurrence of hermaphrodites in some but apparently not all populations, production of subtriangular glochidia with a hook at the ventral margin of each valve, short-term incubation of larvae in the marsupial demibranchs, and by its disjunct occurrence in the southern Ethiopian region (other Unio occurring only in the Palearctic).

These adult shell and anatomical features relate this species to those of several nominal genera in the Oriental region, although the latter are distinguished from it by the production of subovate, hookless glochidia.