Antiparasitic efficacy of dietary administration of trichlorfon (Masoten®) in the control of Neoechinorhynchus buttnerae (Neochinorhynchidae) in Colossoma macropomum (Serrasalmidae)

Aquaculture International - This study investigated the efficacy of trichlorfon against Neoechinorhynchus buttnerae, as well as its palatability, residue analysis, and the blood parameters of...     

Dead-end (dnd) protein in fish—a review

Fish Physiology and Biochemistry - Dead end (dnd) is a germ plasm-specific maternal RNA discovered in zebrafish and then in other vertebrates. Dnd protein is essential for migration and motility of...     

Thyroid hormones down-regulate thyrotropin β mRNA level in vivo in the turbot (Psetta maxima)

Thyroid stimulating hormone (TSH) is a vertebrate pituitary heterodimeric hormone that stimulates the thyroid gland to produce the thyroid hormones, T3 and T4. We report here the cloning, by PCR on reverse-transcribed pituitary RNAs, of a 180 bp fragment of the cDNA encoding TSH subunit in the turbot (Psetta maxima). The deduced amino acid sequence displayed 66 and 75% identity with the corresponding sequence from the European eel (Anguilla anguilla) and the rainbow trout (Oncorchyncus mykiss), respectively. This cDNA was then used as a probe for densitometric analysis of individual pituitary Northern blots. TSH mRNA levels were quantified in turbot where circulating thyroid hormones were modified by dietary treatments or hormone supplementation. Recombinant rainbow trout growth hormone had no effect on circulating thyroid hormone levels or on pituitary TSH mRNA level. In turbot fed heat-treated rapeseed meal, plasma T4 levels were lowered and TSH mRNA increased more than two fold. In contrast, when turbot were fed a standard fish-meal supplemented with T3, circulating T3 levels were elevated and there was a dramatic decrease in TSH mRNA level. It is concluded that both thyroid hormones are able to down-regulate TSH mRNA level in vivo in the turbot. These results are discussed in the context of the evolution of the TH feed-back on TSH production.     

Food selection of burbot (Lota lota L.) larvae reared in illuminated net cages in mesotrophic Lake Maróz (north-eastern Poland)

Feeding and food selection of burbot (Lota lota L.) larvae reared in illuminated cages were studied. The experiment was carried out in mesotrophic Lake Maróz, in north-eastern Poland, for 6 weeks in two successive years. The initial stocking density was 1,250 larvae (20 DPH) per cage. Food selection according to the zooplankton groups (Rotifera, Cladocera and Copepoda) and length classes was expressed by the Strauss linear selectivity index (L). Zooplankton species composition in the lake was similar in the two seasons of the study and organisms shorter than 0.5 mm prevailed in the plankton. The mean number of prey found in burbot alimentary tracts increased from about 40 up to over 200 during the course of the study. A very large inter-individual variation in the amount of food organisms consumed by fish was noted. Analysis of the values of the Strauss food selectivity index shows that at the beginning of the first year of the experiment, burbot larvae preferred copepods, most numerous in the environment at that time; later, fish tended to select cladocerans. In the second year of the study, fish more often ate copepods, irrespective of their quantities in the environment. During the whole study, reared burbot larvae did not eat rotifers, even when they were numerous in cages. Similarly to the rotifers, the smallest planktonic organisms, measuring up to 0.5 mm in length, were typically neglected by fish, while the 0.6–1.0 mm group was most frequently selected. There were also considerable individual differences between particular burbot specimens in their food preferences.     

Vagococcus salmoninarum I—A chronic coldwater streptococcosis in broodstock brook trout (Salvelinus fontinalis) in Wisconsin,USA

In 2018, Vagococcus salmoninarum was isolated from two lots of broodstock “coaster” brook trout (Salvelinus fontinalis) containing ~1,500 fish at the Iron River National Fish Hatchery, at which time it was identified as the causative agent of a chronic coldwater streptococcosis epizootic. Clinical signs included exophthalmia, lethargy, erratic swimming and loss of equilibrium. Female fish experienced disproportionately higher morbidity and mortality than male co-inhabitants, and routinely retained eggs following spawning. The most consistent gross clinical sign was heart pallor and turbid pericardial effusion. An attempted treatment using florfenicol was ineffective at halting the epizootic, which spanned more than a year and resulted in >50% mortality before remaining fish were culled. As there is no previous documentation of V. salmoninarum at this hatchery or in this species, it is still unclear what circumstances led to this epizootic. The inability to treat this chronic disease led to the loss of valuable broodstock, hampering ongoing fishery conservation efforts in the Great Lakes Basin.     

Water quality,phytoplankton composition and growth of Litopenaeus vannamei (Boone) in an integrated biofloc system with Gracilaria birdiae (Greville) and Gracilaria domingensis (Kützing)

A 28-day indoor trial was conducted to evaluate the water quality, phytoplankton composition and growth of Litopenaeus vannamei in an integrated biofloc system with Gracilaria birdiae and Gracilaria domingensis. The experimental design was completely randomized with three treatments: control (shrimp monoculture); SB (shrimp and G. birdiae) and SD (shrimp and G. domingensis), all with three replicates. Random sampling was done (6 % of total population per experimental unit) to confirm white spot syndrome Virus (WSSV) infection using nested-PCR analysis due to suspicion of presence of the virus in the experiment (treatment and control groups). Shrimp L. vannamei (2.63 ± 0.10 g) were stocked in experimental tanks at a density of 425 shrimp m^?3, and the Gracilaria was stocked at a biomass of 2.0 kg m^?3. Shrimp mortality began in both the experimental and control groups at 10 days of culture. The integrated biofloc system (shrimp and seaweed) increased settleable solids (by 26–52 %); final weight (by 6–21 %); weekly growth (by 17–43 %); weight gain (by 17–43 %); specific growth rate (by 16–36 %); and yield (by 5–7 %) and decreased feed conversion ratio (by 21–28 %) and Cyanobacteria density about 16 % as compared to the control (shrimp monoculture). The use of red seaweed Gracilaria in an integrated biofloc system can enhance shrimp growth and reduce Cyanobacteria density in the presence of WSSV.     

狼牙(鱼叚)虎鱼(龙须鱼)

名称狼牙(鱼叚)虎鱼,学名 Odontamblyo-pus rubicundus(Hamilton-Buchanan)。地方名(鱼乃)鱼(广东唐家湾,香洲)、赤(鱼乃)(广海,闸坡)、白(鱼乃)(唐家湾),红头鳝(广西北海)。隶属于鲈形目,鳗(鱼叚)虎鱼科,狼牙(鱼叚)虎鱼属。特征及近似种体长而侧扁,略呈带状。头大,略呈长方形。吻短,中央稍凸出。眼极小,退化,埋于皮下。口大而斜,下颌和颏部向前上方突出。牙尖锐,长而弯曲,突出唇外。体及头部被小而退化鳞片。背鳍和臀鳍基底均甚长,与尾鳍相连;腹鳍大,左右腹鳍     

海(小说)

[接上期]不出半月,海的爹又成了解放军的俘虏,还是那个十七、八岁的解放军少年给他们上政治课,内容与上一次大同小异。那解放军少年终于发现了海的爹,心里直嘀吐:这小子不出半月怎么又干上国民党了?于是。他问他:“伙计,你怎么专门混在俘虏堆里来领现大洋呢?”他说:“不!不!!别误会”。     

鱼王(小说)

吉林省境内有一个白泉镇,此处山高林密,土质肥沃。山脚处有一泓清泉,终日里水汩汩的往外冒,潺潺地流成一条小河,小河连着大河,直流成一条浩浩荡荡、横贯松辽平原的河流,叫辽河。在辽河源头,一个名叫辽河源屯的村落里,如今出息了一个赫赫有名的主儿,人称“鱼王”狗剩。     

渔家乐(钓鱼)

~~渔家乐(钓鱼)@王平~~     

船艺(二)

<正> 十一、船舶从海水进入淡水,其吃水差变化如何计算?一船载重不变,由海水进入淡水,其吃水变化,可用下面公式计算。(T_1)/(T_2)=(r_2)/(r_1)T_1——海水中吃水T_2——淡水中吃水r_1——海水比重(1025)r_2——淡水比重(1000)例:某船在海水中吃水3米,问进入淡水中其吃     

黄琳(技术奖)

正黄琳,从事水生哺乳动物驯养工作已有20年。目前在北京海洋馆从事水生哺乳动物繁育、养护、培训等工作。自2004年以来,黄琳发挥自身专业技术优势,与团队成员一起,通过理论知识与实践探究,先后繁殖近10头太平洋瓶鼻海豚,并总结编写了一套较为完善的《北京海洋馆馆养鲸类动物繁育体系》,随着该技术体系的     

程远通信(上海)有限公司产品介绍(二)

上期本杂志上介绍了RCI-3636机。本期将介绍程远通信公司的又一个新一代的渔业通信机RCI-5656机。RCI-5656通信机具有260个信道,函盖13组国家无委规定的渔业通信频率组别。增加了自动扫描、信道存储等功能,且兼容了RCI-3636机的所有性能,使用更方便,用途更广泛。 RCI-5656机面板采用先进的薄膜开关和液晶显示,控制部分采用微型电脑芯片,整机元件采用无引线表面贴装元件(SMD),使通信机产品进入电子产品的先进行列。产品更为轻巧,可靠性大大提高,赢得了社会各方面的好评。现就在RCI-     

Did volcanic ash from Mt. Kasatoshi in 2008 contribute to a phenomenal increase in Fraser River sockeye salmon (Oncorhynchus nerka) in 2010?

The effect of a widely distributed phytoplankton bloom triggered by volcanic ash from Alaska (Hamme et al., 2010. Geophys. Res. Lett. 37) on juvenile Fraser River sockeye is discussed in terms of the timing of ocean migration and trophic structure of the Gulf of Alaska. Our hypothesis is that the occurrence of a massive diatom bloom in the Gulf greatly enhanced energy ascendancy in the ocean at a time of year when adolescent sockeye migrated from the coast in 2008. We contend this increase in food availability was an important factor for the survival and growth of juvenile sockeye which led to one of the strongest sockeye returns on record in 2010 of 34 million, compared with perhaps the weakest return on record of 1.7 million the previous year.     

下棋(小说)

自从走出校门走进这间办公室,紧张的工作之余,大李和我每天中午的一盘围棋就是雷打不动的。二人下棋,输也罢,赢也罢,总是相安无事。虽然有时输一盘棋能琢磨一下午。最近新分来一个小张,多了一个旁观者,情况就大不一样了。打来午饭,摆上棋盘,小张也端着饭盆凑过来。这位新同志虽然不声不响,可我浑身却感到不自在。正象那句成语,举棋不定。棋输了。当着第三者的面,尤     

Fatty acid compositions of the major phosphoglycerides from fish neural tissues; (n−3) and (n−6) polyunsaturated fatty acids in rainbow trout (Salmo gairdneri) and cod (Gadus morhua) brains and retinas

The fatty acid compositions of brain phosphoglycerides from a freshwater fish, the rainbow trout (Salmo gairdneri), and a marine fish, the cod (Gadus morhua), were determined and compared with those from a terrestrial mammal, the rat. Fish brain lipids were characterized by a higher degree of unsaturation encompassing increased percentages of (n–3)PUFA (226 and 205) and lower percentages of (n–6)PUFA (204 and 224). However the distribution of fatty acids and specific PUFA between different phosphoglycerides was essentially similar in rat and fish brain tissue. PE and PS contained the highest percentages of 226(n–3), PI was characterized by higher 180 and 204(n–6)/205(n–3), and PC had higher 160 and the lowest percentage of PUFA in all species. A generally similar pattern was found in the fish retinal phosphoglycerides except that PC was also rich in 226(n–3). Overall trout brain phosphoglycerides were slightly more unsaturated than the cod lipids but with lower (n–3)/(n–6) ratios whereas cod retinal lipids were more unsaturated than the trout retinal lipids.     

船艺(六)

<正> 五十六、试述静水港前后有船吹开风,靠码头操作方法及应注意些什么?静水港中前后泊位有船,并有吹开风时,靠码头操作:1.可采取较大角度(30°～40°)缓速驶向泊位。2.在船档外稍远处(约5个船身长度)停车淌航,使船藉余速靠向船档内泊位中部。3.在船首离码头不远时,稍用开舵,使艏伸向泊位前端,如冲力太小,可适当用车,并迅速传缆绳。     

斑点叉尾(鮰)养殖技术(上)

斑点叉尾鮰亦称沟鲶,属于鲶形目、鮰科鱼类。斑点义尾鮰天然分布区域在美国中部流域、加拿大南部和大西洋沿岸部分地区,以后广泛地进入大西洋沿岸,现在基本上全美国和墨西哥北部都有分布。现为美国主要淡水养殖品种之一。     

王亮(奉献奖)

正王亮,现任山东省烟台市海洋与渔业监督监察支队科长,负责水生野生动物保护和水产品质量监督监察工作。自1995年参加工作以来,一直在一线从事渔业资源保护执法工作。工作中始终坚持秉公执法、热情服务、勤恳敬业的原则。王亮先后获得省市级渔政管理先进称号。