恩诺沙星及其代谢产物环丙沙星在牙鲆体内代谢消除规律

以80 mg/kg鱼体重对牙鲆单次口灌给药恩诺沙星,给药后在不同的时间点取样,用高效液相色谱荧光检测器检测,研究恩诺沙星及其主要代谢产物环丙沙星在牙鲆体内的代谢消除规律。研究表明,停药后0.25 h,肌肉中恩诺沙星残留量最低。各组织的消除半衰期依次为腮肝脏血液肾脏肌肉,其中肌肉中恩诺沙星消除半衰期最低为67.759 h,消除最快,停药后12 d检测不到恩诺沙星。停药后0.25 h,在牙鲆血液、肝脏、肾脏中均有环丙沙星残留,残留量依次为肝脏肾脏血液,肌肉和鳃中未检出环丙沙星。停药后22 d在血液、肝脏和肾脏3个组织中仍然能够检测出恩诺沙星,但是停药7 d后这3个组织中均检测不出环丙沙星。结果显示,恩诺沙星在牙鲆体内代谢速度较慢,而且只是在一段时间内有脱乙基代谢为环丙沙星的反应发生,但并不是在恩诺沙星消除的全过程都发生,而且代谢物环丙沙星在牙鲆体内的消除速度要比恩诺沙星快。     

Common and Emerging Diseases in Commercially-Cultured Summer Flounder,Paralichthys dentatus

Abstract

Infectious diseases are one of the most common causes of losses in commercial aquaculture for all life stages of fish production. Parasitic infestations such as Trichodinasp., Cryptocaryonsp., Amy-loodiniumsp., Trypanoplasmasp., and monogenic trematodes may have detrimental health consequences when present in high numbers within a cultured population. Bacterial agents such as Vibriosp., Edwardsiellasp., Flexibactersp., and Mycobacteriumsp. may be dormant in some populations but then result in high morbidity or mortality when the fish become stressed by environmental or nutritional factors. Viral diseases are more difficult to diagnose but there are reports of lymphocystis and other viral diseases occurring in flounder species. Many of these diseases result in similar clinical signs of disease. For accurate disease diagnosis, appropriate methods must be implemented to identify and prevent the introduction or dissemination of disease in an aquaculture facility.     

美国大西洋牙鲆南方海上网箱养成技术探讨

针对牙鲆养殖在我国南方养殖普遍存在不能渡夏的现象,本文分析了美国大西洋牙鲆在南方海上网箱养殖的可行性,并根据实践总结出:重视海区选择、精致网箱结构、苗种运输与适度放养、加强日常管理等方面的养殖技术和养殖模式。     

日本条斑星鲽的生物学及增养殖概况

条斑星鲽(Verasper m oseri)为星鲽属中比较大型的鲽类,雌鱼全长可达70 cm,体重可达8 kg,人工放流的2龄鱼全长可达37.8 cm,体重794 g,3龄鱼体长达45.8 cm,体重1325 g。条斑星鲽体表象松树皮一样,因此日文名为“松皮鱼”,由于个体大,其商品名叫“王鲽”。该鱼肉质细嫩,口感好,在     

MS-222对牙鲆麻醉效果

以MS-222为麻醉剂，在13～14℃水温条件下，用浸浴麻醉方法测试了不同麻醉剂浓度和不同麻醉时间对牙鲆复苏时间、复苏率和24h存活率及长时间麻醉对复苏率的影响以及超有效浓度麻醉剂（60mg/L）麻醉后的抗露干能力。预备实验证明，本试验条件下麻醉剂的有效浓度为50mg/L。实验表明，将麻醉剂浓度从50mg/L提高到200mg/L，供试鱼被麻醉的时间由288s缩短至50s，复苏时间由94s延长至106s；用60、100和200mg/L的麻醉液持续麻醉后，可获得100%复苏率的最长麻醉时间分别为64、32和32min，牙鲆经MS-222麻醉后抗露干时间延长。牙鲆麻醉后复苏过程中存在较大的个体差异，但一旦复苏，牙鲆24h内的存活率可达100%。实验表明，MS-222的合理麻醉浓度为60mg/L，此浓度下最长麻醉时间为64min，麻醉露干时间应低于60min。     

格氏乳球菌分离株的血清同源性及血清学检验

以分离于病(死)牙鲆(Paralichthys olivaceus L.)的格氏乳球菌(Lactococcus garvieae)的代表菌株(T030817-1株),分别制备全菌(OK)及热处理(121℃作用1h)菌体(O)免疫原,强化免疫接种家兔制备相应抗血清,对10株格氏乳球菌分离株进行了血清同源性检验。结果表明,供试10株菌均存在同种的表面K抗原和同种的菌体O抗原(血清同源),其中O抗原具有强免疫原性、K抗原免疫原性及O凝集抑制阻断作用弱;以相应OK抗血清为第1抗体、标准的羊抗兔IgG荧光抗体为第2抗体,对10株格氏乳球菌的纯培养物及用代表菌株(T030817-1)人工感染病死牙鲆的肝组织进行了间接荧光抗体染色,结果显示了特异的荧光反应;同时,对从人工感染死亡牙鲆分离的6株纯培养菌以凝集试验进行了检验,亦显示特异凝集反应。     

高效液相色谱法测定牙鲆中两种探针药物及其药动学研究

以健康牙鲆为试验动物,对其注射氨苯砜和氯唑沙宗2种探针药物,采用RP-HPLC法测定其血浆中氨苯砜和氯唑沙宗的浓度。结果表明,RP-HPLC测定方法专属性强、操作简便,能在11 min内将2种探针药物有效分离。     

Channel Catfish,Ictalurus punctatus,Immunity to Saprolegnia sp.

ABSTRACT

The Japanese flounder, Paralichthys olivaceus, is one of the most common finfish cultured in Japan and Korea. Despite the relatively high production of fingerlings, some problems remain, mainly related to the larval feeding and cost of maintaining microalgae and rotifers. In order to determine the effects of different diets on the Japanese flounder larval growth and survival, a series of experiments was carried out related to the size and nutritional value of different live feeds. The larvae culture conditions were at 10 or 20 larvae/L in 50 to 2,000 L tanks, with aeration and with or without “green water,” and a temperature range of 18.5 to 22.5°C. The live foods used were microalgae (Chlorella ellipsoidea and Nannochloris oculata), baker's yeast, experimental n-yeasts, oyster trochophore larvae, three strains of rotifer Brachionus plicatilis (L-type, S-type and U-type) and Artemia nauplii. Variations were detected in size, dry weight, and chemical composition of the three strains of rotifers used. The maximum number of rotifers ingested by flounder larvae increased steadily from 7 individuals, at first feeding (3.13 mm), to 42 individuals at 5.25 mm of total length (6 days after first feeding). There was a relationship between larval total length and size of the rotifers ingested. The effect of rotifer size on larval growth and survival appeared to be limited to the first two days of feeding. Of the diets tested in the growth and survival of larval flounder during 14 days after hatching, rotifers fed on C. ellipsoidea and raised in green-water gave the best results. Rotifers cultured on enriched N. oculata and n-yeasts did not support larval growth and caused higher mortalities. The n-yeasts used as rotifer enrichment appeared to satisfy, partially, the nutritional requirement of 7-day-old flounder larvae, as did n-yeast squid wintering oil the requirements of 14-day-old larvae. From 7-9-days after hatching and throughout the second 14-day period, rotifers and Artemia cultured on N. oculata improved the survival of flounder compared with those fed on rotifers cultured on C. ellipsoidea. Moreover, the larval growth did not vary significantly between both microalgae-rotifer feedings. No clear relation was found between total protein, lipid, amino acids and fatty acids of live feeds with the growth and survival of flounder larvae, although the total lipid was higher in C. ellipsoidea than in N. oculata. The Artemia nauplii San Francisco strain appeared to be more suitable for the growth and survival of flounder larvae, than the Utah strain. The nutritional value of Artemia nauplii (Utah strain) for flounder larvae remained unchanged despite the use of either microalgae as nauplii enrichment.     

Effect of stocking density and addition of proteins on larval survival in Japanese flounder, Paralichthys olivaceus

The effects of larval density, rearing media, and protein additions on fish larval survival were tested by rearing larvae in small containers. Yolk-sac larvae of Japanese flounder, Paralichthys olivaceus, were transferred 1 day after hatching to plastic dishes and cell-culture microplates by Pasture pipette at densities ranging from 0.3 to 30 individuals/ml and incubated at 16 °C without food. Dead larvae were removed and counted every 12 h. Three peaks of larval mortality were observed: the first peak appeared just after the transfer, the second corresponded to the completion of yolk absorption, and the third occurred 10–12 days after the transfer. Since about 50% of larvae survived until the third peak, it was clear that mortality at the second peak (completion of yolk absorption; equivalent to the first feeding) was not due to starvation. At the first mortality peak, better survival was unexpectedly recorded at higher larval densities (30 individuals/ml), suggesting that some material beneficial for survival is derived from the larvae. This idea was further supported by the improved survival in media previously used to rear larvae at high densities. The addition of bovine serum albumin (BSA) at 10 μg/ml effectively reduced mortality in microplates and in 30-l tanks. To reduce the larval mortality just after handling, addition of egg white at a dilution rate of 1/30,000 (vol/vol) or less is recommended as a practical alternative to BSA. Since the addition of polyethylene glycol 6000 (1 μg/ml) also effectively reduced mortality, reduction in mortality could not be attributed to a specific mechanism. The precise determination of the magnitude and timing of larval mortality was attained through the use of small containers, and a method to prevent mortality due to handling was identified in this study. These types of tests may allow the logical evaluation and establishment of better rearing procedures for seed production in aquaculture.     

Rearing of flounder (Platichthys flesus) juveniles in semiextensive systems

A low-technology rearing system was implemented for rearing juvenile flounder for stock enhancement in a Danish fjord, the Limfjord. Each year during 1996–2002, between 13,000 and 153,000 juveniles were reared from the yolk-sac stage until metamorphosis in outdoor ponds relying on phyto- and zooplankton blooms as their main food source. In contrast to other similar systems, the blooms in this system are closely monitored and, to a certain extent, regulated. The zooplankton blooms consisted mainly of calanoid copepods, dominated by the species Temora longicornis and Centropages hamatus. Most juveniles produced (>99.5%) were normally pigmented with average yearly survival rates from hatch to metamorphosis varying from 7±9% to 48±18%, lowest in the first years of production.