香鱼(Plecoglossus altivelis Temminck et Schlegel)海水养殖的初步研究

在水泥池中进行香鱼海水养殖试验，试验香鱼在海水中养殖80d，香鱼的平均体重在试验开始时为7．14g，结束时平均体重35．52g，养殖成活率68．9％，饲料系数2．36。海水水温超过25℃则香鱼出现严重的病害并大量死亡。     

日本香鱼(Plecoglossus altivelis Temminck et Schlegel)生产及其病害防治技术研究

香鱼是重要的养殖经济鱼类，本文作者详细概述日本香鱼养殖生产的现状、香鱼全雌化生产技术以及香鱼病害防治技术的研究，内容较翔实，对香鱼养殖生产单位有一定的参考作用。     

香鱼生物学特性及其养殖技术

香鱼又称海胎鱼、油香鱼、细鳞鱼、瓜鱼、平鱼、八月香、肥鱼等，在日本称鲇，是一种一年生小型珍稀经济鱼类。主要分布在日本的北海道南部至鹿儿岛．朝鲜沿海及我国的渤海、黄海、东海及台湾的某些入海溪河中。     

香鱼人工养殖技术

香鱼为一年生小型经济鱼类，一般个体重１００～１５０克，最大达２５０～３００克。成体香鱼呈纺锤形，背部灰黑，体侧银白，各鳍末端淡黄色，胸鳍上方有一黄色斑块。香鱼肉质细嫩，味道鲜美，背一鳍后有脂鳍，具有浓厚的诱人香味，深受国内外消费者青睐。现将香鱼人工养殖技术介绍如下。１池塘养殖１．１场地选择香鱼喜清新水质，适宜水温为１６～２６℃，当水温超过２８℃会发生死亡。因此，要选择靠近山泉溪流或水库附近建池，夏季高温时，抽取水库底层水经增氧后注入养殖池。１．２池塘建造香鱼养殖池以圆形或椭圆形水泥池为好，面积８…     

香鱼的生物学特性及养殖技术

<正> 香鱼(Plccoglossus altivelis)属鲑亚目、香鱼科、香鱼属。香鱼体细长而侧扁,头小而吻尖。身体上侧绿色、背缘黑色,两侧及下侧为白色。香鱼地方名:海胎鱼、秋生子、日本人称为鲇鱼,因能散发出诱人的香味而得名。香鱼体长10～30cm,重50～100g,最大的可达500g左右。     

香鱼高效养殖新技术

香鱼为一年生小型经济鱼类，一般个体重１００～１５０克，最大达３００克以上。成体香鱼呈纺锤形，背部灰黑色，体侧银白色，各鳍末淡黄色，胸鳍上有一个黄色斑块。香鱼肉质细嫩，味道鲜美，其背脊上有一条充满香脂的腔道，具有浓厚的诱人香味，深受国内外消费者青睐，市场供不应求。香鱼活体市场价每千克３５～４０千克，是近年来新兴的一个养殖珍稀品种。现将香鱼人工养殖技术介绍如下。１池塘养殖１．１场地选择香鱼性喜清新水质，适宜其生长的水温为１６～２６℃，当水温超过２８℃时可能会发生大量死亡。因此，要选择靠近山泉溪流的场…     

香鱼高效养殖技术

香鱼为一年生小型经济鱼类，一般个体重１００～１５０克，肉质细嫩，味道鲜美，其背脊上有一条充满香脂的腔道，具有浓厚的诱人香味，深受国内外消费者青睐，市场供不应求，是近年来新兴的一个养殖珍稀品种。现将香鱼人工养殖技术介绍如下：一、池塘养殖１．场地选择香鱼性喜清新水质，适宜其生长的水温为１６～２６℃，当水温超过２８℃时可能会发生大量死亡。因此，要选择靠近山泉溪流的场地建池，也可在水库附近建池。夏季高温时，抽取水库底层水经增氧后注入养殖池。２．池塘建造香鱼养殖池最好为圆形或椭圆形水泥池，面积８０～１００…     

香鱼(Plecoglossus altivelis)的人工繁殖及胚胎发育

在上海地区首次对香鱼进行了人工繁殖试验,并对亲鱼培育过程中采取的遮光诱导、海水刺激等方法作了探讨。试验结果表明,在人工控制条件下,香鱼性腺发育正常,催产率１００％,在水温１６．５℃￣１８．０℃,盐度５‰的流水环境下,经１０ｄ左右仔鱼大量出膜;出膜后第４天开始摄食,仅靠卵黄,仔鱼能存活１周左右,体长为７ｍｍ。     

饵料系列对香鱼(Plecoglossus altivelis Temminck et Schlegel)人工育苗成活率、畸形率和白化率的影响

通过同一饵料系列(轮虫、卤虫无节幼体、桡足类、颗粒配合饲料)中不同的轮虫投喂时间,桡足类、颗粒配合饲料的比例,比较研究香鱼人工育苗的成活率、畸形率、白化率等育苗效果,以完善香鱼全人工批量育苗工艺.试验表明,在香鱼人工育苗仔稚鱼培育早期延长轮虫的投喂时间到15日龄可提高育苗的成活率及苗种规格;增加桡足类投喂量、减少颗粒配合饲料的投喂或采用研制全价的颗粒配合饲料有助于降低苗种的白化率;苗种的畸形与卵质有直接的关系,但同时与饵料、水质条件等因素有关.     

香鱼的生物学特性及人工养殖技术

香鱼为一年生洄游型鱼类，营养价值高。生长水温为10～27℃，最适水温22～24℃，最大个体可达500g左右；阐述了香鱼的人工养殖技术要点。     

Histopathological studies of bacterial haemorrhagic ascites of ayu, Plecoglossus altivelis (Temminck & Schlegel)

A histopathological study was carried out on ayu, Plecoglossus altivelis, with bacterial haemorrhagic ascites. The fish were obtained from culture ponds in Wakayama Prefecture in 2003. The causative agent was identified as Pseudomonas plecoglossicida by a slide agglutination test using anti-P. plecoglossicida FPC941 serum. Histopathological studies revealed lesions in spleen, kidney, liver, intestine, heart and gills. Lesions in the spleen and haematopoietic tissue were prominent and invaded by P. plecoglossicida. Necrotic lesions accompanied by haemorrhage, fibrin deposition and oedema occurred in the splenic pulp and sheathed tissue, and in the kidney. The liver also had necrotic lesions and abscess formations. However, the intestine, heart and gills were only slightly invaded by P. plecoglossicida. No lesions or bacteria were observed in the brain.     

香鱼人工育苗饵料系列及投喂技术研究

在水温14．8-21．2℃,比重1．008-1．013条件下,采用轮虫、微颗粒饲料、卤虫无节幼体及桡足类,以不同配比组成3组不同的饵料系列投喂香鱼仔、稚鱼。结果表明:采用轮虫 配合饲料-桡足类 配合饲料的系列饵料,在仔稚幼鱼生长速度和成活率等方面优于单纯使用生物饵料组成的饵料系列,并且可以降低育苗成本。     

A novel genotyping technique for distinguishing between Flavobacterium psychrophilum isolates virulent and avirulent to ayu, Plecoglossus altivelis altivelis (Temminck & Schlegel)

We developed a simple genotyping method for Flavobacterium psychrophilum for analysing two single nucleotide polymorphisms (SNPs) in the gyrA gene and to distinguish between isolates that are virulent and avirulent to ayu, Plecoglossus altivelis altivelis (Temminck & Schlegel). The genotyping method is an on/off switch assay and is based on the polymerase chain reaction technique with phosphorothioated primers. We classified 232 isolates from four families of fish (i.e. Plecoglossidae, Osmeridae, Cyprinidae and Salmonidae) into four genotypes (G‐C, A‐T, A‐C and G‐T). The G‐C type isolates exhibited strong pathogenicity to ayu, whereas the A‐T and G‐T types did not show any pathogenicity to this species. The A‐C type exhibited no or weak pathogenicity to ayu. These results indicate that genotyping F. psychrophilum isolates with two SNPs from gyrA can clearly distinguish between isolates potentially harmful to ayu (G‐C type) and those that are potentially not harmful or less harmful (A‐C, A‐T and G‐T type). The on/off switch assay provides a quick, simple, and very powerful DNA genotyping technique for F. psychrophilum isolates.     

A visceral mycosis in ayu fry, Plecoglossus altivelis Temminck & Schlegel, caused by a species of Phoma

Abstract. Epizootics and histopathology of a new visceral mycosis due to fungi impefecti which occurred in farmed ayu, Plecoglossus altivelis Temminck & Schlegel, in Tokushima Prefecture, Japan are described. Histopathological examination suggested that fungal infection occurred primarily in the airbladder. A fungus with characteristics of the genus Phoma isolated from diseased fish is described and its taxonomic position discussed.     

Modification of the hyperosmotic infiltration method of vaccination against vibriosis in cultured ayu, Plecoglossus altivelis Temminck and Schlegel

Abstract. A vaccine solution of a formalin-killed culture of Vibrio anguillarum cells was observed to be toxic to young ayu when administered by the hyperosmotic infiltration method. The toxin was present in the culture broth. After the toxin was removed from the broth by centrifugation, the fish were dipped in 5.32% NaCl solution for 2 min and then in a solution containing precipitated cells for 3 min. The immunized fish were protected against vibriosis when challenged one month after immersion. The bacterin was administered to ayu by a further two methods, both using lyophilized whole cells of formalin-killed V. anguillarum. In one method, the fish were placed in a 5.32% NaCl solution for 2 min and then in a solution containing lyophilized cells at 2 g/l of well water for 3 min (two-step immersion). In the other method, the fish were placed in a 5.32% NaCl solution containing lyophilized cells also at 2 g/l for 3 min (one-step immersion). A high level of protection against artificial challenge was achieved with either method. No agglutinating antibodies to V. anguillarum were detected in either the serum or mucus of fish dipped in a vaccine solution, a supernatant, or a precipitated solution, one month after immersion. On the other hand, serum titres were detected in fish vaccinated by injection, although no titres were detected in mucus. LD₅₀ values are presented for the virulence of the V. anguillarum strain. Compared to the original strain, virulence increased after the third passage in ayu, but decreased after the thirteenth passage in medium.     

Effects of bicarbonate ions and pH on acquisition and maintenance of potential for motility in ayu, Plecoglossus altivelis Temminck et Schlegel (Osmeridae), spermatozoa

The effects of extracellular ions on the acquisition and maintenance of the potential for motility in the spermatozoa of the ayu, Plecoglossus altivelis Temminck et Schlegel (Osmeridae), were examined. Testicular spermatozoa and milt spermatozoa were obtained from fully matured males and diluted with buffered solution (BS, 20 mM HEPES–NaOH, pH 7.5). Testicular spermatozoa showed a significantly low rate of motility (0.8 ± 0.4%), whereas milt spermatozoa showed a high rate (89.4 ± 2.1%). The spermatozoa were incubated with various isotonic media for 2 h, diluted with BS, and changes in the rates of motility were then compared. When incubated for 2 h with artificial seminal plasma (ASP), corresponding in terms of ionic constituents to seminal plasma buffered at pH 8.0, both spermatozoa showed a high rate of motility. Testicular spermatozoa acquired and milt spermatozoa maintained the potential for motility in response to the HCO₃^– ion concentrations (between 0 and 20 mM) in the ASP. The differences in the pH of the ASP had a significant effect on the acquisition and maintenance of the potential for motility, and spermatozoa showed the highest rate of motility with the ASP at pH 8.0 and 8.5. These results suggest that the quality of milt in the ayu can be regulated by controlling the concentration of bicarbonate and the pH of the incubating media.     

Changes in drug resistance of Vibrio anguillarum in cultured ayu, Plecoglossus altivelis Temminck and Schlegel, in Japan

Abstract. Two-hundred-and-fifty-nine strains of Vibrio anguillarum isolated from diseased cultured ayu, Plecoglossus altivelis in various districts of Japan from 1974 to 1977 were studied for their sensitivity to 12 different chemotherapeutic agents: chloramphenicol (CM), tetracycline (TC), streptomycin (SM), kanamycin (KM), aminobenzyl penicillin (ABP), colistin (CL), nalidixic acid (NA), oxolinic acid (OA), piromidic acid (PA), furazolidone (NF), sulpharaonomethoxine (SA) and trimethoprim (TMP). One-hundred-and-thirty-four of the strains were additionally tested for sensitivity to O/129(2,4-diamino-6,7-diisopropyl pteridine) and ormethoprim (OMP). All strains were susceptible to SM, KM and ABP and also highly sensitive to CL. A correlation of resistance was found among the chemically-related drugs NA, OA and PA, and TMP, OMP and O/129, Nine strains were sensitive to all the drugs tested. The remaining 250 strains were resistant to various combinations of six drugs (CM, TC, NA, NF, SA and TMP). In particular, strains resistant to NA and NF (20.1%), to CM, TC, SA, NA and NF (29.7%) and to all six drugs (28.2%) were frequently detected. NA- or NF-resistant strains have increased since 1974 and TMP-resistant strains have increased since 1976. Transferable R plasmids were detected in 165 out of 250 resistant strains. The most common type of R plasmid determined resistance to CM, TC and SA. These multiple drug-resistant strains with transferable R plasmids were isolated from many different districts.     

红鳍东方鲀Fugu rubripes(Temminck et Schlegel)与牙鲆Paralichthys olivaceus(Temminck et Schlegel)的混养越冬技术

红鳍东方Tun与牙鲆是我国重要的养殖经济鱼类和出口创汇品种。在我国北方，这两种于通常是单独越冬。本文作者采用混养越冬技术，不仅降低了越冬成本，提高了水体利用率，而且使牙鲆在河Tun的影响下，明显增重和有效地预防了疾病。