31 March 2012

知识篇---伊东渔场养鱼资料

中国兰寿网

*****腮病最前线*****

在各种文献和信息的基础上,向您说明本养鱼场关于治疗腮病的方法!


一、原因

一种名叫Flexibacter columnaris 的革兰氏阴性细菌引起的感染是导致腮病的主要原因。
这种细菌在1922年在美国发现,1953年被确认能侵害鱼体致病.1966年在日本水槽饲养的泥鳅中发现。

这种细菌是外部寄生性细菌,是饲养池和水槽内常驻的细菌,一定请注意这点!!也就是说,不伦什么样的养殖环境都会存在这种细菌!

二、特征

这种细菌是外部寄生性细菌,没有受伤的腮是不会受到感染的。
但是,一旦腮受到损伤,这种细菌就会从伤口侵入鱼体,导致烂鳃病等发生。

这种细菌有许多不同的变种,各种变种之间的发育繁殖条件有所不同,但总的来讲,水温5-35度都可以发育成活!
在日本的泥鳅中分离出来的病菌,在水温 15-35度,PH值6.5-8.5的条件下生长发育,在水温27-28度,PH值7.5的条件下,繁殖数度惊人!

在海水中,当盐的含量在0.5%的时候,细菌得到最好的生存条件,当浓度超过2%时,停止生长!
在淡水中,这种细菌被证明会随着水的硬度的增加,而生存更长的时间,我们用的井水的硬度就非常高。

随着水温变化,感染的实验报告如下:

水温上升时: 水温每上升 (+2度),感染率:29.9%
水温下降时: 水温每下降 (-2度),感染率: 6.2%


三、发病时期

当鱼过量喂食后,最容易发生!

根据细菌的特征:当水温在15-35度的时候,都有可能发生感染,特别是当水温 27-28度时,细菌会大量的繁殖,受感染的危险性就越大。


四、 感染和传染

这种细菌是水中的常在菌,不会对健康的鱼造成腮病。

但是,这种细菌会寻找受伤的鱼进行攻击,当受伤鱼被感染之后,这种细菌会利用病鱼的营养,反复进行分裂繁殖,一时间细菌的数量得到非常的迅猛增加!
随之,当这种细菌的浓度达到一定值的时候,对健康的鱼也可以进行传染!

有时会有这种情况发生:当一个池中的鱼感染了腮病,无论饲养者多么小心注意,全场的鱼都会被传染。这种现象说明,这种细菌会随着空气传播!

当新鱼引进的时候,新鱼会把这种细菌传播给没有免疫力的原有的鱼,所以一定要做好新鱼的隔离工作!

五、发病的症状

症状会随着鱼种和细菌的变种的不同而有一些差异,但他们都具有以下的共同点:

轻症:最初,腮的一部分变白,有很小的可见黄白色附着物,病鱼会向溶氧高的地方聚集,游动无力,食欲和活动性低下,粘液大量分泌。

重症:一侧鳃或两侧鳃闭合不动,或打开不动,腮组织变成坏死的灰白色,食欲和活动性进一步下降,离群独游!

末期:由于缺氧和体力下降,导致体色变暗,肉瘤萎缩,身体消瘦,呼吸次数减少,离群,静止不动!这时,病情已经扩展到全身,最后由于缺氧和身体衰竭而导致死亡!

六、受伤的对策

受伤的鱼会被感染腮病,所以在饲养当中,最重要的事情是保护好鱼的鳃,防止腮受伤!

腮受伤是以下原因造成的,请特别注意:

1. 水质恶化。 (细菌大量繁殖,这是腮病最多的原因)
2. 用网追逐鱼,粗暴的捞鱼。
3. 把鱼暴露在空气中。
4. 水温的急剧变化。
5. 水质的急剧变化。
6. 池中出现人的阴影,使鱼受到惊吓!(译者注: 日本养鱼者在鱼槽上遮盖席子,是其中的一个作用。)
7. 过量的喂食


七、 传染的对策
水中的细菌对水质有重要的影响,细菌的含量一直在不停的变化。
细菌含量的增加,意味着对健康鱼传染的可能性会变大,抑制细菌的含量是非常重要的环节。

1. 避免使用变质饲料和被氧化的饲料(导致水质恶化的原因)
2. 为减少含菌量的增加,请及早补充新水。
3. 进行一些防止水质恶化的措施。
4. 对状态不佳的鱼,进行早期的隔离治疗。(同时对同缸的鱼要进行仔细的观察和必要的预防性药浴)
5. 死鱼的池子要进行日光暴晒消毒!
6. 对不能进行日光消毒的池子,要用イソジン原液(译者注: 日本药名,主要成分:聚维酮碘溶液,外文名:Povidone Iodine 【别名】 碘伏;碘附;强力碘 )泼洒后,用清水冲洗!

* 喂食活食会增加感染的几率
* 食物的残留和不及时的换水,会对细菌的繁殖起到帮助的作用
* 引进新鱼的时候,要做预防腮病的准备(隔离槽,药品等)


八、 治疗

要按照传染病的基本治疗方法来治疗腮病,有一条鱼发病,要对整缸的鱼进行治疗。这是因为由于病鱼的关系,导致病菌大量繁殖的缘故。

也就是说,要对同池的鱼进行仔细地观察,根据情况进行预防性的药浴。
当出现病鱼死亡的时候,要对鱼池进行几天的暴晒消毒!

本鱼场的诊疗方针

对腮病用以下的方法,1-2天可以治愈。(对于春季-秋季发生的腮病非常有效)

1. 准备一个100% 新水的鱼槽 (绝对不能在水泥池中治疗)
2. 水槽的四个角(最少两个角)暴氧。(腮病会导致缺氧)
3. 0.8% 浓度盐浴(可以用食盐)和エルバージュ(译者注:此为日本的黄粉,主要成分是呋喃类抗生素,对革兰氏阴性细菌有效,具体内容见后篇) 4g/100L。
4. 对鱼进行药浴 ( 注意鱼的密度要低一些)
5. 10点-16点之间, 要用席子遮盖鱼槽的80%的面积。
6. 经过一天的时间,观察腮的动作,如果正常,那就基本治愈。(如果腮的动作没有恢复的话,再进行一天的药浴)
7. 将原池里的水换掉,不必消毒。

*治疗腮病的感觉就像为鱼的腮做一次清理扫除一样。
*对于一天(24小时)的治疗不放心的话,最长进行两天治疗。
*盐和黄粉(エルバージュ),加一次就可以,不用追加。
*没有必要用加热器升温。
*用0.6%浓度盐水药浴的时候,需要一个星期的治疗时间,相反,水会被污染,腮病不会治愈。
*1%浓度的盐浴,对鱼来讲负担太重,目前还缺少成功的案例。


对于治疗效果不明显的时候,用以下的方法进行3到5天的反复药浴

1. 准备一个100% 新水的鱼槽 (绝对不能在水泥池中治疗)
2. 水槽的四个角(最少两个角)暴氧。(腮病是由于缺氧的原因导致)
3. 寒冷的季节,将水温调节到25度 (每天最大只能上升2-3度)
4. 0.5% 浓度盐浴(可以用食盐)和グリーンFゴールド(译者注:Green F Gold 日本药名 主要成分是磺胺甲基嘧啶,呋喃西林,具体内容见后篇) 颗粒。
5. 对鱼进行药浴 ( 注意鱼的密度要低一些)
6. 10点-16点之间, 要用席子遮盖鱼槽的80%的面积。
7. 将原池用イソジン原液(译者注: 日本药名,主要成分:聚维酮碘溶液,外文名:Povidone Iodine 【别名】 碘伏;碘附;强力碘 )

* 根据鱼的活动状态,少量的喂食一些红虫和虾等对治疗是有帮助的。
* 治疗池里的水如果发现腐败变臭,要立即进行更换,不要等到第二天再换。
* 治疗腮病一定要做到及时,早期发现,早期治疗是完全治愈的绝对条件。



九、 疫苗

疫苗是将病原体或其产物制成的各种预防生物制品,使动物获得对此种细菌的免疫力。

接种疫苗,可以使细菌的受感染率下降,即使受到感染,也会发病较轻,死亡率大幅下降。

根据北里研究所的发表数据表明:将因腮病而死亡的鱼作成饲料和一般饲料混合投喂的结果是: 腮病死亡率 8%
而没有混合的一般饲料的死亡率是:48%

但是,像前面介绍的一样,腮病细菌有多种变异存在,一种细菌的疫苗只对这种细菌的预防感染有效。

用疫苗的方法来完全防治腮病,就必须对所有的菌型做出向对应的疫苗,到现在为止,这样的疫苗还没有完全被开发出来。

十、最后

已经说了很多次,这种细菌有很多种的变异(最少9种)。
也就是说,如果你的鱼得过腮病,从此以后就不再得了,这种想法是没有根据的。

也就是说,如果受到没有出现过的变种的攻击,您的鱼还是会感染烂鳃病的,这一点一定要牢记。

***********************************************
译者后记: 请参考网上关于 Flexibacter columnaris 的革兰氏阴性细菌 的介绍

菌名:Flavobaterium columnare

分類地位:原核生物界
bacteroidetes門
黃桿菌綱
黃桿菌科
黃桿菌屬

原本叫做Flexibacter columnaris現在改名為Flavobacterium columnare

曾被誤認為真菌

Flavobacterium:黃桿菌屬 column:柱狀的

Flavobacterium:無色菌科中一屬,為革蘭氏陰性,桿狀運動菌,能產生黃色.橙色.紅色色素,見於土壤和水中

Flexibacter:描述微絲狀,滑行,不進行光合作用等細菌

此種菌名是在早期跟cytophagas有關聯(Cytophagas和Flavobacterium都放在Bacteroides內),直到1989年才確立flavobacterium的劃分

而flavobacterium可分為groupA ,B,C,D四大類

自然界棲息地:淡水,海水,土壤,海洋沉積物,食物裡都有(flavobacterium)最長可見於淡水或海水中

1963年Floodgate和Hayes從海水中的魚的表面,和海水中,還有海泥中分析出來

來自於亞特蘭大地區.美國西北海岸.佛羅里達

McMeekin又發現在乳製品.肉製品中亦發現大量此菌

F.multivorum從土壤中被Hayward在1984分析出來

而Flavobaterium columnare生於水中大約18℃~28℃

pH大約6.7~7.2左右為適合生長條件

致 病性與應用: 柱狀病(columnaris disease) 又稱細菌性爛鰓病,是由病原柱狀溶胞菌(Cytophaga columnaris)以前稱滑走性細菌(Flexibacter columnaris)所引起。 被感染的魚種可見於所有的淡水魚及部份海水魚,尤其是淡水觀賞魚。發病區域分佈北美洲、亞洲和歐洲。 感染本病之病魚最初的症狀是在口部周圍、鱗及鰭的邊緣出現白色棉絮狀的物質,常被誤為水黴菌引起。逐漸全身都可能出現此白灰斑點。唇部腫大鬆軟,魚鰭亦可 能碎如破布或只剩下光禿禿的鰭條。病魚厭食,行動緩慢。此病菌除了感染口、鰭外,也引起鰓絲極大病變,感染後鰓上黏液增加

(利用PFLP來確定16rRNA片段基因.並分析出分類上有用價值.可以減少致病力或是預防傳染病.有效的生產疫苗和藥物)

第四篇 *****腮病治疗试验报告(0.6% 盐浴)*****

腮病发生时,做了如下的试验:

1. 试验目的
试验目的是:比较在养鱼池和养鱼水槽中分别治疗的效果和成绩,以及他们的不同点。

2. 治疗时间

2002年 8月9日 ---

 9日(晴天)・10日(晴天)・11日(晴天)・12日(晴天)・
13日(多云)・14日(多云)・15日(晴天)・16日(晴天)・
17日(晴天)・18日(晴天)・19日(晴天)

※ 9日: 治疗开始日
※13日: 第一回换水日
※17日: 第二回换水日

3. 治疗鱼的数量以及治疗前的状态
总数: 48 条

体长:约 7-8CM
状态:生病前营养状态良好
病史:在此前基本没有生过病。

腮病的程度

48尾中46尾 ・・ 轻症 (食欲和活动性下降状态)
48尾中 2尾 ・・ 重症 (一侧鳃打开不动的状态)

4. 将病鱼分别放入养鱼池和水槽中
养鱼池和水槽都放在距离屋檐1米左右的地方,按以下的原则,分别随机把病鱼分开

养鱼池 (水量 300 L),放入一尾重症鱼,23尾轻症鱼。保留池中的青苔。
水槽 (水量 100 L),放入一尾重症鱼,23尾轻症鱼。没有附着青苔。

5. 水温
养鱼池 (9-16点,80%面积用席子覆盖)
晴天的早晨:26度 ・ 正午:28度
多云的早晨:26度 ・ 正午:27.5度

水槽 (9-16点,80%面积用席子覆盖)
晴天的早晨:26度 ・ 正午:30度
多云的早晨:26度 ・ 正午:29度

6. 实施的治疗方法
养鱼池及水槽都采用以下的方法治疗


①使用100%的新水
②对池的四个角进行加氧
③9-16点,80% 面积用席子覆盖鱼池。
④调整盐的浓度到0.6%。
⑤每100L水加4g黄粉(呋喃西林),以后每一天,在午后,100L水补充1g。


-------------------------------------------------------------------

⑥在治疗开始后第5天的中午之前进行了第一次换水(100%新水)。
和治疗开始时一样,重复进行以上1-5的操作。

⑦在治疗开始后第9天的中午之前进行了第二次换水(100%新水)。
和治疗开始时一样,重复进行以上1-5的操作。

-------------------------------------------------------------------

⑧在确定鱼已经康复前,重复以上的治疗。

7. 康复的判断方法
①腮的动作恢复正常
②游姿恢复正常
③摄食量恢复正常

8. 喂食及换水

在活动性恢复的鱼不足50%的时候,不喂食。
在活动性恢复的鱼占50%以上的时候,用10尾鱼对应1块冰冻红虫的量,在中午之前分两次喂食。
在所有的鱼多恢复的情况下,按以前的量喂食。


8月 9日(治疗开始: 初日) 中午前开始治疗。
8月13日(治疗开始: 第5天) 中午前第一次换水(新水100%)
8月17日(治疗开始: 第9天) 中午前第二次换水(新水100%)

9. 结果
●水槽的结果

治疗开始后第4天,50%以上的病鱼活动性得到恢复,用10尾鱼对应1块冰冻红虫的量,在中午之前分两次喂食。

第5天的中午前,进行了第一的换水,并按最初的治疗方法继续进行治疗,在同一天的午后,确认全部的鱼活动性得到恢复。

第6天,按照以前的喂食量进行喂食,全部吃完,从而确认一尾不落,病鱼全部康复!


●养鱼池的结果

治疗开始后第4天,没有任何活动性恢复,以及病情改善的征兆。而且,50%以上的鱼出现两腮打开不动及漂浮于水面之上的现象(病情加重),很容易地判断出病情有恶化的趋势!

第5天,和前一天一样,没有出现任何得到改善的征兆,所以在中午前进行彻底的换水,不得不将鱼移入水槽中,继续治疗。

第7天,一部分鱼的活动性得到恢复,重症鱼的病情也得到缓解。

第8天,50%以上的鱼活动性得到恢复,用10尾鱼对应1块冰冻红虫的量,在中午之前分两次喂食。
虽然重症鱼没有向鱼食聚集,但可以看到鱼的动作有些恢复。

第9天,中午之前进行了第二次换水,在水槽中,继续按照上面的方法进行治疗。这一天的午后,全部的鱼的活动性得到恢复。

第10天,按照以前的喂食量进行喂食,全部吃完,病鱼全部康复!


10. 观察和思考

养鱼池和水槽的治疗,有非常不同的治疗效果,他们的区别是以下几点:

主要区别:

①池中附着青苔的关系。
②水温在一天中变化的不同。
③水量的差别。
④密度的差别。

在这之中,凭我的经验,水量和密度不是影响治疗的原因,可以排除,所以对于这次的结果,只能认为是青苔以及水温是主要原因。

11. 试验的结论
早期发现的鳃病,可以用以下的方法进行治疗,6天可以完全治愈。

① 把鱼移到水槽中(水量 100L 没有青苔)。
② 100% 新水
③ 水槽四角充氧
④ 9点到16点,80%面积遮阳。
⑤ 水温
  晴天的早上:26度 ・ 正午:30度
  多云的早上:26度 ・ 正午:29度
⑥ 盐的浓度调整到 0.6%
⑦ 黄粉(呋喃西林)每100L水 添加4克,以后每一天100L水补充1g,在下午进行。
⑧ 治疗开始5天后,进行换水,按以上的方法进行继续治疗。

在活动性恢复的鱼不足50%的时候,不喂食。
在活动性恢复的鱼占50%以上的时候,用10尾鱼对应1块冰冻红虫的量,在中午之前分两次喂食。
在所有的鱼多恢复的情况下,按以前的量喂食。

***** 第五篇 兰寿与盐 *****

1. 盐的成分和效果

盐(主要成分:氯化钠)可以调节水的浓度。(水的渗透压)

商品盐有许多钟,例如:食盐、岩盐、大盐等等。

他们的成分有稍许的不同,但主要成分都是氯化钠。

也就是说,不伦是食盐、岩盐还是大盐都可以用来调节水的渗透压!

但是他们不同的成分对鱼来讲会有不同的作用,这一点有必要了解一下。

知道这一点,不论是鱼生病的时候,还是平时饲养的时候,各种盐交替使用,能够达到微妙地调整鱼的状态、增加鱼的活力、健康成长的作用。

但是实际当中,鱼所需要的矿物质在饲料当中已经十分满足了,不用刻意地去追求用盐来补充!

氯化钠 :主成分 作用:⇒ 杀菌作用 ⇒ 调节鱼的渗透压
氯化钾 作用:⇒ 杀菌作用 ⇒ 各种各样的生理作用
氯化镁 作用:⇒ 酵素活化的辅助作用
硫酸镁 作用:⇒ 酵素活化的辅助作用
氯化钙 作用:⇒ 促进骨骼的生长
硫酸钙 作用:⇒ 促进骨骼的生长

2. 什么是渗透压


渗透压是指液体的浓度。

一句话解释就是指液体的浓度。

对于生物来说,决定体液浓度的主要物质是盐分(氯化钠)。换句话说,体液的渗透压比较高就是指体液里盐的浓度比较高的意思。

通常的饲养水当中的渗透压非常的低,这是因为水中基本没有溶入盐分,所以鱼的渗透压要比周围的水高,这种情况会导致把鱼体内的水吸出。

但是,鱼本身具有调节自己的渗透压的能力,凭借这种能力,鱼可以在渗透压很低的淡水中生存!


3. 健康的兰寿的渗透压的调节

兰寿通过腮和肾的工作来调整自己的渗透压

兰寿是淡水鱼,兰寿的渗透压(体液浓度)比周围的水的浓度要高,理论上讲,这将必然导致水会从鱼的体表和腮向鱼体内侵入。

鱼为了保持自己的渗透压,基本上是不喝水的,并且通过腮的工作,积极地吸收水中的盐分,多余的水分会随着尿大量排出体外。

用这种方法来保持自己的体液浓度 0.5% 。(淡水硬骨鱼的浓度)

相反,当周围的水的浓度高于鱼的体液浓度时,必然水分会通过鱼的体表和腮向外渗出。

这时兰寿会积极地喝大量的水,并把多余的盐分通过腮排出体外,少量排泄浓度很高的尿,达到调节的作用。

还有就是鱼体表覆盖的粘膜,这种粘膜的一个作用就是,阻止水分(能很容易的)通过体表,当体表的粘膜受到破坏时,鱼就需要更多的能量去调节渗透压。




● 兰寿的渗透压的调节

 1)当周围的水的浓度低于0.5%时,基本上不喝水,并且通过腮的工作,积极地吸收水中的盐分,多余的水分会随着尿大量排出体外。


 2)当周围的水的浓度高于0.5%时,会积极地喝大量的水,并把多余的盐分通过腮排出体外,少量排泄浓度很高的尿。


4. 生病的兰寿与渗透压

水会从感染的部位渗透到鱼体。

鱼体表覆盖的粘膜能够阻止水分通过体表,但当受到病原体的感染,导致皮肤发炎时,粘液的活动性会下降,此时水会通过发炎的部位侵入鱼体,导致鱼体的渗透压急剧降低。

为了保持自身的正常渗透压,此时鱼会过剩地分泌粘液,腮和肾的调节功能被使用到极限,严重增加了器官的负担,也消耗了大量的能量。

这就是受到感染的鱼体力下降的原因,不是因为感染本身,而是为了调节渗透压造成鱼的体力急剧下降。

在这种状态下,鱼迅速消瘦,也会导致短时间内因衰弱而死亡!


5. 盐浴与兰寿的渗透压

把周围的水调整到0.5%,会使鱼的负担减轻。

生病的鱼因为粘膜遭到破坏,水会侵入到鱼体,这时如果水的浓度和体内的浓度相同,那末水就不会侵入到鱼体,相反,鱼体的水分也不会流失。

在这种情况下,鱼就不必要因为调整渗透压而消耗大量的体力,从而可以把多余的体力用来对付感染。

所以,盐作为重要的渗透压调节剂,可以简单地把水的浓度调整到和鱼体相同的数值 0.5% 。鱼得病时,这样操作是很好的一个方法。

根据我的经验,长时间药浴或永久浴的时候,调整盐水的浓度最好不要超过0.5%,对于突然超过0.5%的浓度,鱼不能适应,相反会变得虚弱,最坏的情况,可以导致鱼的死亡!请一定要注意。

还有,当盐的浓度为0.5%时,可以促进鱼的新陈代谢,推动鱼的生长。当鱼受到外伤时,0.5%的盐水还可以使伤口迅速愈合。

● 0.5%浓度盐浴的效果

 1.0.5% 的浓度和鱼体的浓度相同,所以鱼不用负担调整渗透压的体力

   ⇒ 方法:可以长时间使用或永久使用

 2.0.5% 的盐水,可以促进鱼的新陈代谢,促进生长,治愈外伤,改善消化系统。


  ※ 0.5% 的盐水基本没有杀菌的功效。

6. 盐的杀菌功效

渗透压的变化,是盐能够杀菌的基础。


导致兰寿致病的细菌是单细胞或几个细胞组成的,这些细胞直接受到外部的环境的影响。而这些细胞也不具备腮和肾这些高级的器官,所以没有调节渗透压的能力。

另一方面,兰寿是由许多的细胞组成的,受到周围环境影响的只有表皮细胞。而且拥有腮和肾等高级器官,能够调整自己的渗透压。

因为有这样的差异,所以当水的渗透压突然上升到1.5%-5%的时候,病原菌会马上失去水分,枯萎,并迅速死亡。兰寿不会因渗透压的变化而迅速死亡的。

或者将饲养水的浓度逐步调整到1%-1.5%,兰寿会自己调节渗透压,而细菌没有这样的能力,也会导致死亡。

利用这样的时间差可以起到很好的杀菌的作用,所以盐是很好的治疗用品。

但是,突然高浓度长时间的盐浴,对鱼来讲也是一种谋杀!

还有,因为病毒没有细胞质,所以盐是不能杀死病毒的。


● 盐的杀菌效果

 1.突然调整水的渗透压到1.5%-5%,利用细菌和兰寿的生存时间差来达到杀菌的作用。

   ⇒ 方法是瞬间盐浴或短时间盐浴

 2.利用几天的时间(7天-10天)逐渐地将饲养水的渗透压调整到1%-1.5%,利用细菌和兰寿的渗透压调整能力的不同,杀灭细菌。

   ⇒方法是长时间盐浴和永久盐浴

  ※ 突然高浓度调整渗透压的场合,绝对禁止长时间盐浴
  ※ 盐浴不能杀灭病毒,因为病毒没有细胞质。


7. 0.8% 盐浴法

腮病有一天(24小时)治愈的实绩。

我们饲养金鱼的时候,都不希望爱鱼得病,但是每年都会有几次腮病发生的情况。

在这个时候,最重要的事情,是要在短时间内将病鱼治愈。
经过各种试验,0.8%的盐浴法配合4g/100L的黄粉能够在24小时之内治愈腮病。

用0.5%或0.6%浓度的盐浴法,治疗时间要用一星期左右,水质会污染,相反有可能加重病情,
1%的盐浴法,还没有有效的治愈实绩,我感觉会加大对鱼的负担。

0.8%的盐浴法操作起来比较简单,可以用来进行腮病的预防。

对腮病用以下的方法,1天可以治愈。(对于春季-秋季发生的腮病非常有效)

1. 准备一个100% 新水的鱼槽 (绝对不能在水泥池中治疗)
2. 水槽的四个角(最少两个角)暴氧。(腮病是由于缺氧的原因导致)
3. 0.8% 浓度盐浴(可以用食盐)和エルバージュ(译者注:此为日本的黄粉,主要成分是呋喃类抗生素,对革兰氏阴性细菌有效,具体内容见后篇) 4g/100L。
4. 对鱼进行药浴 ( 注意鱼的密度要低一些)
5. 10点-16点之间, 要用席子遮盖鱼槽的80%的面积。
6. 经过一天的时间,观察腮的动作正常,那就基本治愈.(如果腮的动作没有恢复的话,再进行一天的药浴)
7. 将原池里的水换掉,不必消毒。

*治疗腮病的感觉就像为鱼的腮做一次清理扫除一样。
*对于一天(24小时)的治疗不放心的话,最长进行两天治疗。
*盐和黄粉(エルバージュ),加一次就可以,不用追加。
*没有必要用加热器升温。
*用0.6%浓度盐水药浴的时候,需要一个星期的治疗时间,水会被污染,但相反,腮病会治愈。
*1%浓度的盐浴,对鱼来讲负担太重,目前还缺少成功的案例。

8. 0.8% 盐浴法的注意点 (1)

鱼不游动的原因有很多,像消化不良,感冒,疱疹等都会导致。
0.8%的盐浴法对春秋发生的腮病有很好的效果。

例如:消化不良而导致的病,如果采用药浴,环境的改变会进一步导致恶化,从而进入恶的循环。

黄粉和0.8% 的盐浴法,不能用在感冒和消化不良的治疗上,这一点很重要!


9. 0.8% 盐浴法的注意点 (2)

对于那些原因不明,具有传染性的疾病,初期治疗可以采用这个方法。

对于那些不游动的鱼,在排除了感冒和消化不良的基础上,应当怀疑他们是否具有的传染性。

鱼病能够对症下药是最好不过的,但是往往我们不能及时地判断出疾病的原因和种类,在这个时候建议采用黄药配合0.8%浓度盐浴的方法,进行48小时的治疗后,进行再度确诊!

传感性疾病导致的鱼不游动,基本上都是腮病所致,用以上的方法基本上都可以治愈。

相反,如果不能治愈的话,基本上可以排除腮病的可能。这时可以进行0.5%的盐浴,最大的减少鱼的负担,仔细观察鱼的情况后,再对症下药,是很有必要的。

※ 原因不明,具有传染性的疾病,初期治疗方法

1.首先,按照腮病的方法治疗48小时。
方法是,黄粉配合0.8%盐浴。
黄粉和盐只需要投入一次,不需追加。

2.48小时后,鱼的状态如果没有改善的话,0.5%盐浴法,继续观察鱼的病情,争取确诊!
确诊后,用相应的药配合0.5%的盐浴进行治疗。

 
10. 0.8% 盐浴法的注意点 (3)

不要忘记用自然的方法,对鱼进行逐步的养育。

腮病能够很简单的被治愈,有了这点,很多的人可以进行非正常的养育,把 [顺其自然的培养] 抛在脑后,用各种手段催鱼。

但是盲目地追求大鱼的结果,使鱼失去了平衡,最终会导致失败!

腮病的发生就是对脱离自然养育的一种[警告],请重新改正您的养育方法,这一点很重要。


11. 1.5%-2% 浓度的盐浴法

使用大量的盐是对鱼有害的,请一定记住这一点。

对于那些重症的鱼,做为早期治疗方法,会采用1.5%-2%的盐浴进行治疗。

这是充分利用和发挥盐的强力杀菌的效果,但是1.5%-2%的浓度对鱼来讲,也是非常有害的,
也就是说:高浓度的盐既是很好的治疗药,同时也是杀伤力很强的毒药,这点请一定记牢!


对于那些重症的鱼,做为早期治疗方法以外,极力不推荐使用。

如果要采用这个方法,也请把治疗时间控制在30分钟(1小时太长了!)左右,进行短时间治疗。

注:鱼在30分钟内死亡的例子也有很多。
注:1.5%-2%的浓度下治疗,请不要离开,仔细观察,如果鱼突然变得迟钝,请立即中止!


12. 5% 盐浴法
杀菌效果的最大限度的利用。

5% 的浓度比海水的3%还要高,这时的使用是最大限度地利用它的杀菌效果,当然对鱼的伤害是1.2%和2%浓度无法比拟的。

如果要使用这个方法,一定不能超过90秒。

如果将兰寿放入5%的盐水中的话,鱼会亢奋地分泌大量的粘液,体表会因为脱水而变得惨白,腮的动作急剧降低!

如果治疗的时间超过90秒,鱼就会死亡,所以一定请严格遵守治疗时间。

注:5%浓度的盐浴对鱼来讲,负担简直是太大了,最好不要用,就比较安全了。

13. 盐浴与兰寿的体表

盐水会促进体表粘液的分泌。

鱼接受到盐水的刺激,体表粘液产生亢进,粘液也大量增加分泌。

这种结果对于治疗感染性疾病非常有效。也是说,体表付着的病原菌,会随着分泌的粘液而慢慢的被剥离,从身体上被冲洗掉了。

这样一来,感染的细菌的数量就会减少,细菌被粘液包裹,也会减缓它的繁殖速度。

但是,虽然细菌从鱼体上剥离下来,但细菌并没有死亡,它会再次从水中感染其他的鱼。

为了防止此类的情况出现,建议放入治疗用药物,彻底杀灭细菌,提高治疗效果。

14. 关于盐与药物并用

盐和一种药剂同时使用效果更好。

不同的药剂混用的时候,会产生不良的后果。 有时会反应产生有毒物质、药力有时会增强,有时会减弱。

普通的药剂的成分含量比较容易掌握,根据鱼的病情,考虑副作用等因素,可以计算出大致的用量。如果几种以上药剂并用,某种特定成分的浓度就会增加,导致对
鱼的副作用的急剧增加。

所以,在治疗时,要使用一种单一的药品为基础,把水调整到0.5%渗透压,减缓鱼调节的负担,进行治疗是比较有效的。

特别注意:盐和福尔马林同时使用时,会产生有毒物质,要绝对避免一起使用,切记!!

● 盐与药物并用时的注意事项

 ・ 对鱼病治疗使用一种药物。
 ・ 和其他药物混用会增加毒副作用。
 ・ 最大限度的发挥药力,请参考说明书上的用量使用。
 ・ 盐和福尔马林同时使用时,会产生有毒物质,绝对禁用。

*****鳞的构造及色扬*****

鳞是由以下三层组成的,色素细胞层、鳞层和光彩细胞层。

鳞的组成包括色素细胞层、鳞层(钙质)、光彩细胞层三层,鳞的表面被色素细胞层所覆盖,最里则是被光彩细胞层(白色素细胞)覆盖。

色素细胞层中包含黑色素(Melanin )细胞、发红色的红色素细胞、和黄色素细胞。在鱼褪色之前,黑色素细胞占主导地位,所以小鱼发青黑色。

褪色的时候,黑色素细胞遭到破坏,青黑色被除掉,红色素细胞慢慢开始沉淀,鱼会呈现出十分美丽的红色,我们称之为:普通鳞。


色 素细胞层中的色素细胞当中,黑色素细胞可以通过黑色素细胞刺激荷尔蒙或紫外线等的刺激,而使黑色素变浓。而红色素细胞和黄色素细胞里面含有胡萝卜素 (Carotenoid)和蝶啶 ( pteridine 构成黄色结晶的三环碱 , 见于动物的色素中 )。这些成分就必须从食物中获取了,这就是为什么要使用色扬饲料的原因了。相反在鱼变色之前是不用使用色扬饲料的。

色素细胞层中不含红色和黄色色素细胞的时候,我们就称之为透明鳞,里面的光彩细胞层透出,看起来发银白色的光。之所以呈现出银白色是因为光彩细胞层中含有的鸟嘌呤和腺嘌呤的颗粒中含有白色素细胞的原因造成的。

发锈(鳞片发锈色,无光)的颜色,一种原因是鱼具有锈的系统,或体质虚弱的表现。还有就是与太阳光中紫外线的照射有关。

紫外线可以使黑色素细胞增加,也同时破坏红色和黄色色素细胞。如果鱼的只有背部有发锈的颜色,肯定与紫外线的照射有关。

然而白色的鱼不容易发锈,这和鳞的构造有关。白色素细胞的分布位置和成分不同,所以可以更强的抵御紫外线。

现阶段,还没有找出红色和黄色色素细胞除锈和紫外线的效果之间的关系!

注意: 在水温20度以下的时候,喂食扬色饲料,很容易造成消化不良!请注意!!

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养鱼高手十法(翻译本)


第一法 *********严禁喂食过量**********

喂食过量是许多的养鱼初学者失败的原因
我们使用的养鱼器具的体积是固定的,喂食过多,只能造成水的污染!

(1) 必须投入硝化细菌(市场有售,具体的使用方法请询问卖家)

(2) 2-3天停止喂食 (我的经验:鱼数日不喂食是饿不死的)

(3)3-4天后,少量的循序渐进的喂食

(4) 经过一周左右的时间,如果没有死鱼,此时可以慢慢增大食量 一天喂食两到三次,每次吃到6成饱,尽量要把饵料控制在短时间吃完的程度。

(5) 请购入亚硝酸检测器(NO2 tester),经常检测水的污染程度,了解水质状况。

如果能做到以上几点,您基本上已经达到上级程度。


第二法 *********严禁大量换水**********
养了很长时间的鱼,突然有一天,出现尾巴充血,撕烂,然后在接下来的一周到10天左右,一条一条离你而去,这些是养鱼者的操作失误造成的。。出现的时间大多是新年和黄金周****只是为什么呢?

大量的换水是造成以上结果的原因 (放假,大家有很多的时间?)
****〉大部分的PH值(测量有些困难吗?)发生变化,硝化系统崩溃!(硝化细菌大量死亡)
****〉养鱼槽中的水和自来水的PH值(酸碱度)是不同的。
****〉 养鱼槽中的水,换水的时间越长,慢慢的水会呈弱酸性,而自来水是中性或弱碱性的水,PH值(7-7.8),这样的差距使鱼和消化细菌都难以承受,加重水的 污染,鱼也更容易生病,如果此时还大量喂食的话,您的爱鱼就要到他界等您了。(给病鱼喂食会加重他的病情,逆效果!!)

(1) 尽量少量的慢慢的给鱼换水
一周换水槽的1/3或1/4 是比较理想的,当然要根据水槽的大小和鱼的数量而定

(2) 换水的时候不要清洗过滤,清洗过滤的时候不要换水
(留一点脏的地方对鱼是必要的)

(3) 清洗底沙的时候,要把水槽中一半的水倒出来放在水桶里,然后清洗,清洗完成后,把桶里的老水倒回水槽,此时不能清洗过滤!

第三法 **********金鱼的感冒“白点病”**********

对与大多数饲养金鱼的人来说,从来不会考虑利用加热器来保持水温。但是,事实上,又有非常多的养鱼者因为金鱼得了白点病“就好象人类的感冒”,而丢掉了性命。
特别是,一天当中气温变化比较大的时候,这种病很容易发生。(早春及晚秋时节)

对策非常简单!!

买一个带温度控制的加热器放入水槽中。价格(2500日元左右)为了您爱鱼的健康,是不是很便宜呢?

然而加热器的使用,不仅能有效地防止白点病,同时也可以对付消化不良,即使在寒冷的冬天也能尽情地投饵,好处多多呀!

要象饲养宠物一样饲养您的金鱼呀,他们都是有感情的。


第四法 **********给可爱的鱼儿一些光明**********

金鱼的饲养者当中,有许多的人用水槽饲养(译者注:在日本,兰寿的饲养基本上是利用专用的水槽)但水槽用的照明灯具又有几个人用呢?

热带鱼饲养用的水族箱一定会配上照明用的灯具(有的甚至配两盏灯),但兰寿用水槽是不标配灯具的(种族歧视!!(^^##))
夜晚当我们回到家的时候,水槽上的灯光亮着,在昏暗的房间里,可以一眼看到心爱的金鱼,它们向你游来,嘴里喊着“我要吃,我要吃”这时候你会忘掉一切的疲劳和压力。那是多么幸福的一件事呀!如果没有照明灯。。。。

快去专门店,30水槽-大型水槽用的灯具都有,建议你花一点零花钱买一盏...............
为可爱的金鱼点亮爱的灯火!!



第五法 **********水质的检查非常重要**********

每当有客人说他的爱鱼有这样或那样的不正常的时候,我都会尽量在他描述的症状下,给出他一些处理的建议,最后一定会跟他说“你下次来店里的时候,一定带一杯你水槽里的水来”。这是因为我要检测水中的亚硝酸和PH值,这能使鱼病的原因更加的明确。

虽然有些难,但是如果检测了着两项指标的话,鱼的死亡率会大副的下降。以下就是两项指标不正常的解决方法:

(1)NO2 (亚销酸:水的污染程度检查)的浓度非常高的时候的解决方法
*****》 全部换水+注入消化细菌+停食

*****》 每天测试亚销酸浓度,浓度高的时候,重复上面的操作(尽量多的换水,要在1/2以上)
*****》 无论如何,要让消化细菌正常工作,只有等待和老天帮忙了,别无他法。


(2)PH值低(PHT 6 以下)的时候的处置方法
*****》 首先可以换水,但不要换很多的水,一边换水,一边测试PH值,大致换1/3或1/4的水即可,减少投饵量或干脆停食。
*****》 每天测试一下PH 值,如果低下,就重复以上的动作。
*****》 对过滤器进行部分的清扫。(不可全部清洗,更换滤材)
过滤器如果太脏的话,会导致PH 值迅速减低
*****》 使用PH 上升剂等也能达到同样的目的,但不推荐使用,换水是最好的办法!

一定要切记:透明的水不一定是好水,有时会是毒药!!!!

第六法 *****金鱼的过滤器材*****

经常有客人来店里说:“我要在室内饲养金鱼,我没有养过鱼,能给点建议吗?”

我一定会告诉他:“您要不先养点热带鱼试试怎么样?”

“为什么呀?不是热带鱼更难养吗” 很多的人都有这样的想法!

我们店认为:金鱼比热带鱼更难饲养!(金鱼对水的污染更加严重)
这是因为通常没有金鱼用的过滤器及相应的滤材造成的,(这也是生产厂家的问题!!!(^^##))(译者注:日本的很多玩家都是自己制作材料,包括捞鱼用具,然后互相销售)
通常能买到的金鱼用品,由于价格等问题,往往厂家只配备很简单的水下过滤装置(水妖精),“没有办法,不能卖的太贵!”这是厂家的托辞,但对于鱼商和消费者却是莫大的伤害。(译者注:日本的金鱼从业者有非常好的职业道德。值得广大鱼商学习!!)

在这里建议养鱼一直不能养好的各位

请使用有足够过滤能力的过滤器(如顶部过滤),请使用质量好的滤材!!
请您考虑增加或更换目前的过滤和滤材,你认为如何呢?

养金鱼要远比养热带鱼更需要好的设备,材料。多奢侈也不过份!




第七法 *****有备无患*****

养金鱼久了,有时会突然出现一些问题,比如设备坏了,鱼病了等等,每当此时,我们都会想起来“哎呀,如果有这个或那个就好了。”
我把平时注意准备的东西写着来,请大家随时准备好,以防万一!

(1)过滤器用的备用水泵
无论是上部过滤装置还是水下过滤装置(水妖精,气泵推动),泵头是这些过滤系统的心脏。一定要准备一个,一旦损害可以马上更换。
使用双重过滤器是一个好的办法(顶滤及水妖精同时使用),毕竟两个同时坏的可能性非常小, 不会使过滤系统崩溃,目的还是把损失减到最小!

(2)准备一些粗盐(60cm 的水槽,准备1 公斤)
鱼的状态不正常或有病的时候,盐是重要的宝物,设定浓度:0.3--0.5%

(3)准备一只备用的带温控的加热棒
如果这个东西坏了,你会见到你最不愿看见的事 (我们店里已经发生了很多次.....哭!!)
如果你要经常使用的话,一定要准备一个,不要等坏了再换,使用一段时间就要更换。
(有些加热棒的温控装置是金属触点型的,使用1-2年后,触点会发生粘连,那样你就会看到“水煮鱼”了。)

第8法 ***********金鱼入缸顺序及一周内的注意事项************

刚买来的金鱼不要马上放入您的缸中,最差也要让水温一致以后再放入。

简单的新鱼操作顺序如下:

1. 将金鱼移入水槽(鱼缸)

(1)将装鱼的塑料袋放入水槽,泡20-30分钟,如果在冬天,您使用了加热棒的情况下,缸中水温比较高,那需要泡1个小时左右。

(2)上面的工作完成后,要将鱼慢慢地捞入鱼缸,塑料袋中的水最好不要放入缸中,倒掉!

* 注:上面工作(1)之后,如果能把鱼缸中的水少量的倒入塑料袋,并检测一下PH值,我想是更加安全的。

2. 金鱼入缸后一周内的注意事项

(1)喂食要尽量的少。 (购入日---第3天之间,停食!)
(2)万一金鱼发病,一定要尽早对症治疗。

3. 正确的处理方法(如果有条件)

准备一个为新鱼专用的预备水槽(鱼缸,鱼盆)先把新鱼放入这个水槽中饲养一个星期左右,在这期间请仔细观察鱼的状态,
并要完全停食,放入一些盐和预防用的药是比较好的。

上面的处理方法的道理是这样的:

运输过程或移动过程中,鱼会经历外伤,惊吓,紧张,水温变化等一系列痛苦的过程,就像我们经历了一场长途的奔波一样,
身体很虚弱,非常容易发病。

其次,新来的鱼会携带一些病菌,但这鱼已经对这些病菌有抗体,而你的老鱼没有经历过这种病,没有任何的抵抗力,往往
你的老鱼会全部发病。这就是为什么人们会经常说的,买了新的鱼,而以前的鱼全部死光光的原因。不幸的人真多呀!

为了这可爱的小生灵,不要怕麻烦,让他们慢慢适应你的环境!!



第9法 ***********给你“困的水”加氧!!!******************

这几年来,非常多的客人问我:“进入夏天,金鱼真难养呀,经常死鱼,这是为什么呀?”
听了他们的说法很多,发现一个共同点:
他们晒得水(困的水)在没有加氧的情况下,经常放置许多天!!!!(最恶劣的要放置一个星期.....)

我会很不客气地问他:“这水你自己喝吗?”
肯定回答是:“不喝!”,“为什么不喝呢?”,“不新鲜了!”
原因就是这样,不新鲜了!!(汗)
去掉氯气的自来水,会一天天腐败下去,如果没有氧气,腐败的速度会加快很多!!
那这样的水给金鱼换上,我想谁都知道对金鱼没有好处!!

饲养金鱼的资料非常少,为了能够把可爱的金鱼饲养好,大家拼命收集各种书籍,在网络上寻找,知道金鱼晒水的重要性,并且按照上面说的去做!但是非常遗憾,我发现很少有书上或网络上提示你给晒得水加氧!
在这里我要大声疾呼: “请给你晒的水加氧!”

晒水有许多的好处,特别是在室外饲养,可以调节水温,去除氯气等
但是,在炎热的夏天如果不给晒得水加氧,放置数天,这个水是绝对不能用的!请切记:
换水是无比重要的事,关系到爱鱼的生命!



第10法 ********** 清理你的底沙 **************

底沙是众多的硝化细菌赖以生存的重要场所,他们在这里繁衍生息!

但是,这里也有许多饲料的残留物,鱼粪等,非常容易被污染!一定程度的污染是没有问题的,但是如果太脏了,如导致水质的恶化,也会成为病菌的温床!(在这里也寄存着大量的致命病菌)。。

许多人是把底沙全部取出来清洗,在取的过程中,水变得很混,水质污染严重,这时如果不把鱼放入其他地方,鱼很快就会变得身体虚弱,不适!这样的事经常发生。

建议您到专门店购买洗沙器,这种工具可以使您一边换水一边洗沙,不会造成水的污染,可以分三步完成整个过程,非常便利!
希望您能参考!

30 March 2012

金鱼繁殖

金鱼繁殖是门大学问,如何繁殖出至少不次于亲本的子代是最低要求。首先是要有个好的开头,采卵和孵化这关得过好了,出好鱼的几率会极大提高。这就要求控制 好鱼卵的采集和孵化的各种条件。总的来说对于采集鱼卵,笔者推荐用脸盆人工水法受精,这样受精率高;孵化条件包括,水温,溶氧量,水质等。

   就个人经验来说,家庭小规模繁殖金鱼最好的容器是脸盆,没错就是普通脸盆,一般以20~30cm口径的脸盆为宜,首推搪瓷材质的白脸盆。塑料盆只要是无 毒的也可以。笔者见过渔场也有用小瓦盆接卵的。瓦盆透气性好,易挂苔,也是非常不错的选择。对于家庭小规模繁殖,笔者不建议用太的大盆。至于为什么后面会 稍作解释。

  准备好了盆,下面做的就是等待时机接生了。金鱼是变温动物,通过感知外界温度变化,判断季节,并发情繁殖。健康金鱼的性 腺一般会在水温重新达到15左右时,开始变得活跃。公鱼会出现追星,体色更加艳丽。母鱼会开始抱卵,下腹变得柔软膨大,生殖孔开始外凸。因此金鱼一年会有 两次拨卵,春卵和秋卵。春天万物复苏,鲜活饵料比较容易获得。渔场一般是收春卵。秋卵繁殖成本稍高。但对于家庭小规模繁殖来说,春卵和秋卵都可以使用。出 的鱼并不会有明显差异。尤其是在北方有暖气条件下,金鱼的秋卵和春卵会连在一起,直到夏天水温超过25度以后,性腺才重新开始休眠。母鱼在准备好之后,会 释放一些外激素,刺激发情了公鱼追赶,并用头部顶压母鱼后腹部。这个大家一般称之为追尾。追尾是金鱼即将和产卵的征兆。追尾正常情况下是发生在清晨和上 午,中午一般就结束。待产的母鱼一般也会在换清水之后的一两天内产卵(渔场可以用催产针,让母鱼同时产卵)。笔者感觉,在母鱼差不多准备好之后,彻底撤换 新鲜等温自来水和用催产针的效果差不多。母鱼一般都会在第二天早上甩子。早起要注意母鱼公鱼状态,若是公鱼穷追不舍的顶母鱼下腹,母鱼也比较爱钻角落和水 草,或者是直接看到母鱼有鱼籽从生殖孔排出,这时人工受精的机会就成熟了。

  准备好的盆里装上水(注意一定要用原池的水),水高以淹 过2倍鱼高为宜,水加太满,不利于受精。左手公,右手母,让两鱼泄殖孔正对,然后开始轻轻挤压鱼的腹部,这时卵会倾泻而出。注意抖动母鱼尾巴,让卵均匀散 开,不要大串的粘一起。适当挤压公鱼,让其排精。盆地撒得差不多了,换个盆继续,直到母鱼没卵。一个盆不宜打得太密。完事后,把种鱼放回原池。搅动产盆的 水,让卵充分受精,产盆静置4,5个小时后(至少2小时)倒掉老水,加入等温新鲜晾好的自来水。不宜用晾晒多日的自来水,最好是头天晚上准备好的。丢几根 金鱼草或者蜈蚣草,用个20w白炽灯照着,一来可以让水草吸收氨氮等废物,二来可以保持水温。第二天观察,乳白浑浊的卵是未受精的死卵,需要及时剔除。工 具很简单,给篮球打气的气针串上气泵用的胶管,对准死卵一个个虹吸出来。

  采卵的密度下图1:这盆这样密度下,卵的数量在2千左右。家庭小规模繁殖一定不要贪多。2千一盆足够玩了。



图1.金鱼卵适宜密度 

  温度是影响金鱼孵化时间最关键的一个因素。笔者认为水温最好是保持在22度,不能低于18度。下图是金鱼孵化时间和温度拟合曲线。不难看出20度,金鱼125小时(5天)出壳。22度一般4天就出壳了。



图2.金鱼孵化温度与孵化时间关系(摘自《环境温度对金鱼胚胎发育的影响》由庞诗宜于1961年发表于 《实验生物学报》1961 7卷3期)


孵化并非温度越越好,如图2显示,温度越高,孵化速度越快,孵化速度太快之后,会导致发育不健全便出壳,出壳后较难成活。图3为孵化温度和成活率关系。不难看出,恒温22度23度,金鱼出苗最健康成活率最高的。





图3.有效孵化率与温度关系 (摘自《环境温度对金鱼胚胎发育的影响》由庞诗宜于1961年发表于 《实验生物学报》1961 7卷3期)



   还有一个问题,就是温度波动的问题,温度波动大,胚胎发育时快时慢,会严重影响幼苗成活率,极容易造成残次鱼苗。另外一个是对金鱼四开尾的影响。温度波 动大,幼苗单尾,飞机尾,三尾的比例会显著提高。当然影响金鱼尾巴正品率还有一个非常关键的因素,水体溶氧和氨氮浓度。也有业者依据经验指出高温容易出单 尾,低温出三尾。

    孵化水体小,需要保持水质清洁和较高溶氧量才能保证鱼苗的正品率,尤其是保证尾巴正品率。 这就可以解释前边提到的孵化盆要丢一两颗水草且需要24小时光照了。蜈蚣草光合作用需要色温低,一般的白炽灯的光谱就能让其顺利进行光合作用,前提是灯泡 最好不要离开水面超过20公分,太远了就不成了,1,2m远,那就和没照一样了。也不宜直接丢在阳光下晒,中午阳光强,很容易把水晒热,引起温度变化,导 致残次率升高。白炽灯一个保温二个可以让蜈蚣草光合作用,释放氧气,让水体溶氧量达到极大。这样卵的发育不会因为氧气限制而被抑制,导致残次。可以极大限 度提高幼苗正品率。笔者一对鱼接两盆卵。一盆照光,一盆不照。照光一盆,四开尾巴的比例在95%以上,极少有残、单尾,不照光一盆,残次尾、单尾的比例大 概在30%左右。可见溶氧和和水温恒定对鱼正品率影响非常之大。  

  至于保持温度恒定在22度,也很简单,稍微调高(低)台灯高度即可。

   静等4天左右,小金鱼就开始出壳了。如果前述几个条件满足比较好,那么出壳会非常整齐。齐刷刷的出来,然后开始挂丁。注意挂丁的温度一定不要低过21 度,否则起飞时间会拖后,导致一些苗夭折。越早起飞越好。22度水温,大概3,4天就可以飞起来了,等全部起飞之后,可以用蛋黄开口。第二顿一般是需要用 新孵化丰年虾幼虫了。继续蛋黄不但坏水,而且鱼吸收不了什么营养了。喂丰年虾幼虫前,最好清理一下水底的赃物。


未完待续,请关注后篇,金鱼繁殖之饵料篇

15 March 2012

绿水和新水的饲养区别



新水和绿水的主要特征

新水效果

绿水效果

对鱼的刺激

运动量

经常游动,增加运动量

运动量减少

吃食

促进

抑制

纵向成长

促进

抑制

鱼整体的体形

因为长身体,有些鱼身体有变细的可能

控制鱼的纵向发展,容易控制鱼的体形

肉瘤的发育

因为长身体,肉瘤发育的不充分

容易长头瘤

鱼鳞

因长身体,鱼鳞不整齐,容易出现大鳞片

鱼鳞容易长的整齐细致

尾筒

因运动量增加,尾筒肌肉变得粗壮

因运动量减少,肌肉很难变状

尾鳍

因为运动量的增加,接受水的抵抗较弱,所以张力较好。

反之在老水中张力较弱。

色彩

颜色容易变淡,漂亮的斑点容易消失

色泽鲜艳

老化

用新水强迫鱼生长,容易形成锈色等老化

反之由于水质系统稳定,老化也延迟。

容氧量

通过气泵很容易增加容氧

由于光合作用,白天过饱和,夜里容易造成缺氧

如何大量繁殖水蚤? Cultivate Daphnia




水蚤喂养十分简单,现介绍喂养的方法如下:
拿 到水蚤的虫种后,把袋子打开通气。准备一个十加仑(大约40升水)的大容器来养殖水蚤。养殖水蚤的水质极其重要,对待水要象对待你的鱼一样,千万不能让水 里有金属和有毒物质。准备好已注入水的大容器后,把装水蚤的袋子放在水中,让它在水面上漂20分钟。养殖水蚤的容器每天需16个小时的充分光照和良好通 风,理想温度为21~27摄氏度。
喂养水蚤:把相同份量的马铃薯薄片,鱼食薄片和酵母碾成粉末。取四分之一茶匙(10加仑的养殖缸所需份量)的粉末溶入适量水中,然后把水倒入水蚤养殖缸。在水变得象水晶一样清澈之前,无需再往养殖缸中添加饲料。
也可以用酵母来喂养水蚤,普通的面包酵母就可以了。把酵母溶入适量的水中(注意加入适量的酵母,否则会导致水蚤缺氧),把溶化了酵母的水倒入水蚤养殖缸。水变得有些黑,在水恢复水晶般清澈之前,无需再往养殖缸中添加饲料。
每星期更换一至两次水,每次更换水蚤养殖缸里25%的水。确保添加的水里不含氯,并和养殖缸里的水有相同的温度。
以上内容和建议,仅供参考。

水蚤在缺氧时呈红色,富氧时是透明的颜色

水蚤的血液含血红素,血红素溶于血浆,肌肉、卵巢和肠壁等细胞中也含血红素。血红素的含量常 随环境中溶解氧量的高低而变化。水体中含氧量低,水蚤的血红素含量高;水体含氧量高,水蚤的血红素含量低。由于在污染水体中溶解氧含量低,清水中氧的含量 高,所以,在污染水体中的水蚤颜色比在清水中的红一些,这就时水蚤常呈不同颜色的原因,是适应环境的表现。我们可以利用水蚤的这个特点,判断水体的清洁程 度。

水蚤是指水生枝角类和挠足类两大类浮游动物,其营养丰富、容易消化,是鱼苗、鱼种的适口饵料。人工培育水蚤喂鱼成本低、鱼类生长快、增产效果好。其方法是:

  一、建池 土池和水泥池均可。池深约1米,大小以10平方米~30平方米的长方形为宜。

  二、注水 池中注水约50厘米深。水蚤适宜的水温为18℃~25℃,pH值为7.5~8,溶氧饱和度为70%~120%。

   三、施肥 土池每立方米水体投4公斤牛、马粪或其他畜粪、1.5公斤稻草、麦秸或其他无毒植物茎叶作基肥,10天后追肥一次,追肥量同基肥,此后再根据水色酌情追 肥,使水色保持黄褐色。水泥池每立方米水体投牛、马粪或其他畜粪1.5公斤,加沃土1.5公斤~2公斤,以后每隔8天再追肥一次,追肥量为牛、马粪或其他 畜粪0.75公斤。

  四、培育 不论是土池还是泥池,都可采用酵母与无机肥混合培养法。每立方米水体投酵母20克,酵母可先在水中浸泡3小时~4小时,再泼入池中,每立方米水体施碳酸铵 65克、硝酸铵37.5克,以后每隔5天施一次,其用量为开始的一半。投放酵母后,将池水曝晒1天~3天后,就可以放入水蚤作种,用种量为每立方米水体 30克~50克。

  五、捞取 水蚤种入池15天~20天后,经大量繁殖,可布满全池。这时,即可分批捞取喂鱼。一般每隔1天~2天捞取一次,一次捞取总量的10%~20%。在水温18℃~20℃的环境下,可常捞常有,连续不断。

  首先,准备一个容器,小缸子、宠物盒、保特瓶等等,都可以,最好的建议是用接触空气面积比较大的容器来养最适合;因为水蚤会浮到水面上来有类似呼吸的动作,所以若是数量多的时候怕有些争不到位置而死去~~~

   光源;一般告诉饲养者,只要有光线就可以了,那....晚上呢?不就全沉到底下去了? 没错,就是沉到下面,结果隔天就死了大半,为什么?因为它们懒得呼吸啰~~~所以,建议是光源不可在晚上也关掉,可以用个小光源(例如5w的小夜灯等)照 着,这样就可以避免这个麻烦。当然有人会说,一定要这样养吗?答案是不一定,不过,要有超多的数量这样是有其必要性的,我们养它不是只有养好玩而已,重点 是要那锅数量,数量够才能喂鱼嘛,对吧?

  喂食;一般坊间告诉饲养者,用 酵母粉泡水来喂食,但是若是用量控制不好,水质很快就恶化,造成水蚤快速死亡,那又就要重买水蚤或是再跟别人要啰~~~所以,我的方法算是可以预防这个 吧,同时,也不用太计较去买酵母粉,因为有时候酵母粉不好找,不然就是好大一包,用也用不完,因为我后来想想,酵母粉泡水给它们吃,那是不是只要溶于水的 液体就可以喂呢?答案是肯定的,因为圆水蚤是滤食性的生物,所以一般以滤食水中的营养物来维生,因为我们丢下去的东西若溶于水,它们就吃得到喔~因为,大 雄试了“羊血”(特别感谢小丘热情赞助)来喂食发现效果不错,后来又听说之所以用酵母粉,是因为里面有一些氨基酸类的东西,而水蚤可以吃这个,至于氨基 酸,我弄不到,只好用鲜奶啰~~~相信也有不错的效果..........

   日常照顾;其实也不太用理它们,只要给予光照、一些喂食,就可以了,至于换水的话每次吸出水蚤后,再加入被抽掉的水量就可以了~~若是藻类太多,放一些 苹果螺也不错喔,至于效果,嘿嘿那就要看倌们自己试试啰~~~~至于喂食的量,一次不能太多,以一次...2~3cc就可以了~~~别认为太少了喔,这样 就够了同时也不会造成水质一下就恶化了。至于滤水蚤,这比滤丰年虾好用多了,若是不想滤的话,可以用它的趋旋光性来做,用光照来吸引它们然后用滴管吸出, 再来用大量清水洗一洗,就可以拿来喂了。若是想让它们更营养,在喂食前,再喂一些营养液,过一到两小时,再来喂给鱼吃,呼呼这样子更营养啰~~~~

   滤水蚤。一般我们觉得水蚤够多了,就可以拿来喂食,而由于水蚤有趋旋光性,所以我们在滤的时候,可以用这个特性,将它们吸引到角落,然后再用风管去吸 取。吸出的水蚤,多半又参有原来水蚤缸的脏水,为了避免污染了鱼缸,所以还要做一个滤的动作,可以用细网目的网子,或是化工材料行买的“生物滤网(300 网目的)”来滤,滤完后再以清水浸泡,或是加一些料(牛奶、维他命等等)然后,就可以间接地使鱼鱼吃到这些东西啰

  水蚤的采集和培养

   从河里采到水蚤后,应放在较大的玻璃缸里。缸里应放一些从河里带回的水和绿藻,如水绵等,以便增加水中的氧气,还要放一些由蚯蚓、蝗虫或其他动物制成的 碎肉,作为水蚤的饵料。在水蚤数量增加时,要及时采收,并晒干。到了秋末和冬季,水蚤的繁殖力大为减弱。当冬季,在水缸中看不见水蚤活动时,千万不要把缸 里的水倒掉,因为这时它们都潜伏在绿藻丛中。我们可以把水缸放在向阳房间或暖气片附近。到了春季,室内温度升高时,水蚤又出来活动。到室温上升到28℃以 上时,水蚤开始大量繁殖。水蚤可用于饲养教学上所需的水螅。



Cultivate
Daphnia

Housing:
They do well in a tallish container like a plastic bottle with the neck cut off. Put a little soil or old compost in the bottom. The soil adds a few plant nutrients, salts and food for the daphnia. Then put in some tap water that has no Chlorine (let it stand for a day or so) or use clean creek water. The Daphnia will grow to about 3 mm. Every now and again top up their water with some fresh water. If they start to multiply well put a few into a new container. It is better to use several smaller containers so you won't lose the lot if something goes wrong.

Feeding: Feed then yeast or single celled algae or a little left over liquid from some vegetable soup. Make up the yeast by adding a little dry or frozen yeast to some warm water with a little sugar. Let the yeast multiply for a few hours then feed a little to the Daphnia. They also might like some single celled algae that often thrive in containers left outside. If the daphnia are feeding you should notice some darker colouring through the length of their gut. Because they need Calcium to build their shells, add a little crushed eggshell to the water.

Breeding: Most of the time daphnia produce live young that are just miniatures of the adults. If there are young then you know they are thriving. Sometimes particularly if water quality decreases they make eggs that you will see under the carapace along the daphnia's back. They will shed these off and the eggs will rest on the bottom. The eggs are tough and hatch when conditions are favourable.

Handling: Daphnia can be moved using a large diameter tube with a bulb like a large dropper. Or, pour some water out through a fine strainer then tip them back into a new home. They have to be handled gently because they can get air under their shells and will then float.

Daphnia: An Aquarist's Guide

written & compiled by
John Clare, B.A., Ph.D.

What kinds are there?

There are many different species of Daphnia and closely-related genera. However, those of main concern to the aquarist will probably be Daphnia pulex, Daphnia magna, and the various Moina species. Moina are very tiny Daphnids and are often used as an easier-to-culture substitute for Artemia (brine shrimp) as fry food, because young Moina are only slightly larger than newly-hatched brine shrimp, and first stage daphnia are not much bigger. Identifying Daphnia species accurately is best achieved using their size, the shape of the ephippium, the shape of the rostrum and whether the post-abdominal extension is long/short and/or whether smaller appendages close to it are setose (covered with small hair-like structures). It should be noted that within each species there are usually different strains, some of which may have different traits to the "norm".

Daphnia pulex - Although a species in its own right, D. pulex is very hard to distinguish from a number of closely related forms (some consider them seperate species, others sub-species, since hybridisation is common. One example of this is D. galeata). Generally, it is like a smaller replica of D. magna, and is usually fed to the same size of fish. The strain which I culture and know as D. pulex (from the F.B.A.'s 1966 Key to British Cladocera), tends to be larger than that described by many texts (such as that by the British Columbian Resources Inventory Committee), but it is this latter variety which I have found in the wild and identified as D. pulex. I obtained my Daphnia pulex strain from a local aquarist shop only because it happened to come in on some plants. The males are usually 1.5 mm and females 2.5 - 3.5 mm, but the generic D. pulex is taken to have males of about 1.3 mm, and females up to 2.2 mm. Other than the size difference, the two species are almost exactly the same in appearance. D. pulex's colour ranges from yellow to almost red, and in this respect can be very similar to D. magna. The are a number of ways to distinguish D. pulex from D. magna. These include D. pulex's smaller size, one of the appendages of the carapace near the post-abdominal is setose, the ephippium is more triangular than D. magna's and the embyos in it are not parrallel, and there is only one extension from the top edge of the ephippium. D. pulex produces ephippia quite readily in bad conditions.

Daphnia magna is the species normally associated with the name Daphnia by most aquarists. It has been a favourite live food source since the hobby began. D. magna males are 2 mm in length and females are 3-5 mm. They range in colour from a pale yellow to salmon-pink, often this is affected by their food source. D. magna has a wide temperature tolerance, but its optimum temperature is between 18 and 22 oC (64-72F). In the wild, Daphnia magna is quite rare, but where it does occur, it is usually very abundant. Like all Daphnia spp ephippia, the ephippium of D. magna is shaped like a saddle. However, the embryos inside the ephippium (of which there are usually two in Daphnia species) are parallel, and it is like a curve-edged rectangle, with the top long side having two extensions beyond the rectangle at either end. Although magna does produce ephippia, it is less inclined to do so than D. pulex. D. magna is usually considered more "delicate" than D. pulex and as a result it is not as tolerant of culture fouling as D. pulex.

Moina spp are, although similar to daphnia and other members of the Daphniidae, is quite distinct from the genus Daphnia. They are very small in comparison to most Daphniidae (less than 0.5mm in length), and their young are only about the size of newly-hatched brine shrimp. However, their culture is almost identical to that of Daphnia, and although they are harder to acquire, their use as a cheap alternative to brine shrimp as a first fry food has made them popular with many fish breeders.

Where can I culture them?

Daphnia are undemanding in terms of what you culture them in. I personally culture them in 4 (3.4 US) gallon plastic crates because I don't have the space for multiple aquaria. Many people like to use children's blow-up paddling pools (I've used these in the past with great success), but what you keep them in is really up to you. There are some things to bear in mind though when selecting containers:

  • Is the container made of a material that won't dissolve in water, and/or leech chemicals into the water (some plastics, particularly polypropylene do this)?

  • If you use a metal container, stainless steel is the safest because many metals will react slowly with water over time (e.g. Aluminium oxidises to form a skin of aluminium oxide, but small amounts of aluminium are released into the water).

  • Just like ordinary aquaria, it is desireable to have as high a surface area to volume ratio as possible to ensure that there is good gaseous exchange (though not very demanding, Daphnia appreciate a good oxygen supply).

  • If you're keeping the "tank" outside in strong sunlight or with heavy illumination around, it is a good idea to use a container larger than 10 gallons as the water temperature will fluctuate less markedly, thus providing greater stability for the culture. It is also important when putting a container in strong light that it isn't a dark colour (especially black), because as you probably know, dark colours produce more heat in the light than white or yellow containers.

For someone who only wants a modest amount of Daphnia per week, cultures can be maintained in two litre bottles. For an aquarium, a light bulb in the lid which is on a timer makes it easy to keep indoors (you can get timers from electrical shops or from good aquaria outlets). I have found that Daphnia magna likes gentle aeration. In theory this would seem to be a good idea for all daphnia as it not only helps increase gaseous exchange at the surface of the water, and it also helps stabilise the water conditions and acts against culture-fouling. However, I have found that although Daphnia pulex does better with aeration, very gentle aeration seems to be the key. Airstones should be avoided, since fine bubbles can lodge inside the carapaces of daphnia, floating them to the surface and also preventing them from feeding, and eventually resulting in death (Artemia also suffer from this problem).

Physical Requirements

In places, this section borrows heavily from Kai Schumann's FAQ and Franc Gorenc's article, with additions and changes by myself.

Salinity - Daphnia are typically freshwater organisms and there are no marine species of the Daphnia genus. 99% of Cladocerans are found in freshwater, and the remaining few species are mostly found in brackish, not sea water. Some species have been observed in salinities up to 4 ppt, and salinities of 1.5 to 3.0 ppt are common in pond cultures in the Orient.

Oxygen - Daphnia are generally tolerant of poor water quality, and dissolved oxygen varies from almost zero to supersaturation. Like the Brine Shrimp, their ability to survive in an oxygen poor environment is in their ability to synthesize hemoglobin. The production of hemoglobin may be promoted by high temperatures, and a high population. Also, like brine shrimp, Daphnia are not tolerant of fine air bubbles. A slow aeration is needed with Daphnia as a large bubble column will strip the Daphnia out and kill them. I (and a number of others), have found that Bio-foam filters (designed for fry-tanks) are ideal for aerating Daphnia culture, and the removal of larger particles from the water is an added bonus. However care should be taken to use them at minimal air flow to avoid over-agitating the water.

pH and ammonia - A pH between 6.5 and 9.5 is acceptable, with the optimum being between 7.2 and 8.5. Ammonia is generally highly toxic to all organisms, even in small amounts, but in alkaline conditions, the toxicity is radically increased, and this will drastically impair Daphnia reproduction, but will not affect the actual health of the animals themselves. So it seems that on the small scale that we require, monitoring of pH and ammonia is not critical to success. NOTE: in general, the more extreme the pH, the higher the toxicity of dissolved minerals and gases. Also, remember that pH is a logarithmic scale - a pH of 5 is ten times more acidic than a pH of 6, and likewise, a pH of 9 is ten times more alkaline than a pH of 8.

Dissolved minerals - In contrast to their tolerance of low oxygen, Daphnia are very sensitive to disturbances of the ionic composition of their environment. They become immobile and eventually die with the addition of salts like sodium, potassium, magnesium, and calcium. Low concentrations of phosphorus (less than 0.5 ppm) will stimulate reproduction, but concentrations higher than 1.0 are lethal to the young. Daphnia magna are quite resistant to phosphorus and can withstand concentrations as high as 5-7 ppm. Daphnia are not affected by the addition of nitrogen in fertilizers for the promotion of algae growth. As with any aquarium venture, the water used should be treated with aeration or de-chlorinator to remove chlorine before the culture is started. Concentrations of only 0.01 ppm copper will result in reduced movement in Daphnia. They are extremely sensitive to metal ions like copper and zinc, pesticides, detergents, bleaches and other dissolved toxins. For this reason, they are often used to test waste-water from industry. Municipal and well water may be contaminated enough to kill the culture. The best source of water is from your aquarium water changes, but you could also use filtered stream or lake water (fish-free water bodies are recommended due to possible disease introduction to your fish aquarium by way of the daphnia), or rain water collected from areas of low/no air pollution (and rain water collected in cities or industrial areas is usually safe if left to stand for a week and only the top-most 3/4 used). Never use distilled or deionised water, as it does not have the minerals needed for growth.

A small degree of temporary and permanent hardness in the water usually encourages growth and reproduction because Daphnia make use of calcium and other minerals in their chitinous carapaces. D. magna tends to prefer harder water (170 mg carbonate hardness) and D. pulex a little less hard (90 mg carbonate hardness). I usually add a very tiny pinch of powdered Tufa rock (often used in Marine aquaria) to my water because there is very little temporary hardness in the water I use and no permanent hardness whatsoever.

Temperature - Daphnia have a wide tolerance to temperature. The optimum temperature for Daphnia magna is 18-22 oC (64-72F). D. pulex seems to do well at well at almost any temperature above 10oC. Moina withstand extremes even more, resisting daily variations of 5-31oC (41-88 F); their optimum being 24-31oC (75-88 F). The higher temperature tolerance of Moina make this species a better choice where temperatures may rise above the comfort levels for D. magna at certain times of the year.

What do I feed them?

This is a general section on feeding Daphnia. I have summarised my own experiences at the end of this section. Daphnia have similar feeding habits to other tiny crustaceans (especially to the likes of Artemia). The best foods for culturing are algae (typically free-living green algae species which tend to turn water to "pea soup"), yeasts (Sacromyces spp, and similar fungi), and bacteria. Combinations of the above seem to have the most success (i.e. yeast and algae seem to compliment one another). Each food type will be discussed in turn, together with its advantages and disadvantages, and means of attaining/growing it.

Algae
Micro algae is consumed in great quantities by Daphnia, and the abundance of daphnia is usually proportional to the density of algal blooms. There are a number of ways to grow algae, all of which are very basic and require little effort.

  1. Placing a container of water outside in good sunlight will usually guarantee a good growth of algae within two weeks, usually a lot less. Algal spores are carried on the wind and will colonise the water, but it usually speeds up the process if you "seed" the water with some algae from a container that has already has a bloom.

  2. Miracle grow, an organic plant fertiliser, can be used to grow algae (after all they're just plants). One method is to use 1 gallon containers, 1 for each day of the week. These sit on a window sill which gets good sunlight for as much of the day as possible. By bubbling air through the containers (an airpump with 7 side lines will do, because there really only needs to be a small movement in the water), algae won't grow on the sides of the containers where it can block the sunlight. Add 1 tea spoon of Miracle grow per gallon. This system is then seeded with green water in tank #1 - two days later tank #2 - two days later tank #3, etc. When this has turned bright green (within 2 weeks), pour it into a Daphnia tank. Refill the container with water mixture and seed with tank #2 which should be about to turn bright green. This is repeated with each container as they turn bright green. As you might be able to tell, this will provide about 1 gallon of fresh green water every two days.

The advantages of algae as a food are that it is very easy to culture and it is excellent for growing daphnia. There are no disadvantages really, other than the fact that it requires bi-daily maintenance / renewal.

Yeasts
There are two general kinds of yeast that we need be concerned about - activated and inactive. Activated yeast is generally a better food to feed because it will not foul the water as quickly/as much as the inactive kind. Bakers, brewers, and almost any kind of yeast are suitable for daphnia cultures, but it is recommended that no more than half an ounce of yeast per five gallons of water be fed every five days. If you're using yeast, especially inactive yeast, consider adding some algae to the water as this will counter any fouling which may result from adding the inactive yeast (this isn't so important with activated yeasts). Do take care not to overfeed inactive yeast as it will foul the culture and therefore kill your daphnia.

Some bakers yeasts come with added ingredients like Calcium Sulphate and Ascorbic acid (vitamin C) to aid fast activation of the yeast. These are harmless to daphnia cultures, but care should be taken when adding this kind of yeast because Ascorbic acid can give pHs less than 6, which are far from ideal with Daphnia. However, I have never had any pH changes when using such "mixes" in moderation, and the calcium sulphate gives vital calcium for the daphnia's carapaces.

The advantages of yeast as a food are that it's easy to acquire, and there is a minimum of fuss when preparing it for the culture. The only slight disadvantage is that it's not quite as good a food as algae (the daphnia need to consume more weight of yeast than algae to get the same food value). However, yeast is far better than any other food except some bacteria, which have almost as high a food value.

Bacteria
Bacteria have a similar food value to fungi, but they generally reproduce faster than fungi and algae, although the food value doesn't tend to be as high. Bacteria are "cultured" by taking 5-6 ounces of dried horse, cow or sheep dung (dried for two reasons: it's easier to deal with, and most antibiotics or growth promoters which were fed to the animal will break down if the dung is left to dry for a while) and tying it in a nylon bag (such as tights/pantyhose), and hanging this in the water with the daphnia. Animal dung (including human dung, though don't use human faeces unless you want typhoid or worse...) contains copious quantities of bacteria from the digestive system, and these will leech out of the dung into the water and reproduce. Typically, the water will go cloudy after a time, indicating that the bacteria are starting to multiply. This should be changed once a week for maximum effect. Another method is to soak the dung for weeks until it decomposes into a nutrient slurry, then drip the liquid into the tank at a rate of 16 fluid ounces per five to eight days.

Another way to culture bacteria in a hurry is to throw a handful of salmon (or trout pellets), dog biscuits or other meat-based food into a few gallons of water with some added aquarium water. Within a few days it is usually cloudy with bacteria.

Bacteria are a good food source, and easily acquired/cultivated. The only downside is the smell of the decaying matter (which can be pretty bad at times). An important thing to remember is that horse dung usually contains tetanus (also a bacterium), so care should be taken when handling it (make sure you have no open cuts/sores on your hands or arms).

Other Foods
These include bran, wheat flour, and dried blood. These should be considered similar to inactive yeast, and the same amounts and care should be taken when administering them. The only real difference is that the food value isn't as high as the corresponding weight of yeast.

Some of My Own Experience
Unless you have a very large container, like an outdoor pond, I don't think "green water" is worth the effort. I fertilise the water with salmon pellets (the Indiana University Axolotl Colony's at the moment - May 2000). The amount depends on your container size and current daphnia population. Too much and you foul the water and everything dies. As a guide, I would say for a 4 foot long aquarium one or even two handfuls is enough to fertilise the water if there is an already healthy population of daphnia. If you have less, then don't use as many pellets or the bacteria population will go out of control. this is reliant on temperature, ideally in the early 20s celsius / ~70F.

People recommend green water as the best food for daphnia. I would have to say that I mainly agree with this, but I think that bacteria are just as nutritious. I haven't bothered feeding green water to daphnia since 1998 so draw your own conclusions. I've been maintaining two populations since June 1998 and they have never completely died out. They do pulse though. If you want a recommendation for a quick fix substitute for green
water, get yourself a bag of frozen peas and one of carrots. Mix about 80% peas and 20% carrots together and then stick them in a food blender. Blend these until you have a mulch. You're looking for the "juices", so take any liquid and squeeze the mulch to get all of the liquid from it. This contains particles of a size small enough for daphnia to sieve from the water (less than 50 microns). It's far more concentrated than water with algae in it, so use it sparingly. It gives just as good a result. I've used this a few times, but I'm just too lazy most of the time to bother with anything except rotting pellets.

One final note on pellets - don't crush them much first. If you do you'll release all of the nutrients at once instead of over a few days and you can get the bacteria going out of control. I should mention that I also keep water slaters (the European fresh water louse) in my daphnia cultures because they break down solid waste and prevent the pellets from being covered in fungus and floating at the surface. The fresh water louse is a crustacean
that looks like a wood louse and it is not a fish louse (louse is just the name). I don't recommend snails in the culture either because for one thing, some species can act as a parasite vector, and also because they use up calcium and that's reserved for the daphnia! I've heard of ground-up liver in water being recommended. In that case it's mainly the blood that is the fertiliser. I've tried animal's blood and found it ok, but the pellets win in my opinion, followed by algae and the mixture I mentioned above.

How do I maximise the yield?

Daphnia production is relatively simple, if not an exact science. However, there are proven measures that increase the productivity of a culture.

  • Good aeration (good in so far as the manner in which the water is aerated, not good as in quantity) is probably the largest contributing factor for good production. Some species prefer no aeration, but Daphnia magna seems to do well with it. It allows you to keep more daphnia in the same container. It also circulates the water, (which counters stagnancy and fouling). It minimises the possibility of algae growing on the walls of the container, and it also keeps inert food in suspension which is more conducive to most daphnia feeding habits. The only problem with aeration is that fine bubbles can lodge underneath the daphnia's carapace and float it to the surface and preventing it from feeding. Therefore airstones should be avoided (unless used in a bio-foam filter in which case the air bubbles combine together), or coarse airstones (or better yet, no airstones) should be used instead.
    A good method (tried and trusted) of aerating the water which I have mentioned previously is the bio-foam filter (there are a number of models available, any will do). These are commonly used in fry tanks, but are ideal for daphnia. They trap larger particles in the water (they don't trap algae), and help break them down, releasing nutrient for the algae to feed on. The outlets are usually very good at aerating the water, but care should be taken to use them at low to minimum flow to avoid over-agitating the water (we want some aeration, not a torrent). I haven't had a fouled culture yet while using a bio-foam.

  • Carry out regular maintenance as described in the Maintenance section, especially water changes.

  • Cull/Harvest the culture regularly (again, see the Harvesting section). This encourages constant growth and also keeps the daphnia from exhausting both the oxygen and the food in the water too fast for it to be replaced.

  • Some people like to keep a light on 24 hours a day for their daphnia tank as this can encourage faster growth and reproduction. I haven't tried this myself. However, you probably won't need to do this once your culture gets going. One important note though - continuous 24 hour periods in which the daylight is less than 12 hours and with a temperature significantly below 18

  • Water changes: some people recommend you change up to 75% of the water in a culture every day. This is really dependent on what rate you're "running" the culture at. The more food you feed, the faster the water will be fouled, and therefore the more frequent the water changes. This is really up to the individual, but be aware that output levels will drop if there is a build up of metabolites/toxins/etc in the water. This could lead to crashing.

Harvesting

When it comes to culturing Daphnia, harvesting may be the aim of the exercise, but it's also essential. Overcrowding is a serious danger otherwise. Even if you have to wash the culled ones down the sink because you have too many, still cull them, otherwise the culture could become unstable. If you're culturing below about 25 oC, then it's generally a good idea to begin culling only midway through the second week unless you started out with a large number of daphnia (or your culture is growing like crazy already). This is because a lot of cultures take a few days to settle and start reproducing. When culling, try to use a net which has a large enough mesh to let young daphnia through, but just small enough to catch the adults (some people prefer to drain 1/4 of the tank into a net, and replace the water with new fertilised water, and in this way you do two jobs at once). Not more than 1/4 of the population should be harvested daily, but the harvest may vary according to the quality of the population. But remember to cull regularly. In daylight/roomlight, when you stop the aeration, and let the tank settle, the Daphnia will concentrate on the surface where they're easier to harvest.

Harvested Daphnia can be kept alive for several days in the refrigerator in clean water. They will resume normal activity when the water warms up. The nutritional quality will not be as good because they have been starving for several days, so a supplemental feeding is required for best effect. Daphnia can be stored for long periods by freezing them in a low salinity water (7ppt, 1.0046 density). Of course this kills the Daphnia, so adequate circulation is required to keep them in suspension during feeding. They also will not be as nutritious as the nutrients rapidly leach out in the aquarium. Nearly all the enzyme activity is lost in ten minutes, and in an hour all free amino acids, and most bound amino acids are lost. Fish will not feed on frozen Daphnia as readily either.

Maintenance

A daphnia culture requires very little maintenance other than partial water changes (the amount really depends on the volume of water and the number of daphnia in the culture - more water usually needs less changing, more daphnia usually means more water needs to be changed, to a maximum of 50% per week). Do feed your daphnia on a regular basis.

The key to avoiding population fall-off/crashing is to have constantly good conditions, and to avoid sudden changes, such as large temperature drops, culture fouling, or the addition of dangerous chemicals to the water. Remember that if you're keeping your colonies outside, the population will naturally decrease in winter, but should increase again in the following season.

Should your culture die off, don't despair. Either change most of the water or take the mulm and put it in a new container - if conditions are good, the ephippia should hatch within 4 to 8 days (if you accidentally poisoned the culture with chemicals, you may need to obtain a new starter culture because the daphnia may not have had time to produce ephippia, and even if they did, even ephippia will not survive for very long in strong chemicals like bleach or even mild acid).

If you go on holiday for a few weeks, don't be surprised if your daphnia have produced ephippia and the population has decreased while you were away!

Dos and Don'ts

This section is intended as a reminder of things to remember and a precaution against simple mistakes people often make without realising it.

DOs

  • Do make sure you age your tap water and have a good idea of what's in it:

    • If it contains chlorine (chloramine will also put chloride into the water), it must be left to stand or aerate the water for 24 hours to drive off the chlorine gas (fluoride is usually very low in concentration and isn't really something to worry about).

    • If your water contains lots of ammonia, this will inhibit the population growth of your culture - again, aerating the water vigourously helps drive off ammonia (although it takes a lot longer than with chlorine).

    • Any metals in the water can often be toxic to daphnia. Some can inhibit population growth (see the section on Physical Requirements).

  • Do carry out regular partial water changes.

  • Do feed regular modest amounts of food (this will depend on the culture size).

  • Do make sure you have adequate water hardness for your daphnia, otherwise they will not reproduce at a high rate, and will probably just produce ephippia.

  • Do try to maintain a constant temperature (about 20oC is ideal for most species).

  • Do cull/harvest your cultures at least once a week to avoid overcrowding.

DON'Ts

  • Don't wash your hands with soap/detergent just before you put your hands in a daphnia culture unless you've _thoroughly_ rinsed your hands because soap and detergents are toxic to daphnia.

  • Don't overfeed - if anything, underfeed your daphnia to avoid fouling and toxic build-up of ammonia.

  • Don't put your daphnia in a container of dense algae (and don't change too much water from the tank for algae water at one time) because algal blooms tend to raise pH to very high levels (over pH 9), and coupled with even a low ammonia concentration, this could be disastrous for the daphnia, killing them in short order. Ammonia toxicity increases with higher pH.

  • Don't keep all your eggs in one basket (or daphnia in one container). Even the best of us will have accidents on occasion or have an emergency, etc, and our cultures may be poisoned or die off for no apparent reason. To counter this, it is best to seed as many water vessels, aquariums, and even flower window boxes with daphnia when the culture is first obtained. This will ensure you will be able to "restart" without too much fuss.

  • Don't use insecticides near your daphnia containers, and don't leave your daphnia container in a room that was just painted/varnished/etc, because the fumes/gas can be toxic, and even if it doesn't kill the daphnia, the fish you feed them to may be slowly poisoned.

  • Don't use airstones in a daphnia culture. Use an open airline tube or a bio-foam filter (the latter contains an airstone inside in the apparatus, but the bubbles are not fine enough to harm the daphnia when the bubbles emerge into the tank. Note however, there should only be a weak flow of air through the filter to avoid too much water flow).

  • Don't add miracle grow, etc, directly to the culture. It won't be much use, and it could also poison the culture, in high concentrations.

  • Don't add fresh tap water to a daphnia culture unless you want to kill them all with the chlorine.

  • Don't keep your daphnia in the dark for days at a time as this can stimulate them to produce ephippia.

14 March 2012

漫游 金魚 賞閒 Aug 17 Tue 2010












金魚真好,短短一生,吃呀吃,游呀游,比不少人自由得多。保守估計,中國人玩金魚起碼有 1,500年歷史,多年來玩金魚文化歷久不衰,傳遍世界。靚魚標準雖跟潮流常變,但金魚總是肥肥鈍鈍,代表福氣,絕不受瘦身這些偽健康潮流影響。不過同魚 不同命,同一批金魚,靚的精品金魚身價$3,000至$4,000起跳,甚至過萬。記者:何兆彬攝影:梁細權(部份攝影由勤哥@香港金魚網提供)

蘭壽乃金魚之王

旺角魚街這麼長,兩位專家平時只往三幾家水準較高的魚店跑,今天跑了兩家,一是「賞樂閣」,屬樓上舖,專返福州及泰國金魚,「中國金魚以福州最著 名,也是金魚的發祥地。」二是「幸運水族」,為港人創辦的「東海金魚」獨家代理,近年東海不斷在繁殖上培養出新品種,屬金魚界名牌。說到金魚流行榜三甲, 離不開蘭壽、獅頭和流金。醜的金魚,$10就有一條,美的精品金魚,每條起跳$3,000至$4,000,甚至過萬,「我們聽過東海的頂級金魚,身價要二 萬多!」那麼蘭壽被譽為金魚之王,主要欣賞牠甚麼呢? Kelvin:「看牠的背部線條夠不夠順滑利落,背部最好不要有骨位,也不能有凸凹不平;然後看牠的頭板位置,香港人覺得頭板位置越大越靚;最後要看尾巴 落位,這位置要像一個剔一樣,最好與尾位形成九十度,尾部落位如果太低,魚有時會舂頭,因為蘭壽沒背鰭,游水沒這樣叻。」他補充品種不同,如泰國蘭壽與中 國蘭壽,欣賞方法也有不同,可瀏覽網頁了解。

中國獅頭講霸氣

至於獅頭,怎為之好貨呢?勤哥先講泰獅:「泰獅優勝之處,我認為是尾形張力大闊度夠,而且顏色較鮮,卻輸在頭板沒中國獅頭的味道,所以要看你個人取 向,有人喜歡活潑的獅頭,那泰獅比較適合,但如果講霸氣,我認為中國獅頭較好。」他獨尊中國獅頭:「也許我先入為主,會較看重獅頭的頭板,頭形及身形要肥 胖一點的!泰國獅頭始終身形較窄,中國獅頭頭板夠大,泰國獅頭看點在尾部,始終失卻獅頭的本來優勢,所以我們仍然以中國獅頭為主導。」人可能游得快有着 數,但勤哥提大家,中國金魚另一要點,是不能游得太快,「中國人喜歡的金魚,不會游得太快,這樣才有游閒的味道。」

■虎紋獅頭,東海獨家品種,勤哥購於「幸運水族」,售賣中的 24cm成魚,身價約$3,500。

養金魚,有幾點是要注意的。一是金魚出名能吃,不知飽,主人一直餵,牠會吃到飽死,最好方法是少吃多餐,勤哥:「一天餵夠四次左右最好,飼料方面, 我用日本飼料。」其二,金魚完全靠人工繁殖,沒任何野外求生本領,故體質弱,因此要注重水質控制。「金魚排洩量很大,所以濾水系統必須強勁才 Keep到水質。其實養甚麼魚都一樣,水一定要靚,水才會清。」金魚的基本水質要求是鹼性水( pH 7以上),濾材除了棉及生物環,還有麟黃石、卡其貝及蠔殼穩定 pH值。勤哥:「放生物環是為培養硝化細菌,由於金魚排洩多、阿摩尼亞多,一定要硝化細菌多才能分解,令水沒那麼快變酸。」所謂的強勁濾水系統,二人推 介:「最好用真滴漏系統,濾水系統內的水量與魚缸水量比例是 1:1,濾材多、換棉容易,水自然清。」次一級是「假滴漏」,即在缸中切一角落放濾材,但濾水水量與缸水比例大減。最平民的濾水系統,是沿用多年的「頂 濾」,即放在缸頂的濾水系統,能放置的濾材更少,好處是易清洗易換濾水棉,而且接觸空氣多,能有效製造更多硝化細菌。「養金魚的濾水棉最好天天洗,因為金 魚排洩多,濾水棉會經常塞,至於頂濾,因濾材不多所以換水次數較多,我們天天換三分一缸水,不過很老實,也要看看魚缸是否高密度,養金魚的人,見到靚金魚 又會手痕痕購買,最後越養越多……」



09 March 2012

Blackie





















Not so black after all. Tail damage, he was keep in a bad water condition. Torn tail + fade color to grey orange...