一、春季老水塘易發病的原因

　　眾所周知，能引起魚發病的因素有很多。但總的來說主要與以下三個方麵因素有關：一是環境
，二是病原體
，三是水生動物自身條件。

　　首先我們來了解下老水塘的環境
，所謂“老水塘”一(yi)般(ban)是(shi)針(zhen)對(dui)新(xin)開(kai)挖(wa)的(de)魚(yu)塘(tang)或(huo)者(zhe)是(shi)養(yang)殖(zhi)時(shi)間(jian)不(bu)長(chang)的(de)魚(yu)塘(tang)來(lai)說(shuo)的(de)。老(lao)水(shui)塘(tang)相(xiang)比(bi)於(yu)新(xin)水(shui)塘(tang)最(zui)大(da)的(de)特(te)點(dian)是(shi)魚(yu)塘(tang)自(zi)身(shen)的(de)環(huan)境(jing)變(bian)化(hua)很(hen)大(da)，尤(you)其(qi)是(shi)經(jing)過(guo)多(duo)年(nian)養(yang)殖(zhi)而(er)未(wei)清(qing)整(zheng)的(de)魚(yu)塘(tang)，池(chi)底(di)往(wang)往(wang)會(hui)留(liu)下(xia)大(da)量(liang)的(de)有(you)機(ji)物(wu)如(ru)水(shui)生(sheng)動(dong)物(wu)排(pai)泄(xie)的(de)糞(fen)便(bian)、weichiwandesiliaofubaifajiaodeyoujiwuyijifuyoudongzhiwuheweishengwusiwangliuxiadefuzhizhideng，zheleiwuzhigeilaoshuitangtigonglefengfudeyingyangwuzhi
，erzhexieyingyangwuzhiwangwangshiweishengwuyijifuyoudongzhiwushengchangsuobixude。

　　yinci，dangkaichunyihouzheleilaoshuitangzhongdeweishengwuyijifuyoudongzhiwushengchangfanzhiwangwangjiaoxintanghuoyuehenduo。cishi

，ruguoyangzhideshuishengdongwuzishenyouyixiechuangshangrudongshangjilawangbulaoguochengzhongzaochengyutishoushangshi，bingyuanweishengwujiuhuichengxuerru
，congergeiyangzhidongwudailaijibing。

　　二、春季老水塘一般常見疾病

　　根據筆者這幾年的實踐經驗，春季老水塘往往會出現以下幾種疾病：

　　（1）shuimeibingshuimeibingdaduofashengzaishuiwenbijiaodidejijierudongjihuochunji。dancibingdefashengyibanqiantitiaojianshishuishengdongwuyoushoushangshi，yincibimianshuishengdongwushoushangshiyufangcibingdeyouxiaofangfarubulaolawangyijiyunshuguochengzhongjinliangjianshaoshuishengdongwushoushang。ciwai，yuzhongxiatangshiyidingyaozhuyijinxingxiaoduchuliruyong3%-5%deshiyanshuijinpaoxiaodu
，youyidingdeyufangzuoyong。cibingfashengshiqianqiyibanzhengzhuangbumingxian，yangzhihufaxianyushenshangchangchulebaimaoshi，shuimeijunyijingjishengdaoyutishenshang。yinci，cibingzhongzaiyufang。ruguoyidanfabing，yangzhihushouxianyinggaixuanzeshazhenjundeyaopinruwubeiziyehuoshuiyangsuandeng，yutirunenggoujinshidehuazuihounengzaisiliaozhongtianjiakangjunxiaoyanyaowu
，yijiakuaiyutihuifu。

　　（2）赤皮病該病跟水黴病的發生有些相似
，魚體有受傷史是診斷的依據。治療此病最好能“內外結合”治療，如外潑二氧化氯等消毒藥，內服恩諾沙星等抗菌藥
，以加快魚體盡快恢複。

　　（3）qipaobingchunjilaoshuitangqipaobingdefashengduobanjianyuyumiaopeiyuqi，zhuyaoshiyouyushuitizhongrongyangguobaohezaochengde。zhexieqipaoyouxiehuifuzhezaiyutishenshang，yeyoudehuibeiyuzhongwushi，zaochengyutiyoudongbupingheng。zuichushiyugandaobushufu，zaishuimianzuohunluanwulideliudong。qingkuangyanzhongshi，shentihuishiqupingheng
，shiyoushiting，suizheqipaozengdajitilidexiaohao，shiquziyouyoudongnenglierfuzaishuimian，bujiujisi。tongguojiepoujixianweijingjianzhakefaxiansai、鰭條以及血管中有大量氣泡，引起栓塞而死。

　　yinci
，zhenduicileijibingzuizhuyaodeyufangfangfajiushikongzhishuitizhongrongjieyangdehanliang。youxielaoshuitangkaichunsuizheqiwenzhujianshenggao，zaoleidefanzhihenwangsheng，toumingduhuijiangdi。yangzhihuyinggaijishichouchubufenlaoshui，zhuruxinxianshui。danjiashuiyingzhuyishuiyuan
，buyonghanyouqipaodeshui。ciwai，chitangzhongfuzhizhibuyiguoduo，buyongweijingfajiaodefeiliao。pingshizhangwotousiliangjishifeiliang，zhuyishuizhibianhua
，bushifuyouzhiwufanzhiguoduo。ruguofaxianyouqipaobingyingjishijianghuanbinggetiyiruqingshuizhong
，bingqingqingdenengzhubuhuifuzhengchang。

　　（4）由pH值升高引起的魚死亡春季一些老水塘的pH值zhi往wang往wang會hui較jiao新xin塘tang要yao高gao，尤you其qi是shi養yang殖zhi多duo年nian未wei清qing塘tang的de魚yu塘tang。筆bi者zhe認ren為wei主zhu要yao的de原yuan因yin是shi由you於yu開kai春chun氣qi溫wen升sheng高gao，藻zao類lei繁fan殖zhi生sheng長chang旺wang盛sheng
，光guang合he作zuo用yong相xiang比bi於yu新xin塘tang要yao強qiang，造zao成cheng水shui體ti中zhong二er氧yang化hua碳tan減jian少shao
，pH升高。當pH值(zhi)升(sheng)高(gao)到(dao)一(yi)定(ding)限(xian)度(du)，就(jiu)會(hui)對(dui)水(shui)生(sheng)動(dong)物(wu)造(zao)成(cheng)影(ying)響(xiang)尤(you)其(qi)是(shi)魚(yu)種(zhong)在(zai)轉(zhuan)塘(tang)以(yi)後(hou)，由(you)於(yu)堿(jian)度(du)的(de)變(bian)化(hua)過(guo)大(da)引(yin)起(qi)的(de)應(ying)激(ji)而(er)死(si)亡(wang)。因(yin)此(ci)，針(zhen)對(dui)老(lao)水(shui)塘(tang)春(chun)季(ji)應(ying)適(shi)當(dang)加(jia)大(da)換(huan)水(shui)，但(dan)一(yi)定(ding)要(yao)注(zhu)意(yi)換(huan)水(shui)的(de)水(shui)源(yuan)地(di)水(shui)質(zhi)情(qing)況(kuang)。

　　（5）jishengchongbingchunjiyuzhongganranjishengchongdegailvwangwangjiaoda。youqishiyilaotangweizhudejishengchongfabingbixintangyaoduo，zhezhuyaohaishiyinweilaotangyoujiwubijiaoduoshiyijishengchongdefanzhishengchangzaochengde。yinci

，kaichunyihouyingjishizuohaoshachongxiaodugongzuo。

　　三、如何預防春季老水塘魚病發生

　　針對以上幾種情況，筆者認為養殖多年的魚塘養殖戶在年底清塘以後應及時清除過多的淤泥，一般淤泥以20cm左右為宜。

　　其次，幹塘以後應該對池底進行消毒殺菌工作。如畝用125-150kg的生石灰化水全池潑灑有很好的預防作用。但對於池底本身就是鹽堿地或者往年經常出現pH值都比較高的情況，消毒選用漂白粉或者二氧化氯較好。

　　最後
，筆者認為對於老水塘開春以後
，盡量減少有機肥如雞糞、豬糞等的使用
，尤其是未經發酵的有機肥，以減少疾病的發生。