0.05);試驗(yàn)一各處理組攝食率均高于對照組,其中S2F2組"/>
劉龍龍,唐賢明,付成沖,宋志民,王永波,羅鳴
摘要 [目的]探究周期性饑餓-再投喂處理對豹紋鰓棘鱸幼魚生長和飼料利用的影響。[方法]試驗(yàn)均設(shè)置對照組(持續(xù)投喂)、處理組S1F1(饑餓1 d、再投喂1 d)、S1F2(饑餓1 d、再投喂2 d)、S2F2(饑餓2 d、再投喂2 d),開展了2種規(guī)格豹紋鰓棘鱸幼魚周期性饑餓-再投喂生長試驗(yàn)。[結(jié)果]試驗(yàn)一S1F2、S2F2組和試驗(yàn)二S1F1、S1F2組試驗(yàn)結(jié)束時(shí)體質(zhì)量與對照組均無顯著差異(P>0.05);試驗(yàn)一各處理組攝食率均高于對照組,其中S2F2組攝食率顯著高于對照組,而飼料轉(zhuǎn)化率顯著低于對照組;S1F2組攝食率與對照組差異不顯著,而飼料轉(zhuǎn)化率顯著高于對照組。試驗(yàn)二各處理組攝食率均顯著高于對照組(P<0.05),S1F2組飼料轉(zhuǎn)化率與對照組無顯著差異(P>0.05),而S1F1組飼料轉(zhuǎn)化率顯著高于對照組(P<0.05);試驗(yàn)結(jié)束時(shí),各試驗(yàn)組粗脂肪含量均略低于對照組,水分含量略高于對照組,但均無明顯差異(P>0.05)。[結(jié)論]試驗(yàn)一S1F2、S2F2組與試驗(yàn)二S1F1組、S1F2組均能夠達(dá)到完全補(bǔ)償生長,其補(bǔ)償生長主要是通過提高攝食率和飼料轉(zhuǎn)化率來實(shí)現(xiàn)的,在饑餓過程中豹紋鰓棘鱸幼魚可能首先消耗脂肪作為能量來源。
關(guān)鍵詞 豹紋鰓棘鱸;幼魚;周期性饑餓-再投喂;生長;魚體生化組成
中圖分類號 S965.3 文獻(xiàn)標(biāo)識(shí)碼 A 文章編號 0517-6611(2018)06-0077-03
Effects of the Cyclic StarvationRefeeding Treatment on Growth and Feed Utilization of Plectropomus leopardus Juveniles
LIU Longlong,TANG Xianming,F(xiàn)U Chengchong et al (Hainan Academy of Ocean and Fisheries Sciences,Haikou,Hainan 571126)
Abstract [Objective] To study the effects of cyclic starvationrefeeding on the growth and feed utilization of Plectropomus leopardus juveniles.[Method] Test groups S1F1(starvation for 1 day,then rerefeeding 1 day),S1F2(starvation for 1 day,then refeeding 2 days),S2F2(starvation for 2 days,then rerefeeding 2 days),control group(continuous feeding) were designed in the treatment.The growth experiment of cyclic starvationrefeeding of P.leopardus juveniles with different sizes was conducted.[Result] The final body mass in S1F2 group and S2F2 group in experiment 1,S1F1 group and S1F2 group in experiment 2 had no significant difference with control group(CK).In experiment 1,the feeding rate of all test groups were higher than that of CK,feeding rate of S2F2 group was significantly higher than that of CK,but the feed conversion rate was significantly lower than that of CK; The feeding rate of S1F2 group had no significant difference with that of CK,its feed conversion rate was significantly higher than that of CK(P<0.05).In experiment 2,the feeding rate of all test groups were significantly higher than that of CK,feed conversion rate in S1F2 group had no significant difference with CK.The feed conversion rate in S1F1 group was significantly higher than that of CK (P<0.05).At the end of the experiment,the crude fat content in all test groups were all slightly lower than that of CK,water content in all test groups were slightly higher than that of CK,but there was no significant difference(P>0.05).[Conclusion] The completely compensatory growth of P.leopardus juveniles was achieved in S1F2 group and S2F2 group of experiment 1,S1F1 group and S1F2 group in experiment 2,which was mainly accomplished by increasing the feeding rate and feed conversion rate.The fat of P.leopardus juveniles might be firstly consumed as source of energy in the starvation process.
Key words Plectropomus leopardus;Juveniles;Cyclic starvationrefeeding;Growth; Body biochemical composition
豹紋鰓棘鱸(Plectropomus leopardus),俗稱東星斑,隸屬鱸形目鱸亞目鮨科石斑魚亞科鰓棘鱸屬,屬于暖水性島礁魚類,主要分布于西太平洋至印度洋熱帶海區(qū),在我國南部海域也有發(fā)現(xiàn)。豹紋鰓棘鱸肉味鮮美、營養(yǎng)豐富,經(jīng)濟(jì)價(jià)值高,屬于高值養(yǎng)殖品種,且魚體顏色鮮艷,具有較高的觀賞價(jià)值。近幾年,豹紋鰓棘鱸已成為廣東、福建及海南等沿海地區(qū)海水養(yǎng)殖的重要名優(yōu)品種之一。目前,國內(nèi)外對豹紋鰓棘鱸的研究大多集中在生活習(xí)性[1-2]、養(yǎng)殖技術(shù)[3]、人工繁育[4-5]、疾病防治[6]及餌料營養(yǎng)[7]等方面,目前有關(guān)豹紋鰓棘鱸補(bǔ)償生長的研究鮮見報(bào)道。筆者以2種規(guī)格豹紋鰓棘鱸幼魚為研究對象,采用“饑餓-投喂-再饑餓-再投喂…”交替投喂方式,研究周期性饑餓-再投喂模式對豹紋鰓棘鱸生長和飼料利用的影響,摸索出一套“饑餓-再投喂”循環(huán)投喂模式來調(diào)整投飼技術(shù),以期為豹紋鰓棘鱸魚種的高效培育提供技術(shù)支持。
1 材料與方法
1.1 材料 試驗(yàn)豹紋鰓棘鱸均取自海南海研熱帶海水魚類良種場,試驗(yàn)在科研基地水泥池中進(jìn)行。試驗(yàn)一于2016年8—9月進(jìn)行,豹紋鰓棘鱸平均體質(zhì)量為(8.22±1.04) g;試驗(yàn)二于2017年3—4月進(jìn)行,豹紋鰓棘鱸平均體質(zhì)量為(81.69±2.81) g。試驗(yàn)所用飼料為海水魚配合飼料,飼料主要成分如下:粗蛋白≥48.0%,粗脂肪≥10.0%,水分≤10.0%,粗纖維≤2.0%,粗灰分≤17.0%,賴氨酸≥2.5%,總磷1.5%~3.0%。
1.2 方法
1.2.1 試驗(yàn)魚的馴化。試驗(yàn)前將魚在10.0 m×1.5 m×1.1 m水泥池馴養(yǎng)7 d。馴化期間,使用經(jīng)砂濾的三級過濾海水,海水經(jīng)進(jìn)水管流入經(jīng)溢水管溢出池外。使用鼓風(fēng)機(jī)經(jīng)池底的“曰”字形、有排氣孔的氣管連續(xù)供氧。水溫(28±1) ℃,鹽度31,pH 7.9。每天7:30和17:00飽食投喂2次,并記錄投飼量。
1.2.2 試驗(yàn)設(shè)計(jì)。2次試驗(yàn)均設(shè)置對照組(CK,持續(xù)喂食36 d),S1F1組(饑餓1 d、再投喂1 d,18個(gè)循環(huán)周期),S1F2組(饑餓1 d、再投喂2 d,12個(gè)循環(huán)周期),S2F2組(饑餓2 d、再投喂2 d,9個(gè)循環(huán)周期),每組3個(gè)重復(fù),每個(gè)重復(fù)隨機(jī)放80尾,2次試驗(yàn)均進(jìn)行36 d,試驗(yàn)均在水泥池規(guī)格1.2 m×0.8 m×1.0 m網(wǎng)箱內(nèi)進(jìn)行,日常管理同馴化期間。試驗(yàn)結(jié)束時(shí),從試驗(yàn)二每個(gè)網(wǎng)箱隨機(jī)取5尾魚進(jìn)行體成分分析。采用直接干燥法測定魚體水分含量(GB 5009.3—2016);采用凱氏定氮法(GB 5009.5—2016)和索氏抽提法(GB 5009.6—2016)分別測定粗蛋白和粗脂肪含量;采用高溫爐550 ℃灼燒法(GB 5009.4—2016)測定灰分含量。
1.3 指標(biāo)計(jì)算 按照以下公式計(jì)算SGR、FR和FCE:
SGR=(lnW2-lnW1)/t×100%
(1)
FR=C/[t×(W2+ W1)/2]×100%
(2)
FCE=(W2-W1)/C×100%
(3)
式中,SGR為特定生長率;FR為攝食率;FCE為飼料轉(zhuǎn)化率;W1為試驗(yàn)開始時(shí)魚體質(zhì)量;W2為試驗(yàn)結(jié)束時(shí)魚體質(zhì)量;C為總攝食量; t為投喂天數(shù)。
1.4 數(shù)據(jù)統(tǒng)計(jì)與分析 試驗(yàn)數(shù)據(jù)以平均值±標(biāo)準(zhǔn)差表示,試驗(yàn)數(shù)據(jù)使用SPSS 16.0統(tǒng)計(jì)軟件進(jìn)行統(tǒng)計(jì)與分析,對試驗(yàn)數(shù)據(jù)進(jìn)行單因素方差分析,并采用Duncans多重比較進(jìn)行差異顯著性檢驗(yàn)。
2 結(jié)果與分析
2.1 周期性饑餓-再投喂對豹紋鰓棘鱸生長的影響 由表1可知,經(jīng)過36 d的周期性饑餓再投喂,試驗(yàn)一S1F2組、S2F2組試驗(yàn)結(jié)束時(shí)體質(zhì)量與對照組(CK)無顯著差異(P>0.05),但均顯著高于S1F1組(P<0.05)。試驗(yàn)二S1F1組、S1F2組試驗(yàn)結(jié)束時(shí)體質(zhì)量與對照組(CK)無顯著差異(P>0.05),S2F2組試驗(yàn)結(jié)束時(shí)體質(zhì)量顯著低于對照組(P<0.05),但與S1F2組無顯著差異(P>0.05)。
2.2 周期性饑餓-再投喂對豹紋鰓棘鱸攝食量、攝食率和飼料轉(zhuǎn)化率的影響 從表2可以看出,試驗(yàn)一S2F2組攝食量顯著高于其他3組(P<0.05),S1F1組、S1F2組攝食量無顯著差異且均顯著低于對照組(P<0.05);S1F1組、S1F2、S2F2組攝食率均高于對照組,其中S1F1組、S2F2組顯著高于對照組(P<0.05),S1F2組攝食率與對照組無顯著差異(P>0.05);各組飼料轉(zhuǎn)化率差異顯著,其中S1F1組、S2F2組飼料轉(zhuǎn)化顯著低于對照組,而S1F2組飼料轉(zhuǎn)化率顯著高于對照組(P<0.05)。試驗(yàn)二各試驗(yàn)組攝食量均顯著低于對照組(P<0.05),S1F1組、S2F2組無顯著差異且均顯著低于S1F2組;各試驗(yàn)組攝食率均顯著高于對照組(P<0.05);各試驗(yàn)組飼料轉(zhuǎn)化效存在顯著差異,其中S1F1組飼料轉(zhuǎn)化率最高,且顯著高于對照組(P<0.05),S1F2組飼料轉(zhuǎn)化率與對照組無顯著差異(P>0.05)。
2.3 周期性饑餓-再投喂對豹紋鰓棘鱸特定生長率的影響 由圖1可知,在整個(gè)試驗(yàn)過程中,試驗(yàn)一各試驗(yàn)組特定生長率均顯著高于對照組(P<0.05),S2F2組特定生長率顯著高于其他3組(P<0.05),S1F1組和S1F2組之間差異不顯著(P>0.05);試驗(yàn)二各試驗(yàn)組特定生長率均顯著高于對照組(P<0.05),其中S1F1組特定生長率最高,且顯著高于其他3組(P<0.05)。
2.4 周期性饑餓-再投喂對豹紋鰓棘鱸魚體生化組成的影響 從表3可以看出,各試驗(yàn)組粗脂肪含量略低于對照組,水分含量略高于對照組,但均無顯著差異(P>0.05);各試驗(yàn)組粗蛋白和灰分含量與對照組相比無顯著差異(P>0.05)。
3 討論
3.1 豹紋鰓棘鱸補(bǔ)償生長的特點(diǎn)及機(jī)制 魚類補(bǔ)償生長程度因受種類、饑餓或限食程度等因素的影響而存在較大差異,即使同一種魚類在不同生長階段,其補(bǔ)償生長程度也不盡相同。一般來說,補(bǔ)償生長按補(bǔ)償量的程度可分為3類:超補(bǔ)償 [8-9]、完全補(bǔ)償[10]和部分補(bǔ)償[11-13]。該研究中試驗(yàn)一S1F2組、S2F2組,試驗(yàn)二S1F1組、S1F2組試驗(yàn)結(jié)束時(shí)體質(zhì)量與對照組無顯著差異,出現(xiàn)完全補(bǔ)償生長現(xiàn)象;試驗(yàn)結(jié)束時(shí),試驗(yàn)一S1F1組與試驗(yàn)二S2F2組試驗(yàn)結(jié)束時(shí)體質(zhì)量均低于對照組,但特定生長率均顯著高于對照組,發(fā)生了部分補(bǔ)償生長。這表明豹紋鰓棘鱸幼魚在周期性饑餓-再投喂模式下,能夠發(fā)生補(bǔ)償生長,饑餓時(shí)間及恢復(fù)投喂時(shí)間是影響補(bǔ)償生長程度的因素。
對于魚類補(bǔ)償生長的生理機(jī)制,目前主要有3種假說:①代謝滯后假說。魚在饑餓狀態(tài)下,機(jī)體通過降低代謝水平
來延長生命;恢復(fù)進(jìn)食時(shí),饑餓時(shí)較低的代謝水平仍能持續(xù)一段時(shí)間,用于生長的能量比例增加,提高食物轉(zhuǎn)化率從而達(dá)到補(bǔ)償或超補(bǔ)償生長[14]。②食欲增強(qiáng)假說。饑餓后恢復(fù)喂食,代謝水平?jīng)]有降低反而升高,魚的攝食率大幅增加而食物轉(zhuǎn)化率并沒有明顯提高,即主要是通過提高攝食水平來到達(dá)補(bǔ)償生長的[15]。③綜合作用假說。魚類在饑餓后恢復(fù)喂食,食物轉(zhuǎn)化效率和攝食水平均有所提高,即補(bǔ)償生長是食物轉(zhuǎn)化效率和攝食水平這兩種因素共同作用的結(jié)果[16]。
試驗(yàn)一各處理組攝食率均高于對照組,其中S2F2組攝食率顯著高于對照組,而飼料轉(zhuǎn)化率顯著低于對照組,表明S2F2組主要是通過提高攝食率來達(dá)到補(bǔ)償生長的;S1F2組攝食率與對照組差異不顯著,而飼料轉(zhuǎn)化率顯著高于對照組,表明S1F2組主要是通過提高飼料轉(zhuǎn)化率來到達(dá)完全補(bǔ)償生長的。試驗(yàn)二各處理組攝食率均顯著高于對照組,S1F2組飼料轉(zhuǎn)化率與對照組無顯著差異,而S1F1組飼料轉(zhuǎn)化率顯著高于對照組,這表明S1F2組主要是通過提高攝食率來達(dá)到完全補(bǔ)償生長的,S1F1組則通過提高飼料轉(zhuǎn)化率和攝食率達(dá)到完全補(bǔ)償生長。2次試驗(yàn)表明,豹紋鰓棘鱸幼魚主要是通過提高攝食率和飼料轉(zhuǎn)化率來實(shí)現(xiàn)補(bǔ)償生長的。
3.2 周期性饑餓-再投喂對豹紋鰓棘鱸魚體生化組成的影響 魚類在面對饑餓或食物不足等營養(yǎng)限制時(shí),消耗自身的儲(chǔ)能物質(zhì)以維持生命活動(dòng)。魚類的補(bǔ)償生長現(xiàn)象主要就是體內(nèi)儲(chǔ)能物質(zhì)被大量消耗后所采用的一種生理調(diào)節(jié)策略。研究表明,大多數(shù)水產(chǎn)動(dòng)物在饑餓期間主要消耗的能源物質(zhì)為脂肪和糖原[17-18],一般脂肪被大量消耗后才會(huì)利用蛋白質(zhì)作為能量來源[19-20]。在該試驗(yàn)中,試驗(yàn)結(jié)束時(shí)試驗(yàn)組粗脂肪含量略低于對照組,水分含量略高于對照組,但差異不顯著,各處理組粗蛋白、灰分含量與對照組無明顯差異,表明在饑餓過程中豹紋鰓棘鱸幼魚可能首先消耗儲(chǔ)備脂肪作為能量來源,通過周期性短期饑餓-再投喂處理不僅可以促進(jìn)豹紋鰓棘鱸的補(bǔ)償生長,而且不會(huì)影響魚體的營養(yǎng)質(zhì)量。
4 結(jié)論
豹紋鰓棘鱸幼魚經(jīng)過周期性短期饑餓(1~2 d)再恢復(fù)投喂后能達(dá)到完全補(bǔ)償生長,其中節(jié)約飼料最多可達(dá)20%,因此,從實(shí)際補(bǔ)償效果、飼料及勞動(dòng)力成本方面考慮,在幼魚階段可選用饑餓1 d同時(shí)恢復(fù)投喂1和2 d交替使用可能效果較佳,由于試驗(yàn)組平均體質(zhì)量均低于對照組,在后續(xù)試驗(yàn)中可適當(dāng)延長連續(xù)投喂時(shí)間來精細(xì)調(diào)整投飼策略。
參考文獻(xiàn)
[1] LIGHT P R,JONES G P.Habitat preference in newly settled coral trout (Plectropomus leopardus,Serranidae)[J].Coral reefs,1997,16(2):117-126.
[2] YOSEDA K,YAMAMOTO K,ASAMI K,et al.Influence of light intensity on feeding,growth,and early survival of leopard coral grouper (Plectropomus leopardus) larvae under massscale rearing conditions[J].Aquaculture,2008,279(1):55-62.
[3] 王永波,鄭飛,劉金葉,等.豹紋鰓棘鱸工廠化養(yǎng)殖試驗(yàn)[J].熱帶生物學(xué)報(bào),2014,5(1):15-19.
[4] 劉天密,王永波,符書源,等.豹紋鰓棘鱸室外大型水泥池的人工育苗技術(shù)[J].海洋漁業(yè),2012,34(4):400-405.
[5] 王永波,陳國華,林彬,等.豹紋鰓棘鱸胚胎發(fā)育的初步觀察[J].海洋科學(xué),2009,33(3):21-26.
[6] 徐曉麗,邵蓬,李灝,等.豹紋鰓棘鱸致病性哈維氏弧菌的分離鑒定與系統(tǒng)發(fā)育分析[J].華中農(nóng)業(yè)大學(xué)學(xué)報(bào),2014,33(4):112-118.
[7] 周邦維,李勇,高婷婷,等.主要營養(yǎng)素源對工業(yè)化養(yǎng)殖豹紋鰓棘鱸生長、體色和消化吸收的影響[J].動(dòng)物營養(yǎng)學(xué)報(bào),2014,26(5):1387-1401.
[8] HAYWARD R S,NOLTIE D B,WANG N.Use of compensatory growth to double hybrid sunfish growth rates [J].Transactions of the American fisheries society,1997,126(2):316-322.
[9] 區(qū)又君,劉澤偉.千年笛鯛幼魚的饑餓和補(bǔ)償生長[J].水產(chǎn)學(xué)報(bào),2007,31(3):323-328.
[10] KIM M K,LOVELL R T.Effect of restricted feeding regimens on compensatory weight gain and body tissue changes in channel catfish Ictalurus punctatus in ponds[J].Aquaculture,1995,135(4):285-293.
[11] WANG Y,CUI Y,YANG Y,et al.Compensatory growth and related bioenergetic mechanism in hybrid tilapia (Tilapia mossambicus× T.niloticus)[R].Wuhan,China:Institute of Hydrobiology,Chinese Academy of Science,1999:41-57.
[12] WEATHERLEY A H,GILL H S.Recovery growth following periods of restricted rations and starvation in rainbow trout Salmo gairdneri Richardson[J].Journal of fish biology,1981,18(2):195-208.
[13] 樓寶,毛國民,駱季安,等.不同的饑餓時(shí)間對黑鯛補(bǔ)償生長的影響[J].浙江海洋學(xué)院學(xué)報(bào)(自然科學(xué)版),2006,25(4):385-389.
[14] GAYLORD T G,GATLIN D M Ⅲ.Dietary protein and energy modifications to maximize compensatory growth of channel catfish (Ictalurus punctatus)[J].Aquaculture,2001,194(3/4):337-348.
[15] KIM M K,LOVELL R T.Effect of restricted feeding regimens on compensatory weight gain and body tissue changes in channel catfish Ictalurus punctatus in ponds[J].Aquaculture,1995,135(4):285-293.
[16] RUSSELL N R,WOOTTON R J.Appetite and growth compensation in the European minnow,Phoxinus phoxinus (Cyprinidae),following short periods of food restriction[J].Environmental biology of fishes,1992,34(3):277-285.
[17] JOBLING M,MIGLAVS I.The size of lipid depots:A factor contributing to the control of food intake in Arctic charr,Salvelinus alpinus?[J].Journal of fish biology,1993,43(3):487-489.
[18] 姜志強(qiáng),賈澤梅,韓延波.美國紅魚繼饑餓后的補(bǔ)償生長及其機(jī)制[J].水產(chǎn)學(xué)報(bào),2002,26(1):67-72.
[19] BARCLAY M C,DALL W,SMITH D M.Changes in lipid and protein during starvation and the moulting cycle in the tiger prawn,Penaeus esculentus Haswell[J].Journal of experimental marine biology and ecology,1983,68(3):229-244.
[20] 鄧?yán)?,張波,謝小軍.南方鲇繼饑餓后的恢復(fù)生長[J].水生生物學(xué)報(bào),1999,23(2):167-173.