齊占會(huì),王 珺,毛玉澤,張繼紅,方建光

(1. 農(nóng)業(yè)部南海漁業(yè)資源開(kāi)發(fā)利用重點(diǎn)實(shí)驗(yàn)室,廣東省漁業(yè)生態(tài)環(huán)境重點(diǎn)實(shí)驗(yàn)室,中國(guó)水產(chǎn)科學(xué)研究院南海水產(chǎn)研究所, 廣州 510300； 2. 中國(guó)水產(chǎn)科學(xué)研究院黃海水產(chǎn)研究所,青島 266071)

兩種海星對(duì)三種雙殼貝類(lèi)的捕食選擇性和攝食率

齊占會(huì)1, 2,王 珺1,毛玉澤2,張繼紅2,方建光2

(1. 農(nóng)業(yè)部南海漁業(yè)資源開(kāi)發(fā)利用重點(diǎn)實(shí)驗(yàn)室,廣東省漁業(yè)生態(tài)環(huán)境重點(diǎn)實(shí)驗(yàn)室,中國(guó)水產(chǎn)科學(xué)研究院南海水產(chǎn)研究所, 廣州 510300； 2. 中國(guó)水產(chǎn)科學(xué)研究院黃海水產(chǎn)研究所,青島 266071)

在實(shí)驗(yàn)室條件下,研究了多棘海盤(pán)車(chē)和海燕這兩種海星對(duì)櫛孔扇貝、菲律賓蛤仔和貽貝三種雙殼貝類(lèi)的捕食選擇性和攝食率及溫度的影響,測(cè)定了捕食Q10溫度系數(shù)。結(jié)果顯示：多棘海盤(pán)車(chē)和海燕對(duì)三種貝類(lèi)均可捕食,且表現(xiàn)出明顯的捕食選擇性,選擇順序依次為菲律賓蛤仔、貽貝和櫛孔扇貝。海星對(duì)菲律賓蛤仔的攝食率顯著高于其他兩種貝類(lèi),分別為0.50和0.37個(gè)/d；對(duì)扇貝的攝食率最低,分別為0.05和0.07個(gè)/d。海星攝食率隨水溫升高而呈上升的趨勢(shì),總平均攝食干重分別為0.69 和0.79 g/d。水溫從4.3 ℃升高到7.8 ℃多棘海盤(pán)車(chē)和海燕捕食Q10系數(shù)分別為6.38和2.33,而水溫從7.8 ℃升高至13.3 ℃時(shí),Q10系數(shù)沒(méi)有顯著升高,分別為1.13和1.22。說(shuō)明水溫從4.3 ℃升高時(shí),海星捕食強(qiáng)度顯著升高,是防御海星的重點(diǎn)時(shí)期。根據(jù)海星對(duì)貝類(lèi)捕食的選擇性,可在養(yǎng)殖籠內(nèi)放入貽貝等低值貝類(lèi)來(lái)保護(hù)扇貝,緩沖海星對(duì)扇貝的捕食,并在緩沖期間對(duì)養(yǎng)殖籠內(nèi)的海星進(jìn)行清除。

海星；多棘海盤(pán)車(chē)；海燕；捕食選擇性；攝食率

海星屬于棘皮動(dòng)物,海星綱(Asteroidea),是典型的掠食性動(dòng)物,可捕食貝類(lèi)、海膽、珊瑚和螃蟹等,對(duì)潮間帶生物和底棲生物群落的異質(zhì)性和生物多樣性具有重要影響[1- 4]。我國(guó)沿海分布的海星主要屬于海盤(pán)車(chē)科(Asteriidae)和海燕科(Asterinidae)的種類(lèi)。海星爆發(fā)時(shí)數(shù)量可達(dá)150000—720000個(gè)/公頃[5- 6],是養(yǎng)殖貝類(lèi)主要敵害生物之一[7- 11]。2007年青島附近海域海星出現(xiàn)暴發(fā)性增殖,幾乎使沿岸海域養(yǎng)殖的貝類(lèi)損失殆盡。作者對(duì)青島流清河海域吊養(yǎng)的櫛孔扇貝養(yǎng)殖籠內(nèi)海星的情況進(jìn)行了調(diào)查統(tǒng)計(jì),發(fā)現(xiàn)幾乎所有籠內(nèi)都有海星存在,扇貝死亡率在80%以上。

弄清海星的攝食率、捕食選擇性及關(guān)鍵受控因素是揭示其對(duì)海洋生物群落影響和作用機(jī)制的基礎(chǔ)[12- 15],也是研究其防治策略,規(guī)避其危害的前提[16- 18]。但目前國(guó)內(nèi)對(duì)海星捕食選擇性、捕食速率及影響因素等的研究還較少[19, 33]。

多棘海盤(pán)車(chē)Asteriasamurensis和海燕Asterinapectinifera是我國(guó)沿海兩種最常見(jiàn)的海星種類(lèi)。本文以這兩種海星為對(duì)象,研究了它們對(duì)櫛孔扇貝、菲律賓蛤仔和貽貝三種貝類(lèi)的捕食選擇性和攝食率以及溫度的影響,探討了海星捕食機(jī)制,旨在揭示海星捕食生理生態(tài)學(xué)特征,為進(jìn)一步研究海星防控策略,減少其對(duì)養(yǎng)殖貝類(lèi)的危害提供科學(xué)依據(jù)。

1 材料與方法

1.1 實(shí)驗(yàn)材料

實(shí)驗(yàn)用多棘海盤(pán)車(chē)(輻徑114—135 mm)和海燕(輻徑41—53 mm)均從山東榮成桑溝灣尋山海區(qū)用地籠網(wǎng)捕獲。所用櫛孔扇貝Chlamysfarreri、菲律賓蛤仔Ruditapesphilippinarum和貽貝Mytilusgalloprovincialis均取自桑溝灣養(yǎng)殖海區(qū)。

1.2 養(yǎng)殖條件

實(shí)驗(yàn)于2008年3月19日至4月5日在山東榮成尋山集團(tuán)海洋生物實(shí)驗(yàn)室進(jìn)行。海星和貝類(lèi)在水泥池(長(zhǎng)×寬×高=6.0 ×1.0 ×0.5 m,水體2400 L)內(nèi)養(yǎng)殖。實(shí)驗(yàn)用海水為桑夠?yàn)澈Ｓ蛱烊缓Ｋ?經(jīng)過(guò)沉淀和沙濾后使用。實(shí)驗(yàn)期間海水水質(zhì)參數(shù)用YSI6600測(cè)量,溶解氧在5.0 mg/L以上,鹽度32.14-32.54,pH 7.93—8.10。每天8:00全部換水一次。采用自然光照。實(shí)驗(yàn)開(kāi)始前海星暫養(yǎng)馴化一周,使其適應(yīng)養(yǎng)殖環(huán)境和實(shí)驗(yàn)處理。馴化期間混合投喂實(shí)驗(yàn)貝類(lèi),待海星攝食穩(wěn)定后開(kāi)始實(shí)驗(yàn)。

1.3 實(shí)驗(yàn)設(shè)計(jì)

多棘海盤(pán)車(chē)和海燕在水泥池內(nèi)的養(yǎng)殖密度為5只/池,每水泥池內(nèi)投喂櫛孔扇貝、菲律賓蛤仔和貽貝各30粒。投喂時(shí)將這三種貝類(lèi)充分混合,使各種貝在水泥池底隨機(jī)分布,遭遇海星捕食的條件相同。每天7:00和17:00觀察記錄海星對(duì)貝類(lèi)的捕食情況,撿出死殼,不補(bǔ)充貝類(lèi)。研究這兩種海星對(duì)三種不同貝類(lèi)的攝食率和捕食選擇性。每實(shí)驗(yàn)處理設(shè)置三個(gè)重復(fù)。實(shí)驗(yàn)用貝均是達(dá)到商品規(guī)格的貝類(lèi),貝類(lèi)的軟體組織在65 ℃下烘干48 h后稱量干重,實(shí)驗(yàn)貝類(lèi)生物學(xué)參數(shù)見(jiàn)表1。

1.4 數(shù)據(jù)處理

1.4.1 攝食率

從3月19日至4月5日記錄分別記錄多棘海盤(pán)車(chē)和海燕所捕食的貝類(lèi)種類(lèi)和數(shù)量,某種貝類(lèi)開(kāi)始被捕食即計(jì)為計(jì)算海星對(duì)該種貝類(lèi)攝食率的起始時(shí)間。攝食率(個(gè)/d；Feed intake (FI): ind/d) 的計(jì)算公式為：

FI=D/t

式中,D為海星對(duì)某種貝類(lèi)的捕食數(shù)量(個(gè)),t為時(shí)間(d)。

1.4.2 捕食比例

統(tǒng)計(jì)3月19日—24日,3月25日—30日和3月31日—4月5日三個(gè)時(shí)間段內(nèi),多棘海盤(pán)車(chē)和海燕所捕食的貝類(lèi)的種類(lèi)和數(shù)量,分析各種貝類(lèi)在海星獵物中所占比例及隨時(shí)間的變化。捕食比例(P)的計(jì)算公式為：

P=n/N×100%

式中,n為被海星所捕食的某一貝類(lèi)的數(shù)量(個(gè)),N為海星捕食的三種貝類(lèi)的總數(shù)量(個(gè))。

1.4.3 捕食溫度系數(shù)

記錄兩種海星在4.3 ℃、7.8 ℃和13.3 ℃下的總攝食干重?？倲z食干重以所捕食的三種貝類(lèi)軟體組織的總干重計(jì)算,連續(xù)記錄5d,以平均值作為該溫度下海星的捕食強(qiáng)度(g/d)。溫度系數(shù)(Q10) 的計(jì)算公式為：

Q10=(V2/V1)10/(t2-t1)

式中,Q10表示溫度每升高10 ℃時(shí)捕食強(qiáng)度增加的倍數(shù)；V1和V2為捕食強(qiáng)度；t1和t2分別為各階段的開(kāi)始和結(jié)束溫度。

1.4.4 統(tǒng)計(jì)分析

數(shù)據(jù)以平均值±標(biāo)準(zhǔn)誤(mean±S.E.)表示。采用單因子方差分析(one-way ANOVA)和Duncan多重比較對(duì)數(shù)據(jù)差異進(jìn)行分析,以Plt;0.05作為差異顯著標(biāo)準(zhǔn)。數(shù)據(jù)統(tǒng)計(jì)分析采用Statistica 6.0軟件進(jìn)行。

表1 實(shí)驗(yàn)貝類(lèi)的生物學(xué)參數(shù)指標(biāo)

2 實(shí)驗(yàn)結(jié)果

2.1 海星捕食行為觀察

圖1 海星捕食行為(A)海燕捕食櫛孔扇貝,(B)多棘海盤(pán)車(chē)捕食櫛孔扇貝,(C)海燕捕食貽貝,(D)多棘海盤(pán)車(chē)捕食菲律賓蛤仔Fig.1 The feeding behavior of sea stars: (A) A. amurensis prey on C. farreri, (B) A. amurensis prey on C. farreri, (C) A. amurensis prey on M. galloprovincialis, (D) A. amurensis prey on R. philippinarum

觀察發(fā)現(xiàn)多棘海盤(pán)車(chē)和海燕捕食時(shí)主要靠腕足上細(xì)小的管足將獵物“包裹”住,抱縛于腹面盤(pán)中央的“口”部。管足吸附在貝殼上并向兩側(cè)拉伸,拉開(kāi)很小的縫隙,將賁門(mén)胃伸及貝殼內(nèi)注入消化液消化并吸食貝類(lèi)軟體組織,之后將完整的貝殼拋棄。實(shí)驗(yàn)過(guò)程中發(fā)現(xiàn)多棘海盤(pán)車(chē)和海燕可同時(shí)捕食兩只或多只菲律賓蛤仔或貽貝(圖 1)。相對(duì)于海燕,多棘海盤(pán)車(chē)的警惕性更高,對(duì)外界刺激也更為敏感,捕食過(guò)程中受到干擾時(shí),很容易將已捕獲的獵物“吐出”放棄捕食,而海燕可以忍受更大程度的干擾,這可能是其獵食活動(dòng)更為旺盛的原因之一。實(shí)驗(yàn)過(guò)程中發(fā)現(xiàn)兩種海星在白天和夜間均有捕食活動(dòng),但夜間捕食強(qiáng)度明顯高于白天,這可能是海星對(duì)光線較暗的海底生境產(chǎn)生的適應(yīng)性。

2.2 海星對(duì)貝類(lèi)的捕食選擇性

海星對(duì)貝類(lèi)的選擇性和捕食比例見(jiàn)圖2。兩種海星對(duì)這三種貝類(lèi)均有捕食,且表現(xiàn)出明顯的主動(dòng)選擇性。實(shí)驗(yàn)初期兩種海星均明顯優(yōu)先捕食菲律賓蛤仔,其次為貽貝,當(dāng)這兩種貝類(lèi)數(shù)量減少時(shí),對(duì)櫛孔扇貝的捕食比例才有所增加。3月19日—24日,多棘海盤(pán)車(chē)捕食的菲律賓蛤仔、貽貝和櫛孔扇貝比例分別為64.28%,28.57%和7.14%；海燕對(duì)這三種貝類(lèi)的捕食占比例分別為50%,44.44%和5.56%。結(jié)果表明多棘海盤(pán)車(chē)和海燕三種貝類(lèi)的主動(dòng)選擇順序依次為：菲律賓蛤仔、貽貝和櫛孔扇貝。

圖2 多棘海盤(pán)車(chē)(A)和海燕(B)對(duì)3種貝類(lèi)的捕食比例Fig.2 The percentage of bivalves preyed by sea stars (A) Asterias amurensis and (B) Asterina pectinifera

2.3 海星對(duì)貝類(lèi)的攝食率

多棘海盤(pán)車(chē)和海燕均是對(duì)菲律賓蛤仔的攝食率顯著高于對(duì)其他兩種貝類(lèi)的攝食率,分別為0.50和0.37個(gè)/d,對(duì)扇貝的平均攝食率最低,分別為0.05和0.07個(gè)/d。對(duì)菲律賓蛤仔的攝食率顯著高于其他兩種貝類(lèi)(Plt;0.05)(表2)。在本實(shí)驗(yàn)條件下,多棘海盤(pán)車(chē)和海燕攝食率均隨水溫升高而呈上升的趨勢(shì),每天總的平均攝食干重分別為0.69 g/d和0.79 g/d(表2,圖3)。從4.3℃到7.8℃多棘海盤(pán)車(chē)和海燕的Q10系數(shù)分別為6.38和2.33,而水溫從7.8℃繼續(xù)升高至13.3℃時(shí),Q10系數(shù)變化不顯著,分別為1.13和1.22(表3)。

圖3 海星攝食率隨溫度變化趨勢(shì)(A)多棘海盤(pán)車(chē)和(B)海燕Fig.3 Variation of feeding rates with water temperature (A) Asterias amurensis and (B) Asterina pectinifera on bivalves

種類(lèi)Species攝食率Feedingrate/(個(gè)/d)櫛孔扇貝Chlamysfarreri菲律賓蛤仔Ruditapesphilippinarum貽貝Mytilusgalloprovincialis總攝食干重(g/d)Totalfeedingrate多棘海盤(pán)車(chē)Asteriasamurensis0.05±0.02a0.50±0.10b0.26±0.09c0.69±0.08海燕Asterinapectinifera0.07±0.02a0.37±0.08b0.27±0.06c0.79±0.04

同一行中沒(méi)有相同字母上標(biāo)的數(shù)值之間差異顯著

表3 多棘海盤(pán)車(chē)和海燕的捕食溫度系數(shù)

3 討論

3.1 海星捕食選擇性

海星捕食過(guò)程包括搜索遭遇獵物、捕食獵物和處理取食獵物等環(huán)節(jié)[20- 22]。每個(gè)環(huán)節(jié)如海星個(gè)體大小和處理獵物所需時(shí)間[20, 23]以及獵物的種類(lèi)、大小和密度等都會(huì)影響海星對(duì)食物的選擇[24, 33]。海星對(duì)食物的選擇,分為主動(dòng)選擇和被動(dòng)選擇。Wong and Barbeau[16]研究了海星Asteriasvulgaris對(duì)扇貝Placopectenmagellanicus和貽貝Mytilusedulis的捕食選擇性,發(fā)現(xiàn)在貽貝存在的情況下,無(wú)論是主動(dòng)選擇還是被動(dòng)選擇,海星都優(yōu)先選擇貽貝,主要是由于貽貝不能通過(guò)游泳移動(dòng)來(lái)逃避捕食,更易被捕獲。與之相一致,本研究也發(fā)現(xiàn)多棘海盤(pán)車(chē)和海燕也都表現(xiàn)出了對(duì)食物的主動(dòng)選擇性,均優(yōu)先選擇捕食菲律賓蛤仔和貽貝,只有這兩種貝類(lèi)數(shù)量變小時(shí)才增加對(duì)櫛孔扇貝的捕食。這可能主要受到捕食能量效率的影響,海星捕食的能量效率主要受到獵物的豐度和能量含量高低以及搜尋和處理獵物時(shí)的能量消耗等因素的影響,這些因素是決定了海星對(duì)食物的選擇[1, 25- 26]。從能量效益角度分析,單次捕食選擇較大規(guī)格的貝類(lèi)能量收益較高,但在捕捉和處理獵物過(guò)程中能量消耗也較多,尤其是還存在捕食不成功的風(fēng)險(xiǎn),反而降低了捕食的能量效率。

本實(shí)驗(yàn)采用的櫛孔扇貝個(gè)體相對(duì)較大,閉殼肌發(fā)達(dá)閉合力強(qiáng),并且扇貝殼上有尖利的棘刺,不利于海星捕食,反而是選擇小規(guī)格的貝類(lèi)比較容易捕食,能量效率也相對(duì)更高[27- 28]。Sommer等[29]研究了個(gè)體大小對(duì)海星Asteriasrubens捕食貽貝M.edulis的影響,也發(fā)現(xiàn)海星傾向于捕食個(gè)體相對(duì)較大的貽貝,但不捕食殼長(zhǎng)在4.8 cm以上的貽貝,也主要是由于能量效率的原因。杜美榮等[19]研究報(bào)道多棘海盤(pán)車(chē)優(yōu)先選擇貽貝,而不是菲律賓蛤仔,與本實(shí)驗(yàn)結(jié)果存在一定差異。這可能是由于他們所采用的貽貝(殼長(zhǎng)10—21mm)小于菲律賓蛤仔(殼長(zhǎng)19—27mm),而本實(shí)驗(yàn)采用的貽貝和菲律賓蛤仔規(guī)格相近(表 1),這也證明了貝類(lèi)的個(gè)體大小是影響海星捕食選擇的重要因素。

3.2 海星攝食率及溫度的影響

不同種類(lèi)海星的攝食率存在很大差異。Nadeau等[17]研究結(jié)果顯示,在水溫10—15 ℃條件下,海星A.vulgaris(輻徑70—90 mm)和L.polaris(輻徑90—110 mm)對(duì)扇貝P.magellanicus(殼長(zhǎng)25—35 mm)的攝食率分別為0.9和0.02個(gè)/d,高于本實(shí)驗(yàn)中海星的攝食率(表2),這主要是由于海星種類(lèi)和貝類(lèi)規(guī)格不同,本研究采用的扇貝規(guī)格較大,能量含量較高,且對(duì)海星捕食具有一定防御抵抗能力,而小規(guī)格扇貝更易受到攻擊捕食。

溫度對(duì)于變溫動(dòng)物的生命活動(dòng)具有顯著的影響。研究發(fā)現(xiàn)海星捕食強(qiáng)度主要受到獵物密度和規(guī)格[17- 18]、底層基質(zhì)[24]和水溫[30]等的影響。溫度升高會(huì)使捕食者用于捕食活動(dòng)的時(shí)間增加,尋找獵物時(shí)的活動(dòng)速度也更快,進(jìn)而使發(fā)現(xiàn)獵物的機(jī)率升高,并且也會(huì)使捕捉和處理獵物的時(shí)間縮短,總體上提高了捕食效率[30]。這一現(xiàn)象在其它水生生物如蟹類(lèi)等的捕食研究中也得到了證實(shí)[31- 32]。本研究結(jié)果顯示,在一定范圍內(nèi)多棘海盤(pán)車(chē)和海燕對(duì)貝類(lèi)的捕食強(qiáng)度均隨著溫度的升高而增加。這與Barbeau和Scheibling[30]的研究結(jié)果相一致,他們也發(fā)現(xiàn)海星A.vulgaris對(duì)扇貝P.magellanicus的捕食強(qiáng)度在一定范圍內(nèi)隨水溫上升而升高,但捕食強(qiáng)度升高的溫度范圍與本研究結(jié)果存在顯著的差異。他們發(fā)現(xiàn)當(dāng)水溫從4 ℃升高至8 ℃,海星的捕食強(qiáng)度沒(méi)有明顯的變化,而溫度從8 ℃繼續(xù)升高至15 ℃時(shí),捕食強(qiáng)度顯著提高(Q10=6.9)。本研究中從4.3 ℃到7.8 ℃海星捕食強(qiáng)度明顯提高(Q10系數(shù)分別為6.38和2.33),但繼續(xù)升高至13.3 ℃,捕食強(qiáng)度變化不明顯(Q10系數(shù)分別為1.13和1.22)(表3)。這些不同的實(shí)驗(yàn)結(jié)果表明不同種類(lèi)海星最適捕食的溫度不同。本實(shí)驗(yàn)是在水溫4.3—13.3 ℃條件下進(jìn)行的,海星在其他溫度范圍下的捕食情況以及捕食的最適溫度還需要進(jìn)一步研究確定。

3.3 海星防御建議

網(wǎng)籠養(yǎng)殖的貝類(lèi)主動(dòng)逃避海星捕食的能力較差,一方面由于櫛孔扇貝等貝類(lèi)的成熟個(gè)體通過(guò)足絲附著在養(yǎng)殖籠上營(yíng)固著生活,另一方面具有一定游泳遷移能力種類(lèi),也幾乎不可能從養(yǎng)殖籠內(nèi)逃脫,因此只能通過(guò)采取其它措施來(lái)防御海星捕食。本研究的結(jié)果顯示水溫從4.3℃升高至7.8℃時(shí)海星的捕食強(qiáng)度顯著升高,這一階段是防御海星的重點(diǎn)時(shí)期。根據(jù)海星對(duì)貝類(lèi)捕食的選擇性,可在養(yǎng)殖籠內(nèi)放入貽貝等低值貝類(lèi)來(lái)保護(hù)扇貝,緩沖海星對(duì)扇貝的捕食,并在緩沖期間對(duì)養(yǎng)殖籠內(nèi)的海星進(jìn)行清除。

[1] Sloan N A. Aspects of the feeding biology of asteroids. Oceanography and Marine Biology Annual Review, 1980, 18: 57- 124.

[2] Power M E, Tilman D, Estes J A, Menge B A, Bond W J, Mills L S, Daily G, Castilla J C, Lubchenco J, Paine R T. Challenges in the quest for keystones. BioScience, 1996, 46: 609- 620.

[3] Witman J D, Dayton P K. Rocky subtidal communities // Bertness, M.D., Gaines, S.D., Hay, M.E. eds. Marine Community Ecology. Sinauer Associates, Massachusetts, 2001. 339 - 366.

[4] Verling E, Crook A C, Barnes D K A, Harrison S S C. Structural dynamics of a sea starMarthasteriasglacialispopulation. Journal of the Marine Biological Association of the United Kingdom, 2003, 83: 583- 592.

[5] Hendler G, Miller J E, Pawson D L, Kier P M. Echinoderms of Florida and the Caribbean. Washington: Smithsonian Institution press, 1995: 390.

[6] Farias N E, Meretta P E, Cledón M. Population structure and feeding ecology of the bat starAsterinastellifera(M?bius, 1859): Omnivory on subtidal rocky bottoms of temperate seas. Journal of Sea Research, 2012, 70: 14- 22.

[7] Hatcher B G, Scheibling RE, Barbeau M A, Hennigar A W, Taylor L H, Windust A. Dispersion and mortality of a population of sea scallopPlacopectenmagellanicusseeded in a tidal channel. Canadian Journal of Fisheries and Aquatic Sciences, 1996, 53: 38- 54.

[8] Hawkes G, Day R. Review of the biology and ecology ofAsteriasamurensis：status report to Fisheries Research and Development Corporation // Fisheries Research and Development Corporation (Australia). Hobart: CSIRO Division of Fisheries,1993：38．

[9] Barbeau M. A, Hatcher B G, Scheibling R E, Hennigar A W, Taylor LH, Risk A C. Dynamics of juvenile sea scallopPlacopectenmagellanicusand their predators in bottom seeding trials in Lunenburg Bay, Nova Scotia. Canadian Journal of Fisheries and Aquatic Sciences, 1996, 53: 2494- 2512.

[10] Cliche G, Giguère M, Vigneau S. Dispersal and mortality of sea scallops,Placopectenmagellanicus(Gmelin 1791), seeded on the sea bottom off Iles-de-la-Madeleine. Journal of Shellfish Research, 1994, 13: 565- 570.

[11] Thompson M, Drolet D, Himmelman J H. Localization of infaunal prey by the sea starLeptasteriaspolaris. Marine Biology, 2005, 146: 887- 894.

[12] Gaymer C F, Himmelman J H. Mussel beds in deeper water provide an unusual situation for competitive interactions between the sea starsLeptasteriasPolarisandAsteriasvulgaris. Journal of Experimental Marine Biology and Ecology, 2002, 277: 13- 24.

[13] Gaymer C F, Himmelman J H, Johnson L E. Distribution and feeding ecology of the seastarsLeptasteriaspolarisandAsteriasvulgarisin the northern Gulf of St. Lawrence, Canadian Journal of the Marine Biological Association of the United Kingdom, 2001, 81: 827- 843.

[14] Gaymer C F, Himmelman J H, Johnson L E. Effect of intra- and interspecific interactions on the feeding behavior of two subtidal seastars. Marine Ecology Progress Series, 2002, 232: 149- 162.

[15] McClintock J B, Lawrence J M. An optimization study on the feeding behavior ofLuidiaclathrataSay (Echinodermata: Asteroidea). Marine Behavior amp; Physiology, 1981, 7: 263- 275.

[16] Wong M C, Barbeau M A. Prey selection and the functional response of sea starsAsteriasvulgarisVerrill and rock crabsCancerirroratusSay preying on juvenile sea scallopPlacopectenmagellanicusGmelin and blue musselsMytulisedulisLinnaeus. Journal of Experimental Marine Biology and Ecology, 2005, 327: 1- 21.

[17] Nadeau M, Barbeau M A, Brêthes J. Behavioural mechanisms of sea stars (AsteriasvulgarisVerrill andLeptasteriaspolarisMüller) and crabs (CancerirroratusSay andHyasaraneusLinnaeus) preying on juvenile sea scallops (Placopectenmagellanicus(Gmelin)), and procedural effects of scallop tethering. Journal of Experimental Marine Biology and Ecology, 2009, 374: 134- 143.

[18] Barbeau M A, Scheibling R E, Hatcher B G. Behavioural responses of predatory crabs and sea stars to varying density of juvenile sea scallops. Aquaculture, 1998, 169(1/2): 87- 98.

[19] Du M R, Fang J G, Zhang J H, Mao Y Z, Ge C Z, Gao Y P, Liu D H. Feeding rate and food preference ofAsteriasamurensison four species of bivalves. Fishery Modernization, 2012, 39(2): 25- 47.

[20] Himmelman J H, Dutil C, Gaymer C F. Foraging behavior and activity budgets of sea stars on a subtidal sediment bottom community. Journal of Experimental Marine Biology and Ecology, 2005, 322: 153- 165.

[21] Holling C S. The functional response of invertebrate predators to prey density. Memoirs of the Entomological Society of Canada, 1966, 48: 1- 86.

[22] Osenberg C W, Mittelbach G G. Effects of body size on the predator-prey interaction between pumpkinseed sun fish and gastropods. Ecological Monographs, 1989, 59: 405- 432.

[23] Arnold W S. The effects of prey size, predator size, and sediment composition on the rate of predation of the blue crab,CallinectessapidusRathbun, on the hard clam,Mercenariamercenaria. Journal of Experimental Marine Biology and Ecology, 1984, 80: 207- 219.

[24] Wong M C, Barbeau M A. Effects of substrate on interactions between juvenile sea scallops (PlacopectenmagellanicusGmelin) and predatory sea stars (AsteriasvulgarisVerrill) and rock crabs (CancerirroratusSay). Journal of Experimental Marine Biology and Ecology, 2003, 287: 155- 178.

[25] Allen P L. Feeding behaviour ofAsteriasrubens(L.) on soft bottoms bivalves: a study in selective predation. Journal of Experimental Marine Biology and Ecology, 1983, 70: 79- 90.

[26] Beddingfield S D, McClintock J B. Feeding behavior of the sea starastropectenarticulates(Echinodermata: Asteroidea): an evaluation of energy-efficient foraging in a soft-bottom predator. Marine Biology, 1993, 115: 669- 676.

[27] Juanes F, Hartwick E B. Prey size selection in dungeness crabs: the effect of claw damage. Ecology, 1990, 71: 744- 758.

[28] Gaymer C F, Dutil C, Himmelman J H. Prey selection and predatory impact of four major sea stars on a soft bottom subtidal community. Journal of Experimental Marine Biology and Ecology, 2004, 313: 353- 374.

[29] Sommer U, Meusel B, Stielau C. An experimental analysis of the importance of body-size in the seastar-mussel predator-prey relationship. Acta Oecologica, 1999, 20(2): 8l- 86.

[30] Barbeau M A, Scheibling R E. Temperature effects on predation of juvenile sea scallops (PlacopectenmagellanicusGmelin) by sea stars (AsteriasvulgarisVerrill) and crabs (CancerirroratusSay). Journal of Experimental Marine Biology and Ecology, 1994, 182: 27- 47.

[31] Nickell T D, Moore P G. The behavioural ecology of epibenthic scavenging invertebrates in the Clyde Sea area: laboratory experiments on attractions to bait in moving water, underwater TV observation in situ and general conclusions. Journal of Experimental Marine Biology and Ecology, 1992, 159: 15- 35.

[32] Yu Z H, Yang H S, Liu B Z, Xing K, Xu Q, Zhang L B. Predation of scallopChlamysfarreriby crab Charybdis japonica. Marine Sciences, 2010, 34(12)：62- 66.

[33] Liu J, Zhang X M. Study on the prey selection of sea starsAsteriasamurensispreying on juvenile oysterCrassostreagigas, musselsMytilusedulisand clamsRuditapesphilippinarum. Journal of Ocean University of China, 2012, 42(7/8): 98- 105.

參考文獻(xiàn)：

[19] 杜美榮, 方建光, 張繼紅, 毛玉澤, 葛長(zhǎng)字, 高亞平, 劉頂海. 多棘海盤(pán)車(chē)對(duì)四種貝類(lèi)攝食率和選擇性的初步研究. 漁業(yè)現(xiàn)代化, 2012, 39(2): 25- 47.

[32] 于宗赫, 楊紅生, 劉保忠, 邢坤, 許強(qiáng), 張立斌. 日本蟳捕食櫛孔扇貝機(jī)制的初步研究. 海洋科學(xué), 2010, 34(12)：62- 66.

[33] 劉佳,張秀梅. 多棘海盤(pán)車(chē)對(duì)太平洋牡蠣、紫貽貝、菲律賓蛤仔攝食選擇性的研究.中國(guó)海洋大學(xué)學(xué)報(bào), 2012, 42(7/8): 98- 105.

PreyselectionandfeedingrateofseastarsAsteriasamurensisandAsterinapectiniferaonthreebivalves

QI Zhanhui1, 2, WANG Jun1, MAO Yuze2, ZHANG Jihong2, FANG Jianguang2,*

1KeyLaboratoryofSouthChinaSeaFisheryResourcesDevelopmentandUtilization,MinistryofAgriculture;KeyLaboratoryofMarineFisheryEcologyEnvironmentofGuangdongProvince/SouthChinaSeaFisheriesResearchInstitute,ChineseAcademyofFisherySciences;Guangzhou510300,China2YellowSeaFisheriesResearchInstitute,ChineseAcademyofFisheriesSciences,Qingdao266071,China

Sea stars are one of the primary predators of shellfish and often cause mass mortality among cultured shellfish. To develop effective control strategies, it is critical to understand the feeding ecophysiology (e.g., feeding rate and prey selection) of sea stars.

AsteriasamurensisandAsterinapectiniferaare the dominant sea star species in the coastal waters of China. We evaluated prey selection and the feeding rate of these two sea stars on three species of bivalves: scallopsChlamysfarreri, clamsRuditapesphilippinarum, and blue musselsMytilusgalloprovincialis. The experimental sea stars and bivalves were collected from Sanggou Bay, Northern China and transported to our seaside laboratory. The animals were acclimated to laboratory conditions for 7 d prior to the initiation of the experiment. The experiment was conducted between March 19 and April 5, 2008, at different seawater temperatures. Following acclimation, the sea stars were placed in cement tanks (L×W×H=6×1×0.5 m) at a density of 5 individuals per tank (single species per tank). The sea water was pumped from Sanggou Bay and sand filtered. Daily water exchange was ca 100%. We placed the bivalves (N=30 per species) evenly in each tank to ensure the sea stars had an equal probability of encountering the three species of bivalves. Each treatment was conducted in triplicate (N= 3 tanks). The number of bivalves of each species preyed upon by the sea stars was recorded twice daily at 7:00 and 17:00. In addition, we measured theQ10coefficient at water temperatures ranging from 4.3—7.8℃ and from 7.8—13.3℃.

Both species of sea star preyed on all three bivalve species. Similarly, both species exhibited preference in the order clamgt;musselgt;scallop. During the first part of the experiment (March 19—24),A.amurensispreyed on 64.28, 28.57, and 7.14% of the scallops, clams, and blue mussels, respectively.A.pectiniferapreyed upon 50, 44.44, and 5.56% of the bivalve species, respectively. The mean feeding rates ofA.amurensisandA.pectiniferaon the clam (0.50 and 0.37 ind/d, respectively) and blue mussel (0.26 and 0.27 ind/d, respectively) were significantly higher than those on the scallop (0.05 and 0.07 ind/d, respectively). The feeding rate was significantly influenced by water temperature and generally increased with increasing water temperature. The total mean feeding rates of the two sea stars were 0.69 and 0.79 g·d-1, respectively (based on dry tissue weight of bivalves). As water temperature increased from 4.3 to 7.8℃, theQ10coefficients forA.amurensisandA.pectiniferawere 6.38 and 2.33, respectively. However, when the water temperature was increased from 7.8 to 13.3℃, there was no increase in the feeding rate (Q10=1.13 and 1.22, respectively). Our results have implications for the provision of protective refuges for the species of interest (i.e., scallops) during culture in suspended lantern nets. Protective strategies are most likely to be needed when the water temperature increases above 4.3℃, as the feeding rate and activity of sea stars increased significantly above this point. Based on prey selectivity, bivalves that have a lower commercial value (e.g., blue mussels) may be co-cultured in the scallop lantern nets to serve as a buffer against predators. Furthermore, any sea stars present in the cultivation nets should be removed during the buffering period.

sea star;Asteriasamurensis;Asterinapectinifera; prey selection;feeding rate

國(guó)家自然科學(xué)基金(41106088)；“十二五”國(guó)家科技支撐計(jì)劃(2011BAD13B02)；863計(jì)劃(2012AA052103)；重點(diǎn)實(shí)驗(yàn)室開(kāi)放課題(201104,MESE- 2011- 02,開(kāi)- c10- 09)

2012- 08- 21;

2013- 08- 20

*通訊作者Corresponding author.E-mail: Fangjg@ysfri.ac.cn；qizhanhui@scsfri.ac.cn

10.5846/stxb201208211174

齊占會(huì),王珺,毛玉澤,張繼紅,方建光.兩種海星對(duì)三種雙殼貝類(lèi)的捕食選擇性和攝食率.生態(tài)學(xué)報(bào),2013,33(16):4878- 4884.

Qi Z H, Wang J, Mao Y Z, Zhang J H, Fang J G.Prey selection and feeding rate of sea starsAsteriasamurensisandAsterinapectiniferaon three bivalves.Acta Ecologica Sinica,2013,33(16):4878- 4884.