金(jin)錢龜(gui)(gui)的學名為(wei)三(san)線閉(bi)殼龜(gui)(gui)(Cuora trifasciata),別名紅(hong)邊龜(gui)(gui)、紅(hong)肚龜(gui)(gui)、斷(duan)板龜(gui)(gui)、金(jin)頭龜(gui)(gui)等,隸屬(shu)于(yu)龜(gui)(gui)鱉目(Testudines)、龜(gui)(gui)科(Emydidae)、淡水龜(gui)(gui)亞科(Batagurinae)、閉(bi)殼龜(gui)(gui)屬(shu)(Cuora)。主要(yao)分布于(yu)我國(guo)的廣東、廣西、海南(nan)、福(fu)建、香港(gang)等省區及越南(nan)、老撾等東南(nan)亞國(guo)家,為(wei)我國(guo)的二級保護動物。
金錢龜是珍貴的動物資(zi)源,渾身都是寶,在藥用、觀賞、工藝制作、食用以及現代(dai)科學研(yan)究等方面都具(ju)有重要的意義和經(jing)濟價值。人們對(dui)金錢龜的需求不斷增加,但(dan)在自然(ran)界(jie)中,金錢龜由于其(qi)繁殖數量(liang)(liang)低,加上(shang)遭到人們的狂(kuang)捕(bu)濫(lan)殺,其(qi)種群數量(liang)(liang)日(ri)益下降(jiang), 在野(ye)外已(yi)難覓(mi)其(qi)蹤。
三線閉殼龜(gui)頭較(jiao)細(xi)長,頭頂部光(guang)滑無鱗,吻鈍,上喙略(lve)勾曲,喉部、頸(jing)部呈(cheng)淺橘紅(hong)色(se)(se)(se),頭兩側眼(yan)后(hou)具(ju)棱形(xing)褐斑塊。頭背部蠟(la)黃色(se)(se)(se),背甲紅(hong)棕色(se)(se)(se),有3條(tiao)(tiao)黑(hei)色(se)(se)(se)縱紋,似“川”字(zi)且中央(yang)的條(tiao)(tiao)紋較(jiao)長(幼體(ti)無),背甲前后(hou)緣光(guang)滑不呈(cheng)鋸齒狀。腹甲黑(hei)色(se)(se)(se),邊緣為(wei)黃色(se)(se)(se),背、腹甲間、胸、腹盾(dun)間均靠韌(ren)帶相連,龜(gui)殼可完全閉合。腋窩、四(si)肢(zhi)、尾(wei)部的皮膚(fu)呈(cheng)橘紅(hong)色(se)(se)(se)。指、趾間具(ju)蹼,尾(wei)短而尖細(xi)。
三(san)線(xian)(xian)閉殼(ke)龜用肺呼吸,營水、陸(lu)兩棲生(sheng)活(huo)(huo)(huo)(huo)。多生(sheng)活(huo)(huo)(huo)(huo)在(zai)(zai)山區(qu)和丘(qiu)陵地(di)帶的(de)峽谷、小溪、河叉、湖泊中(zhong),有時(shi)(shi)(shi)也(ye)爬到潮濕的(de)山澗(jian)、草叢及稻田(tian)內活(huo)(huo)(huo)(huo)動(dong)(dong)。晴(qing)朗天(tian)氣喜在(zai)(zai)陸(lu)地(di)上曬太陽,而天(tian)氣炎(yan)熱時(shi)(shi)(shi)則大部(bu)分藏于暗處,有群居(ju)、穴居(ju)習(xi)性。三(san)線(xian)(xian)閉殼(ke)龜屬變溫(wen)(wen)動(dong)(dong)物,其(qi)活(huo)(huo)(huo)(huo)動(dong)(dong)直(zhi)接受外界溫(wen)(wen)度(du)(du)(du)的(de)影響(xiang),適宜的(de)生(sheng)長溫(wen)(wen)度(du)(du)(du)為(wei)(wei)24~32℃,致(zhi)死高(gao)(gao)溫(wen)(wen)為(wei)(wei)45℃,致(zhi)死低溫(wen)(wen)為(wei)(wei)4℃。當環境溫(wen)(wen)度(du)(du)(du)達到23~28℃時(shi)(shi)(shi),活(huo)(huo)(huo)(huo)動(dong)(dong)頻繁;在(zai)(zai)水溫(wen)(wen)29~31℃時(shi)(shi)(shi)活(huo)(huo)(huo)(huo)躍,食欲旺盛,生(sheng)長快(kuai)。當氣溫(wen)(wen)高(gao)(gao)于36℃或低于16℃時(shi)(shi)(shi),其(qi)活(huo)(huo)(huo)(huo)動(dong)(dong)量(liang)及攝(she)食量(liang)明顯減少(shao)。在(zai)(zai)高(gao)(gao)溫(wen)(wen)季(ji)節,多集中(zhong)在(zai)(zai)夜晚及早晨較涼爽的(de)時(shi)(shi)(shi)候活(huo)(huo)(huo)(huo)動(dong)(dong),飽食后則潛(qian)入水中(zhong)或隱藏在(zai)(zai)窩內作短時(shi)(shi)(shi)夏(xia)眠(mian)(mian)。氣溫(wen)(wen)低時(shi)(shi)(shi),其(qi)活(huo)(huo)(huo)(huo)動(dong)(dong)多在(zai)(zai)中(zhong)午(wu)進行。在(zai)(zai)溫(wen)(wen)度(du)(du)(du)下降至10~15℃左右時(shi)(shi)(shi),三(san)線(xian)(xian)閉殼(ke)龜進入冬眠(mian)(mian),華南(nan)地(di)區(qu)每年(nian)12月至翌年(nian)2月為(wei)(wei)三(san)線(xian)(xian)閉殼(ke)龜的(de)冬眠(mian)(mian)期,至3月初(chu)開始(shi)離(li)窩尋食。三(san)線(xian)(xian)閉殼(ke)龜性情溫(wen)(wen)和,不咬(yao)人,同(tong)類很少(shao)互相攻擊,遇敵害僅有躲避(bi)能力而無反擊能力。
三線閉殼龜屬雜食(shi)性,在(zai)野(ye)外覓食(shi)各種水生動物如魚蝦(xia)等,也(ye)采食(shi)少量(liang)野(ye)菜、野(ye)果,喜歡采食(shi)蚯(qiu)蚓、蜂蛹(yong)及動物內臟等。人工養殖時,以肉(rou)食(shi)性為主,也(ye)可用蛋白含量(liang)在(zai)40%左右的(de)全價配合餌(er)料投喂。
性成熟年(nian)齡與性別鑒定(ding)
龜類性(xing)(xing)(xing)成(cheng)熟年齡(ling)因性(xing)(xing)(xing)別(bie)不同而有差異。野(ye)生三線閉殼龜雌龜的性(xing)(xing)(xing)成(cheng)熟年齡(ling)為6~7齡(ling),體(ti)重1.25~1.50kg;雄龜的性(xing)(xing)(xing)成(cheng)熟年齡(ling)為4~5齡(ling),體(ti)重0.70~1.00kg。在人工養殖(zhi)(zhi)環境(jing)中,雌龜的性(xing)(xing)(xing)成(cheng)熟年齡(ling)為7齡(ling),雄龜為4~5齡(ling)。性(xing)(xing)(xing)成(cheng)熟的三線閉殼龜雌性(xing)(xing)(xing)個體(ti)的泄殖(zhi)(zhi)孔內緣僅到達背(bei)殼后緣,尾較(jiao)粗(cu)短;雄性(xing)(xing)(xing)個體(ti)的泄殖(zhi)(zhi)孔內緣超出背(bei)殼后緣,尾較(jiao)細長。
發情與產卵
三線(xian)閉殼(ke)龜(gui)的發情(qing)和交配(pei)時(shi)間(jian)均(jun)在每(mei)年(nian)的春(chun)季(ji)和秋季(ji),氣溫在20~28℃、水溫在16~25℃范(fan)圍(wei)內,三線(xian)閉殼(ke)龜(gui)均(jun)有交配(pei)行(xing)為。而在廣州(zhou)地(di)區,雌、雄(xiong)龜(gui)一(yi)般(ban)在每(mei)年(nian)的秋季(ji)發情(qing)和交配(pei)。交配(pei)多(duo)在黃昏后(hou),并在水中(zhong)(zhong)完(wan)(wan)成(cheng)。交配(pei)時(shi)間(jian)持續約20min。三線(xian)閉殼(ke)龜(gui)在人工(gong)養殖(zhi)環(huan)境中(zhong)(zhong),在氣溫25~35℃范(fan)圍(wei)內均(jun)能自(zi)然(ran)產(chan)卵(luan),產(chan)卵(luan)一(yi)般(ban)在每(mei)年(nian)的5~9月進行(xing),高(gao)峰(feng)期在6月中(zhong)(zhong)旬至(zhi)7月底。雌龜(gui)多(duo)在傍晚上岸尋找適宜的產(chan)卵(luan)場所(suo),并常在靠近(jin)水邊的樹根旁、土(tu)質松軟處(chu)用后(hou)肢挖窩產(chan)卵(luan),窩深(shen)70~100mm、直徑50~60mm、呈瓶頸狀(zhuang)。雌龜(gui)產(chan)完(wan)(wan)卵(luan)后(hou)再用后(hou)肢和腹部將卵(luan)用沙土(tu)壓平,然(ran)后(hou)自(zi)行(xing)離開(kai),具無護卵(luan)習性(xing),與黃喉擬水龜(gui)(Mauremys mutica Cantor)的產(chan)卵(luan)習性(xing)相(xiang)似。三線(xian)閉殼(ke)龜(gui)每(mei)年(nian)產(chan)卵(luan)1~2次,每(mei)次1~9枚(mei),平均(jun)3.6枚(mei)。
長(chang)期(qi)以來(lai),將產于(yu)廣東(dong)、廣西、海南及(ji)越南等地的(de)(de)(de)背(bei)甲(jia)棕紅(hong)色(se)(se)(se),具3條黑色(se)(se)(se)條紋,腹甲(jia)黑色(se)(se)(se),腋部(bu)(bu)(bu)(bu)和胯部(bu)(bu)(bu)(bu)橘(ju)紅(hong)色(se)(se)(se),頭背(bei)部(bu)(bu)(bu)(bu)蠟黃(huang)色(se)(se)(se),喉部(bu)(bu)(bu)(bu)、頸部(bu)(bu)(bu)(bu)淺橘(ju)黃(huang)色(se)(se)(se)的(de)(de)(de)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)稱(cheng)(cheng)為(wei)(wei)三線(xian)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui),即金錢龜(gui)(gui)(gui)。但部(bu)(bu)(bu)(bu)分(fen)專(zhuan)家認(ren)為(wei)(wei),金錢龜(gui)(gui)(gui)包括2種(zhong)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui),即三線(xian)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)(Cuora trifasciata也稱(cheng)(cheng)中國三線(xian)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui))和圓(yuan)(yuan)(yuan)(yuan)(yuan)麗(li)(li)(li)(li)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)(Cuora cyclornata也稱(cheng)(cheng)越南三線(xian)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui))。三線(xian)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)的(de)(de)(de)頭部(bu)(bu)(bu)(bu)呈(cheng)(cheng)金黃(huang)色(se)(se)(se),腹甲(jia)為(wei)(wei)黑色(se)(se)(se);而(er)圓(yuan)(yuan)(yuan)(yuan)(yuan)麗(li)(li)(li)(li)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)的(de)(de)(de)頭部(bu)(bu)(bu)(bu)為(wei)(wei)灰色(se)(se)(se),腹甲(jia)淡(dan)(dan)黃(huang)色(se)(se)(se),前(qian)半(ban)部(bu)(bu)(bu)(bu)呈(cheng)(cheng)米字(zi)上(shang)半(ban)部(bu)(bu)(bu)(bu)形狀(zhuang)或呈(cheng)(cheng)黑色(se)(se)(se)蘑(mo)菇狀(zhuang)斑(ban)紋。三線(xian)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)的(de)(de)(de)背(bei)甲(jia)中央(yang)較(jiao)(jiao)隆(long)起,外形呈(cheng)(cheng)長(chang)矩(ju)形,后(hou)部(bu)(bu)(bu)(bu)最(zui)寬;而(er)圓(yuan)(yuan)(yuan)(yuan)(yuan)麗(li)(li)(li)(li)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)的(de)(de)(de)背(bei)甲(jia)較(jiao)(jiao)平坦,呈(cheng)(cheng)卵圓(yuan)(yuan)(yuan)(yuan)(yuan)形,中部(bu)(bu)(bu)(bu)最(zui)寬,其(qi)腋部(bu)(bu)(bu)(bu)和胯部(bu)(bu)(bu)(bu)更鮮(xian)紅(hong),具有(you)更美麗(li)(li)(li)(li)的(de)(de)(de)外表,故(gu)稱(cheng)(cheng)圓(yuan)(yuan)(yuan)(yuan)(yuan)麗(li)(li)(li)(li)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)(其(qi)種(zhong)名(ming)cyclornata中的(de)(de)(de)cycl是從希(xi)臘單詞“kyklos”轉化而(er)來(lai),意(yi)(yi)為(wei)(wei)圓(yuan)(yuan)(yuan)(yuan)(yuan)的(de)(de)(de);ornata來(lai)自(zi)(zi)于(yu)拉(la)丁(ding)語“ornatus”,意(yi)(yi)為(wei)(wei)華麗(li)(li)(li)(li)的(de)(de)(de))。三線(xian)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)的(de)(de)(de)種(zhong)名(ming)trifasciata則來(lai)自(zi)(zi)拉(la)丁(ding)字(zi)母tria(表示(shi)三的(de)(de)(de)意(yi)(yi)思)和fascia(表示(shi)條紋的(de)(de)(de)意(yi)(yi)思)。圓(yuan)(yuan)(yuan)(yuan)(yuan)麗(li)(li)(li)(li)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)又(you)可分(fen)為(wei)(wei)2個(ge)亞(ya)(ya)(ya)(ya)種(zhong),即圓(yuan)(yuan)(yuan)(yuan)(yuan)麗(li)(li)(li)(li)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)指(zhi)名(ming)亞(ya)(ya)(ya)(ya)種(zhong)(Cuora cyclornata cyclornata,又(you)稱(cheng)(cheng)為(wei)(wei)越南三線(xian)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)指(zhi)名(ming)亞(ya)(ya)(ya)(ya)種(zhong))和圓(yuan)(yuan)(yuan)(yuan)(yuan)麗(li)(li)(li)(li)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)梅氏亞(ya)(ya)(ya)(ya)種(zhong)(Cuora cyclornata meieri,又(you)稱(cheng)(cheng)為(wei)(wei)越南三線(xian)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)邁氏亞(ya)(ya)(ya)(ya)種(zhong))。其(qi)主要(yao)區別是圓(yuan)(yuan)(yuan)(yuan)(yuan)麗(li)(li)(li)(li)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)指(zhi)名(ming)亞(ya)(ya)(ya)(ya)種(zhong)的(de)(de)(de)背(bei)甲(jia)為(wei)(wei)圓(yuan)(yuan)(yuan)(yuan)(yuan)形,較(jiao)(jiao)平坦;下(xia)頜(he)橙色(se)(se)(se);腹甲(jia)前(qian)半(ban)部(bu)(bu)(bu)(bu)呈(cheng)(cheng)米字(zi)上(shang)半(ban)部(bu)(bu)(bu)(bu)形狀(zhuang),后(hou)半(ban)部(bu)(bu)(bu)(bu)黑色(se)(se)(se);邊緣淡(dan)(dan)黃(huang)色(se)(se)(se)。圓(yuan)(yuan)(yuan)(yuan)(yuan)麗(li)(li)(li)(li)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)梅氏亞(ya)(ya)(ya)(ya)種(zhong)的(de)(de)(de)背(bei)甲(jia)卵圓(yuan)(yuan)(yuan)(yuan)(yuan)形;下(xia)頜(he)白(bai)色(se)(se)(se);腹甲(jia)黑色(se)(se)(se),似蘑(mo)菇狀(zhuang)。圓(yuan)(yuan)(yuan)(yuan)(yuan)麗(li)(li)(li)(li)閉(bi)(bi)殼(ke)(ke)(ke)(ke)(ke)(ke)龜(gui)(gui)(gui)是否(fou)能訂為(wei)(wei)新(xin)種(zhong),值得進一步探討。