Please use this identifier to cite or link to this item: http://hdl.handle.net/11455/21606
標題: 高雄林園沿岸帆鰭茉莉之鑑種,仔魚生長,及環境鹽度適應機制之探討
Species identification, larval growth, and strategies for salinity adaptation of the sailfin molly from the coast of Lin-Yuan, Kaohsiung
作者: 楊文凱
Yang, Wen-Kai
關鍵字: 帆鰭茉莉
環境鹽度
滲透壓調節
鈉鉀幫浦
出版社: 生命科學系
摘要: 帆鰭茉莉(sailfin molly)為外來魚種,能在不同鹽度(0-35 ‰)的環境中生存,是一種廣鹽性魚類。由於帆鰭茉莉為觀賞用魚,目前的文獻與圖鑑中,對於數種外形相似,且通稱為帆鰭茉莉之魚種,種名記錄並不一致。為達到實驗之準確性,故先由外部形質測量及mitochondrial NADH dehydrogenase subunit 2(NADH2)的序列比對,進行鑑種實驗。從結果發現其外部形質與基因序列皆與茉莉花鱂(Poecilia latipinna)最為相似。茉莉花鱂為體內授精之卵胎生魚類,實驗室中觀察發現,在淡、海水中皆可進行交尾並產下仔魚。為瞭解其對環境鹽度的耐受力,進行鹽度變化轉移死亡率測試。發現在成魚方面,淡水(FW)族群可直接轉移至半淡鹹水(BW、15 ‰)中繼續存活,但是如要直接轉移至海水(SW、35 ‰),必須先在半淡鹹水中適應24小時後才能存活。反之,海水族群可直接轉移至淡水中存活下來。而仔魚方面則是在半淡鹹水與海水中出生的可直接轉移至淡水中,但在淡水中出生的直接進入海水則會在24小時內死亡超過半數。轉移後的仔魚其生長發育(體長、體重)與含水量皆與未轉移的控制組沒有差異。進一步探討其成魚的適應機制,發現長期(超過一個月)適應在海水、半淡鹹水及淡水環境中,血液滲透壓與氯離子會隨著環境鹽度而增加,而其肌肉含水量(MWC)及血液鈉離子皆無顯著性差異。在調控機制中,鰓的Na+, K+-ATPase(NKA)活性以淡水與半淡鹹水中的個體最低,耗能最少;而Na+, K+-ATPase免疫反應細胞(Na+, K+-ATPase immunoreactive cells)則與Na+, K+-ATPase活性有相似的趨勢,在半淡鹹水中的個體最少。 結果顯示:(1)高雄林園沿岸之帆鰭茉莉其種名為茉莉花鱂(Poecilia latipinna);(2)不論成魚或仔魚,適應海水環境的族群其鹽度耐受力廣於適應淡水環境的族群;(3)由肌肉含水量與血液分析的結果顯示,其滲透壓調節機制相當有效率,才能在不同鹽度環境中仍能維持體內恆定;(4)在血糖方面則呈現與環境鹽度正相關的表現,顯示其在海中所受到的逆境壓力大於在淡水之中;(5)在淡水及半淡鹹水(15 ‰)下的Na+, K+-ATPase活性最低,顯示生活於淡水與半淡鹹水的帆鰭茉莉較不需要以Na+, K+-ATPase進行離子調節。
Sailfin molly, an exotic fish in Taiwan, is an euryhaline teleost which can survive in either freshwater or seawater environments. Because the mollies are aquarium fish, they have a few variations in appearance. In order to achieve accuracy of the experiment, we performed measuring morphometric characters and contrasting the sequences of mitochondrial NADH dehydrogenase subunit 2 (NADH2) to identify species. The results indicated that the sailfin molly is the most similar with Poecilia latipinna. Sailfin molly is ovoviviparous fish, and it can reproduce in fresh water and seawater in laboratory. To test the salinity tolerance, the adult sailfin molly can be transferred directly from freshwater (FW) to brackish water (BW, 15 ‰) or from seawater (SW, 35 ‰) to FW without mortality. Also, the FW group was transferred to SW without mortality when transferred to BW for 24 hrs prior to SW. On the other hand, the larvae born in BW or SW can be transferred directly to FW without mortality, but those born in FW were found over 50 % mortality in 24 hrs after transfer to SW. Water contents, body length, and body weight of larvae of transferred groups did not reveal significant difference compared to control groups. Plasma analyses showed that the osmolality, [Cl-], and [glucose] correlated positively with environmental salinity; but [Na+] as well as the muscle water contents (MWC) did not show significant difference among experimental groups. The Na+, K+-ATPase (NKA) activity of gills of FW and BW groups are significantly lower than the SW group, and the number of Na+, K+-ATPase immunoreactive (NKIR) cells of BW group is less than the SW group. The results revealed that: (1) the sailfin molly from Lin-Yuan, Kaohsiung is Poecilia latipinna; (2) in larvae or adult, the SW group have wider salinity tolerance than the FW group; (3) the analyses of MWC and plasma showed the effective osmoregulatory mechanism for osmoregulatory balance in different salinities; (4) the lowest NKA activity in the FW and BW groups indicates sailfin molly inhabiting in FW and BW (15 ‰) needs less ionic regulation by NKA.
URI: http://hdl.handle.net/11455/21606
Appears in Collections:生命科學系所

文件中的檔案:

取得全文請前往華藝線上圖書館



Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.