台灣潮間帶圍胸總目藤壺及珊瑚共生之尖胸總目藤壺之幼體發展及生態學之研究

Larval development and ecology of intertidal thoracican barnacles and coral associated acrothoracican barnacles in Taiwan

蔡沛哲(Pei-Che Tsai)

指導教授 ： 陳國勤

國立臺灣大學/生命科學院/生態學與演化生物學研究所/碩士(2015年)

https://doi.org/10.6342/NTU.2015.01863

摘要

藤壺之生活史中具有浮游期與成體兩種階段，浮游期又包含了無節幼體和腺介幼體之兩種不同形態。藤壺成體為固著性生物，一旦附著於棲息地終其一生便無法移動，因此幼體形態和浮游期對藤壺分佈而言至關重要。浮游生物形態之鑑定使我們了解幼體期之形態特徵及幼體週期長短。故探討不同品種之幼體週期及形態發展對浮游動物生態學有舉足輕重之地位。本研究首先對於圍胸總目之黑潮笠藤壺(Tetraclita kuroshioensis)、美麗笠藤壺(T. japonica formosana)及卡氏小笠藤壺(Tetraclitella karandei)和尖胸總目之紫班氏石鑿藤壺(Berndtia purpurea)及富氏班氏石鑿藤壺(B. utinomii)的幼體做全面的形態探討，聚焦於各期的無節幼體比較和腺介幼體。本研究利用光學及掃描式電子顯微技術(SEM)描述無節幼體和腺介幼體的超微結構，將各期附肢(小觸腳、觸角和顎足)的節數和剛毛模式分佈做詳細清楚的表達。
於西太平洋黑潮笠藤壺(T. kuroshioensis)有廣泛之分佈，美麗笠藤壺(T. japonica formosana)只分佈於台灣與日本兩地。藤壺為固著性生物，因此浮游幼體期為其隨洋流播遷進而影響地理分佈的關鍵。本研究推論兩種笠藤壺幼體對溫度及鹽度的適應性不同，因而產生兩種笠藤壺在地理分佈上的差異。本研究於台灣東北角採集黑潮與美麗笠藤壺，進行幼體型態及幼體於不同溫度(20、25、30度)和鹽度(20、25、30、35‰)下發育之比較。黑潮與美麗笠藤壺幼體型態僅有泳肢之綱毛排列之細微差異，故種間型態變異不會產生游泳能力的差異。然而，飼養於溫度20度之兩種藤壺幼體於所有鹽度條件皆無法轉變為腺介幼體。兩種笠藤壺幼體週期於溫度25和30度下無太大差異，應不是造成地理分佈差異的原因。飼養於溫度溫度25和30度，各鹽度之條件下，黑潮笠藤壺第六期無節幼體數量顯著高於美麗笠藤壺。除此之外，在大部分的飼養條件下黑潮笠藤壺變態為腺介幼體之數量也顯著高於美麗笠藤壺。本研究證實黑潮笠藤壺具有較高的變態成功率和存活率，暗示黑潮笠藤壺幼體有較高的機率可在環境逆壓存活，可能因此有較廣泛之地理分佈。
本研究藉由探討幼體形態進而提供(1)西北太平洋分佈的笠藤壺科品種之間分類的新依據。(2)全球首次建立尖胸總目之石鑿藤壺科幼體完整發展週期及形態資訊，提供未來研究及分類學上的參考。(3)以幼體生態學角度釐清笠藤壺於西太平洋分佈差異之原因。

關鍵字

黑潮笠藤壺 ； 美麗笠藤壺 ； 卡氏小笠藤壺 ； 紫班氏石鑿藤壺 ； 富氏班氏石鑿藤壺 ； 溫度 ； 鹽度

並列摘要

Life cycle of barnacles is divided into two phases, with planktonic larval stage and adult sessile stage. Larval morphology and duration of larval development can affect the geographical distribution of barnacles. Examination of larval morphology and duration of larval development are important for further understanding of the larval ecology of intertidal species. The present study applied scanning electron microscope and optical microscopy techniques to examine the larval morphology of intertidal thoracican barnacles Tetraclita kuroshioensis, Tetraclita japonica formosana, Tetraclitella karandei, and the Acrothoracican barnacles Berndtia purpurea and B. utinomii.
In the west Pacific, T. kuroshioensis has a wider range of distribution than T. japonica formosana which only present in Taiwan and Japan. Planktonic larval stage is the key period for dispersal with ocean current, which can affect the geographical distribution of species. In addition variations in tolerance to environmental stress, such as temperature and salinity between two species can result in different distribution pattern. Therefore, we compared the survival of larvae of T. kuroshioensis and T. japonica formosana at different temperatures (20, 25 and 30°C) and salinity (20, 25, 30 and 35 ‰). At 20°C, both larvae cannot metamorphosis to cyprids in all salinity treatment. At 25 and 30°C, naupliar duration is not significant different between two species. Therefore, variation in naupliar developmental duration between the two species did not affect their variation in geographical distribution. There are, however, greater percentage of stage VI larvae in T. kuroshioensis than T. japonica formosana at 25 and 30°C in all salinity situation. In addition, the number of metamorphosed cyprids is higher in T. kuroshioensis in most culture conditions. T. kuroshioensis has both high survival and metamorphosis rate, suggest they can survive in more strict condition, thus implying T. kuroshioensis has wider geographical distribution. This study provides 1) extensive database on larval morphology of Tetraclitidae barnacles of the West Pacific 2) first larval study of Acrothoraicican barnacles and 3) use larval ecology aspects to examine the factors affecting the geographical distribution of Tetraclita species in the west Pacific waters.

並列關鍵字

Tetraclita kuroshioensis ； Tetraclita japonica formosans ； Tetraclitella karandei ； Berndtia purpurea ； B. utinomii ； temperature ； salinity

參考文獻

王中賢 (2012)。黑潮笠藤壺和美麗笠藤壺之生殖週期在台灣黑潮流域及東海海域的比較研究。國立台灣大學生命科學院生態學與演化生物學研究所碩士論文，p: 14。

Anderson, D. T. (1994). Barnacles: structure, function, development and evolution. Springer Science & Business Media.

Anderson, D. T., & Anderson, J. T. (1985). Functional morphology of the balanomorph barnacles Tesseropora rosea (Krauss) and Tetraclitella purpurascens (Wood)(Tetraclitidae). Marine and Freshwater Research, 36(1), 87-113.

Anil, A. C., & Kurian, J. (1996). Influence of food concentration, temperature and salinity on the larval development of Balanus amphitrite. Marine Biology, 127(1), 115-124.

Anil, A. C., Desai, D., & Khandeparker, L. (2001). Larval development and metamorphosis in Balanus amphitrite Darwin (Cirripedia; Thoracica): significance of food concentration, temperature and nucleic acids. Journal of Experimental Marine Biology and Ecology, 263(2), 125-141.