臺灣東北角潮間帶海藻相組成與端足類群聚時間變動之關係

Abstract

端足類為小型無脊椎動物，利用海藻當作食物來源及庇護所。其種類組成與 數量變動會受到海藻季節性變動與空間分布影響。本論文調查時間從 2013 年 1 月 到 2014 年 2 月，逐月採集台灣東北角澳底與龍洞潮間帶海域常見大型海藻及其附 生端足類，探討端足類物種組成、豐度與族群結構的季節變動及其與大型海藻之 關係。結果顯示，石蓴、裂片石蓴、滸苔與異邊孢藻為澳底與龍洞地區潮間帶的 主要藻種，石蓴科海藻主要分布於冬季與春季，而異邊孢藻全年都有出現。在這 些常見海藻中，共發現 8075 隻端足類，分屬於 33 分類單元，其數量在春天達到 高峰，其組成有明顯的分群，大致可分為三群: (1) 春天與冬天群，以 Platorchestia sp. 1 及 Ampithoe sp. 1 為優勢物種；(2) 夏天群，以 Paracorophium sp. 1 為優勢物 種； (3) 秋天群，以 Paracorophium sp. 1 與其他種類為主。此外，主要端足類物 種的族群結構也呈現季節性變動，Platorchestia sp. 1 與 Ampithoe sp. 1 的抱卵個體 主要分布於冬季與春季，此季節的石蓴科海藻數量豐富，可提供其生殖所需的資 源；Paracorophium sp. 1 的幼體與抱卵個體一整年都有出現，推測其可能利用石蓴 與異邊孢藻作為棲所，並以附生生物為食，以維持其族群量。本研究結果顯示台 灣東北角潮間帶端足類的物種多樣性高，其豐度、種類組成及族群結構變動與海 藻的季節性變動及端足類生活史特徵相關。

Amphipods are mesograzers using macroalgae as food and habitat. Due to their close associations, the amphipods assemblages may be influenced by the seasonal variations of macroalgal flora. In this study, the macroalgae and associated amphipods at the intertidal zones of Aodi and Longdong in northeastern Taiwan were sampled monthly for 14 months from January 2013 to February 2014. The results showed that Ulva lactuca, U. fasciata, Ulva spp. (=Enteromorpha) and Marginisporum aberrans were the most abundant macroalgal species at both sites, and they had a clear seasonal variation. A total of 8,075 individuals representing 33 amphipod taxa were collected from both sites. The amphipod assemblages were associated with seasonal macroalgal flora at both sites and could be classified into three groups: (1) the winter and spring groups (dominated by Ampithoe sp. 1 and Platorchestia sp. 1); (2) the summer group (Paracorophium sp. 1); (3) the fall group (Paracorophium sp. 1 and other species). The winter and spring groups were mainly associated with the presence of Ulvaceae and they possibly utilized the green algae for food and shelter. The summer and fall groups were mainly associated with M. aberrans. The juveniles and pregnant individuals of Paracorophium sp. 1 appeared throughout the year and they might use all macroalgae as habitats. This study demonstrated that the temporal variation of amphipod assemblages were possibly determined by the interactions between seasonal pattern of macroalgal flora and the life history traits of amphipods