新竹市濱海野生動物保護區鴨嘴海豆芽Lingula anatina Lamarck, 1801的分類探討與棲息地特徵研究

根據形態及粒線體COI基因序列特徵將新竹市濱海野生動物保護區棲息的物種鑑定為鴨嘴海豆芽Lingula anatina Lamarck, 1801，本區目前的鴨嘴海豆芽族群是台灣西海岸溼地密度最高的群集，密集區的棲息密度每平方米達7隻，根據粒線體COI基因的分化程度，台灣新竹的鴨嘴海豆芽與日本及中國大陸的族群均有關聯，其與日本的族群遺傳距離相對較遠於台灣和大陸之間的距離。鴨嘴海豆芽在溼地若未經劇烈干擾通常會在定點固著，新竹的棲息地粒徑中值介於0.15～0.19mm之間，屬於含泥量較高的泥砂混合結構，棲地所在位置通常為較低窪且不易被侵蝕的灘地，退潮後灘地仍有水層覆蓋或是處於含水飽和的狀態。濾食維生的鴨嘴海豆芽埋藏在土中，海水掩蓋時洞口呈現三個約4－5mm之孔洞以直線排列，兩側為進水孔，中間為出水孔，當無水掩蓋時的洞口則呈現一梭狀狹口，軀體的殼瓣下潛至含水量飽和的深度。

關鍵字

腕足動物；溼地；分類；粒線體基因

並列摘要

Based on morphology and mtDNA COI gene, the brachiopod from Costal Wild Life Protection Area of HsinChu City is identified as Lingula anatina Lamarck, 1801. In this protection area, each square meter could find 7 individuals of L. anatina at high density site, it was the most populated site on wet land of west coast in Taiwan. According to the divergence of mtDNA COI gene, the L. anatina population from HsinChu Taiwan was close related to the population from Japan and China, the genetic distance between Taiwan and Japan was farther than Taiwan and China. If it was not under critical disturbance, the L. anatina would stay within substrate without large scale movement. The intermediate grain size of substrate was 0.15-0.19mm in the habitat of HsinChu, sand with some mud mixing together. In general, the substrate of their habitat was anti-erosion and could still cover by water after ebb tide or 100% saturated with water. Filter feeding L. anatina living within substrate, borrowing by shaking the shell and pulling down by contraction of pedicle. When substrate cover with water, the surface forming three small holes in line, the width of each hole about 4-5mm, each hole on later corner was inhalent, in the middle one was exhalent. When the substrate surface without water, the shell will retreat into deeper area saturated with water, only one small slit can be found on the substrate surface.