Dataset: First record of bioluminescence in a sipunculan worm

During a search for bioluminescent marine annelids around the island of Carrie Bow Cay, Belize, we discovered bioluminescence in the sipunculan worm Nephasoma pellucidum. The identification of N. pellucidum was verified by DNA barcoding of ~650 bp of the mitochondrial cytochrome c oxidase I gene, using sequences of the same species from previous studies as references. Our study constitutes the first record of a bioluminescent sipunculan species. Green luminescence was detected in four of the five individuals of N. pellucidum collected from coral rubble from a shallow reef flat and one deeper (14 m) site. To test for bioluminescent activity, all collected annelids (including sipunculans) were sorted into morphotypes and identified to the lowest taxonomic level possible. After several hours of dark adaptation, they were mechanically stimulated, and luminescent reactions were noted and recorded by photography and/or video whenever possible. Of a total of nine examined sipunculan species, N. pellucidum was the only one that showed bioluminescent activity. The underlying biochemical processes for the bioluminescence are so far unknown, but transcriptome data indicate the presence of proteins with similarities to Renilla-type luciferases. We did not find similarities to any known photoproteins. Our findings broaden the known diversity of bioluminescent annelid taxa and support the notion that bioluminescence arose multiple times in annelids. The bioluminescent properties of N. pellucidum add a new reason to pursue this species as a model species, as has been previously proposed.在伯利兹Carrie Bow凯岛周边海域开展发光海洋环节动物（annelids）调查期间，我们在星虫类（sipunculans）蠕虫透明肾形星虫（Nephasoma pellucidum）中发现了生物发光（bioluminescence）现象。本研究通过对线粒体细胞色素c氧化酶亚基I（mitochondrial cytochrome c oxidase I, COI）基因约650 bp片段的DNA条形码（DNA barcoding）技术，以既往研究中该物种的序列作为参照，验证了透明肾形星虫的物种鉴定结果。本研究首次报道了具有生物发光特性的星虫类物种。 在采自浅礁坪珊瑚碎屑及一处水深14米的深水采样点的5尾透明肾形星虫样本中，有4尾检测到绿色生物发光。为检测生物发光活性，研究人员将所有采集到的环节动物（包括星虫类）按形态型进行分类，并尽可能鉴定至最低分类阶元。经过数小时的暗适应后，对样本进行机械刺激，记录发光反应，并在条件允许时通过摄影及/或录像进行留存。在总计检测的9种星虫类物种中，透明肾形星虫是唯一表现出生物发光活性的物种。 目前该生物发光现象的潜在生化机制尚不明确，但转录组（transcriptome）数据显示其存在与海肾（Renilla）型荧光素酶（luciferases）具有同源性的蛋白质，未发现其与任何已知光蛋白（photoproteins）存在同源性。本研究结果拓宽了已知发光环节动物类群的多样性，并支持环节动物类群中生物发光现象多次独立起源的学术观点。正如此前研究所提出的，透明肾形星虫的生物发光特性为将该物种作为模式物种（model species）开展研究提供了新的佐证。