METHODS: On the basis of a citizen science project, we received observations in the field, photographs and specimens from non-professionals and local scientists in Martinique and Guadeloupe. We barcoded (COI) specimens from both islands and studied the histology of the reproductive organs of one specimen. Based on Next Generation Sequencing, we obtained the complete mitogenome of A. expatria and some information on its prey from contaminating DNA.
RESULTS: We add records from 2006 to 2019 in two French islands of the Caribbean arc, Guadeloupe (six records) and Martinique (14 records), based on photographs obtained from citizen science and specimens examined. A specimen from Martinique was studied for histology of the copulatory organs and barcoded for the COI gene; its anatomy was similar to the holotype, therefore confirming species identification. The COI gene was identical for several specimens from Martinique and Guadeloupe and differed from the closest species by more than 10%; molecular characterisation of the species is thus possible by standard molecular barcoding techniques. The mitogenome is 14,962 bp in length and contains 12 protein coding genes, two rRNA genes and 22 tRNA genes; for two protein genes it was not possible to determine the start codon. The mitogenome was compared with the few available mitogenomes from geoplanids and the most similar was Obama nungara, a species from South America. An analysis of contaminating DNA in the digestive system suggests that A. expatria preys on terrestrial molluscs, and citizen science observations in the field suggest that prey include molluscs and earthworms; the species thus could be a threat to biodiversity of soil animals in the Caribbean.
方法:在公民科学项目的基础上,我们收到了现场的观察,马提尼克岛和瓜德罗普岛的非专业人士和当地科学家的照片和标本。我们对来自两个岛屿的(COI)标本进行了条形码化,并研究了一个标本的生殖器官的组织学。基于下一代测序,我们从污染的DNA中获得了A.expatria的完整有丝分裂基因组和一些有关其猎物的信息。
结果:我们在加勒比海弧的两个法国岛屿中添加了2006年至2019年的记录,瓜德罗普岛(六项记录)和马提尼克岛(14项记录),根据从公民科学和标本检查获得的照片。对马提尼克岛的标本进行了交配器官的组织学研究,并对COI基因进行了条形码化;它的解剖结构与整型相似,从而确认物种鉴定。马提尼克岛和瓜德罗普岛的几个标本的COI基因相同,与最接近的物种相差10%以上;因此,通过标准分子条形码技术可以对物种进行分子表征。有丝分裂基因组长度为14,962bp,包含12个蛋白质编码基因,两个rRNA基因和22个tRNA基因;对于两个蛋白质基因,不可能确定起始密码子。将有丝分裂基因组与来自地平面的少数可用的有丝分裂基因组进行了比较,最相似的是奥巴马·南加拉,一种来自南美洲的物种。对消化系统中污染DNA的分析表明,外籍人士捕食陆生软体动物,该领域的公民科学观察表明,猎物包括软体动物和earth;因此,该物种可能对加勒比海土壤动物的生物多样性构成威胁。