摘要
轮螺科(Architectonicidae)是一类成体螺壳右旋而面盘幼虫螺壳左旋的腹足类,其面盘幼虫在国内一直被误定为强卷螺属(Agadina)种类,归在螔螺科(Limacinidae)中。本文基于线粒体16SrRNA基因序列和胚壳的形态特征,对轮螺科面盘幼虫进行了物种鉴定。结果表明,根据胚壳壳顶和脐孔的形态特征,面盘幼虫可大致分为2种明显不同的形态类型:形态类型I的个体壳扁,壳顶凹陷,脐孔形状规则,圆而深;形态类型II的个体壳顶突出,脐孔形状不规则,浅或深,肛区龙骨有或无。GMYC(GeneralizedMixedYuleCoalescent)和ABGD(AutomaticBarcodingGapDiscovery)分析显示,轮螺科面盘幼虫16S rRNA基因的50种单倍型形成19个分子可操作分类单元(molecular operationaltaxonomic units,MOTUs),同一MOTU的幼虫具有相同的胚壳形态。其中,11个MOTUs中的幼虫属于形态类型I,8个MOTUs中的幼虫属于形态类型II。此外,不同MOTUs的面盘幼虫,其软体部黑色幼体器官(Black Larval Organ)的位置和大小也不同。根据研究结果推测,轮螺面盘幼虫的形态具有种或属特异性。轮螺科面盘幼虫单倍型形成的MOTU数量明显多于国内目前已记录的物种数,其种类多样性可能被低估。基于16SrRNA序列能直接鉴定到种的仅Psilaxisradiatus和配景轮螺(Architectonica perspectiva)2种。本文也从分子水平订正了国内长期以来的分类错误。
Species of the family Architectonicidae are a group of gastropods that shells of adults are dextral but the protoconchs of veliger larvae are sinistral.The architectonicid veliger larvae have been mis-identified as Agadina species(Limacinidae) for more than a half century in China due to their sinistral shells.In this study,we analyzed the protoconch morphological characteristics of veliger larvae and sequenced the partial mitochondrial 16 S rRNA gene from 66 veliger larvae and three adults of Architectonicidae to clarify the taxonomic debate.The veliger larvae can be divided into two morphotypes in morphology.The protoconchs of morphotype I are characterized by the sunk apex and the round and deep umbilicus.The protoconchs of morphotype II are distinguished from those of morphotype I by their raised apex and retuse umbilicus.The 50 haplotypes derived from the 16 S rRNA gene were grouped into 19 distinct molecular operational taxonomic units(MOTUs) using GMYC and ABGD analyses.Larvae of morphotype I could be assigned into 11 MOTUs,while the 8 remaining MOTUs had shell characteristics of morphotype II.The position and size of black larval organs are also distinct among different MOTUs.These results suggest that the morphological characteristics of shells and black larval organs are valuable for species and/or genus recognition.However,only a few haplotypes were identified to the species level because of the insufficient reference sequences in GenBank,and the biodiversity of Architectonicidae could be underestimated in China.
引文
刘瑞玉,中国科学院海洋研究所,2008.中国海洋生物名录.北京:科学出版社,493-494
李海涛,何薇,周鹏等,2015.伶鼬榧螺(Oliva mustelina)的分子鉴定及其形态变异.海洋学报,37(4):117-123
张福绥,1964.中国近海的浮游软体动物.I.翼足类、异足类及海蜗牛类的分类研究.海洋科学集刊,5:125-226
林森杰,王路,郑连明等,2014.海洋生物DNA条形码研究现状与展望.海洋学报,36(12):1-17
罗文增,劳柏瑄,2016.台湾海峡浮游翼足类群聚之季节动态.生物多样性,24(7):757-766
徐兆礼,2008.东海浮游翼足类(Pteropoda)环境适应类型的划分.海洋与湖沼,39(4):381-387
Baldwin C C,Mounts J H,Smith D G et al,2009.Genetic identification and color descriptions of early life-history stages of Belizean Phaeoptyx and Astrapogon(Teleostei:Apogonidae)with comments on identification of adult Phaeoptyx.Zootaxa,2008:1-22
Barber P,Boyce S L,2006.Estimating diversity of Indo-Pacific coral reef stomatopods through DNA barcoding of stomatopod larvae.Proceedings of the Royal Society B,273(1597):2053-2061
Bieler R,1993.Architectonicidae of the Indo-Pacific(Mollusca,Gastropoda).Abhandlungen des Naturwissenschaftlichen Vereins in Hamburg,30:1-376
Drummond A J,Rambaut A,2007.BEAST:bayesian evolutionary analysis by sampling trees.BMC Evolutionary Biology,7:214
Folmer O,Black M,Hoeh W et al,1994.DNA primers for amplification of mitochondrial cytochrome c oxidase subunit I from diverse metazoan invertebrates.Molecular Marine Biology and Biotechnology,3(5):294-299
Fujisawa T,Barraclough T G,2013.Delimiting species using single-locus data and the generalized Mixed Yule Coalescent approach:a revised method and evaluation on simulated data Sets.Systematic Biology,62(5):707-724.
Hirose M,Hirose E,Kiyomoto M,2015.Identification of five species of Dendrodoris(Mollusca:Nudibranchia)from Japan,using DNA barcode and larval characters.Marine Biodiversity,45(4):769-780
Ko H L,Wang Y T,Chiu T S et al,2013.Evaluating the accuracy of morphological identification of larval fishes by applying DNA barcoding.PLoS One,8(1):e53451
Levin L A,1990.A review of methods for labeling and tracking marine invertebrate larvae.Ophelia,32(1-2):115-144
Pradillon F,Schmidt A,Peplies J et al,2007.Species identification of marine invertebrate early stages by wholelarvae in situ hybridisation of 18S ribosomal RNA.Marine Ecology Progress Series,333:103-116
Puillandre N,Lambert A,Brouillet S et al,2012.ABGD,Automatic Barcode Gap Discovery for primary species delimitation.Molecular Ecology,21(8):1864-1877
Puillandre N,Strong E E,Bouchet P et al,2009.Identifying gastropod spawn from DNA barcodes:possible but not yet practicable.Molecular Ecology Resources,9(5):1311-1321
Robertson R,1964.Dispersal and wastage of larval Philippia krebsii(Gastropoda:Architectonicidae)in the north Atlantic.Proceedings of the Academy of Natural Sciences of Philadelphia,116:1-27
Robertson R,Scheltema R S,Adams F W,1970.The feeding,larval dispersal,and metamorphosis of Philippia(Gastropoda:Architectonicidae).Pacific Science,24(1):55-65
Scheltema R S,Williams I P,Lobel P S,1996.Retention around and long distance dispersal between oceanic islands by planktonic larvae of benthic gastropod mollusca.American Malacological Bulletin,12:67-75
Simon C,Frati F,Beckenbach A et al,1994.Evolution,weighting,and phylogenetic utility of mitochondrial gene sequences and a compilation of conserved polymerase chain reaction primers.Annals of the Entomological Society of America,87(6):651-701
Tesch J J,1946.The thecosomatous pteropods I.the Atlantic.Dana Report,28:1-82