福建海域海地瓜(Acaudina molpadioides)形态特征及系统发育的初步分析

Morphological characteristics and phylogenetic analysis of the sea cucumber Acaudina molpadioides in Fujian coastal waters

本研究应用形态学和分子生物学方法对福建海域的一种海参——海地瓜(Acaudina molpadioides)进行了观察和分析,描述了海地瓜的骨片、触手、石灰环、波里氏囊、呼吸树、性腺等重要特征。观察到的骨片类型有哑铃体、颗粒体、杆状体、C形体、穿孔板和环形体,数量上以哑铃体为主。与之前的报道相比,颗粒体和C形体是两种新观察到的骨片类型。获得了一段海地瓜的mtCOⅠ基因片段序列(长度为596 bp),基于mtCOⅠ序列的系统发育树(NJ树、ML树和Bayes树)在一定程度上支持了海地瓜属于海参纲芋参目尻参科物种的分类地位。将该序列与GenBank中已收录的4条海地瓜mtCOⅠ序列(登录号:MK050109、EU827691、FJ971405.KX874336)进行了遗传距离分析,结果显示MK050109序列样本与本研究样本为相同物种,即海地瓜,其余3条mtCOⅠ序列的物种命名还需要进一步论证。

The sea cucumber Acaudina molpadioides from Fujian was observed and analyzed with morphological and molecular biological methods.The characteristics of spicules,tentacles,calcareous ring,Polian vesicle,respiratory tree and gonad were described.The spicules had types of dumbbell,granule,rod,C-form,perforated plate and ring,most of which was dumbbell.Comparing with the previous reports,the granule and C-form were two newly observed spicule types.A partial sequence(596 bp in length)of mtCOⅠ gene of A.molpadioides was obtained.To some extent,the phylogenetic tree(NJ tree,ML tree and Bayes tree)based on mtCOⅠ sequences supported A.molpadioides belonging to the family Caudinidae,order Molpadida,class Holothuroidea.Our sequence was compared with four mtCOⅠ sequences of A.molpadioides from GenBank(accession number:MK050109,EU827691,FJ971405,KX874336),and the genetic distances between these sequences were calculated.Results showed that the sample of sequence MK050109 was the same species(A.molpadioides)as the sample in this study,however,the naming of other three mtCOⅠ sequences needs further verification.