鲟形目鱼类重要形态与生态特征的演化格局与适应策略  

EVOLUTIONARY PATTERN AND ADAPTIVE STRATEGIES OF KEY MORPHOLOGICAL AND ECOLOGICAL CHARACTERS IN THE ACIPENSERIFORMES

作　　者：姜明 刘焕章[2] JIANG Ming;LIU Huan-Zhang(College of Fisheries and Life Science,Dalian Ocean University,Dalian 116023,China;The Key Laboratory of Aquatic Biodiversity and Conservation,Institute of Hydrobiology,Chinese Academy of Sciences,Wuhan 430072,China)

机构地区：[1]大连海洋大学水产与生命学院,大连116023 [2]中国科学院水生生物研究所水生生物多样性与保护重点实验室,武汉430072

出　　处：《水生生物学报》2023年第12期1932-1947,I0022-I0025,共20页Acta Hydrobiologica Sinica

基　　金：国家重点研发计划(2022YFC3202404);中国科学院战略性先导科技专项(B类)(XDB31040000);中国生物多样性监测与研究网络-内陆水体鱼类多样性监测网,三峡工程运行安全综合监测系统,库区维护和管理基金(2136703)资助。

摘　　要：文章从GenBank下载得到27种鲟形目鱼类线粒体全基因组序列,以多鳍鱼为外类群,构建鲟形目鱼类分子系统树。以此为基础,采用系统发育比较方法(Phylogenetic comparative methods,PCMs)分析鲟形目鱼类的12个形态、生态特征的宏进化格局,重建祖先特征状态,分析特征的系统发育限制性,以及特征之间的相关性。结果表明,有8个特征(生活习性、身体大小、背鳍条数、臀鳍条数、背鳍后骨板数、臀鳍后骨板数、鳃耙数和卵径)的演化受到系统发育限制,说明这些特征的演化与系统发育相关,受到强烈的自然选择作用;另外有4个特征(食性、雌性初次性成熟年龄、雄性初次性成熟年龄和产卵间隔时间)的演化不受系统发育的限制,而表现为对环境的适应。祖先状态重建分析显示,鲟形目鱼类许多特征的演化格局表现为:祖先种呈现中间状态,然后分别向变大或变小两个方向演化,例如身体大小、背鳍条数、臀鳍条数和初次性成熟年龄等。在适应策略上表现为一些基础形态特征不容易发生变化,如鳃耙数和卵径等;但食性、性成熟年龄、卵径和产卵间隔时间这些生态习性特征容易发生变化,从而适应不同的环境。文章的研究结果可为理解鲟形目鱼类宏进化机制和进行物种保护提供信息。In this study,we downloaded complete mitochondrial genome sequences of 27 Acipenseriformes species,with Polypteriformes species as outgroups,to construct molecular phylogenetic trees.Based on these trees,we analyzed macroevolutionary pattern of 12 morphological and ecological traits with the phylogenetic comparative methods(PCMs),such as reconstructing ancestral character states,analyzing character phylogenetic constraints and testing the character correlations.The results showed that 8 traits such as habitat,body size,dorsal fin rays,anal fin rays,posterior dorsal fin scutes,posterior anal fin scutes,gill rakers and egg size,were phylogenetically constrained,indicating that the evolution of these characters were associated with phylogeny and strongly affected by natural selection.Four traits including diets,female first maturity age,male first maturity age and spawning interval,showed no phylogenetic signals,indicating their adaptations to the environments.Reconstruction of ancestral character states showed that many Acipenseriformes species exhibited a pattern of evolution from the intermediate state of ancestral species evolving to two directions:becoming larger and smaller respectively.For example,body size,dorsal fin rays,anal fin rays,first maturity age all showed this pattern.For the adaptive strategies,the Acipenserformes showed the constraints of some morphological characters such as gill rakers,egg size and the flexible adaptations to different environments for the coordinating ecological characters such as diets,first maturity age,egg size,spawning interval.Results of this study can provide valuable information for understanding macroevolutionary pattern of the Acipenseriformes and give hints for species conservation.

关 键 词：鲟形目 特征演化 系统发育信号 宏进化 祖先状态重建 适应策略 

分 类 号：Q951.3[生物学—动物学]