Klett Vera, Meyer Axel
Department of Biology, University of Konstanz, Germany.
Mol Biol Evol. 2002 Jun;19(6):865-83. doi: 10.1093/oxfordjournals.molbev.a004144.
We estimated a novel phylogeny of tilapiine cichlid fish (an assemblage endemic to Africa and the Near East) within the African cichlid fishes on the basis of complete mitochondrial NADH dehydrogenase subunit 2 (ND2) gene sequences. The ND2 (1,047 bp) gene was sequenced in 39 tilapiine cichlids (38 species and 1 subspecies) and in an additional 14 nontilapiine cichlid species in order to evaluate the traditional morphologically based hypothesis of the respective monophyly of the tilapiine and haplochromine cichlid fish assemblages. The analyses included many additional cichlid lineages, not only the so-called tilapiines, but also lineages from Lake Tanganyika, east Africa, the Neotropics and an out-group from Madagascar with a wide range of parental care and mating systems. Our results suggest, in contrast to the historical morphology-based hypotheses from Regan (1920, 1922 ), Trewavas (1983), and Stiassny (1991), that the tilapiines do not form a monophyletic group because there is strong evidence that the genus Tilapia is not monophyletic but divided into at least five distinct groups. In contrast to this finding, an allozyme analysis of Pouyaud and Agnèse (1995), largely based on the same samples as used here, found a clustering of the Tilapia species into only two groups. This discrepancy is likely caused by the difference in resolution power of the two marker systems used. Our data suggest that only type species Tilapia sparrmanii Smith (1840) should retain the genus name TILAPIA: One particular group of tilapiines (composed of genera Sarotherodon, Oreochromis, Iranocichla, and Tristramella) is more closely related to an evolutionarily highly successful lineage, the haplochromine cichlids that compose the adaptive radiations of cichlid species flocks of east Africa. It appears that the highly adaptable biology of tilapiines is the ancestral state for all African cichlids and that the more stenotypic lifestyle of the haplochromine cichlids is derived from this condition. We reconstructed the evolution of the highly variable parental care systems on the basis of the most inclusive composite phylogeny to date of the African, Neotropical, and Madagascan cichlids with special emphasis on a group of tilapiines comprising the substrate-spawning genus Tilapia, and the mouthbrooding genera Sarotherodon and OREOCHROMIS: We demonstrate several independent origins of derived mouthbrooding behaviors in the family Cichlidae.
我们基于完整的线粒体烟酰胺腺嘌呤二核苷酸脱氢酶亚基2（ND2）基因序列，估算了非洲丽鱼科鱼类中罗非鱼丽鱼（一种非洲和近东特有的鱼类组合）的新系统发育关系。对39种罗非鱼丽鱼（38个物种和1个亚种）以及另外14种非罗非鱼丽鱼物种的ND2（1047 bp）基因进行了测序，以评估基于传统形态学的关于罗非鱼丽鱼组合和帚齿丽鱼组合各自单系性的假说。分析纳入了许多其他丽鱼科谱系，不仅包括所谓的罗非鱼，还包括来自东非坦噶尼喀湖的谱系、新热带地区的谱系以及来自马达加斯加的一个外类群，这些谱系具有广泛的亲代抚育和交配系统。我们的结果表明，与Regan（1920年、1922年）、Trewavas（1983年）和Stiassny（1991年）基于历史形态学的假说相反，罗非鱼并不构成一个单系类群，因为有强有力的证据表明罗非鱼属不是单系的，而是至少分为五个不同的类群。与此发现相反，Pouyaud和Agnèse（1995年）的一项等位酶分析（很大程度上基于与本文相同的样本）发现罗非鱼物种仅聚为两个类群。这种差异可能是由所使用的两种标记系统的分辨率能力差异导致的。我们的数据表明，只有模式种罗非鱼（Tilapia sparrmanii Smith，1840年）应保留罗非鱼属名：罗非鱼的一个特定类群（由帚齿罗非鱼属、奥利亚罗非鱼属、伊朗丽鱼属和三角丽鱼属组成）与一个进化上非常成功的谱系——构成东非丽鱼物种群适应性辐射的帚齿丽鱼更为密切相关。看来罗非鱼高度适应的生物学特性是所有非洲丽鱼的祖先状态，而帚齿丽鱼更狭域的生活方式是从这种状态衍生而来的。我们基于迄今为止非洲、新热带地区和马达加斯加丽鱼最全面的综合系统发育关系，重建了高度可变的亲代抚育系统的演化，特别强调了一组罗非鱼，包括在底物上产卵的罗非鱼属以及口育的帚齿罗非鱼属和奥利亚罗非鱼属：我们证明了丽鱼科中衍生口育行为的几个独立起源。
