Data from: Mitochondrial and morphological variation of Tilapia zillii in Israel

BACKGROUND: Tilapia zillii is widespread in the East Levant inland aquatic systems as well as in artificial water reservoirs. In this study we explore the genetic and morphological variation of this widespread species, using mitochondrial control-region sequences and meristic characters. We examine the hypothesis that T. zilli's population structure corresponds to the four Israeli aquatic systems. RESULTS: Out of seven natural water bodies, only two were found to possess genetically divergent populations of T. zillii. In addition to its presence in fish farms, the species was found in two artificial recreational ponds which were supposed to have been stocked only with other fish species. In these two artificial habitats, the haplotype frequencies diverged significantly from those of natural populations. Finally, fish from the Dead Sea springs of Ne'ot HaKikar appear to differ both genetically and morphologically from fish of the same aquatic system but not from fish of other water systems. CONCLUSIONS: Our results show that the population structure of T. zillii does not match the geography of the Israeli water-basins, with the exception of the Dead Sea and Kishon River, when considering natural populations only. The absence of a significant divergence between basins is discussed. Our results and observations suggest that the Ne'ot HaKikar Dead Sea population and those of artificial ponds could have originated from the "hitchhiking" of T. zillii, at the expense of some other cultivated tilapiine species.

研究背景：齐氏非鲫（Tilapia zillii）广泛分布于东黎凡特内陆水生系统及人工蓄水水库。本研究采用线粒体控制区序列与分节可数性状，对该广布物种的遗传与形态变异展开探究，并验证“齐氏非鲫的种群结构与四个以色列水生系统相匹配”这一假说。

研究结果：本次调查涵盖7个自然水体，其中仅2个水体存在遗传分化的齐氏非鲫种群。除水产养殖场外，该物种还在2座原本仅投放其他鱼类的人工休闲池塘中被发现；这两处人工生境的单倍型频率与自然种群存在显著差异。最后，内奥特哈基卡尔（Ne'ot HaKikar）死海泉域的齐氏非鲫个体，在遗传与形态特征上均与同一水生系统内的其他个体存在差异，但与其他水系的个体无显著分化。

研究结论：仅考虑自然种群时，齐氏非鲫的种群结构与以色列流域的地理分布并不匹配，仅死海与基顺河（Kishon River）流域除外。本研究对流域间未出现显著分化的现象进行了讨论。综合研究结果与观测数据可知，内奥特哈基卡尔死海种群及人工池塘种群，可能是通过搭便车方式伴随其他养殖罗非亚科物种一同被引入的齐氏非鲫种群。