The recent colonization of south Brazil by the Azores chromis Chromis limbata
The recent colonization of south Brazil by the Azores chromis Chromis limbata
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DOI：
10.1111/jfb.13363
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发表时间：
2017-08-01
影响因子：
2
通讯作者：
Floeter, S. R.
中科院分区：
文献类型：
--
作者：
Anderson, A. B.;Salas, E. M.;Floeter, S. R.
雀鲷Chromis limbata原产于Macaronesian Archipelagos（亚速尔群岛，马德拉群岛和加那利群岛）以及塞内加尔和安哥拉之间的非洲西海岸。在2008年和2009年的夏季，该物种在巴西圣卡塔里纳州弗洛里亚诺波利斯的坎佩切和泽维尔群岛附近的西南大西洋首次被记录。这里，C. limbata在巴西南部沃茨的描述，使用视觉计数和遗传调查和变化的本地同源Chromis multilineata的密度也进行了调查。2009年至2014年，对两种光鳃鱼进行了水下视觉普查。收集光鳃鱼组织样本，对mtDNA控制区进行测序，并与自然范围内的mtDNA单倍型进行比较，以确认物种身份，比较遗传多样性，并推断新建立的巴西种群之间的连接。巴西C. limbata在过去5年中显著增加，并且对C.如果多线物种的数量仍然是一个悬而未决的问题，则需要更长的时间序列数据来澄清可能的相互作用。分子分析证实了物种的身份，揭示了巴西研究地点之间强大的单倍型连接，并显示与本土种群相比，巴西的遗传多样性较低，这表明很少有个体开始入侵。四种假说可以解释这一殖民事件：C。limbata是由水族馆鱼类饲养员释放的;幼虫或青少年通过船舶压载水运输;该物种沿着石油钻井平台漂流;他们通过正常的幼虫传播或沿着漂流物体自然漂流穿越大西洋。漂流假说是有利的，但所有四种可能性都是合理的，并且可能同时发生。
The damselfish Chromis limbata is native to the Macaronesian Archipelagos (Azores, Madeira and Canaries) and the western coast of Africa between Senegal and Angola. During the austral summers of 2008 and 2009 the species was recorded for the first time in the south-western Atlantic Ocean around Campeche and Xavier Islands, in Florianopolis, Santa Catarina State, Brazil. Here, the progression of C. limbata in southern Brazilian waters is described using visual counts and genetic surveys and changes in the density of the native congener Chromis multilineata were also investigated. Underwater visual censuses of both Chromis species were carried out from 2009 to 2014. Chromis limbata tissue samples were collected and the mtDNA control region was sequenced and compared with mtDNA haplotypes from the natural range to confirm species identity, compare genetic diversity and to infer connectivity between newly established Brazilian populations. The Brazilian population of C. limbata increased significantly over the past 5years and the effect on C. multilineata is still an open question, longer time-series data will be necessary to clarify possible interactions. The molecular analyses confirmed species identity, revealed strong haplotype connectivity among Brazilian study sites and showed a low genetic diversity in Brazil when compared with the native populations, suggesting few individuals started the invasion. Four hypotheses could explain this colonizing event: C. limbata was released by aquarium fish keepers; larvae or juveniles were transported via ship ballast water; the species has rafted alongside oil rigs; they crossed the Atlantic Ocean through normal larval dispersal or naturally rafting alongside drifting objects. The rafting hypotheses are favoured, but all four possibilities are plausible and could have happened in combination.