The Mediterranean Sea is a biodiversity hotspot, being home to a vast array of marine species. Furthermore, seawater warming is facilitating the arrival and spread of new thermophilic species, posing a severe threat to biodiversity. Among the species currently extending their range and increasing in abundance in Mediterranean waters, sea chubs (genus Kyphosus) are one of the most enigmatic. One challenge arises from the high phenotypic similarity between the two congeneric species documented in the basin: Kyphosus vaigiensis and Kyphosus sectatrix. Their resemblance has often led to identification challenges, resulting in incorrect or omitted species-level classifications. Therefore, despite the growing presence of these fish in the Mediterranean, it remains unclear whether only one or both species are experiencing a demographic increase and range extension. To date, there have been 26 reports of Kyphosus individuals in the Mediterranean Sea, documented in 24 separate papers. Here, we reviewed the history of the genus in the basin and provided 13 new records of these fish from multiple localities along Mediterranean coasts. In addition, we sequenced the entire mitogenomes of two specimens, assessed their phylogenetic relationships with published Kyphosus mitochondrial DNAs from around the world, and conducted detailed morphological and meristic analyses on one of them, allowing us to provide accurate species-level identifications. Our results indicate that K. vaigiensis is the species currently expanding its range in the Mediterranean Sea, while K. sectatrix is still very rare and only sporadically reported. Notably, our mitogenome data indicate that Mediterranean K. vaigiensis individuals most likely came from Atlantic waters, while there is no evidence to support an entrance through the Red Sea or any other anthropogenic vector. Finally, the potential ecological and fishing impacts associated with the proliferation of these fish in the region are discussed.

中文翻译：

---

地中海脊椎后凸编年史：新记录和完整的线粒体基因组支持一种鱼类不断扩张的情况


地中海是生物多样性热点地区，是大量海洋物种的家园。此外，海水变暖正在促进新的嗜热物种的到来和传播，对生物多样性构成严重威胁。目前在地中海水域扩大其活动范围并增加数量的物种中，海鲢（属脊柱后凸）是最神秘的之一。盆地中记录的两个同属物种之间的高度表型相似性带来了一项挑战：驼背蝾螈和后凸蜂。它们的相似性常常导致识别挑战，导致物种级别分类不正确或被遗漏。因此，尽管这些鱼类在地中海的数量不断增加，但目前尚不清楚是否只有一种或两种鱼类正在经历种群数量的增加和活动范围的扩大。截至目前，已接到26起举报脊柱后凸地中海的个体，记录在 24 篇单独的论文中。在这里，我们回顾了该属在该盆地的历史，并提供了来自地中海沿岸多个地点的 13 条该鱼的新记录。此外，我们对两个样本的整个线粒体基因组进行了测序，评估了它们与已发表的系统发育关系脊柱后凸来自世界各地的线粒体 DNA，并对其中之一进行了详细的形态学和分枝分析，使我们能够提供准确的物种水平鉴定。我们的结果表明威吉岬该物种目前正在地中海扩大其活动范围，而K. sectatrix仍然非常罕见，只有零星报道。 值得注意的是，我们的线粒体基因组数据表明地中海威吉岬个体最有可能来自大西洋水域，但没有证据支持通过红海或任何其他人为媒介进入。最后，讨论了与该地区这些鱼类增殖相关的潜在生态和渔业影响。