In Mexico, the study of the class Cubozoa has been limited. Most studies have addressed ecological or toxicological issues. In Mexican territory, Carybdea marsupialis (Linnaeus, 1758) has been historically reported off the Caribbean and the southern Gulf of Mexico. This species, however, was recently established as the Mediterranean type species, while C. xaymacana Conant, 1897 was established as that of the Caribbean region. Despite this, C. xaymacana is not reported in the last checklists of Mexican medusozoans. Thus, the taxonomic identity of Mexican populations remains uncertain. Herein, we report the occurrence of C. xaymacana off Mexican coasts and provide the first morphological description for Mexican populations. Specimens were collected in the northeast of the Mexican Caribbean. The species was defined based on the shape, structure, and features of the phacellae, pedalia, and velarial canals. This record has important implications for the creation of jellyfish stings protocols since there exist reports of the Irukandji syndrome occurring in the Caribbean in adjacent zones to the study area, and this species has been associated with this syndrome. The present study evidences the importance of conducting more taxonomical research on the cubozoans from Mexico in order to clarify the identity of other possible misidentified species and make new records in the area, which would contribute to having a clearer picture of the cubozoan diversity in Mexico.

在墨西哥，对立方水兽纲的研究很有限。大多数研究都解决了生态或毒理学问题。在墨西哥境内，Carybdea marsupialis (Linnaeus, 1758) 历史上曾在加勒比海和墨西哥湾南部发现过。然而，该物种最近被确定为地中海类型物种，而C. xaymacana Conant, 1897 被确定为加勒比地区类型物种。尽管如此，C. xaymacana并未出现在最新的墨西哥水生动物清单中。因此，墨西哥种群的分类学身份仍然不确定。在此，我们报告了C. xaymacana的出现墨西哥海岸附近，并为墨西哥人口提供了第一个形态描述。标本是在墨西哥加勒比海东北部采集的。该物种是根据 phacellae、pedialia 和 vellarial canal 的形状、结构和特征来定义的。该记录对于水母蜇伤方案的制定具有重要意义，因为有报告称在加勒比海地区与研究区域相邻的区域发生了伊鲁坎吉综合症，并且该物种与该综合症有关。本研究证明了对墨西哥的立方体动物进行更多分类学研究的重要性，以澄清其他可能被错误识别的物种的身份并在该地区做出新的记录，这将有助于更清楚地了解墨西哥的立方体动物多样性。