Dong Zhijun, Morandini André C, Schiariti Agustin, Wang Lei, Sun Tingting
Muping Coastal Environment Research Station, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai, Shandong, P.R. China.
Center for Ocean Mega-Science, Chinese Academy of Sciences, Qingdao, Shandong, P.R. China.
PeerJ. 2019 Jan 9;7:e6191. doi: 10.7717/peerj.6191. eCollection 2019.
It has been suggested that aquaculture ponds on the Chinese coast could act as breeding grounds for scyphozoans. Here, we present the first record of the scyphomedusa sp. in an aquaculture pond on the coast of the southern Yellow Sea, based on a combination of morphological characteristics and mitochondrial 16S DNA sequence data.
A field survey was performed on June 29, 2017 in a pond used for culturing the shrimp , located in the southern Yellow Sea, China. Jellyfish specimens were collected for morphological and genetic analysis. The morphological characters of the jellyfish specimens were compared to taxonomic literature. Additionally, phylogenetic analysis of the mitochondrial 16S fragments of these specimens were also conducted.
These specimens had the following morphological characters: hemispherical umbrella without scapulets; J-shaped oral arms; a single larger terminal club on each arm; bluish colored with a slightly expanded white tip; and mouthlets present only in the lower half to one-third of each arm. These morphological features of the medusae indicated that the specimens found in the shrimp culture ponds belong to the genus Agassiz, 1862, but did not match with the description of any of the known species of the genus Phylogenetic analyses of the mtDNA 16S regions revealed that these specimens, together with sp. from Malaysian coastal waters, belong to a sister group of . Juveniles and ephyrae of sp. were observed in the aquaculture pond. The mean density of sp. medusa in the surface water within the pond was estimated to be 0.05 individuals/m.
Based on our observations of the gross morphology and molecular data, we state that the specimens collected in the aquaculture pond can be identified as sp. This is the first record of sp. in Chinese seas. Large scale dispersal through ballast water or the expansion of jellyfish aquarium exhibitions are possible pathways of invasion, but this needs to be confirmed in further studies.
有人提出中国沿海的水产养殖池塘可能成为钵水母纲动物的繁殖地。在此，我们基于形态特征和线粒体16S DNA序列数据，首次记录了黄海沿岸一个水产养殖池塘中的钵水母纲物种。
2017年6月29日，在中国黄海沿岸一个用于养殖虾的池塘进行了实地调查。收集了水母标本进行形态学和遗传学分析。将水母标本的形态特征与分类学文献进行了比较。此外，还对这些标本的线粒体16S片段进行了系统发育分析。
这些标本具有以下形态特征：半球形伞状体，无小肩板；口腕呈J形；每条口腕上有一个较大的末端棒状体；呈蓝色，白色尖端略有膨大；口孔仅存在于每条口腕的下半部至三分之一处。这些水母的形态特征表明，在对虾养殖池塘中发现的标本属于1862年的阿氏水母属，但与该属任何已知物种的描述均不相符。对线粒体DNA 16S区域的系统发育分析表明，这些标本与来自马来西亚沿海水域的物种属于一个姊妹群。在水产养殖池塘中观察到了该物种的幼体和碟状体。估计池塘表层水中该水母的平均密度为0.05个/立方米。
基于我们对总体形态和分子数据的观察，我们指出在水产养殖池塘中收集的标本可鉴定为该物种。这是该物种在中国海域的首次记录。通过压载水的大规模扩散或水母水族展览的扩大可能是其入侵途径，但这需要在进一步研究中得到证实。
