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Wanying Chen Jieying Na Chengcheng Shen Ruiyan Zhang Bo Lu Hong Cheng Chunsheng Wang Dongsheng Zhang 《海洋学报(英文版)》2021,40(12):55-78
Seamounts are vulnerable ecosystems in the deep sea and can be heavily impacted by human activities, such as bottom fishing and deep-sea mining. The species composition and distribution patterns of benthic fauna is key information for the designation of marine protected areas and environmental management plans. Three contracts for cobalt-rich crust exploration have been granted to China, Japan and Korea in the Northwest Pacific Ocean by the International Seabed Authority. However, our knowledge of benthic biodiversity in this area is extremely insufficient. During 2013–2020, eight Chinese Ocean Mineral Resources R&D Association (COMRA) cruises were conducted to investigate the benthic assemblages of nine seamounts in this region. In this study, 191 ophiuroids collected from seamounts in the Northwest Pacific were identified into 29 species in 11 families. Ophiacanthidae and Euryalidae were the two most dominant families with 12 and 6 species, respectively. Ophiotomidae and Ophiopyrgidae were represented by two species each, while seven families were represented by only one species. Four species were widely distributed among 4–5 seamounts, and 17 species were found only at a single site. An integrated regional taxonomic dataset of Ophiuroidea was generated and analyzed. A total of 23 and 14 species were obtained from the Magellan Seamount Chain (MSC) and the Marcus-Wake seamounts (MWS), respectively, with 8 species shared between the two seamount groups. The individual-based rarefaction curves did not reach an asymptote, suggesting that the sampling effort was inadequate for either the entire region or each single seamount. Most species distributed in a narrow depth range, and the species composition was different between water depths above and below 2000 m. Our results greatly improve the understanding of megafaunal biodiversity from seamounts in the Northwest Pacific Ocean, and highlight the necessity of further surveys to provide more robust information for environmental protection and management in this region. 相似文献
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The species of Ophiuroidea that commonly occur on coral reefs can be found on different substrates and associated with other organisms including algae, sponges, and corals. This study evaluated the temporal variability of the ophiuroid fauna associated with the alga Amphiroa fragilissima on the Ponta Verde coral reef on the coast of Maceió in Alagoas, Northeastern Brazil. Replicate samples of algal substrate were collected at low tide during in the dry and rainy seasons, over a 10‐year period, from 1998–2007. Eight species of Ophiuroidea were identified, with a total of 8736 individuals associated with A. fragilissima. The most dominant and frequent species of Ophiuroidea were Amphipholis squamata and Ophiactis savignyi; all other species were rare. Cluster analysis and nMDS detected four groups, with two groups each occurring only in summer or winter periods, as well as other groups occurring in both periods. 相似文献
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Jieying Na Wanying Chen Dongsheng Zhang Ruiyan Zhang Bo Lu Chengcheng Shen Yadong Zhou Chunsheng Wang 《海洋学报(英文版)》2021,40(12):79-89
Many seamounts are covered with cobalt-rich ferromanganese crusts, and are increasingly attracting interest for the potential extraction of valuable mineral resources from deep seabed environments. However, the impacts of potential mining activities on the vulnerable seamount ecosystem remain unclear. To enhance the understanding of connectivity in benthic invertebrate populations in the Northwest Pacific, several seamounts were surveyed and biological samples collected. In the present study, the ophiuroid species Ophioplinthaca defensor is reported for the first time from four deep seamounts in the Northwest Pacific, and described, providing more detailed morphological diagnosis characters. To assess the population structure of the species between and within seamounts, two mitochondrial markers (COI and 16S) were sequenced. In total, 20 haplotypes from 32 COI sequences and 8 haplotypes from 3716S sequences were recovered. The star-shaped TCS networks and non-significant pairwise population differences reveal the absence of distinct population structures between and within seamounts. In addition, the O. defensor population seemed to have undergone a demographic expansion in history. This is the first study on the genetic population structure of a benthic invertebrate from seamounts in the Northwest Pacific, and this results suggest a potentially high, long distance dispersal capacity in O. defensor between seamounts, which could inform the development of the Regional Environmental Management Plans for the cobalt-rich crust seamounts in the area. 相似文献
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Brooding in ophiuroids (Echinodermata: Ophiuroidea) is a highly-developed reproduction strategy and has evolved independently several times. In South African waters, brooding occurs both in the very small amphiurid Amphipholis squamata, which is hermaphroditic, and in the large ophiodermatid Ophioderma wahlbergii, which is gonochoric. For the first time, microcomputed tomography was applied to visualise and compare brooding and brooded young of these two brittle star species from two distantly related families. The scanned A. squamata brooded six young, whereas O. wahlbergii brooded 13 young. Volume measurements of the adults revealed that A. squamata dedicated about 25% of its disc volume to brooding and O. wahlbergii about 14%. Although the brooded young of O. wahlbergii are thought to be among the largest of all known ophiuroids, young of A. squamata were four times larger in relation to adult body disc volume. Other than differences in the sizes of brooded young, these distantly related species have evolved very similar brooding adaptations. All juveniles were found lying with the mouth upward, pressed against the mother's bursal wall, strengthening the hypothesis that the bursal wall acts as a nutritive organ. In both species, the large size of the young can only be explained by maternal nutrient supply. Both brittle star species, therefore, are regarded as truly viviparous. 相似文献
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通过对2018年4—5月在南海中部黄岩海山采集的蛇尾样品进行形态学分类研究,鉴定发现棘蛇尾科Ophiacanthidae汁蛇尾属Ophiurothamnus两个新记录种:(1)双环汁蛇尾Ophiurothamnus discycla (H. L. Clark, 1911);(2)短简汁蛇尾Ophiurothamnus clausa (Lyman, 1878)。本文分别对这两个新记录种的外部形态特征和内部骨骼进行了描述,并与相似种进行了分类学讨论。 相似文献
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