Non-viable seasonal settlement of larvae of the upper bathyal brittle star Ophiocten gracilis in the Rockall Trough abyssal
Non-viable seasonal settlement of larvae of the upper bathyal brittle star Ophiocten gracilis in the Rockall Trough abyssal
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罗卡尔海槽深海中上半深海脆星 Ophiocten gracilis 幼虫的非存活季节性沉降
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发表时间：
1981
期刊：
影响因子：
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通讯作者：
P. Tyler
中科院分区：
文献类型：
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作者：
J. Gage;P. Tyler
从1975年至1980年在东北大西洋罗卡尔海槽南部2900米深的永久站点采集的一系列样本中，对先前被确认为深海种的幼虫的INE结构的重新检查表明，脆星幼虫夏季大高峰的大部分属于第二种。大多数都是残缺不全的，在收集时可能是身体。少数几个完整的标本与从邻近大陆斜坡的海底样本中收集的仔鱼相同，那里有密集的半深海物种Ophiocten gracilis(G.O.Sars)，在600至1200米深的地方存在。对人口规模结构的审查表明，1月/2月同步繁殖，每年招募人口。3/4月在永久监测站附近的中水浮游生物样本中发现了“Ophiostorteus ramosus”和完整的Ophiocten gracilis幼体，这被认为是来自邻近的斜坡种群，或者，较不可能的是，来自北大西洋洋流中从纽芬兰外的佛兰德海角地区运输的幼体。在深水中，这些底栖仔鱼的生存能力很低，没有一条能在罗卡尔海槽中活得比下一个冬天更长。这些观察表明，作为食物的不能存活的幼虫和幼虫后的斜坡有很大的季节性转移到深海底栖群落。
Re-examination of ine structure of postlarvae previously identified as the abyssal species Ophiura ljungmani (Lyman) in a time series of samples taken from 1975 to 1980 from a 2900 m deep permanent station in the southern Rockall Trough (Northeast Atlantic Ocean) has shown the majority of the large summertime peak of brittle-star postlarvae to belong to a second species. Most were incomplete and probably corpses when collected. The few intact specimens present were identical to postlarvae collected in benthic samples from the neighbouring continental slope, where a dense population of the bathyal species Ophiocten gracilis (G. O. Sars) is present from 600 to 1 200 m depth. Examination of population size-structures indicates synchronous reproduction in January/February and annual recruitment to the population. The presence both of “Ophiopluteus ramosus” and intact postlarvae of Ophiocten gracilis in midwater plankton samples from the vicinity of the permanent station in March/April are thought to derive either from the adjacent slope population or, less probably, from larvae transported in the North Atlantic Current from the Flemish Cap area off Newfoundland. In deep water, viability of these benthic postlarvae is low, none surviving longer than the following winter in the Rockall Trough. These observations suggest a large seasonal transfer from the slope of non-viable larvae and postlarvae as food to the abyssal benthic community.