Supplementary materials for PhD thesis “Benthic assemblage development and larval ecology of marine invertebrates at Adelaide Island, Antarctica” -Settlement ID images

This dataset comprises the files contained on a CD-ROM which was attached to the thesis when it was submitted in 2005. It was uploaded to ORDO in 2024 for preservation purposes. For more information, please refer to the thesis Benthic assemblage development and larval ecology of marine invertebrates at Adelaide Island, Antarctica via ORO.This thesis describes the first regularly resurveyed study of marine benthic colonisation processes at a location within the Antarctic Circle (660 30' S). Invertebrate assemblages on hard substrata were studied at 8 m and 20 m depths at three locations near Rothera Point, Adelaide Island (670 34' S, 68° 07' W). Assemblages on natural substrata were surveyed photographically and by sampling of cryptic sessile fauna. Recruitment to upper and lower surfaces of artificial substrata was monitored at monthly intervals through 1.5 yr and subsequent survival and growth of sessile assemblages was monitored photographically over 3 yr. Planktonic larvae of benthic invertebrates were surveyed at monthly intervals through 1.5 yr.Recruitment took place throughout the year but was strongly seasonal in most taxa. Many sessile taxa recruited during winter; apparently in direct contrast to a general pattern of summer recruitment in temperate latitudes. All vagile taxa, by contrast, recruited in summer, regardless of developmental type or time of spawning. Rates of assemblage development, and maximum growth rates of individual species, were slow compared with temperate latitudes but a biotic and biotic disturbances caused realised growth rates to be highly variable at scales of m - km. Ice impacts affected substrata at 8 m but the establishment of assemblages at both depths was controlled principally by postsettlement mortality from biotic disturbances, particularly grazing by the urchin Sterechinus neumayeri.Larvae were present in all months but most taxa showed strong seasonality of occurrence. Diversity of larval types was comparable with data from other Antarctic and temperate studies but abundances were higher than in a similar study at Signy Island (60043' S, 45° 36' W). The range of larval types, durations, and times of spawning argues against any strong selective pressures acting on developmental mode itself. Rather, the timing of settlement appears to be the characteristic of the life cycle that is most strongly selected for. It is suggested that differences between sessile and mobile taxa in the timing of settlement may be caused by the seasonal availability of food types for juvenile stages.

本数据集收录了于2005年提交论文时所附CD-ROM中的所有文件。为保存目的，该数据集于2024年上传至ORDO。欲了解更多信息，请参阅通过ORO提供的论文《南极洲阿德莱德岛海底群落发育与无脊椎动物幼虫生态学》。该论文描述了首次对南极圈内（南纬66°30'）某地点的海洋底栖殖民过程进行定期复查的研究。在阿德莱德岛罗瑟拉角（南纬67°34'，西经68°07'）附近三个地点的8米和20米深度，对硬质底质上的无脊椎动物群落进行了研究。通过对自然底质上的群落进行摄影调查和隐栖固着生物的采样，对人工底质上上下表面的定居情况进行了为期1.5年的每月监测，并通过对固着群落的摄影监测，在随后的3年内跟踪了其生存和生长情况。底栖无脊椎动物的浮游幼虫在1.5年的每月间隔内进行了调查。整个年度都有定居发生，但在大多数类群中，定居表现出强烈的季节性；与温带纬度夏季招募的一般模式形成鲜明对比。所有游动类群均于夏季招募，无论其发育类型或产卵时间。群落的发育速率和个体物种的最大生长速率与温带纬度相比较慢，但生物及生物干扰导致的实际生长速率在米至千米的尺度上表现出高度可变性。冰的影响影响了8米处的底质，但两个深度群落的建立主要受生物干扰后的定居死亡率控制，尤其是海胆Stereochinus neumayeri的摄食。幼虫在所有月份都存在，但大多数类群表现出强烈的季节性出现。幼虫类型的多样性与其他南极和温带研究的数据相当，但丰度高于在辛尼岛（南纬60°43'，西经45°36'）的类似研究。幼虫类型、持续时间和产卵时间的范围表明，对发育模式本身没有强烈的选择性压力。相反，定居的时间似乎是最受生命周期选择的特征。有建议认为，固着和游动类群在定居时间上的差异可能是由于幼体阶段食物类型季节性可用性的差异所致。