海洋生物分类与系统演化实验室知识库

有孔虫是一类数量众多、全球性分布的单细胞原生动物，分为底栖和浮游两类，分别生活在沉积物和水体中。有孔虫个体微小、生长快、繁殖迅速，大部分有孔虫具有钙质或胶结质的壳，可以在地层中长期保存，因此被广泛应用于古海洋环境和古气候重建。全球变化引起的海水温度升高、海平面上升、海洋酸化等严重威胁着海洋生物，而有孔虫对环境变化非常敏感，是良好的环境指示物种。

本论文以温度、盐度和pH为重点环境因子，研究从近岸 (青岛湾潮间带) 到陆架区 (黄海) 的底栖有孔虫群落和开放大洋 (热带西太平洋) 中的浮游有孔虫Globigerinoides sacculifer对其的响应，主要开展了以下4个方面的工作：

1. 青岛湾潮间带底栖有孔虫群落对温度和盐度的响应研究

对采自青岛湾潮间带的底栖有孔虫群落在3个温度 (6 °C、12 °C和18 °C) 和4个盐度 (15 psu、20 psu、25 psu和30 psu) 下进行10周的实验室培养，共获得活体底栖有孔虫18种，2616只。研究表明，该区域底栖有孔虫群落对温度和盐度变化的响应非常迅速，尤其对温度非常敏感。群落丰度、物种数、Margalef丰富度和Shannon-Wiener多样性与温度呈显著正相关，Pielou’s均匀度与温度和盐度呈显著负相关。优势种Ammonia aomoriensis、A. beccarii和Quinqueloculina seminula的丰度均与温度呈显著正相关。玻璃质Rotaliida目有孔虫含量与温度呈显著负相关而瓷质Miliolida目有孔虫含量与温度呈显著正相关。本研究建立的底栖有孔虫群落参数与温度和盐度之间的相关关系可以在生态研究中用于指示环境变化，并可能为反演古海洋环境提供参考依据。

2. 青岛湾潮间带底栖有孔虫群落对pH的响应研究

对采自青岛湾潮间带的底栖有孔虫群落在5个pH (pH 8.5、pH 8.0、pH 7.5、pH 7.0和pH 6.5) 下进行4个月的实验室培养，共获得活体底栖有孔虫15种，2246只。研究表明，海水pH降低导致底栖有孔虫群落丰度显著减小，但多样性和均匀度增加。优势种Ammonia aomoriensis的丰度 (N) 和含量 (C) 与pH呈显著正相关 (N = 25.6*pH - 163.1, p < 0.0001; C = 0.24*pH - 1.36, p < 0.0001)，而Ammoglobigerina globigeriniformis的丰度 (N) 和含量 (C) 与pH呈显著负相关 (N = -4.1*pH + 41.9, p = 0.0353; C = -0.21*pH + 1.80, p < 0.0001)，这两种底栖有孔虫可作为海水pH变化的指示种。随pH降低，底栖有孔虫壳质类型组成改变：玻璃质和瓷质有孔虫含量减少而胶结质有孔虫含量增多。本研究表明本海区底栖有孔虫物种组成和壳质类型变化可以指示海水pH变化并能够作为重建古海洋pH的依据。

3. 黄海陆架区底栖有孔虫群落对pH的响应研究

对采自黄海陆架区5个不同水深站位的底栖有孔虫群落在3个pH (pH 8.3、pH 7.8和pH 7.3) 下进行6周和12周的实验室培养，共获得活体底栖有孔虫60种，5918只。研究表明，海水pH降低对底栖有孔虫群落产生不利影响，导致其群落丰度、物种数和多样性减少。培养时间仅对近岸站位的底栖有孔虫群落参数影响显著，随培养时间增加群落丰度升高，而物种数和多样性降低。本海区中的底栖有孔虫Lagenammina atlantica、Verneuilinulla advena、V. propinqua、Haplophragmoides applanata和H. canariensis的含量随pH降低而增加，这些种是低pH耐受种；而Protelphidium tuberculatum和Cribroelphidium frigidum对海水pH降低非常敏感，其含量随pH降低而减少，是低pH敏感种。底栖有孔虫群落中的玻璃质类群含量与pH呈显著正相关，而胶结质类群含量与pH呈显著负相关。本研究表明，海水pH降低对黄海不同海区底栖有孔虫的影响存在差异，近岸海区受到的影响最小，而离岸海区所受的影响最大。其中，黄海冷水团中央海区的底栖有孔虫最容易受到海水pH降低的不利影响。

4. 热带西太平洋浮游有孔虫Globigerinoides sacculifer对温度的响应研究

对采自热带西太平洋的浮游有孔虫Globigerinoides sacculifer在22 °C和27 °C下进行单种培养及对整个浮游有孔虫群落在4个温度 (24 °C、27 °C、30 °C和33 °C) 下进行群落培养，研究表明，G. sacculifer的个体生长受温度影响显著，27 °C下生长率 (29.72 μm/day）显著高于22 °C (17.28 μm/day)。22 - 27 °C之间的温度系数Q₁₀为2.96，按照本实验得出的体长增长率 (17.28 - 29.72 μm/day)，G. sacculifer达到成体大小 (~ 400 μm) 约需2周。24 - 30 °C内，G. sacculifer的个体和最后房室随温度升高而增大，G. sacculifer的体长 (L)、体宽 (W) 与温度 (T) 分别符合函数关系式：L = (3.87 ± 0.77) T + (75.54 ± 20.33)，r² = 0.96；W = (2.89 ± 0.73) T + (63.66 ± 19.20)，r² = 0.94。表明温度每升高1 °C，G. sacculifer的体长和体宽分别增大3.87 μm和2.89 μm。在实验模拟的极端高温33 °C时，G. sacculifer的个体和最后房室骤减，推断高温 (33 °C) 可能抑制G. sacculifer的生长。实验温度范围内，G. sacculifer的体态长宽比例 (虫体长宽比和最后房室长宽比) 基本不变，温度未影响G. sacculifer的体态长宽比例。

Foraminifera is numerous single-celled protozoan species that are distributed globally. They are divided into benthic and planktonic species and live in sediment and seawater, respectively. Foraminiferal individuals are tiny with fast growth and reproduction. Most foraminifera have carbonate shells or cementitious shells that can be preserved in the strata for a long period. Therefore, they are widely used in the reconstruction of paleoenvironments and paleoclimates. Global changes such as global warming, rising sea levels and ocean acidification are influencing marine organisms. Foraminifera is very sensitive to environmental changes and is a good environmental indicator species.

Our work focuses on the main environmental factors— temperature, salinity and pH. We study the response of benthic foraminiferal community from the coastal area (Qingdao Bay) to the continental shelf (Yellow Sea) and the planktonic foraminifera Globigerinoides sacculifer from the open ocean (tropical western Pacific Ocean) to these factors. There are four parts of work listed as follows.

1. Study on the response of benthic foraminiferal community from the intertidal area in Qingdao Bay to temperature

Benthic foraminiferal community from intertidal zone in Qingdao Bay were cultured at 3 temperatures (6 °C, 12 °C and 18 °C) and 4 salinities (15 psu, 20 psu, 25 psu and 30 psu) in laboratory for 10 weeks. A total of 18 species and 2616 living benthic foraminifera were obtained. Our results showed that benthic foraminiferal communities in this area responded very quickly to changes in temperature and salinity, and are particularly sensitive to temperature. Community abundance, species richness, Margalef index and Shannon-Wiener diversity were positively correlated to temperature, and Pielou’s evenness was significantly negatively correlated to temperature and salinity. The abundance of the dominant species, Ammonia aomoriensis, A. beccarii and Quinqueloculina seminula, were positively correlated to temperature. The proportion of hyaline Rotaliida was significantly negatively correlated to temperature, whereas the proportion of porcellaneous Miliolida was positively correlated to temperature. The relationships between benthic foraminiferal community parameters and temperature and salinity established in this study can be used to indicate environmental changes in ecological study and may provide a reference for the paleoenvironmental reconstruction.

2. Study on the response of benthic foraminiferal community from the intertidal area in Qingdao Bay to pH

The benthic foraminiferal community from the intertidal zone of Qingdao Bay was cultured at 5 pH (pH 8.5, pH 8.0, pH 7.5, pH 7.0 and pH 6.5) for 4 months in laboratory. A total of 15 species and 2246 living benthic foraminifera were obtained. Results showed that the decrease in seawater pH resulted in a significant reduction in the abundance of benthic foraminiferal communities, but increased diversity and evenness. The abundance (N) and proportion (C) of dominant species Ammonia aomoriensis were positively correlated to pH (N = 25.6 * pH-163.1, p < 0.0001; C = 0.24 * pH-1.36, p < 0.0001), and the abundance (N) and proportion (C) of Ammogloblogerina globigeriniformis showed a significant negative correlation with pH (N = -4.1 * pH + 41.9, p = 0.0353; C = -0.21 * pH + 1.80, p < 0.0001). These species could be used as indicator species for the change of seawater pH. Decreased, benthic foraminifera crust type composition changes: vitreous and porcelain foraminifera content decreased and cementitious foraminifera content increased This study indicates that the benthic foraminifera species composition and shell type changes in this area can indicate Changes in seawater pH can be used as a basis for reconstructing the pH value of the ancient ocean. With the decrease of pH, the composition of the benthic foraminifera was altered: the proportions of hyaline and porcellaneous taxa decreased, and the agglutinated taxa increased. Our study showed that the benthic foraminiferal species composition and shell type composition in this area could indicate changes in seawater pH and be used as a basis for reconstructing paleo-ocean pH.

3. Study on the response of benthic foraminiferal community from the continental shelf of the Yellow Sea to pH

The benthic foraminiferal community from five stations of different depths in continental shelf of the Yellow Sea was subjected to laboratory culture for 6 weeks and 12 weeks at three pH (pH 8.3, pH 7.8 and pH 7.3). A total of 60 species and 5918 living benthic foraminifera were obtained. Our results showed that the declining seawater pH had an adverse effect on benthic foraminiferal community, resulting in a reduction in community abundance, species richness and diversity. The incubation time only had a significant effect on the benthic foraminiferal community parameters in the nearshore stations. With the increase of incubation time, the community abundance increased, while the species richness and diversity decreased. The proportions of benthic foraminifera Lagenammina atlantica, Verneuilinulla advena, V. propinqua, Haplophragmoides applanata, and H. canariensis increased with decreasing pH and these were pH-tolerant species. However, Protelphidium tuberculatum and Cribroelphidium frigidum were highly sensitive to declining pH and decreased with the declining pH. The proportion of hyaline taxa was positively correlated to pH, ​​while the proportion of agglutinated taxa was negatively correlated to pH. Our study showed that the impact of lowering seawater pH on benthic foraminifera varied in different areas in the Yellow Sea. The offshore foraminiferal community was more sensitive to the declining pH than the nearshore one in the Yellow Sea. Especially, benthic foraminifera in the central sea area of the Yellow Sea Cold Water Mass was most vulnerable to the adverse effect of the lowering of seawater pH.

4. Study on the response of planktonic foraminifera Globigerinoides sacculifer from the tropical western Pacific Ocean to temperature

The planktonic foraminiferal community including Globigerinoides sacculifer were collected from the tropical western Pacific Ocean. The individual species were cultured at 22 °C and 27 °C and the whole communities were cultured at four temperatures (24 °C, 27 °C, 30 °C and 33 °C). The results showed that the growth of G. sacculifer was significantly affected by temperature, and the growth rate (27.72 μm/day) at 27 °C was significantly higher than that at 22 °C (17.28 μm/day). The temperature coefficient Q₁₀ between 22 °C and 27 °C was 2.96. According to the growth rate of body length (17.28 - 29.72 μm/day) obtained in this experiment, it took approximately two weeks for G. sacculifer to reach the adult size (~ 400 μm). Between 24 °C and 30 °C, the equations between length (L) and width (W) of G. sacculifer and temperature (T) were L = (3.87 ± 0.77) T + (75.54 ± 20.33), r² = 0.96 and W = (2.89 ± 0.73) T + (63.66 ± 19.20), r² = 0.94. Our results showed that the length of G. sacculifer would increase 3.87 μm with 1 °C rise and the width of G. sacculifer would increase 2.89 μm with 1 °C rise. Under laboratory simulated extreme high temperature (33 °C), the size of G. sacculifer showed a dramatic decline. We speculated that high temperature had adverse effects on the growth of G. sacculifer. The results also showed that the length/width ratios of G. sacculifer and of the final chamber were basically unchanged between 24 °C and 33 °C. The morphology (length/width ratio) of G. sacculifer wasn’t changed by temperature.