The variability of modern Cyprideis salebrosa and Cyprideis americana (Ostracoda) from the northern Neotropics were investigated in order to understand site specific influences on the isotopic composition of their valves (δ¹⁸O, δ¹³C) in comparison to their host water and to connect this to morphological features of their valves (valve size, nodosity). C. salebrosa was found in a stream (Shell Creek, Florida) and a slightly brackish lake (Laguna del Rincon, Dominican Republic; salinity <0.7 psu) while C. americana occurred in a coastal lake with polyhaline waters (Parrotee Pond, Jamaica; salinity: >20 psu). Valve size and position of nodes differed between the two species. A reverse temperature dependency have been considered to influence Shell length (seasonally in Shell Creek, summer: 1076 µm; winter: 1092 µm, supposedly permanently in Laguna del Rincon, 1035 µm). But, regarding the small dataset other factors could not be excluded to influence ostracod valve size. A decline of node frequency of C. salebrosa is mainly related to an increase in salinity. Isotopic values of ostracod valves reflect the trend in stable isotopes of their host water. Variations in Cyprideis salebrosa δ¹⁸O and δ¹³C values signify differences in their host water. Offsets of ostracod valves to a theoretical calcite precipitated in their host water with an uncertain time lag (+0.015 to +2.63 ‰) needs to be clarified. This study presents a contribution to the understanding of environmental influences on modern ostracod shell characters as basis for paleontological applications.

中文翻译：

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北部新热带地区现代水域中Cyprideis（Ostracoda）的形态和地球化学变化。

现代的变异Cyprideis salebrosa和Cyprideis美洲来自北方新热带区（介形类），以了解他们的阀门的同位素组成现场的具体影响进行了调查（δ ¹⁸ O，δ ¹³相比C）给他们的主人水和连接这取决于阀门的形态特征（阀门尺寸，结节度）。C. salebrosa是在一个流（壳牌溪，佛罗里达）和微咸水湖泊实测值（丽德尔林孔，多米尼加共和国;盐度<0.7 PSU）而C.美洲发生在一个多卤水的沿海湖泊中（牙买加Parrotee Pond；盐度：> 20 psu）。阀的大小和节的位置在两个物种之间有所不同。人们已经考虑到温度的反向依赖性会影响壳的长度（Shell Creek的季节：夏季：1076 µm；冬季：1092 µm； Laguna del Rincon可能是永久性的1035 µm）。但是，关于小型数据集，不能排除其他因素来影响rac鱼瓣的大小。塞氏梭状芽孢杆菌的节点频率下降主要与盐度增加有关。rac鱼瓣的同位素值反映了其宿主水的稳定同位素趋势。变化Cyprideis salebrosa δ ¹⁸ O和δ ¹³C值表示其宿主水的差异。需要澄清在不确定的时间滞后（+0.015至+2.63‰）中，在其宿主水中析出的方解石阀与理论方解石的偏移。这项研究为理解环境对现代鱼壳特征的影响做出了贡献，以此作为古生物学应用的基础。