Contributions to Zoology 89 (2020) 247-269 CTOZ brill.com/ctoz Shell and appendages variability in two allopatric ostracod species seen through the light of molecular data Ivana Karanovic Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea Institute for Marine and Antarctic Studies, University of Tasmania, Private Bag 49, 7001, Hobart, Tasmania, Australia
[email protected] Pham Thi Minh Huyen Department of Life Science, College of Natural Sciences, Hanyang University, Seoul 04763, Republic of Korea Hyunsu Yoo Marine Environmental Research and Information Laboratory (MERIL), 17, Gosan-ro, 148 beon-gil, Gunpo-si, Gyoenggi-do, 15180, Republic of Korea Yuriko Nakao Department of Earth & Environmental Sciences, College of Humanities and Sciences, Nihon University, Sakurajousui 3-25-40, Setagayaku, Tokyo, 156-8550, Japan Akira Tsukagoshi Department of Geoscience, Faculty of Science, Shizuoka University, Ohya 836, Suruga-ku, Shizuoka City, 422-8529 Japan Abstract Ostracod crustaceans are among the most abundant microfossil animals. Understanding intra- and in- terspecific variability of their shell is of pivotal importance for the interpretation of paleontological data. In comparison to appendages, ostracod shell displays more intraspecific variability (in shape, size, and ornamentation), often as a response to environmental conditions. Shell variability has been studied with sophisticated methods, such as geometric morphometrics (GM), but the conspecificity of examined spec- imens and populations was never tested. In addition, there are no GM studies of appendages. We build on previously published high cytochrome c oxidase subunit I (COI) divergence rates among populations of a brackish water species, Ishizakiella miurensis (Hanai, 1957). With landmark-based GM analyses of its shell and appendages, and additional genetic markers (ITS, 28S, 18S), we test if the genetic variability is structured in morphospace.