THECAMOEBIANS (TESTATE AMOEBAE) AND FORAMINIFERA FROM THREE ANCHIALINE CENOTES IN MEXICO: LOW SALINITY (1.5-4.5 psu) FAUNAL TRANSITIONS

Abstract

Research Article| October 01, 2008 THECAMOEBIANS (TESTATE AMOEBAE) AND FORAMINIFERA FROM THREE ANCHIALINE CENOTES IN MEXICO: LOW SALINITY (1.5–4.5 psu) FAUNAL TRANSITIONS P. J. Van Hengstum; P. J. Van Hengstum 1 School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1 1Correspondence author. Current Address: Department of Earth Sciences, Dalhousie University, Halifax, Nova Scotia, B3H 4J1, Canada. E-mail: vanhengstum@dal.ca Search for other works by this author on: GSW Google Scholar E. G. Reinhardt; E. G. Reinhardt School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1 Search for other works by this author on: GSW Google Scholar P. A. Beddows; P. A. Beddows School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1 Search for other works by this author on: GSW Google Scholar R. J. Huang; R. J. Huang School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1 Search for other works by this author on: GSW Google Scholar J. J. Gabriel J. J. Gabriel School of Geography and Earth Sciences, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada, L8S 4K1 Search for other works by this author on: GSW Google Scholar Journal of Foraminiferal Research (2008) 38 (4): 305–317. https://doi.org/10.2113/gsjfr.38.4.305 Article history received: 24 Mar 2008 accepted: 18 Jun 2008 first online: 03 Oct 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation P. J. Van Hengstum, E. G. Reinhardt, P. A. Beddows, R. J. Huang, J. J. Gabriel; THECAMOEBIANS (TESTATE AMOEBAE) AND FORAMINIFERA FROM THREE ANCHIALINE CENOTES IN MEXICO: LOW SALINITY (1.5–4.5 psu) FAUNAL TRANSITIONS. Journal of Foraminiferal Research 2008;; 38 (4): 305–317. doi: https://doi.org/10.2113/gsjfr.38.4.305 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyJournal of Foraminiferal Research Search Advanced Search Abstract This study presents the first systematic documentation of thecamoebians and foraminifera in anchialine cenotes (sinkholes) from Quintana Roo, Mexico. Thirty-three surface sediment samples (upper 5 cm) were collected from cenotes Carwash (1.5 psu), Maya Blue (2.9 psu) and El Eden (>3.3 psu). Q-mode cluster analysis of the faunal distributions isolated four low-diversity (Shannon diversity index 1.0–1.5) and salinity-controlled assemblages. Assemblage 1 (1.5 psu) is dominated by the thecamoebians Centropyxis aculeata “aculeata” (53%) and Arcella vulgaris (21%). Assemblage 2 (2.9 ± 0.2 psu) is dominated by Centropyxis aculeata “discoides” (41%) and Centropyxis aculeata “aculeata” (27%). Dwarfed (~50 μm) Centropyxis constricta “aerophila” (20%) with an autogenous test and Jadammina macrescens (29%) dominate Assemblage 3 (3.4 ± 0.2 psu). Finally, Ammonia tepida (51%), Tritaxis sp. (29%) and Elphidium sp. (11%) dominate Assemblage 4 (3.7 ± 0.4 psu). Thecamoebian and foraminiferal populations in the subtropical cenotes are distributed according to salinity variations as found in other temperate paralic systems. The centropyxid taxa trended towards ecophenotypes without spines with increasing salinity, and dwarfed and autogenous-shelled Centropyxis constricta “aerophila” were determined as the most euryhaline thecamoebian, persisting at the ecological boundary of the group (~3.3 psu). Importantly, the transition from a thecamoebian-dominated assemblage to a foraminiferan-dominated assemblage occurs at a salinity of approximately 3.5 psu. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.