"Morphotypes of the lacustrine ostracod Limnocythere rionegroensis Cusminsky & Whatley from Patagonia, Argentina, shaped by aquatic environments"

RAMOS LORENA; ALPERÍN, M; SCHWALB, A,; CUSMINSKY , G. C.

HYDROBIOLOGIA

SPRINGER

Lugar: Bruselas; Año: 2017 vol. 786 p. 137 - 148

0018-8158

Abstract 10 This study describes and quantifies morphological valve traits of the ostracod 11Limnocythere rionegroensis from Patagonian steppe lakes and explores their association with 12 lake water characteristics. Surface ornamentation was examined by scanning electron and 13transmitted light microscope, and valve size and shape were analyzed using morphometric 14 techniques. Limnocythere rionegroensis shows remarkable variations in surface ornamentation, 15based on which three morphotypes (MI, MII and MIII) were identified. Valves of morphotypes 16 MI and MIII are larger, show slight to moderate external reticulation, and a higher shape 17variability, whereas MII is characterized by a very conspicuous reticulation, lower shape 18 variability and smaller valves. Outline analysis yielded a great shape disparity related to the 19dorsal margin slope. MI was found in sexual populations from euhaline to mesohaline 20 ephemeral lake; MII occurs in parthenogenetic populations from mesohaline to oligohaline 21permanent or ephemeral lakes, and MIII, from both sexual and asexual populations, inhabits a 22 broad range of environmental conditions in terms of salinity and stability. Limnocythere 23rionegroensis intraspecific variations may be caused by environmental parameters and genetic 24 factors associated to reproductive strategies. These results contribute to the knowledge of extant 25L. rionegroensis morphological variability and provide additional clues to improve the 26 environmental interpretation of fossil assemblages.