Distribution and salinity tolerance of marine mysids from a subtropical estuary, Brazil

ABSTRACT

We studied the spatial and temporal distribution pattern of three marine mysids (Chlamydopleon dissimile, Metamysidopsis elongata atlantica and Mysidopsis coelhoi) from the Cananeia-Iguape Coastal System, southeast Brazil, in relation to environmental variables and zooplankton abundance. We also analysed mysid reproductive traits, and tested their tolerance to salinity gradients in laboratory experiments. Salinity was identified as a major factor influencing mysid spatial and temporal distribution, selectively limiting their distribution within the estuary. Chlamydopleon dissimile and M. coelhoi were common, but occurred at low abundances throughout the year, whereas the numerically dominant M. elongata atlantica had abundance peaks in spring, when thermohaline conditions were more favourable. Mysid brood size varied interspecifically; the occurrence of juveniles throughout the year indicated that mysids breed continuously in the region. The high biomass of M. elongata atlantica observed in spring confirms the importance of mysids in coastal regions' food webs.

RESPONSIBLE EDITOR:

• Frederieke Kroon

KEYWORDS:

• Mysidacea
• benthopelagic
• subtropical estuary
• salinity gradient
• biomass

Acknowledgements

We thank June Dias, Luis Silva and Tomas Silva for technical support; Marcio Ohkawara, Davi Secomandi, Marcio Yamashita, and the staff of the Cananeia coastal station (Oceanographic Institute, University of São Paulo) for their assistance during sampling; Mario Katsuragawa and Monica Petti for allowing the use of the facilities of the Biological Collection Prof. E.F. Nonato; two anonymous referees for comments that contributed to improve an earlier version of this manuscript; and the MBRJ Editorial Office for revising the English and text editing. In memory of Lika (1998–2015).

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

LKM was supported by the National Council for Scientific and Technological Development (CNPq, grants 142203/2010-6, 142050/2012-1 and 245466/2012-6). DC was partially supported by CSIC-UdelaR Grupos I+D, grant 1037.