Life histories of two hyperbenthic mysids (Mysidacea: Mysidae) in an open estuary

ABSTRACT

Mysidae are widely distributed in aquatic ecosystems and form a large proportion of the hyperbenthic biomass in estuaries. The seasonality, spatial distribution and reproductive biology of the two hyperbenthic mysid species, Tenagomysis chiltoni and Tenagomysis novaezealandiae, were studied in an open estuary. Sampling was conducted bi-monthly at night between February 2008 and April 2009. These two mysid species are spatially segregated along a salinity gradient, with T. chiltoni upstream and T. novaezealandiae downstream in the estuary. The life cycle and breeding dynamics of T. chiltoni (bivoltine life cycle) and T. novaezealandiae (multivoltine life cycle) were similar to those described in intermittently closed estuaries, but their breeding period (December to April) was relatively shorter and densities were lower. Life-stage specific segregation in summer in both mysid species likely provided favourable conditions for maximum growth rates, short maturation times, and sheltering, enhancing reproductive success of both mysid species.

KEYWORDS:

• Distribution
• life-stage specific segregation
• population dynamics
• reproduction
• New Zealand

Acknowledgement

We thank staff and students of the Department of Zoology, University of Otago, for their help in field and lab, and the Department of Zoology, University of Otago, for funding. B. M. Bierschenk was supported by a University of Otago Postgraduate scholarship.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by University of Otago: University of Otago Postgraduate scholarship.