ePrints

Do benthic sediment characteristics explain the distribution of juveniles of the deposit-feeding sea cucumber Australostichopus mollis?

Lookup NU author(s): Dr Matt Slater

Downloads

Full text for this publication is not currently held within this repository. Alternative links are provided below where available.

Abstract

Despite the economic importance of many deposit-feeding sea cucumbers, the ecology of their juveniles is poorly understood and factors influencing juvenile habitat selection remain largely unexplained. We investigated the importance of the characteristics of the available sediment in determining the highly localised distribution of juveniles of the deposit-feeding Australasian sea cucumber Australostichopus mollis. Wild-caught juveniles were displaced to non-juvenile habitats with surface sediments characterised by lower total organic content (TOM) and nitrogen content, higher chlorophyll-a content and coarser grain size profiles compared to juvenile sites. The growth of displaced individual animals was monitored over 9months and compared to control animals caged in the juvenile habitats. Displaced juvenile sea cucumbers had high survival rates that did not differ significantly from juvenile habitats. Displaced juveniles exhibited significantly higher specific growth rate (SGR) than those at juvenile sites (p<0.001), although the growth of individuals was highly variable within individual cages and among sites. The lower TOM and nitrogen content, and coarser grain size profiles at non-juvenile sites did not result in reductions in juvenile survival or growth. Higher microphytobenthic activity may have resulted in the higher growth rates observed at shallow non-juvenile sites. The SGR of juveniles over the first 6months of the experiment ranged between 0.45%d-1 and 0.74%d-1 for all sites. This was followed by marked growth limitation between 6 and 9months either as a result of increasing juvenile biomass in cages or seasonal growth limitation. A subsequent reduction in juvenile density resulted in markedly increased growth over the following 3month period. Juvenile A. mollis show an ability to exploit a variety of benthic sediment food sources, indicating that their highly localised distribution is not due to differences in the food quality of sediments, but is more likely to be due to other localised effects, such as larval settlement or predation. © 2010 Elsevier B.V.

Publication metadata

Author(s): Slater M, Jeffs A

Publication type: Article

Publication status: Published

Journal: Journal of Sea Research

Year: 2010

Volume: 64

Issue: 3

Pages: 241-249

Print publication date: 27/03/2010

ISSN (print): 1385-1101

ISSN (electronic): 1873-1414

Publisher: Elsevier BV

URL: http://dx.doi.org/10.1016/j.seares.2010.03.005

DOI: 10.1016/j.seares.2010.03.005

Altmetrics

Share