MEPS

Marine Ecology Progress Series

MEPS is a leading hybrid research journal on all aspects of marine, coastal and estuarine ecology. Priority is given to outstanding research that advances our ecological understanding.

Online: ISSN 1616-1599

Print: ISSN 0171-8630

DOI: https://doi.org/10.3354/meps

Volume contents
Mar Ecol Prog Ser 340:1-8 (2007)

Physiological condition of Balanus amphitrite cyprid larvae determines habitat selection success

ABSTRACT: A field experiment was used to assess the relationship between the physiological condition of barnacle larvae and habitat selectivity at settlement. Three experiments were carried out on methacrylate (Plexiglas) disks precolonized with biofilms of different ages (0, 7, 14 and 21 d) that were arranged within 3 blocks and placed at 3 intertidal positions corresponding to the upper limit, mid zone and lower limit of the adult Balanus amphitrite (Darwin) habitat. To limit the effect of post-settlement mortality, each experiment was conducted over 2 full tidal cycles only. During these periods, larvae in the water column were sampled and abundance estimated at each high tide at the depths corresponding to the 3 intertidal positions. Larval physiological condition was assessed using lipid classes analyzed by liquid chromatography. Ratios of total triacylglycerols to sterol content (TAG/ST) were used to quantify the energy status of larvae. Our results indicate that the cyprids’ TAG levels reflect the level of settlement success independent of cyprid abundance in the water column. Intertidal position and biofilm characteristics were significant factors determining the settlement success with respect to cyprid energy content. The number and the energy content of settling cyprids were maximal on clean surfaces and decreased gradually with the degree of biofilm precolonization. Our study shows (1) the importance of lipid levels, particularly TAG, in habitat discrimination at small temporal scales in B. amphitrite cyprids and (2) that larval energy content is a critical variable for understanding benthic–pelagic coupling.

KEYWORDS

Cyprid larva of the barnacle Balanus amphitrite containing lipid droplets, its main energy reserve. Photo: Réjean Tremblay

The importance of larval supply and of the energetic quality of settling larvae for habitat selection and recruitment are central themes in marine population dynamics. This study on barnacle larvae by Tremblay and co-workers contributes to the understanding of the linkage between larval physiological condition and settlement behaviour. Field experiments indicated that the energetic reserves (mainly triacylglycerol content) determine habitat selection behaviour on intertidal surfaces in Balanus amphitrite cyprids. More specifically, larvae with lower energetic reserves risk settling on poor quality sites. The data support the ‘desperate larva hypothesis’, which postulates that nonfeeding larvae become less selective with regard to settlement sites as they age, due to the consumption of the energy reserves required for metamorphosis.

Réjean Tremblay (Co-author)

  • Institut des sciences de la mer–Université du Québec à Rimouski, 310 allée des Ursulines, Rimouski, Québec G5L 3A1, Canada

Frédéric Olivier (Co-author)

  • Station Marine de Dinard USM 0404 (MNHN), Département Milieux et Peuplements Aquatiques, UMR 5178 BOME, 17 avenue George V, BP 70134, 35801 Dinard Cedex, France

E. Bourget (Co-author)

  • Vice-rectorat à la recherche, Pavillon central, Université de Sherbrooke, Sherbrooke, Québec J1K 2R1, Canada

D. Rittschof (Co-author)

  • Marine Laboratory, Nicholas School of the Environment, Earth and Ocean Sciences, Duke University, 135 Duke Marine Laboratory Road, Beaufort, North Carolina 28516, USA