Settlement of Macoma balthica larvae in response to benthic diatom films

C. van Colen, J. Lenoir, A. De Backer, B. Vanelslander, M. Vincx, S. Degraer, T. Ysebaert

Research output: Contribution to journalArticleAcademicpeer-review

25 Citations (Scopus)


The role of multi-species benthic diatom films (BDF) in the settlement of late pediveliger larvae of the bivalve Macoma balthica was investigated in still-water bioassays and multiple choice flume experiments. Axenic diatom cultures that were isolated from a tidal mudflat inhabited by M. balthica were selected to develop BDF sediment treatments characterized by a different community structure, biomass, and amount of extracellular polymeric substances (EPS). Control sediments had no added diatoms. Although all larvae settled and initiated burrowing within the first minute after their addition in still water, regardless of treatment, only 48-52% had completely penetrated the high diatom biomass treatments after 5 min, while on average 80 and 69% of the larvae had settled and burrowed into the control sediments and BDF with a low diatom biomass (<3.5 mu g Chl a g(-1) dry sediment), respectively. The percentage of larvae settling and burrowing into the sediment was negatively correlated with the concentration of Chl a and EPS of the BDF. This suggests higher physical resistance to bivalve penetration by the BDF with higher diatom biomass and more associated sugar and protein compounds. The larval settlement rate in annular flume experiments at flow velocities of 5 and 15 cm s(-1) was distinctly lower compared to the still-water assays. Only 4.6-5.8% of the larvae were recovered from BDF and control sediments after 3 h. Nonetheless, a clear settlement preference was observed for BDF in the flume experiments; i.e., larvae settled significantly more in BDF compared to control sediments irrespective of flow speed. Comparison with the settlement of polystyrene mimics and freeze-killed larvae led to the conclusion that active selection, active secondary dispersal and, at low flow velocities (5 cm s(-1)), passive adhesion to the sediment are important mechanisms determining the settlement of M. balthica larvae in estuarine biofilms.
Original languageEnglish
Pages (from-to)2161-2171
JournalMarine Biology
Issue number10
Publication statusPublished - 2009


  • polychaete hydroids-elegans
  • active habitat selection
  • bryozoan bugula-neritina
  • balanus-amphitrite
  • streblospio-benedicti
  • microbial biofilms
  • settling larvae
  • marine biofilms
  • barnacle larvae
  • spatial scales


Dive into the research topics of 'Settlement of Macoma balthica larvae in response to benthic diatom films'. Together they form a unique fingerprint.

Cite this