Gregarious settlement in cypris larvae: The effects of cyprid age and assay duration

• Gregarious behaviour of marine larvae is perhaps most clearly associated with finding a suitable habitat in a changeable or restricted environment, or with finding other conspecifics with which to mate. Prior work has shown that in settlement assays using cypris larvae of the barnacle Balanus amphitrite , gregarious interactions significantly affected the interpretation of experiments testing the activity of organic settlement promoters and inhibitors. Other studies have also shown effects of cyprid age and pheromone concentration on settlement behaviour. However, the effects of interactions between gregariousness and these two factors are not known. The aim of this study was to test the hypotheses that i) as cyprids age the effects of gregariousness become less apparent, and ii) as the duration of the experiment increases gregarious effects become more apparent, using cypris larvae of B. amphitrite and Balanus improvisus . Three age classes of cyprids were used at six densities in a fully factorial design. For B. improvisus cyprids significant gregarious effects occurred between 3 or more larvae, and although larval age and experiment duration had significant main effects, there were no interactions between these important factors and gregariousness. For B. amphitrite cyprids significant gregarious effects also occurred with greater than or equal to3 larvae per well, though this effect was strongly dependent upon experiment duration. B. amphitrite cyprid sensitivity to conspecific cues does not change with age, although increasing experiment duration and age interact to increase settlement. Differences between species may be due to different thresholds to conspecific larval cues, or B. improvisus cyprids release much more larval temporary adhesive during exploration.

Subject headings

NATURVETENSKAP  -- Biologi -- Ekologi (hsv//swe)

NATURAL SCIENCES  -- Biological Sciences -- Ecology (hsv//eng)

Keyword

barnacles

larval settlement

bioassays

larval density

BALANUS-AMPHITRITE DARWIN

MICRO-TEXTURED SURFACES

PROTEIN COMPLEX

SIPC

PHYSIOLOGICAL CONDITION

SEMIBALANUS-BALANOIDES

BARNACLE

RECRUITMENT

BEHAVIOR

METAMORPHOSIS

SPECIFICITY

Publication and Content Type

ref (subject category)

art (subject category)