ISSN:
1573-5117
Keywords:
Settlement
;
cue
;
barnacle
;
scale
;
Semibalanus balanoides
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Abstract Numerous physical and biological factors have been identified which affect the probability of larvae settling on hard substrata. The spatial scale at which these factors operate ranges from km's to sub-mm's. The wide variety of cues that barnacle larvae respond to coupled with the subtleties of cue response to factors like surface roughness, suggests that larvae are fastidious in their choice of settlement sites and thus, (i) settlement is not rapid and, (ii) larvae carry out search behaviour to sample settlement cues. An experimental frame with settlement pits untreated or with either barnacle settlement factor, or cyprid settlement factor, or a squashed cyprid larvae were exposed for a duration of 10 minutes during the Semibalanus balanoide settlement season in the Clyde Sea, UK. A total of 102 of the 240 pits were settled within the 10 minutes. More settlement occurred in the chemically treated pits than the untreated pits suggesting that settlement can be both selective and rapid. Video-photography was carried out in the laboratory of the tracks of S. balanoides cyprids prior to settlement in pits. With untreated pits little search behaviour was identified, cyprids tended to encounter the pit and then settle. Pits treated with squashed cyprid showed a chemical cue-mediated behaviour with cyprids tending to slow down and carryout antennular crawling in the vicinity of the pit. The mean time from entering a 40× 40 mm window around the pit and settlement was 24.9 s ( n =11, SE = 5.4). Within the last 1.25 s prior to settlement, cyprids settling in untreated pits moved faster than cyprids settling in CL treated pits (P 〈 0.01), with a 4 times difference between the mean speeds These data suggest that settlement can be rapid and the pre-settlement track does not necessarily display search behaviour.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1017029627006
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