Merged with duplicate record 10026.1/2675 on 27.02.2017 by CS (TIS)Merged with duplicate record 10026.1/2675
Submitted by Collection Services ([email protected]) on 2013-11-07T13:30:24Z No. of bitstreams: 1 RICHARD MICHAEL LESLIE KENT.PDF: 5596525 bytes, checksum: 642b67eeb4f6588a9495fd9da490351c (MD5) Approved for entry into archive by Collection Services([email protected]) on 2013-11-07T13:36:35Z (GMT) No. of bitstreams: 1 RICHARD MICHAEL LESLIE KENT.PDF: 5596525 bytes, checksum: 642b67eeb4f6588a9495fd9da490351c (MD5) Made available in DSpace on 2013-11-07T13:36:35Z (GMT). No. of bitstreams: 1 RICHARD MICHAEL LESLIE KENT.PDF: 5596525 bytes, checksum: 642b67eeb4f6588a9495fd9da490351c (MD5) Previous issue date: 1977The ecology of Polydora, epp was reviewed and the infestation
of molluscs by the boring, spionid polychaete, Polydora ciliata, was
studied in detail.
X-radiography showed that, P. ciailt a infested a wide variety of
molluscan substrates, but it . occurred in greatest abundance on large,
rough-surfaced, epibenthic shells, which were collected from the-sublittoral
zone and the level of extreme low water spring tides, of
shores sheltered from wave action. P. ciliata was contagiously
dispersed on mussel--shells. Monthly radiographs of mussels indicated
that maximum settlement of P. ciliata larvae in the river Fowey,
1
occurred in May.
The effect of heavy infestations of P. ciliata on limpets
P. vul ata , mussels (Eytilus edulis), and oysters (Crassostrea is9
was investigated.
At certain times of the year, heavy infestations of P. ciliata
reduced the dry weight condition and fecundity of limpets and mussels,
but did not seem'to adversely affect C. i ae.
Compression tests showed that P. ciliate weakened mussel shells.
Predation experiments, with Cancer a s, indicated that this might
increase the mussels' vulnerability to predation.
Heavy P. ciliata infestation also reduced the mussels' resistance
to loads which tended to force the mussele' valves apart. This may
decrease the mussels' phyeico-chemical tolerance, and increase their
vulnerability to starfish predation. Limpet adhesion, measured on the shore with a simple dynamometer,
was impaired by P. ciliata infestation. This may reduce the limpets'
resistance to wave action, and increase their vulnerability to
predation.
Reasons for the adverse effects of P. ciliata infestation on
limpets and mussels are suggested, and the ecological and commercial
implications of the infestation are discussed