Population variation in Ficopomatus enigmaticus (Fauvel) (Polychaeta, Serpulidae) in a brackish water millpond at Emsworth, West Sussex, U.K
Thorp, C.H. (1994). Population variation in Ficopomatus enigmaticus (Fauvel) (Polychaeta, Serpulidae) in a brackish water millpond at Emsworth, West Sussex, U.K. Mém. Mus. natl. hist. nat., Sér. A Zool. 162: 585-591
In: Mémoires du Muséum national d'Histoire naturelle. Série A, Zoologie. Editions du Muséum: Paris. ISSN 0078-9747, meer
Ook verschenen in:Dauvin, J.-C.; Laubier, L.; Reish, D.J. (Ed.) (1994). Actes de la 4ème Conférence internationale des Polychètes, Angers, France. Mémoires du Muséum national d'Histoire naturelle. Série A, Zoologie, 162. Éditions du Muséum: Paris. ISBN 2-85653-214-4. 642 pp., meer
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Trefwoorden |
Taxa > Species > Introduced species Ficopomatus enigmaticus (Fauvel, 1923) [WoRMS] ANE, British Isles, England, West Sussex [Marine Regions] Marien/Kust |
Abstract |
Since 1982, a population of Ficopomatus enigmaticus has been monitored with respect to larval settlement and to the accumulation on settlement panels. Prodigious settlements (1.3x10 super(7)/m- super(2) max.) were recorded over the period 1982-85 and globular, reef-like aggregations increased in number on the muddy floor of the pond but, prior to the onset of breeding in 1986, the population `crashed' dramatically. While live adults were not observed in the years 1986-88 larval settlements continued, but with greatly reduced and decreasing maxima (1.6xlO super(3)/m- super(2), 1986; 1.1x10 super(3)/m- super(2), 1987 and 9.7x10 super(2)/m- super(2), 1988). Since 1989 the adult population has recovered, being observed on the tide-gates and adjacent walls in particular (1989-90) and as small aggregates on the pond bottom (1991). The increase in the adult population has been reflected in increasing settlement densities (2.8x10 super(5)/m- super(2), 1989 to 2.5x 10 super(6)/m- super(2), 1991). Evidence is offered to explain the population "crash" of 1986 and it is suggested that it resulted from the age of the adult population and a lack of both overwintering reserves and recruitment. It is also suggested that serpulid polychaetes which exhibit population "explosions", such as F. enigmaticus are equally likely to suffer population "crashes" and, further, that population numbers may well fluctuate in a cyclical manner. |
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