Bryozoa verzameld tijdens de SWG-reis naar Bretagne in april 2005
De Blauwe, H. (2005). Bryozoa verzameld tijdens de SWG-reis naar Bretagne in april 2005. De Strandvlo 25(3-4): 76-82
In: De Strandvlo: Driemaandelijks Tijdschrift van De Strandwerkgroep België. De Strandwerkgroep België: Ursel. ISSN 0773-3542, more
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| Abstract |
During the fieldtrip of the Belgian marine biology association 'Strandwerkgroep' to the coast of Brittany (France) in April 2005 (6th-11th), the author paid special attention to Bryozoans. We visited the beaches of St-Lunaire and St-Aubin only shortly during unfavourable tide. At Erquy, le-Val-André and St-Jacut, bryozoans were collected on the lower beach at low tide. About 75 species were collected. The article gives a review of the species with collecting locations and substrates.A lot of empty bivalve shells are overgrown with encrusting bryozoans in the harbour of Erquy. Especially Glycymeris glycymeris ghosts lots of species and colonies. Perhaps because empty Glycymeris take a long time to get disarticulated they form an ideal microhabitat for Bryozoans. Once disarticulated, the shells soon get in the hydrodynamically stable convex-up orientation and the bryozoans colonizing the concave (inner) surface of the shell are cut off from food and oxygen.44 species were collected from le-Val-André, most of them encrusting disarticulated bivalve shells. A lot of spot colonies (Bishop, 1989) were found in those shells, among them an unknownEscharoides resembling colonies recently found at the Belgian coast. Further investigation and SEM photography is required.Watersipora subovoidea was discovered at St-Jacut during our fieldtrip in 1999 (De Blauwe, 2000). Now it is the most common species in St-Jacut, covering to 80% of the underside of some boulders.Watersipora is probably introduced with oysters as St-Jacut is a centre of oyster culture. Watersipora was not found at Erquy nor at le-Val-André, where Escharoides coccinea is the commonest species on the lower beach. |
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