Organisms associated with burrowing whelks of the genus Bullia

ENGLISH ABSTRACT: Organisms found associated with the psammophilic neogastropod Buttia include hydroids, a boring sponge and algae which grow on, and burrow into, the shell. The shell may also be the recipient of the egg capsules of other species of gastropods. Peridinian ciliates are commonly found attached in some numbers to the tentacles and an occasional rotifer occurs on the soft parts of the animal. The gut is rich in bacteria, some of which are symbiotic. Digenetic trematode larvae are the most common internal parasites and larval cestodes also occur. Preliminary descriptions are given of two apparently new trematode larvae and of a cestode cysticercoid. A nematode worm is occasionally present in the gut. The absence of external parasitesis noted and it is suggested that the shells of the whelk represent a refuge for smaller organisms or their eggs in an unstable environment lacking geological diversity. ****** AFRIKAANSE OPSOMMING: Organismes wat in assosiasie met die sandbewonende Bullia (Neogastropoda) gevind word sluit hidro ede, ‘n borende spons en alge wat op die oppervlakte en in die skulp groei in. Die skulp dien moontlik ook as 'n ontvanger van eierkapsules van ander Gastropoda spesies. Peridiniese siliate heg algemeen in redelike getalle aan die tentakels vas en Rotifera word af en toe op die sagte dele van die organisme aangetref. Die Spysverteringskanaal is ryk aan bakterie, sommiges simbioties. Digenetiese Trematoda laruves is die mees algemene interne parasiete, en Cestoda larwes kom ook voor. Voorlopige beskrywings word gegee van twee klaarblyklike nuwe Trematoda larwes, asook van 'n Cestoda sistiserkus. ‘n Nematood word ook soms in die spysverteringskanaal aangetref. Die afwesigheid van uitwendige parasiete word gemeld en daar word voorgestel dat die wulk skulp 'n veilige hawe aan kleiner organismes of hul eiers bied, in 'n onstabiele omgewing met min geologiese diversiteit.