Abstract

Norway lobsters (Nephrops norvegicus) with cpizoans were held in tanks with seawater and C-14-labelled microalgae (Rhodomonas baltica) for 24 h. The isotopic activity of two epizoans on the month parts of the host, the bryozoan Triticella flava and the cycliophoran Symbion pandora, were compared by liquid scintillation counting. There was no isotopic activity recovered in Symbion pandora but Triticella flava actively ingested the labelled algae and accumulated isotopic activity over time. The cycliophoran feeding activity was assessed further by direct observation of detached feeding stages in a recirculation system. Feeding stages did not respond when algae were offered, but immediately began feeding when diluted hemolymph or homogenized mussel was offered. The results explain why cycliophorans Only Occur on the mouthparts of the host and Support the notion that cycliophorans are obligatory commensals that solely depend oil the food provided by their host. Cycliophorans start feeding when the host be-ins to feed and high concentrations of food particles become available. It is likely that cycliophoran feeding individuals have developed sensory mechanisms to synchronize their food supply with the feeding activity of the host but the precise mechanism is still unknown. In contrast T.flava is a facultative commensal that Call sustain on plankton independent of host feeding activities. In agreement with this T.flava Often Occurs Oil other parts of the host than the Mouth parts.

Keywords

COMMENSALISM; EPIBIOSIS; FILTER-FEEDING

Published in

Vie et Milieu
2008, Volume: 58, number: 2, pages: 185-188
Publisher: OBSERVATOIRE OCEANOLOGIQUE BANYULS

UKÄ Subject classification

Ecology


Permanent link to this page (URI)

https://res.slu.se/id/publ/120128