General Morphology and Behaviour of Gastrozoids and Dactylozoids in Two Species of Millepora (Milleporina, Coelenterata)
de Kruijf H. 1975. General Morphology and Behaviour of Gastrozoids and Dactylozoids in Two Species of Millepora (Milleporina, Coelenterata). Marine Behaviour and Physiology. 3:181-192
The morphology of living gastrozoids and dactylozoids of Millepora alcicornis and M. complanata (Milleporina, Coelenterata) is described. Living polyps differ from descriptions in literature. Spontaneous behaviour of M. complanata gastrozoids and dactylozoids and M. alcicornisgastrozoids consists of slow swaying, fast swaying (search behaviour), and retraction. M. alcicornis dactylozoids lack search behaviour. Retraction is a graded movement, gradation depending on stimulus strength and nutritional state. Retraction inhibits all types of behaviour in dactylozoids and gastrozoids; but itself is not inhibited by movements. Inhibition of search behaviour depends on the degree of retraction. Retraction serves a defensive function; expanded dactylozoids serve mainly an offensive function. Gastrozoids capture prey and are occasionally offensive. Mouth opening is caused by chemical stimuli, actual ingestion is due to mechanical stimuli and is not necessarily preceded by mouth opening. Mouth opening need not be followed by actual ingestion. There is no coordination in passing food from dactylozoidsto gastrozoids.
- Type
- Journal Article
- Authors
- de Kruijf, H.
- Units
- SFCN
- Keywords
- Chemical stimuli, Coral, mechanical, polyps, Reef, Retraction