engleski

Behaviour of the seashell Corbula gibba (Olivi, 1792) under aquarium conditions

The species Corbula gibba (Corbulidae, Bivalvia) has been found on various types of bottom and in various benthic communities, also in some polluted areas, and is therefore regarded as a species of wide ecological distribution. The behaviour of this species concerning the motion and burrowing is not enough examined. It is known that the animal moves on the muddy sediment searching for food and for suitable substrate to attach with byssus or to escape from predators. In order to follow the motion and burrowing adult specimens were put on the surface of muddy substrate un an experimetal vessel containing sea water. The length of the track was measured during three days with intermitted leveling of the surface without disturbing the animals. The minimum, maximum and average length of the path after twelve hours was determined, as well as the height and the width of the track and the degree of burrowing. The lengths as well as the height and the width of the track and the degree of burrowing. The lengths of the paths before the first and second burrowing were compared. Light dependency of motion was studied by artificial darkening. The animals were very active regarding to length of tracks. They moved on the sediment surface, burrowing once, after a while coming out of the sediment again and continued to move. Specimens were found with one third to whole body burrowed or not at all. The movements didn't depend whether the animal was primarily positioned on the left or right shell. It was hard to asccrtain the direction of movements, because animal uses already made tracks. It has been shown that the animals react on light and dark, because the movements and the burrowing occur during night time and also during day time if darkened arificially.

Corbula gibba; behaviour; aquarium conditions

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