Observations sur les comportements de Lucifuga Subterranea Poey (Pisces, Ophidiidae), poisson cavernicole de Cuba

The swimming behaviour and the sensory reactions of the blind Cuban cave fish Lucifuga subterranea Poey were studied on a single individual during a period of 6 months. Mechanical stimulation elicits but slight reactions. Gustatory substances in solution elicit fairly typical motor responses which are not followed by systematic exploration behaviour, the same being true for stimulations by odours of prey. The presence of moving prey provokes an oriented exploration with a slight plunging movement of the kind evidenced in other cave fishes. Actual seizing of the prey requires an active approach of the latter towards the anterior part of the body of the fish

AIRES DE RÉSIDENCE PRÉFÉRENTIELLES D'UN GROUPE DE VACHES LAITIÈRES EN STABULATION LIBRE

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Effets des informations chimiques provenant d\u27un milieu habité par des congénères sur I\u27orientation topographique du poisson cavernicole Phreatichthys andruzzii Vinciguerra (Pisces, Cyprinidae)

Two series of experiments were performed on the oriented locomotor responses of 27 specimens of the blind cave fish Phreatichthys andruzzii from Somalia using a three-compartment choice apparatus. The oriented responses were observed individually from the central compartment towards either of the extreme ones. In one of them, 500 ml water were introduced from either the tank in which the test fish had previously resided with conspecifics (1st series, 46 experiments) or from another tank occupied by unknown conspecifics, the other compartment receiving an equivalent volume of pure water. The two series were performed in random blocks of 6 experiments, the momentary position of the test fish being noted every 30 seconds after an adaptation period of at least 4 hours. Results, analyzed in 9 blocks of 5 minutes show a definite preferential orientation of the fishes for the compartment containing chemical information from both known or unknown conspecifics. This effect is discussed in relation to the ecological conditions in which the species under study lives