Variabilité de la reproduction examinée au laboratoire entre populations naturelles d'Helix aspersa Müller de la région Bretagne

International audienc

Variations des capacités reproductrices de l'escargot « Petit-gris », Helix aspersa Müller (Mollusque Gastéropode Pulmoné Stylommatophore), selon son origine géographique. II. Incubation des oeufs et éclosion des jeunes

International audienc

Variations des capacités reproductrices de l'escargot « Petit-gris », Helix aspersa Müller (Mollusque Gastéropode Pulmoné Stylommatophore), selon son origine géographique. I - Accouplement et ponte

International audienc

Reproductive cycle of the cuttlefish, Sepia officinalis (L.) in the northern part of the bay of Biscay

The sexual cycle of the cuttlefish, Sepia officinalis, from the northern part of the Bay of Biscay was followed over several years (1988 to 1990 and 1992 to 1993). Sucessive maturity stages are reached at the same time regardless of site in the northern part of the Bay. In this area, the majority of cuttlefish reproduce during their second year of life (group II) whereas the remainder reproduce in their first year (group I). The first visible signs of sexual development concern the testis in males and the genital tract in females. Males mature earlier than females: the first spermatophores appear in July (group II) and October (group I) while mature eggs appear from December (group II) and March (group I). The breeding season lasts from about mid-March to late June (3.5 months)

Alimentation et croissance des civelles d'Anguilla anguilla L. (Poisson Téléosteen-anguilliforme) élevées expérimentalement en « canalisation », au laboratoire

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