Induced Spawning of the Decapod Crustacean Sicyonia ingentis

¹ Department of Animal Science and the Bodega Marine Laboratory, University of California, Davis, Bodega Bay, California 94923

The dark portion ofthe light/dark cycle initiated pre-spawning behavior in the penaeid shrimp, Sicyonia ingentis. Persistent swimming in the water column (pre-spawning behavior) correlated well with ovulation. Over 96% of the animals that exhibited active swimming behavior were ovulated as determined by the presence of green oviducts and/or their subsequent spawning. More than 87% of the ovulated animals responded to probing of the ovipores, located at the bases of the third pair of pereiopods, by immediately spawning. The ova from probe-induced spawns underwent a normal developmental sequence. A reliable and predictable technique for the assessment of ovulation and acquisition of viable ova from S. ingentis is described.