Catshark breeding

For once this post will not feature too much dead stuff, but there will still be plenty of fish. We've had our own small catshark (Scyliorhinus canicula) breeding facility for a few months now. We currently have 15 mature individuals kept in a large tank at a nearby marine station, where they're happily reproducing and laying plenty of eggs.

The adults. They usually rest on the bottom of the tank but grow quite animated during feeding time.

Curious catsharks.

Plenty of eggs. Embryos are visible through many of them.

We bring the eggs to the lab every week or so, where we keep them in a large aquarium until the reach the desired developmental stage. The nice part is that although the eggcase color will vary from female to female, you can always see through it and check on the developing embryo inside.

Developing embryo.

We keep our weekly harvest in individual baskets in a large aquarium. The sausage shaped things on the bottom are tunicates (Ciona intestinalis). In the lower right corner you can see a newly hatched catshark resting on the bottom of the aquarium.

Catshark embryos at various developmental stages. From left to right: 1.5, 4 and 5 months old.

Scale bars: 0.4/0.6/0.8 cm