Joris van Alphen Photography

Mating Common Cuttlefish

Courting Common cuttlefish.

Not long after my previous attempt to witness Common cuttlefish mating, I joined my friends Jelmer and Floor in Zeeland for a second chance, and what turned out to be one of the most beautiful dives I've ever made.

I would say we saw around 30 cuttlefish — courting, fighting, mating, feeding, females depositing eggs, you name it — as well as a young Lumpsucker, several Bluefire and Compass jellyfish, and to top it off, I even caught sight of a Common European squid darting by!

In spring, around the time when the water temperature reaches 12°C, Common cuttlefish Sepia officinalis gather in the shallow waters of the Oosterschelde (Eastern Scheldt), an estuary in the south of the Netherlands: the spawning season has arrived.

When courting, the male will hover alongside the female, while drawing his arms over her mantle, head and arms. Eventually he will grasp her and mate in a head-to-head position. Using a modified arm, known as the hectocotylus, the male passes spermatophores to the female's seminal receptacle.

After mating, the female deposits eggs in clusters on substrates like seaweeds, shells and even debris. To render them less visible, the eggs are colored with the same black ink that is used to flee from large predators.

A female Common cuttlefish deposits an egg.

There is a massive mortality among the large females after spawning, while adult males may retreat to deeper waters to return for another reproductive bout the following year.

The eggs hatch after 30 to 90 days, depending on the water temperature. Hatchlings are highly developed and start feeding on small prey such as shrimp soon after hatching.

In most territories where it occurs, the Common cuttlefish is an important commercial resource for fisheries. The production is probably against the maximum sustainable yield in the more heavily fished areas. Tunisia, Greece, Spain, and Portugal are the most important players.

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