On the sides of the body are two pairs of irregular lobes with toothed edges and squared ends known as cerata.

[1][2][3] Scyllaea pelagica occurs globally in pantropical oceans among floating masses of weed.

[4] Scyllaea pelagica is nearly always a pelagic species but is occasionally found on brown seaweed anchored to the seabed.

It feeds by grazing on the hydroids that grow on the weed[3] and if it gets detached from the fronds can swim to a limited extent by flexing its body.

The eggs are laid in a jelly coated mass on the weed and the trochophore larvae are planktonic.