Goniodorididae Family

Family Goniodorididae

The body size of goniodorids ranges from small to medium (i.e. less than 30 mm crawling length). The mantle skirt can be reduced to a lateral ridge which may carry a few small or quite long processes or may have a distinct prominent brim that is sometimes enlarged into a flange or long appendages each side at the level of the gills – extra branchial processes.
The rhinophores are long (especially so in the genus Okenia), tapered, and lamellate, sometimes sparsely so, and although contractile possess no pocket or sheath for complete retraction. Species of the genus Trapania also have a pair of long extra-rhinphoral papillae. Their simple gills too, are contractile, but do not possess a pocket for retraction under the surface of the mantle. They form a circle around the anal papilla posteriorly on the midline of the dorsum.
There can be as few as three small and simple gills. The oral veil forms either flattened lateral lobes or a pair of long tentacles.
The dorsum can have a midline ridge with papillae that can range from short to very long processes either side of the gills.
The foot tapers posteriorly to either a rounded point, or it can be sharper and deeper like a keel.
They prey on bryozoans or ascidians.