The genus Cucumaria distinguishes from other genera of sea cucumbers through its members’ small to medium sizes, uniquely shaped branching tentacles and the ability to produce various toxins and substances that they use for defensive purposes. Dozens of species are part of this widespread genus, including better known specimens such as the orange sea cucumber, Cucumaria frondosa – or the orange-footed sea cucumber – and C. echinata. Cucumariidae species from this genus can be found in large areas across the seabeds of the North Atlantic, as well as places like the Red Sea and as far east as Japan and China.
Depending on the species, there are many appearance-related traits that can be assigned to this important genus of the family Cucumariidae. Most species can grow to sizes between 8 and 20 cm in length, while their bodies can be of various colors and hues between gray and bright orange. The species are set apart from other sea cucumbers due to being filter feeders, and using their five rows of tentacles to pass microfauna to their mouths. Their smooth, leathery skin is also one of their most easily recognizable features.
C. echinata, C. frondosa and C. miniata are the most famous varieties of sea cucumbers from the family Cucumariidae. Frondosa is one of the most widespread and abundant species in North America and on the coast of the United States, while miniata is known for its striking orange or red coloring and fifteen sets of imposing feeding arms. The oldest member of this genus was discovered by Brandt as early as 1835, and its name is C. nigricans. Other species include C. salma, C. turbinata and the relatively newly discovered C. dudexa.
Rocky areas and a relatively low depth of up to 100 meters are commonly associated with sea cucumbers for the Cucumariidae family, including the genus presented here. Species like C. miniata can be found as far north as Alaska, although most of the sea cucumbers will prefer slightly warmer, albeit temperate regions. It would not be a surprise to find these creatures as far south as the Gulf of Mexico. Their preferred habitats are rocky areas and crevices in stones at the bottom of the sea, usually being found in areas where the currents are stronger, in order to avoid predation. Cucumaria are mainly suspension feeders, using their oral tube feet as tentacles that surround the mouth, pulling detritus and phytoplankton from the nearby water columns.