Which of the following are elongated in the oral-aboral axis?
A)class Crinoidea (sea lilies and feather stars)
B)class Asteroidea (sea stars)
C)class Ophiuroidea (brittle stars)
D)class Echinoidea (sea urchins and sand dollars)
E)class Holothuroidea (sea cucumbers)

Question

Quizplus · Accepted Answer

Sea cucumbers (class Holothuroidea) are elongated along the oral-aboral axis, unlike other echinoderms which have a more radial symmetry.

Which of the Following Are Elongated in the Oral-Aboral Axis