Young sea star

Close-up view of a young sea star or starfish, demonstrating two of the key anatomical features  of echinoderms, the phylum to which they belong. The first is the pentaradial (five-way radial) symmetry that gives it its characteristic star shape, which is highly unusual. This symmetry means that, unlike most ‘higher’ animals, the sea star has no head or…

Mouth of a brittle star, Ophiocoma echinata

  Five mouth parts of a brittle star, with teeth. Brittle stars often eat detritus and sometimes filter organic particles in the water column. This specimen was collected in Bocas del Toro, Panama. Image: LSR