Diet

• Echinometra vanbrunti is primarily a herbivorous grazer, feeding mainly on algae growing on rocks and other hard substrates. Its diet can include brown, red and green algae, with smaller amounts of animal material and other organic matter.

• By grazing algae from exposed rock surfaces, it helps maintain open areas of substrate that can subsequently be colonized by other marine organisms.

Range

• Echinometra vanbrunti is a tropical eastern Pacific sea urchin ranging from the Pacific coast of Mexico southward through Central America to Peru, including the Galápagos Islands.

• It is well established along the Pacific coast of Mexico.

• It occurs along the Guerrero coast and is suitable for the rocky intertidal and shallow-water habitats around Zihuatanejo.

Habitat

• This is primarily a rocky-shore and shallow-water species. It lives in crevices, tide pools and cavities that it excavates in rock, coral and other hard substrates.

• Although records extend from the intertidal zone to approximately 53 m, it is particularly characteristic of shallow rocky habitat and can remain in small depressions containing water when the tide falls.

• Around Zihuatanejo, it can be expected on rocky shores, reef flats, tide pools and shallow rocky areas exposed to moderate wave action.

Description

• Echinometra vanbrunti is a medium-sized, somewhat flattened sea urchin with an oval to slightly elongated test. The test can reach about 7 cm across, although individuals in shallow rocky habitats are often considerably smaller.

• The body is typically dark purple, violet, brownish-purple or nearly black. It is covered with numerous relatively short, stout, sharply pointed spines that are usually purple to black.

• A particularly characteristic behaviour is its ability to excavate and occupy holes in rock. Individuals often fit tightly into these cavities, using their spines and tube feet to brace themselves against waves and surge.