The Kina Urchin is a marine invertebrate that belongs to the phylum Echinodermata meaning “spiny-skinned.”  The kina urchin has five teeth that come out of a small hole in the shell and scrapes and chews seaweed off rocks. An interesting fact I read about was that researchers recorded something that they think was the kina urchin eating.  They think that the kina urchin actually makes a low-frequency sound as its chewing seaweed by moving their teeth in and out.

The Kina Urchin can grow to be 40 to 50 mm in 7yrs, the largest found was 150 to 250 mm. Their coloration is black, dull green, olive, brown, purple, and red.  They have a spiny shell used to protect their body inside. The kina urchin has a large variety of short spines protruding out of its shell. The kina urchins have tube feet and a water vascular system. Their water vascular system helps them with locomotion, food and waste, and respiration.

The kina urchin lives in New Zealand on the rocky and sandy sea floor. They live on shallow rocky reefs, cobbled areas, and on sand mud substrates. It spends the day in rocks and comes out to eat algae at night. There seems to be less kina urchins inside Kapiti Marine Reserve than outside. This is because of the number of predators, such as the blue cod and the rock lobster that have increased in the reserve. Outside the marine reserves there are fewer predators and the kina urchin numbers seem to have grown.

The Kina Urchin eats larger brown algae, red algae, and kelp. If kina urchin populations were to get out of control entire kelp forests can be eaten away. This urchin competes with a range of invertebrate herbivores, most notable the paua. The kina urchins predators consists of large rock lobsters, seven armed starfish, spiny lobsters, eleven armed starfish, cymatiid gastropods, and otters. The kina urchin avoids being eaten by its predators by hiding in crevices.

I found the Kina Urchin interesting to learn about and found many interesting facts. When the Kina Urchin eats an entire kelp forest it’s called Kina barrens.  The kina urchin is also considered a delicacy by the Maori. Their test or shell looks like a green hedgehog. The kina urchin has five teeth called Aristotle’s Lantern.

Author: Brianna B                                                                                                                                                                  Date Published: 2/2013                                                                                                                                                  Sources: http://www.echinoids.nl/Echinoids/Evechinus-chloroticus/Evechinus-chloroticus.htm2006  http://www.sciencelearn.org.nz/contexts/The-Noisy-Reef/NZ-reasearch/NoisyKina 2011                                                                                                                       http://www.mahingakai.org.nz/mahinga-kaispecies/kina 2000-2013 Photo credit: http://en.wikipedia.org/wiki/Kina_(animal) 2010 Natali Delorme