Lytechinus variegatus (variegated sea urchin) (Sanibel Island, Florida, USA) 3

Description:

Description: English: Lytechinus variegatus (Lamarck, 1816) - variegated sea urchin (oral side) in Florida, USA (December 2013). The echinoids are a group of echinoderms - they are starfish relatives. On modern Earth and in the fossil record, echinoids are exclusively marine. Two broad groups exist - the regular echinoids (sea urchins) and the irregular echinoids (heart urchins and sea biscuits and sand dollars). Sea urchins have subglobular to slightly flattened, radially symmetrical skeletons (tests) composed of calcite (CaCO3 - calcium carbonate). The sea urchin test is covered with spines - these readily detach after death. Sea urchins have a mouth with a pentaradial structure called an "Aristotle's lantern" (see the center of the urchin in the above photo) that is used to graze on algae and other biofilms on hard substrates. The live sea urchin shown above is Lytechinus variegatus, the variegated sea urchin, or short-spined sea urchin. Classification: Animalia, Echinodermata, Echinoidea, Temnopleuroida, Toxopneustidae Provenance: marine beach immediately south of Sanibel Inn, southern shoreline of Sanibel Island, southwestern Florida, USA More info. at: en.wikipedia.org/wiki/Lytechinus_variegatus. Date: 15 December 2013, 18:59:31. Source: https://www.flickr.com/photos/47445767@N05/25741826352/. Author: James St. John. Camera location26° 25′ 43″ N, 82° 03′ 19″ W View all coordinates using: OpenStreetMap 26.428611; -82.055278.