''Echinometra lucunter'', the rock boring urchin, is a
species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...
of sea urchin in the
family
Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...
Echinometridae. It is found in very shallow parts of the western Atlantic Ocean and the Caribbean Sea.
Description
''Echinometra lucunter'' has an elliptical rather than a round
test
Test(s), testing, or TEST may refer to:
* Test (assessment), an educational assessment intended to measure the respondents' knowledge or other abilities
Arts and entertainment
* ''Test'' (2013 film), an American film
* ''Test'' (2014 film), ...
(shell). It can grow to a diameter of about and grows larger at the extreme north and south ends of its range than it does in the centre. It has moderately short spines with wide bases and sharp tips. The colour of the test varies from black to deep brownish-red, often being more ruddy on its aboral (upper) surface than on its oral (lower) surface. The spines are usually black.
Distribution and habitat
''Echinometra lucunter'' is common throughout the Caribbean Sea and also occurs in Florida, Bermuda and the South American coast as far south as Brazil. It occurs on shallow rocky areas and on
coral reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
Co ...
s usually at depths of or less but occasionally in deeper water down to about . It is sometimes found among
seagrass
Seagrasses are the only flowering plants which grow in marine environments. There are about 60 species of fully marine seagrasses which belong to four families (Posidoniaceae, Zosteraceae, Hydrocharitaceae and Cymodoceaceae), all in the orde ...
es and often under rock slabs or broken coral especially in places with high water movement. It sometimes occurs in large numbers and causes considerable damage to coral reefs through its boring activities.
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]
Biology
''Echinometra lucunter'' uses the teeth that surround its mouth to grind away at the rock underneath it so as to make a hemispherical depression in which it takes refuge during the day. It emerges at night to graze on algae growing within a few centimetres (inches) of its home.goby
Goby is a common name for many species of small to medium sized ray-finned fish, normally with large heads and tapered bodies, which are found in marine, brackish and freshwater environments. Traditionally most of the species called gobies have b ...
conceal themselves underneath its test.[
]
References
{{Taxonbar, from=Q153395
Echinometridae
Animals described in 1758
Taxa named by Carl Linnaeus