<p><em style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium;"><strong>Acanthurus</strong></em><span style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium;"> is the </span><a href="http://en.wikipedia.org/wiki/Type_genus" style="font-family: "Times New Roman"; font-size: medium;" title="Type genus">type genus</a><span style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium;"> of the </span><a href="http://en.wikipedia.org/wiki/Family_(biology)" style="font-family: "Times New Roman"; font-size: medium;" title="Family (biology)">family</a><span style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium;"> </span><a href="http://en.wikipedia.org/wiki/Acanthuridae" style="font-family: "Times New Roman"; font-size: medium;" title="Acanthuridae">Acanthuridae</a><span style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium;">. Approximately half of all members of the family are members of the genus </span><em style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium;">Acanthurus</em><span style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium;">. They are found in tropical oceans, especially near </span><a href="http://en.wikipedia.org/wiki/Coral_reef" style="font-family: "Times New Roman"; font-size: medium;" title="Coral reef">coral reefs</a><span style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium;">, with most species in the </span><a href="http://en.wikipedia.org/wiki/Indo-Pacific" style="font-family: "Times New Roman"; font-size: medium;" title="Indo-Pacific">Indo-Pacific</a><span style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium;">, but a few are found in the </span><a href="http://en.wikipedia.org/wiki/Atlantic_Ocean" style="font-family: "Times New Roman"; font-size: medium;" title="Atlantic Ocean">Atlantic Ocean</a><span style="color: rgb(0, 0, 0); font-family: "Times New Roman"; font-size: medium;">. As other members of the family, they have a pair of spines, one on either side of the base of the tail, which are dangerously sharp (hence the name "surgeonfish"). Depending on species, they grow to a maximum length of 15 to 50 centimetres (5.9 to 19.7 in). Many are very colourful and consequently popular in the marine aquarium trade.</span></p>