Head of a male Prussian carp (<i><a href="//commons.wikimedia.org/wiki/Carassius_gibelio" title="Carassius gibelio">Carassius gibelio</a></i> (Bloch, 1782)) showing lots of epithelial tubercles which appear at spawning time. The operculum (gill cover) has a round scar from an old injury. This fish was caught in the Southern Bug river, Ukraine.
<a href="//commons.wikimedia.org/wiki/User:George_Chernilevsky" title="User:George Chernilevsky">George Chernilevsky</a>
2009-06-21
<span class="int-own-work" lang="en">Own work</span>