fins
... that fins are used on artefacts and by aquatic animals such as killer whales to generate thrust, to control motion, or to regulate temperature?
... that <b id="mwvg"><a href="./Fin" id="mwvw" rel="mw:WikiLink" title="Fin">fins</a></b> are used on artefacts and by <a href="./Aquatic_animal" id="mwwA" rel="mw:WikiLink" title="Aquatic animal">aquatic animals</a> such as <a class="mw-redirect" href="./Killer_whale" id="mwwQ" rel="mw:WikiLink" title="Killer whale">killer whales</a> <i id="mwwg">(pictured)</i> to generate thrust, to control motion, or to regulate temperature?