Golden banded goby
... the Golden banded goby was originally differentiated from similar species by the structure of its anal fin?
... the <b id="mwDiw"><a href="./Brachygobius_nunus" id="mwDi0" rel="mw:WikiLink" title="Brachygobius nunus">Golden banded goby</a></b> was originally differentiated from similar <a href="./Species" id="mwDi4" rel="mw:WikiLink" title="Species">species</a> by the structure of its <a class="mw-redirect" href="./Anal_fin" id="mwDi8" rel="mw:WikiLink" title="Anal fin">anal fin</a>?