What shape do brown recluses have on their backs?

Question

What shape do brown recluses have on their backs?

Answer 1

It looks like a violin or a fiddle in a mature brown recluse.

But young brown recluses won't sport a fiddle, and other nonrecluse spiders may display the mark.

To be a brown recluse, a spider must have six eyes in dyads (pairs), uniformly colored abdomen with fine hairs, no spines on the legs, uniformly colored legs and a body not more than 3/8” in length.

Answer 2

Violin/fiddle.

http://www.brown-recluse.com