On the short run coastal rivers we've caught chrome "downers" during all parts of the season. Yes, some are very distinguishable, but on larger hens it can be difficult to determine if they've spawned. We look for a slight "fold" or a channel on the belly, up around the pec fins. This sunken-in area is from an empty cavity.

The "red-hang down thingy" can be seen on both spawned and ripe hens though.