Pond Boss Forums MANAGING AN EXISTING POND Evaluating and adjusting fish populations Differentiating between male and female bluegill

great thread - learned a lot, ty!

Is it easier to figure their sex while they are smaller? Because i have some colorful and some plain color BG's. I think maybe the colorful ones are males. (They are 4-5 months old by the way)

Faith , BG are more difficult to sex when they are smaller and immature.

What kind (Northern, Coppernose, etc.) of BG are being sexed. When it comes to the male side, you can, and more often than not do have more than one functional type of male and they complicate sexing based on looks alone.

Pics

Here are the missing pics from the PB article on BG sexing by Bruce , Bill and Cecil lost due to Photo Bucket. They do not attempt to cover the sexing of alternative lifestyle BG male cuckhold/sneekers etc.

See Important Notes below from Jim Wetzel

Be assured this is not a strictly academic concern so I am hardcore when it comes to sexing BG because messing up gets expensive.

Focusing on Northern BG;

Dorsal spot is not a reliable indicator as is has more to deal with mental state that is generally independent of reproduction.

Urogenital opening works when females mature. Opening I am concerned with is the most posterior as I am not not able to sex a fish based on appearance of the poop. Expressing gametes is better. The yellow coloration of male's vent area works best on the first type of male below.


Northern BG males come in three flavors with different names according to who you are talking to. First is bull / primary / nest building that has the large opercular tab, dark spots on nape and sometimes dorsal part of flank as well as a generally blackish cast ventrally. Such males can possess solid bars on flanks. This variant most people will pick up off nest or out of raceway and call a male with little hesitation. Second differs first by having a smaller opercular tab and less developed black spots. Solid bars can also be present. This variant can be confused from a distance, especially when keying in on opercular tab and sooty look of the first type. This dude looks like a lady and seldom makes a nest and when he does has a hard time sticking with it. The third type is small like a juvenile without taking on pattern of either female or male. These guys sneak into nest and drop a load when female is extruded eggs with the first type of male doing most of the work.

Northern BG females have a freckling pattern on flanks, generally smaller opercular tabs that can occasionally be larger than those of the second male type, and generally a yellowish belly early in breeding season. As breeding season progresses, actively spawning females start to look silvery as pigments are depleted as they are invested in eggs.

Jim, there seems to be more confusion about sexing BG than just about any other topic here. We'd love to see pictures if you have time at some point in the future. It is intriguing that there are 3 distinct males and at least 2 patterns for females. No wonder we study so many pictures of BG on this forum and always find it so hard to decide male or female.

We first must get bet beyond using the term BG as like not distinguishing a LMB from a SMB and a SB.

I have been working with wild stocks from all over. Northern BG are pretty consistent no matter where you get them from. Coppernose BG really mess things up and I am still trying to figure out Han-paint BG. The some of the Coppernose BG stocks are very different from each other as well making so generalizing not so easy. I have messed with what I think were Southwestern BG which are very similar to Northern BG but not enough to say much with confidence. Give me time to work up pictures which may take more than a year.

The BG clan is almost as much fun as the LES clan.

I think sexing LMB is much harder than Northern BG when there is no milt/eggs present.

When I'm sexing Northern BG, I go by the rule of thumb that if I'm not 100% sure it's a female then I consider it a male.

Same for a male. If I'm not 100% sure then all bets are off. I also agree with Jim, don't even start going down the hybrid or different species Bluegill path in regards to male/female.

Here on the forum I consider "BG" to be synonymous with Northern pure strain Bluegill.