Pond Boss Forums MANAGING AN EXISTING POND Corrective stocking Unwanted bluegill in SMB, yp pond

Adding one LMB into a population of SMB is I think a doable thing HOWEVER I would do it as a last resort if it is discovered the SMB population is not effectively keeping the RES from becoming over crowded.

IMO the current concern of an over abundance of YOY RES is unnecessary because the RES parentage was from Arkansas and now living in winters of southern MI. It is very possible that the pond could lose 90% of the current number of RES after trying to endure the 2024-25 MI winter. More on this later.

For RES that survive overcrowding will be evidenced by their average slow grow rates of each year class. IMO this likely will not occur because of the limited fecundity of RES as they have basically one spawn per year especially northern regions. Carlander’ Fishery Biology says Average fecundity of RES is 16K to 25K for average mature females. Whereas fecundity of BG ranges from 33K to 73K per female. Generally fewer eggs laid to me means less egg hatch resulting fewer fry survival each year.

It is very possible that a lot of the YOY RES will not survive during the Odessa MI winter conditions. Evaluating the RES numbers and recording all the catch results from numerous Z-trap sets in Fall and then doing the same number of traps sets again in Spring will provide a good estimate of the year class and how well the RES overall will survive in a Michigan pond.

IMO I think the YOY RES will not survive the MI winter very well as their parentage gene pool and history was adapted to the mild winter of probably Arkansas. Plus RES are well adapted to eating small mollusks as a major food item although they will also survive and eat insect larvae. With a large YOY crop of the RES main food of snails are likely sparse due to their high number and their over harvesting the pond’s main RES snail food reserve. Winter is the hardest season for fish survival. Thus lots of YOY, especially if not in good body condition with adequate fat reserves, will have to endure a colder winter than their genetic make-up is adapted to enduring. Thus I expect a majority of the YOY and some of the mature RES going into winter will die during the normal conditions of southern MI winters. Even in northern and central Ohio numerous RES are stocked and we get most all RES are never to be seen again after enduring winter’s snow and ice cover conditions.

If the RES each Spring are very abundant (doubtful) as evidenced by trap sets then I would buy a long beach seine to remove what you think are excess RES. IMO and experience the fewer of one specie that is present the better they grow and the larger the size they become. Allow yor SMB to accomplish one spawn and produce a crop of new YOY smallies to prey on RES fry. If excess RES persist after the 3nd or 4rd year, then I would consider adding more SMB or one LMB 10”-12” long as a helper tool to remove more RES per year than the SMB are eating.

Comments have expressed a hybridization concern of adding one LMB into a pond with just SMB predators. Hybrid LMbass have been reported, however reports indicate this mainly happens as a cross of LMB with spotted bass. Very, very rarely have their been reports of a hybrid LMB X SMB occurring. The hybrid LMB bass have been called “mean mouth bass”. I have looked into this and IMO the hybrid bass has been over exaggerated and as I noted it most commonly occurs with LMB X Spots. If the “mean mouth” was a real doable thing some adventurous fish farm would be naturally hybridizing and producing these 'mean mouth' hybrids by crossing SMB with LMB. None exist and it is not done by fish growers I think for a very good reason. See next.

Let’s look at this from a perspective of biological and behavioral processes for the spawning of LMB and SMB. As you will see there are unique spawning behaviors that LMB and SMB use to recognize and utilize the same specie as a spawning partner. These behaviors are strongly engrained into each of the spawning species behavior. These specialized behaviors are different for very good evolutionary reasons for the keeping the specie reproductively isolated. IMO the chances are very slim or none for one LMB getting a SMB to naturally spawn with it. Thus IMO there is almost no chance that Josh will see any hybrid mean mouth bass in his pond. If Josh can produce any ‘mean mouth bass’, these will be highly valuable as an extremely rare fish to use for barter, sharing or exchange. I would pay high dollar for some of them. Note -- there may be no need for adding a LMB to his pond because IMO the RES survival of YOY will be minimal after each MI winter.

Pay attention of individual unique different spawning behaviors for each of the fishes of the pair of LMB and the SMB. Spawning behaviors of lots of animals especially birds are uniquely different that help dramatically to keep then as separate breeding species. Other wise mass hybridization would be commonplace.

LMB spawn at 59F-75F with mostly actual egg laying at 62-65F. Males leave the nest to search for ripe females. Male attracts females to the nest using courtship displays and rapid changes of body color patterns. LMB Males use nudging, nipping, and parallel swimming. Then the male positions vertical and female 45deg.
One detailed study found that LMB spawning usually happens around dusk. The LMB Male circled the female & bit her flank as she moved away. Then the female returned to the nest and turned with her head slanted & pointed downward and appeared to float in this position appearing motionless and half dead. Male LMB also assumed this position. Then both laid on the bottom side by side with tails parallel. Then one turned partly on its side as eggs were laid and fertilized. Shortly both moved out a short distance as the female stayed in the head down in the floating position fashion. For 30 minutes the two repeat the lying on the bottom with female in head down floating position and then with both lying close together on the bottom as movements are repeated as noted above as more eggs were laid and fertilized.

SMB egg deposition most often at 61-65F. Spawn behavior: Fishes of WI indicate that SMB will generally spawn a little sooner when both SMB & LMB are present. Thus there is often a temperature spawning difference and preference between these two species.
Behaviors - As SMB female moves into nest the male turns on his side with dorsal spines fully distended toward her, male and female go through considerable pre-spawn activity of display rubbing & nipping. Eventually they rest side by side on the bottom very close to touching bottom with the male vertical and female tilts 45deg as male remains upright w/ head just back of her pectoral fin or opposite of it. When Female is “ready” for egg drop she has a marked color change as dark mottling becomes prominent while the background color fades as she also displays peculiar fin movements when eggs are released.

Spotted bass spawn behavior appears to be less complex compared to LMB & SMB. Spotted males actively court a receptive female by circling and guiding her around in the nest while biting at her gill cover and vent. This encourages her egg drop as the male releases milt to fertilize the eggs. This less complex spawning behavior of Spotted bass maybe suggests why the hybrid Spotted bass (aka as ‘mean mouth bass) are much more common in nature compared to LMB X SMB.