Pond Boss Forums INTRO Questions & Observations Are female smallmouth larger than their male

counterparts in the way it is with largemouth bass? I'm not seeing much on the Internet and the only thing I've found is one entry that says there is no size difference. I don't always believe some of those entries as I've see a lot of hearsay on the Internet.

I'm asking because I'm moving smallmouth to my hatchery pond and I seem to have two size groupings. The large ones are not obviously gravid but stocky. Perhaps it's just a little early yet?

Anybody know for sure?

CB1: Maybe not for sure but one study - of R.J. Danehy & N.H.Ringler 1991. A total of 110 bass were sampled.(Ecology of smallmouth bass (Micropterus dolomieui) in the nearshore of Mexico Bay, Lake Ontario.) they say ""If one considers all other age classes (ages 1-8; other than 9&10 yr old fish), it appears that the differences in those age classes 1-8 were insufficient to consider growth rate of male to be more rapid than females."" I also note in my article that male and female SMB grow at about the same rate in Part 5, Rule 3 Growth Rates, of "Growing Smallies Into Trophies". Pond Boss Magazine Nov-Dec 2009.


FYI for those interested: diet of SMB showed distinct differences in feeding habits influenced by substrate type. On sand bass were almost entirely piccivorous with no invertebretes except for a few crayfish in midsummer. Diet of bass inhabitating cobble/rubble fed heavily on crayfish and crays represented the entire diet in September. Overall SMB associated with shoal type structure was a benthic feeder whereas over sand substrate they were primarily pelagic feeders. This is why SMB are often considered opportunistic feeders.

Growth of SMB begins when water temps reach 50F. This temperature coincides with when my YP begin actively feeding at the surface. Optimum growth for SMB in the lab was considered to be 74-84F.

In another study Cantin & Bromage found that SMB begin spawning when the day length is 14 hrs and water temps reach and stabilize at 64.5F. These data were based on laboratory studies. Current day length for our area is 13hrs 19 minutes.

Thank you Bill, invaluable stuff for SMB fans.

More valuable information for SMB fans is SMB are surviving the second year in a Texas small pond after stocking of SMB fingerlings in 2010. No LMB are in this pond. The interesting thing besides eduring hot dry weather last year in Texas, is this particular pond is turbid due primarily to suspended silt/clay and minimal phytoplankton is present due to silty conditions. It is not known if these Texas smallies have or will sucessfully spawned to recruit YOY. Stay tuned for more info on this topic.

So trying to sex them by size would be unwise?

Maybe not unwise, but surely not the most accurate way....

True but I hate to put too many fish in the pond just to makes sure I have enough of each sex!

I think I'm going to have to find some catheter tubes, anesthetize the fish and see if I can determine their sex.

I stock 14-20 just to be safe...don't want to wait until gravid as I'm afraid I'll be too late. Fishing out 20 adults isn't too hard, but it's kinda a pain. I wish I have a better system...with Condello around it doesn't take too long to get em corraled tho.

There are alternative systems for SMB. One can use the fry transfer method or make portable nesting boxes. SMB fry do not school well and scatter quicker after swim-up compared to LMB. When the fry have almost hatched move the nesting box to another pond. Both methods require an underwater viewer glass of PVC tube 3-4" dia fitted with glass on one end.
In fry transfer method, nests are inspected daily with viewer. When eggs are found the nest is tagged or marked to indicate when eggs should hatch. In warmer water of high 60's to 70F egg hatch can occur in 2-4days. Spawn to swim-up is usually 10-21 days depnding on temperature. When eggs hatch a retainer screen is placed around nest to confine fry. Retainer screen is often about 3ft in diameter & 40" deep, covered with window screen. Swim up fry are then dipped out of retainer screen enclosure and transferred to rearing pond.

Portable nesting boxs are built using 1X4 lumber, 24" square with window screen bottom. Inside a 16"X16" 2" high hardware or plastic mesh 'basket' holding 1"-3" rocks is placed in the nesting box. The mesh basket also could be made from 1/4 nylon seine netting that has surplus material around the edges to create a 'bag basket' when edges are pulled together. When the fry hatch and before swim-up the fry are harvested by lowering the pond level and gently moving the 'basket' up & down washing the fry through the rocks and onto the screen bottomed frame. Rinse fry into a bucket or tub for transfer.

I'm aware of this Bill as it's in the "black book." However it's not practical in my steep sided pond and frankly it seems to be a lot of trouble.

I think I'm going to either have my vet do a portable ultrasound on the fish to see roe (anesthetized) or wait until I am closer to the spawn and do a catheter probe.

Is that covered under obama care?

No need with vet care. It's actually affordable!

My vet probably wouldn't charge much for an ultrasound of a few fish. I'm going to call tomorrow. I'll take in about 10 smallies in a large cooler and she can bring out the ultrasound. Worth a try!

She used a small portable ultrasound the other day for my dog as the dog has a bladder infection. The dog's bladder showed up clear as day! Entire bill was $54.

CB1 - Maybe with ultrasound you can see if there is an outward difference between males and females.

Cecil, you never cease to amaze me in the high tech things you do in the name if fish culture. Ultrasound on bass to look for eggs! Pretty cool... HAHA

It may sound crazy but if I was a serious producer that wanted to produce a lot of smallmouth fingerlings at a one or two dollars an inch or more, using a portable ultrasound, if it got the job done quick and easily wouldn't be so crazy.

If you get a pic of the ultrasound can you share it ?

Of course! Appointment is at 2 P.M. Wednesday.
She didn't think anesthesia was necessary. I said actually it is as these are smallmouth bass -- unless you want to get really wet!

No promises on if this will work but I will take pictures and we will give it a shot! I'll tag the females with a temporary clip on tag on the lingual tissue and get close ups of the urogenital orifices of both egg laden fish and non egg laden fish.

She offered to come out to the farm but she's only 3 miles down the road and I can easily catch a few, put them in large cooler in the back of the SUV and head down the road. I will line the back of the wife's SUV with plastic of course!

Speaking of ultrasonic stuff.

I was wondering if any one knew if ultrasonic level sensors would have any negative effects on fish? I could just pulse it every so often, and not run continuous. One less thing to have to clean.

Don't know but I know a aquaponics producer that uses vibratory feeders to produce vibrations to dislodge waste particles in his media for his media based plants.

I can see how that works. I use to design and build vibratory bowl and track feeders. Pretty simple. Choke coil mounted on a spring with a variable transformer. I should have a few choke coils laying around, and I know I have a couple variable transformers. I was thinking about building a vibratory fish feeder. If you know how to tune them, they work really well.

Cecil:

I have a tagging gun from Greg Grimes. Mike has red and yellow non-numbered floy tags. All I have are the yellow numbered floy tags. You could mark them permanently if you want.

I can have it in the mail tomorrow and it'll be at your place on Wed.

Scott,

Thanks for the offer but I'll pass. I have a clip on tag I'll take off just before I plant. I don't want to do anything that will make them less valuable when i go to sell them. If I really wanted to mark them permanently I'd cut off a dorsal spine or two.

I've also see those tags cause a heck of an infection.

True, I keep forgetting about the market.

The offer is much appreciated though.

Any discoveries from the ultrasound today?