Pond Boss Forums Thread Like Summary - Anyone with GAMs habitat experience?

Adding FHM and GAMs into the new pond. Been reading around on FHM structures and spawning habitats. I know FHM may not survive a couple seasons with SMB, but why kind of areas and structures are needed for successful GAMs? RES, YP and SMB not being added until next season so these little guys will have a year all to themselves to set up.

I have found that gambusia stay in shallow water.... have seen LMB slide up on the bank flopping then getting back into the water , fun to watch. Have never had them in a predator free pond so they might go all over the place if nobody is trying to eat them

Gams are live bearers, so no special spawning structure is needed. They should do fine; the structures you are likely to add for SMB and YP will provide any hiding spots the Gams might want.

They are fast little fish.

+1

It has been found that smaller ponds can support greater densities of GAMS. This is because the shallow edges provide the cover they seek and smaller ponds have a greater ratio of perimeter to area. I have noticed that APW greatly extends the habitat allowing sufficient cover to protect a larger population. So some pond weeds are a benefit for them.

Swingle added 1623/acre of Gams (~2 lbs/acre) to treatments of 1625 BG/acre (~52 lbs/acre) in fertilized ponds. The Gams provided sufficient food over the 5 month grow out to increase production of BG by 145 lbs/acre ... a greater than 86 % increase in BG production. So very good forage. One way to wrap your head around their impact is to calculate how much feed would have been required to do the same at a conversion rate of say ... 1.8. So around a value of 261 lbs/acre of formulated feed with no increase in nutrients relative to the control. Pretty amazing when you think about it.

On a sunny winter day it's not unusual to see the gams in my pond swimming in the shallows under ice.

Spring of '19 I put in ~2 dozen that I collected in the marsh. Now there are thousands.

It's great entertainment watching the YP hunt them, like watching paint dry, and then KABOOM!

esshup,

Most GAMs surviving winter will be mid-summer or later born fry. This is normal even for a population of without predator fish. Their numbers get relatively weak by spring. Kingfisher, Green Heron, Crayfish, Frogs, large carnivorous insects etc take a toll on them too. The good news for anyone who can maintain a population is that winter survival of only a percent or two is probably enough to keep them going. Their footprint, even when they peak in numbers will always be a minor portion of the biomass. But they can produce more than one generation in the summer that able reproduce grandchildren in the same year. This is what tips the balance for them making them able to grow a population while being cropped.

GAMs show promise as annual introductions because of the same. In other words, one can stock a relatively small number of them at the start of the reproductive season and they can produce a lot of forage before they are fully consumed over winter in a pond like yours even with insufficient cover. So when you build those little production ponds, you might consider dedicating one of them to GAMs. Anyone following a annual introduction regimen could get a big boost of cover for GAMs if they have a syphon with a standpipe where they could adjust the maintained pool at two different levels. In the north of the GAMs range, lower the level after ice-out and grow a winter annual along the ponds edge (something like Italian Ryegrass) or even winter wheat. Time flooding with the start of the first releases of fry and stock the adults at that time. This cover will only last a few weeks but it would be sufficient to get off a couple of generations all the while providing cover for them and habitat and food for the organisms they would feed on. In the south, one could lower the levels in the fall if they wanted more growing season.

A similar flooding regimen could be used with buried crayfish introductions also. For a slope of 3 to 1, a 16" drawdown provides a perimeter of 4 foot of crayfish habitat. These crops should be grown in late summer and fall and flooded early spring with berried crayfish introduction at or after flooding. 20 to 30 berried females/acre (around two to three pounds) would probably be ideal.