Pond Boss Forums FISH & FISHING Fly Fishing & Other Fish Species what kind of shad is this?

I'm in deep south-texas, is this a threadfin or gizzard shad? i forgot to mention that its almost 2 inches long. thanks for the help. caught them from my pond in brownsville...i did not stock these, they were already there..water levels rose after the hurrican a couple yrs ago? its fat from gorging on aquamax. the pond is not connected to another body of water like a river or anything.

It's neither a threadfin or gizzard. I don't recognize it right off the bat.

Where did it come from...pond, river, lake, bay, Syria?

Mr. Lusk..I added more pictures and gave a more detailed explanation in the original Post...how do u find out what they are?

Looks a little like a fat Gambusia

The two facing right look like gambusia....but the others... the head looks different.

Looks like a Mexican Tetra.

To me the 4 on the bottom look like Gambusia. The one on the top is the puzzle.

+1

USGS Mexican Tetra (Astyanax mexicanus)

One pic I saw of them looks like they have some decent size bony teeth.

so is this a sign of more immigrants?

Subtropical America. Mostly eastern and central Mexico and also the lower Rio Grande, lower Pecos, and Nueces rivers in Texas (Lee et al. 1980 et seq.; Page and Burr 1991). Historically, found in the Pecos River drainage and lower Rio Grande in New Mexico, but now restricted to the Pecos drainage downstream of Dexter (Sublette et al. 1990).

From reading the USGS page, it looks like it has been found in AZ and OK, possibly by bait bucket stocking (transferred with other bait minnows when collected from the wild). It's a predator unlike GSD and THS.

I think this is the first I have seen anyone with Mexican tetras in their pond. Very neat! They are pretty aquarium fish and are often traded in the native fish aquarium trade.

They are more of stream/creek fish, interesting this one was collected from a pond. Does this pond have a feeder creek or experience occasional flooding from a nearby creek?

They reach about 4" in size, so they certainly can be a forage fish. One that doesn't get so large to not be effectively preyed on. However, like many forage species they are predacious in nature and feed on other living animals and such will compete with young bass and sunfish for food.

Food habits from the Texas Fish ID website: This species is usually highly carnivorous, feeding on smaller fish, although in northeastern Mexico it has been reported to be omnivorous, with plants, filamentous algae, and aquatic insect comprising the bulk of its diet (Birkhead 1980). In the lower Rio Grande, diet includes green algae and plants, various terrestrial and aquatic insects, and occasionally fish (majority Gambusia affinis; Estrada 1999); at Phantom Springs, near Toyavale, Texas, tetras consumed similar foods as did lower Rio Grande population, although no fishes were observed in the diets of individuals from Phantom Springs (Winemiller and Anderson 1997). In each of three Balmorhea State Park environments sampled, a variety of foods were consumed, including green algae, amphipods, ostrocods, insects, crayfish, snails, and (at one site only) fish (Edwards 1999). Young-of-year observed feeding voraciously on insects, in Waller Creek (tributary of Colorado River), Texas (Edwards 1977).

The pond is about a 1/2 mile from the Rio Grande River. So it makes alot of sense..I wanted to use this smaller pond as a bream pond and didn't want to put any bass in untill i grew them 8lbs or better from my larger pond..do u think these tetras will help control the bream population in the mean time? that brings up something else, i have yet to see a single bream or fathead minnow that i stocked a couple mths ago? theres tons of gambusia..Do u thing those tetras ganged up and ate my 2-3in CNBG adn 3-4in fatheads?

I doubt Mexican tetras will control a BG population. I am sure some larger ones will prey on the small fry, but that will be the extent of it. Gambusia are aggressive little buggers, but I doubt they would be able to eat 2-3" BG or 3-4" FHM... Could you have had a serious drop in DO and had a fish kill? Gambusia and tetras are highly tolerant of low DO, FHM are as well but not as much, BG would be the first to go of the 4. In all likelihood, they're there you just aren't seeing them...