Plecostomus (family Loricariidae)
Other names these fish goes by: Pleco, Suckermouth Catfish, Algae Eater
This one might come as a surprise to some people. After all, pet store employees are very quick to recommend plecos to beginners. These fish, however, should be avoided unless you’ve done extensive research. Many of them grow to be really big (including the common pleco or Hypostomus plecostomus) and shouldn’t be kept in your average, small community aquarium. Plecos are also messy and many have specialized needs such as requiring a low pH or needing to chew on driftwood. The term “algae eater” is usually used to describe a pleco but the truth is they rarely eat algae unless starving. These fish should be supplemented with a variety of foods, including fresh vegetables. All plecos aren’t bad for beginners, though! There are a few smaller species that can make excellent community fish and the bristlenose pleco (Ancistrus triradiatus) is a good example of that. When it comes to plecos it’s extremely important to research the species in question BEFORE making a purchase.
I want elaborate more on the Plecostomus or "sucker fish. They might look cute when young and recommend by your local pet shop. People tend to release them when they get to big not knowing that it is consider hazardous when release these fish into natural waterways, natural ponds, rivers and lake. Many countries are facing this serious issue as these sucker fish have the biggest appetite on feeding on as many native fish eggs as they can find. Greatly reducing the numbers of other fish species.
---Taken From Yahoo---
An armored catfish (Image credit: U.S. Army Corps of Engineers/Sun-Sentinel)
A species of "armored catfish" are damaging South Florida's lakes, causing coastal erosion and even burrowing holes that trip up humans walking along the water's edge.
Catfish are usually one of the more popular breeds of aquatic life, with their smooth skin and flavorful meat. There's even a highly unconventional form of fishing known as "noodling," in which people use their bare hands to capture catfish.
But the Sun-Sentinel reports that the Loricariidae (armored catfish) are far less welcome. The non-native and invasive species have rugged scales along their backs and spiky fins. Catching the South American natives can be difficult, as the armored catfish reportedly are not baited by fishing hooks and must instead be caught by nets or even spears.
"There are some people who get totally upset, and I can understand why," Ralph LaPrairie, a fisheries biologist with the Florida Fish and Wildlife Conservation Commission, told the Sun-Sentinel.
The Loricariids are a popular aquarium fish, as they use their suckered mouths to clean algae from tanks. But that same behavior that is helpful in fish tanks actually erodes local shorelines up to 10 feet as the fish devastate aquatic plant life. They have also been wreaking havoc in Texas waterways for a number of years.
"One, it's a safety issue. Two, it's a curb-appeal issue," Chip Sollins, owner of Lake Erosion Restoration, a contractor in Boca Raton, Fla., told the paper.
Invasive fish are a growing problem across the U.S. with wildlife officials in Maryland offering a $200 gift certificate raffle to residents who capture and kill snakehead fish, which have been devastating local wildlife in tributaries along the Potomac River.
However, any potential solution for the pests would be an expensive one for local residents. The Sun-Sentinel says hiring a contractor to eradicate any local armored catfish populations can cost as much as $100,000. And there are reportedly millions of the small armored fish currently living in South Florida, with no known natural predators.
"If we do nothing, I think eventually we're going to end up with a sinkhole," said Susanne Ury, president of the Royal Lakes Homeowners Association.
In addition to contributing to erosion, the armored catfish lay their eggs in 18-inch-deep holes along the water's edge, creating potentially dangerous foot traps for people walking in the water.