Why are motoro stingrays illegal in California? (serious question)

[tampa_bass]

I've always wondered that. When I started my time keeping FW rays at the aquarium in Dallas, the water they were tied into as the crocodile pool. It was pretty good, but not nearly what hobbiests say they require. You can imagine what a pair of 1,000 lbs (or more) crocs can do to water quality with a good poop or just walking around stirring up the substrate. The large volume was stable, and I would bet that was the key. We were keeping leo (breeding leos at that) in that pool back when keeping black rays alive was a very touchy subject. LOL

I couldn't agree more zoodiver. While on my fishing trips to south Florida I wonder how exotics including the cichla flourish in what looks to be such rancid water(in some areas) with all the garbage and even dead animals floating by! LOL
Like you said it's the volume of water and the stability it brings I guess..


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[tampa_bass]

What species of rays and where? Just curious. I know Florida is full of non-natives. And there are "tropical" marine fish from Florida/Caribbean that end up in Maine during the summer. I got my username from a spotfin butterfly I caught up here many years ago at the size of a nickle. Have also seen/caught short bigeyes, crevalle jack, grey triggers, flying gurnards, and look downs.

As far as 50F water, do you think they could maintain at this temperature for extended periods of time? I would guess reproduction would cease as well.
I think we all agree that rays can live at temps lower than 80F, but in rivers and lakes in the US I just can't see them "taking over". It takes a few years for them to reach sexual maturity and they don't produce a lot of offspring. There would have to be a large group of individuals released in the same locality at the same time, and several years (generations) for them to become established. Again, I don't condone the release of any aquarium fish into a local body of water.

Remember all of florida's rivers are spring feed even in north Florida. The water feeding these rivers comes out of the ground a constant 72 degrees.. So yes rays could easily takeover the river systems in Florida.. Also the danger this would pose to the millions of people who use these rivers for swimming,snorkeling,fishing,boating, etc. would be a big hit to the economy.. Do you think tourists or even a lot of locals would go in these rivers again once the media found out there were FW rays that could injure or kill you?


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[MN_Rebel]

Remember all of florida's rivers are spring feed even in north Florida. The water feeding these rivers comes out of the ground a constant 72 degrees.. So yes rays could easily takeover the river systems in Florida.. Also the danger this would pose to the millions of people who use these rivers for swimming,snorkeling,fishing,boating, etc. would be a big hit to the economy.. Do you think tourists or even a lot of locals would go in these rivers again once the media found out there were FW rays that could injure or kill you?


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Bingo! Everyone thinks that invasive species are all about take over the ecosystems. That's partially true but let's see definition of what an invasive species is. An invasive species is defined as an organism that is not native and has negative effects on our economy, our environment, or our health. Not all introduced species are invasive..So the FW ray fits in economy & health category.

That is why piranhas, FW rays and electric eels are banned in southern United States. Same thing with the pythons in Florida. Piranha attacks and FW ray attacks on humans are common in the native home.

 

[Karl K]

Bingo! Everyone thinks that invasive species are all about take over the ecosystems. That's partially true but let's see definition of what an invasive species is. An invasive species is defined as an organism that is not native and has negative effects on our economy, our environment, or our health. Not all introduced species are invasive..So the FW ray fits in economy & health category.

That is why piranhas, FW rays and electric eels are banned in southern United States. Same thing with the pythons in Florida. Piranha attacks and FW ray attacks on humans are common in the native home.

I've heard that piranhas attack humans, very rarely. They eat dead people however, like im sure every other scavenger does.

 

[MN_Rebel]

I've heard that piranhas attack humans, very rarely. They eat dead people however, like im sure every other scavenger does.

That's what everyone thought that piranhas rarely attacks on humans but seems that it may not true after reading up on few piranha attacks. Turns out that piranha attacks are common in areas where highest density of humans at. It is not uncommon to see a warning sign posted at the swimming areas.

 

[Karl K]

That's what everyone thought that piranhas rarely attacks on humans but seems that it may not true after reading up on few piranha attacks. Turns out that piranha attacks are common in areas where highest density of humans at. It is not uncommon to see a warning sign posted at the swimming areas.

There was an river monster episode about it. Jeremy Wade concluded, that they attacked humans, because arapaimas had migrated into there territory, if i remember correctly, and it was threadening the piranhas. There for they attack live humans sometimes, in special areas. What do you think about that? Sounds true to me.

 

[MN_Rebel]

There was an river monster episode about it. Jeremy Wade concluded, that they attacked humans, because arapaimas had migrated into there territory, if i remember correctly, and it was threadening the piranhas. There for they attack live humans sometimes, in special areas. What do you think about that? Sounds true to me.

Possible! They did installed few dams in some rivers, therefore the fishes cannot migrate out to their feeding grounds. Piranha attacks on humans have been increased in recent years and started to become more common occurrence in these specific areas.

 

[Nabbig2]

Can't wait for them to start banning more fish in MN and other states too. I guess that's what it's going to take for people to wake up.

 

[ashtonmccants]

Hey guys. I know I'm a couple of years late on this post, but I wanted to add my input on the matter. So rather than stating my personal opinion, which is what most of us do, I conducted a literature review that provided evidence to the present question. Personally, I do not feel that rays would thrive in California waters (in general). If they did survive, it would be in very secluded parts of the state's waterways. With that being said, I know that rays are aa adaptive species and can withstand drastic changes in their environment and temperature. They will find ways to breed, even outside of their ideal conditions. There was a study (that I have attached) that was conducted in Singapore. This study started with scientist catching a motoro in waters that they are not native. After a short study, they were able to catch a pregnant female and several others over the course of a couple of days. Now, I did my research on the actual water system in which they were caught and the overall climate and weather conditions of the area. Basically a cold day in Singapore is around 77 F. This basically indicates that the waters are very warm. There is also an abundant food supply, no known predators and lots of rain. These are ideal conditions (similar to South America). The article concluded with the following statement:

"Although our sampling did not indicate high abundance of stingrays in the reservoir, because the species is established, an eradication program is likely to be ineffective or prohibitively costly at best (Courtenay and Robins 1975; Lodge et al. 2006) for managing this problem. Instead, greater emphasis should be placed on preventing further introductions or spread of P. motoro and other potamotrygonid stingrays in Singapore while controlling the stingrays at the present low abundance within the Upper Seletar Reservoir by removal using fishing or trap- ping methods. Although there is legislation regulating the release of animals in Singapore’s nature reserves, which includes the Central Catchment Nature Reserve that the Upper Seletar Reservoir is part of, and a ban on local retail sale of P. motoro is now in effect, enforcement of these regulations remains a challenge. At the same time, educating the general public on the hazards posed by P. motoro and the relevant precautions to take to avoid injury or spread of the species should be done as a means of societal adaptation to the potentially permanent presence of this freshwater stingray in Singapore."

The purpose of this was to provide a more scientific approach to such a controversial and misunderstood topic. To answer the original poster's question: They are banned in California because they could potentially populate in warmer waters with a heavy food supply and constant temperature. Although this can happen, I agree that the chances are very unlikely based on the current evidence provided. Do I agree that the species should be banned in CA? No. I do not. I live in California and have lived here for the past 9 years. This is one of the more cumbersome states to live in for aquarist. I hope everyone can get something from the article. Happy fishkeeping.

 

[CANAMONSTER]

Isn't Stingray Biology in California!