What common occurrence today is responsible for the global presence of the X-Ray Tetra outside of South America?
Answer
The international ornamental fish trade
The current global presence is almost entirely due to the international ornamental fish trade, meaning specimens are typically wild-caught from native locales or captive-bred globally.

Related Questions
What is the scientific name for the X-Ray Tetra?To which family does the X-Ray Tetra belong according to its scientific classification?Which continent represents the native geography for the X-Ray Tetra?Besides the Amazon River basin, which two other major drainage areas are principally associated with this species?What specific habitat feature do X-Ray Tetras generally prefer over massive river channels?What physical trait is responsible for the common name 'X-Ray Tetra'?What characteristic of the water chemistry is often found in the natural areas these tetras inhabit?What feature distinguishes the X-Ray Tetra from many other tetras sharing its habitat regarding pigmentation?What small splash of color is typically observed on the otherwise translucent X-Ray Tetra?What common occurrence today is responsible for the global presence of the X-Ray Tetra outside of South America?