Which anatomical feature, common to Characiformes, is present on the X-Ray Tetra between the dorsal and caudal fins?
Answer
Adipose fin
As a member of the order Characiformes, the *Pristella maxillaris* possesses the characteristic adipose fin. This structure is defined as a small, fleshy fin located on the back of the fish, positioned specifically between the terminus of the dorsal fin and the base of the caudal fin. Unlike the paired pectoral/pelvic fins or the median dorsal/anal fins, the adipose fin is distinctive because it is un-rayed and lacks skeletal support. While ichthyologists still debate its exact role, its presence serves as a reliable visual marker for identifying fish belonging to the Characidae family and related groups.
Related Questions
What is the scientific classification for the fish commonly known as the X-Ray Tetra?Which South American river basins are the native origin of the *Pristella maxillaris*?What unique feature allows aquarists to observe the internal anatomy of the X-Ray Tetra, earning it the name X-Ray Fish?What is the maximum standard length (SL) typically achieved by the X-Ray Tetra in aquarium settings?On which fin is the bright red or orange pigmentation most visibly pronounced on the *Pristella maxillaris*?Which anatomical feature, common to Characiformes, is present on the X-Ray Tetra between the dorsal and caudal fins?What base tone do the underlying musculature and skin present on the X-Ray Tetra, despite its overall transparency?What environmental factor causes the brilliant red and orange pigmentation on the fins of the *Pristella maxillaris* to diminish?How does the X-Ray Tetra's body shape compare morphologically to extremely slender tetras or the Neon Tetra?What physical trait contributes to the *Pristella maxillaris* being slightly more sensitive to rapid changes in water chemistry?