Manta rays are magnificent ocean dwellers, often seen gliding through marine environments with remarkable grace. Their large size, unique appearance, and aquatic habitat frequently lead people to wonder if they are classified as fish. This article explores their biological characteristics to answer that question.
Defining What Makes a Fish
Most people envision a creature with a streamlined body, covered in scales, and propelled by fins when thinking of a typical fish. These characteristics describe bony fish, which constitute the majority of fish species globally. A defining feature of these aquatic vertebrates is their skeleton, composed primarily of bone. Many bony fish also possess a swim bladder, an internal gas-filled organ that helps them maintain buoyancy. Their gills are typically covered by a bony flap called an operculum, providing protection and aiding in respiration.
Understanding Manta Ray Characteristics
Manta rays present a different set of biological features. Unlike many familiar fish, manta rays lack scales, having smooth, leathery skin, though their skin does contain tiny, tooth-like structures called dermal denticles. Their bodies are flattened, with broad pectoral fins that resemble wings, enabling their distinctive “flying” motion through the water. Instead of a single operculum covering their gills, manta rays have five distinct gill slits on their underside, a characteristic shared with sharks and skates. Their feeding method also differs; they are filter feeders, consuming vast quantities of plankton by swimming with their large mouths open.
Manta Rays: A Unique Aquatic Classification
Cartilaginous Fish
Given their unique characteristics, manta rays are considered fish, belonging to a distinct group known as cartilaginous fish, or Chondrichthyes. This class includes sharks and skates, all sharing a skeleton made of cartilage rather than bone. This cartilaginous skeleton, lighter and more flexible than bone, is a primary differentiator from bony fish. The presence of multiple gill slits, typically five pairs, directly exposed to the water, further distinguishes them from bony fish with their single operculum.
Broader Classification of Fish
Their classification within the Chondrichthyes places them in an ancient lineage of vertebrates adapted to marine life for millions of years. While “fish” is often used broadly to describe any aquatic animal with fins, scientifically, it encompasses a wide array of groups, including both bony and cartilaginous forms. Therefore, while a manta ray might not fit the common image of a goldfish or a trout, its biological classification places it within the diverse category of fish. This distinction highlights the variety within aquatic life and the different evolutionary paths that have led to diverse forms.