Manta rays are large, filter-feeding rays found in tropical and subtropical waters globally. This article explores their various colorations, from typical patterns to rarer variations, and the biological reasons behind them.
Typical Manta Ray Coloration
The most common coloration observed in manta rays is a pattern known as countershading. This involves a dark dorsal (top) side and a light ventral (underside) side. The dorsal surface typically appears black or a very dark grey to steely blue, sometimes with subtle pale markings on their “shoulders.”
The ventral surface, in contrast, is usually white or off-white. This two-toned appearance is a primary identifier for both the Oceanic Manta Ray (Mobula birostris) and the Reef Manta Ray (Mobula alfredi). While both species share this general countershading, specific markings can differ; for instance, the Oceanic manta ray often has a T-shaped marking on its back, while the Reef manta ray may have a Y-shaped pattern.
Exploring Color Variations
Beyond typical countershading, manta rays display less common color variations. Melanistic manta rays are almost entirely black due to excess melanin production. These black mantas can have a completely black dorsal surface and a predominantly black underside, often with a central white blaze that varies in size. While melanism is rare in marine species, manta rays are a notable exception, with some populations having a significant percentage of melanistic individuals.
Conversely, rare cases of leucistic or albino manta rays have been documented, appearing predominantly white. Leucism involves a reduction in pigment, resulting in a lighter or white appearance, typically without the red eyes associated with true albinism. Regardless of these variations, unique patterns of dark spots and markings on their white undersides serve as distinct “fingerprints” for individual identification by researchers.
The Purpose Behind Their Colors
The characteristic countershading of manta rays serves as camouflage, providing adaptive benefits in their marine environment. When viewed from above, their dark dorsal side blends with the darker ocean depths, making them less conspicuous to predators like large sharks and orcas. This dark coloration helps them merge with the deep water below.
Conversely, the light ventral side blends with the bright, sunlit surface of the water when viewed from below. This makes it difficult for predators and prey looking upwards to distinguish the manta ray against the light. This dual camouflage strategy allows them to approach unsuspecting prey and evade potential threats by disappearing into their surroundings.