Mobula yarae
- 演化之聲
- Mar 12
- 4 min read
Updated: Apr 10
Taxonomy
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Order: Myliobatiformes
Family: Myliobatidae
Genus: Mobula
Species: Mobula yarae
Morphological description
The Atlantic manta ray (Mobula yarae) is a large member of the family Mobulidae with a broad, dorsoventrally flattened body. It possesses a terminal mouth, and the tooth band is restricted to the lower jaw, a condition shared with its closest relatives Mobula birostris and Mobula alfredi. The teeth are small and cusped, arranged in 9–13 transverse rows, fewer than in M. birostris (12–16 rows) but more numerous than in M. alfredi (6–8 rows).
The dorsal surface of the head is flat. The anterior margin of the rostrum is concave and gradually widens laterally toward the bases of the cephalic fins. When unfurled, the cephalic fins can meet at the center of the mouth. The tail base is comparatively robust near the dorsal fin.
The skin is covered with stellate-shaped dermal denticles. These denticles are arranged in longitudinal ridges aligned along the body axis and are regularly distributed across both dorsal and ventral surfaces. Ventral denticles are generally larger and more widely spaced, whereas denticles on the dorsal surface, pelvic fins, and the trailing edges of the pectoral fins are more densely packed. The morphology and arrangement of these denticles differ markedly from those observed in M. birostris and M. alfredi, making them one of the key diagnostic features of the species.
Behind the dorsal fin lies an ellipsoidal calcified cartilaginous mass known as the caudal bulb. Embedded within this structure is a reduced caudal spine with a serrated structure. Only the tip of the spine slightly protrudes, and it is directed upward rather than posteriorly as in M. birostris. The dorsal surface of the spine is slightly concave and bears several longitudinal grooves, while the ventral side has a pronounced longitudinal ridge that supports the entire spine structure.
The branchial filtering apparatus is well developed. Filter lobes occur anterior to the gill filaments and are laterally fused with one another. Their surfaces bear transverse brush-like projections, making the filtering structure more compact and efficient. The distal ends of the filter lobes are rounded and grayish-white in color. Internally, the chondrocranium is large and contains a dense network of blood vessels within the cranial cavity. The digestive system includes a J-shaped stomach, and a distinct pyloric sphincter separates the stomach from the intestine.
The dorsal coloration is typically black and includes a pair of symmetrical white supra-branchial patches arranged diagonally across the back, which constitute an important visual identification feature. The ventral surface exhibits species-specific spot patterns that clearly distinguish this species from other manta rays.
Etymology
The generic name Mobula has two possible origins. One interpretation links it to the Latin word mobilis, meaning "movable" or "capable of movement," referring to the species' mobility or migratory behavior. Another interpretation suggests it may derive from a vernacular or regional term used for these rays in the Azores. Both explanations appear in different sources, and no definitive origin has been universally accepted.
The species epithet yarae honors Yara (also spelled Iara or Uiara), a water mother or goddess from Tupi and Guaraní mythology in Brazil. According to the legend, Yara was a beautiful and skilled Amazonian indigenous woman who was thrown into the water and rescued by fishes. She thereafter assumed a half-human, half-fish form endowed with enchanting and mysterious powers.
Biological description
Although the Atlantic manta ray occurs sympatrically with Mobula birostris in parts of its range, all confirmed records to date remain restricted to the Atlantic Ocean, extending from southeastern Brazil to the northeastern United States.
Its habitat preferences differ somewhat from the more oceanic M. birostris. The Atlantic manta ray appears more frequently in coastal and estuarine environments that are strongly influenced by human activity. As a consequence, the species is more directly exposed to threats such as coastal pollution, shipping traffic, and fishing pressure. It has also been recorded around oceanic islands.
Observed life-history patterns vary among regions. Along the Brazilian coast, most recorded individuals are juveniles, with males frequently displaying undeveloped claspers and relatively small body size. In contrast, sightings in Mexican waters are predominantly adults, with males exhibiting fully developed claspers. Researchers therefore propose that the life history of this species may resemble that of M. birostris and M. alfredi.
Juveniles of the Atlantic manta ray have been documented primarily along the Amazon coast, around the Fernando de Noronha archipelago in Brazil, and in the Flower Garden Banks National Marine Sanctuary and along the eastern coast of Florida in the United States. These regions may function as potential nursery areas.
Behavioral observations indicate that adults are most commonly recorded near the Yucatán Peninsula and along the central to northeastern coast of the United States. Feeding behavior has been observed around the Fernando de Noronha archipelago and the Yucatán Peninsula, while reproductive activity has been documented in U.S. waters.
Multiple anthropogenic threats affect this species. In Brazil, mobulid rays are frequently captured in gillnets, trawl nets, and longline fisheries, after which they may be discarded, consumed, or sold. Along the southeastern coast of the United States, the species has been reported as an important bycatch component in shrimp trawl fisheries. Additional threats include recreational fishing targeting cobia (Rachycentron canadum) within important feeding or reproductive habitats, vessel strikes in potential nursery areas, entanglement in fishing gear, and unmanaged interactions with divers and snorkelers. The potential impacts of climate change, pollution, and habitat degradation on the population remain poorly understood and require further investigation.
（Author: Shui-Ye You）
Reference
Bucair N et al. (2025). An integrative taxonomy investigation unravels a cryptic species of Mobula Rafinesque, 1810 (Mobulidae, Myliobatiformes), from the Atlantic Ocean. Environmental Biology of Fishes.
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