Spinetail mobula

What it is

This large ray belongs to the family Mobulidae, which includes manta rays and devilfish. It has a flattened body with wide triangular fins on each side. Two horn-like cephalic fins sit at the front of its head. These structures can roll into spirals for swimming or flare out to guide water into the mouth. A small spine sits at the base of its tail, giving the species its name. The upper surface is deep blue-mauve with a black band across the eyes. The underside is white, helping it blend with sunlight from above or dark depths below.

Where it lives

These rays live in tropical and temperate waters across the globe. They inhabit the Indo-Pacific region and the eastern Atlantic Ocean. Populations exist in the Gulf of Mexico, Mediterranean Sea, and southwest Pacific. They move between inshore areas and the open ocean. Their location depends on food availability and water conditions. Many stay on continental shelves before summer, then migrate to tropical zones. They follow seasonal upwelling systems where cold coastal waters bring nutrients. This movement makes them sensitive to environmental shifts.

How it lives

Spinetail mobulas are highly mobile and often travel in small groups. They perform aerial jumps, leaping clear of the water. As filter feeders, they strain nutrient-rich seawater to catch small organisms. Their diet consists mainly of zooplankton and tiny crustaceans. Studies show their stomachs contain mostly decapods, along with copepods and gastropods. They dive deep during the day and rise to the surface at night to feed. This vertical migration helps them track prey abundance. Larger sharks and killer whales hunt them, but their colouring offers camouflage.

Breeding and life cycle

Females give birth to live young after internal development. The eggs hatch inside the mother’s oviduct. Embryos first feed on yolk, then receive a milky secretion. Each female typically produces only one pup per cycle. Newborns measure between 70 and 85 cm in width. The species has a slow growth rate and low reproductive output. This biology means populations recover slowly from declines. The southern Gulf of California serves as a key area for mating and birthing.

Fish and people

Fisheries target these rays for their gill plates, used in traditional medicine. Artisanal and commercial boats catch them in warm habitats. They also die as bycatch in gill and trawl nets meant for other fish. In New Zealand, the Wildlife Act of 1953 protects them. Harming devil rays there can result in heavy fines or prison. Global demand for gill plates continues to drive landings despite conservation efforts. Their role in local ecosystems remains significant due to their plankton control.

Status and threats

The species faces pressure from targeted fishing and accidental capture. Low birth rates and slow growth make it vulnerable to overexploitation. Climate change threatens their food supply by altering zooplankton distribution. Ocean acidification and warming waters may shrink their comfortable range. Habitat destruction and pollution add further stress. Legal protection exists in some territories, but global enforcement varies. Recovery from population depletion would take considerable time due to their life history.

Questions people ask about Spinetail mobula

Good reading and sources

• Spinetail mobula on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data