Japanese angelshark - Squatina japonica

The Japanese angelshark Squatina japonica is a strongly flattened bottom shark with a broad front body, large pectoral fins and a ray-like silhouette. Taxonomically it remains clearly a shark: WoRMS leads the species within the Squalomorphi, the order Squatiniformes, the family Squatinidae and the genus Squatina.

The eyes and spray holes are on top of the head, while the gill slits are on the sides. The broad pectoral fins are not completely fused to the head; This detail separates angel sharks in the field from real rays, even though both appear similarly flat on the ground.

Identifying features

• Broad, flat head shape with large, laterally projecting pectoral fins.
• Simple, spatula-shaped nasal barbels and smooth to slightly fringed anterior nasal lobes.
• Two small dorsal fins are located far back, both behind the base of the pelvic fins.
• Dark brown to grey-brown upperside with small dark and light spots, but no ocelli.
• Several rows of larger thorns lie along the middle of the back, on the tail, on the snout and above the eyes.

The species can reach a total length of up to two meters. Photos of the head, barbels, dorsal line, spot markings and the position of the dorsal fins are particularly helpful for reliable field identification.

The Japanese angelshark lives in the northwest Pacific. Shark-References names Japan, the Yellow Sea, Korea and North China as core areas; are also in the species profile China, Japan, North Korea, South Korea, Russia and Taiwan relevant countries or coastal areas.

The species is found near the coast and shelf, but is not restricted to extreme shallow water zones. The depth range of 10 to 352 m stored in the species profile suits sandy shelves, bays, near reefs and transitions to deeper soft bottom areas.

Sandy bottoms, shelves and marginal seas

Typical habitats are sandy or muddy soils, often near rock or reef structures. In such areas the shark can partially burrow and is difficult to see despite its size.

For divers, the species is therefore not a classic shark encounter that can be planned. Good evidence depends more on calm observation over suitable ground, clear photos and precise documentation of location, depth and habitat.

FishBase describes Squatina japonica as a little-known, terrestrial species that lives on or near the seafloor and uses sandy bottoms. Like other angel sharks, it is not a persistent open water hunter, but rather a bottom hunter.

Hunting and food

During the day, the Japanese angelshark may rest partially buried; It becomes more active at dusk and at night. Prey includes bottom-hugging fish, cephalopods and crustaceans. The attack is short and explosive: the mouth opens forward, creating suction and drawing prey within reach.

The camouflage pattern is functional. Small light and dark spots break up the body contour, while the eyes and spray holes remain free. This allows the shark to breathe and observe its surroundings without completely detaching itself from the sediment.

Reproduction

The species is aplacental viviparous: embryos develop in the mother and are nourished by the yolk. Small to medium-sized litters are mentioned for the species; Young animals are born fully developed and use flatter, structured soil habitats.

The maximum age of around 23 years stored in the species profile corresponds to a slower life cycle. Late maturity, small litter sizes and the close connection to soils used for fishing make local stocks sensitive to long-term fishing pressure.

The IUCN Red List classifies the Japanese angelshark as threatened with extinction a. The key factor is the combination of a terrestrial lifestyle, low recovery rates and high fishing intensity in many parts of the northwestern Pacific.

The IUCN-Bewertungsdaten indicate strong exploitation across the entire spatial and depth distribution. An angel shark lying on the bottom or burrowing has little room to escape from bottom trawls, gillnets and bottom-hugging longlines.

Main hazards

• Targeted catch and bycatch in bottom trawls, gillnets and other bottom-level fisheries.
• Use of meat and rough skin, including shagreen leather.
• Heavy pollution of sandy shelf and marginal sea habitats in the Yellow Sea and adjacent coastal areas.
• Low reproduction rate and slow recovery after local population declines.
• Fuzzy catch statistics if angel sharks are not clearly identified to the species.

Effective protection therefore requires catch reduction for ground-level devices, reliable species identification, closed areas in important shelf habitats and the documentation of live sightings or releases. For a species that has become rare, even small, well-documented data sets are valuable.

The Japanese angelshark is not normally an actively dangerous shark to humans. It becomes risky when a resting animal is touched, uncovered from the sand, pulled by the tail or treated as a catch. Then an angel shark can snap forward or sideways very quickly.

FAO Fisheries and Aquaculture In the fishing context, the species goes by the English name Japanese angelshark. This describes the most important human relationship better than spectacular encounters: the species is caught, marketed or landed as bycatch, even though biologically it can only be replaced slowly.

Observation and handling

• Do not kneel on sandy areas or use your hands to look for hidden animals.
• Do not expose, touch or harass resting animals for photos.
• Keep your distance to the side and do not place the camera, hands or lamps directly in front of your mouth.
• Document sightings with photos, location, depth and habitat without moving the animal.

For shark diving, the Japanese angelshark represents a quiet but important side of shark watching: a perfectly camouflaged bottom predator whose protection works primarily through clean fishing rules and respectful treatment of sandy habitats.