Small-spotted catshark

Typical body shape and skin structure

The small-spotted catshark is a small and slender shark species, usually measuring 60 to 80 centimeters in length, although specimens of up to one meter have been observed. Its body is wedge-shaped, elongated, and perfectly adapted to life on the seabed. Its rough skin is striking, feeling like sandpaper due to tiny placoid scales, which provide excellent protection. The upper side is gray, beige, or brownish, covered with numerous small dark spots that give the shark its German name. In contrast, the underside is light and usually unspotted. Characteristic features include the large, round eyes with a typically cat-like streak, giving the shark its distinctive appearance.

Mouth area, fins and special features

The mouth is small, almost twice as wide as it is long, and located on the underside of the head, ideal for detecting prey on the seabed. The five gill slits are positioned laterally beneath the head and are hardly noticeable at first glance. The first dorsal fin starts clearly behind the pelvic fins, while the second, smaller dorsal fin follows further back. The catshark has an asymmetrical tail fin that provides strong propulsion. Its teeth are bristle-like, perfectly suited for cracking shells and holding onto prey.

Sense organs and adaptations

The small-spotted catshark has particularly well-developed sense organs. Thousands of electroreceptors, the ampullae of Lorenzini, are located around the snout and help detect prey even in poor visibility. These sharks also have a keen sense of smell to precisely locate crustaceans, mollusks, and small fish on the seabed. Their cartilaginous skeleton provides high flexibility and low weight while swimming.

Differences between males and females

Adult males and females differ mainly in the development of certain reproductive organs. Males have two elongated claspers on the underside behind the pelvic fins, which serve as copulatory organs. Females lack these claspers, making them easy to distinguish. On average, females are slightly larger and stronger than males, as they produce egg capsules and show a more robust body shape during the breeding season. The coloration and spotting are the same in both sexes and serve as camouflage on the seabed.

Comparison with other shark species

Compared to other catshark species, the small-spotted catshark stands out due to its particularly fine and dense dermal denticles, which give it a durable surface. Its spots are smaller than those of the related larger-spotted catshark, the snout is shorter and broader, and the nasal flaps extend strikingly to the mouth. With its slender body shape and large eyes, it is often perceived as especially graceful.

Geographical distribution

The small-spotted catshark is one of the most common and widely distributed shark species along the coasts of Europe. Its range extends from the northeastern Atlantic and the west coast of Africa up to Norway, around the British Isles, and along the Spanish and French Atlantic coasts. The species is particularly abundant throughout the Mediterranean and the North Sea. These sharks inhabit not only open sea areas but are also found in shallow coastal waters and bays. Small populations even exist in the Black Sea.

Habitat: On the seabed and in coastal areas

The small-spotted catshark is a typical bottom-dweller and prefers sandy, gravelly, or muddy seabeds. It is often found among algae beds, seagrass meadows, or reef areas. Depending on the region and water conditions, it moves from very shallow waters down to depths of about 400 meters, and in exceptional cases even up to 800 meters. In cooler regions, it tends to stay in shallower waters, while in the warmer Mediterranean it is more frequently encountered at greater depths. Juveniles usually seek out the protected, shallower areas of coastal zones.

Lifestyle: Structured Bottom-Dweller

The small-spotted catshark leads a hidden life on the seabed and is primarily crepuscular and nocturnal. During the day, females often stay in small groups, hiding in rock crevices, caves, or among seagrass, while males usually rest alone. At night, the sharks become active, gliding over the seabed in search of prey. This shark species is highly adaptable and can survive both in shallow coastal waters and at greater depths of up to 800 meters. Its typical movement is slow and graceful, but when threatened or hunting, the catshark can strike with lightning speed.

Diet and Hunting Behavior

The small-spotted catshark eats anything that is small and lives near the seabed. This includes small fish, shrimp, crabs, squid, octopuses, snails, and various worms. It can locate prey even in poor visibility, aided by an excellent sense of smell and fine electroreceptors that detect the weak electric fields of animals. While feeding, it uses its small, sharp teeth to efficiently crack shells or exoskeletons. Its main hunting time is at night, during which the shark proceeds with careful patience and strikes only at the last moment.

Reproduction and Development

This shark species is an egg-laying bottom-dweller. Reproduction occurs throughout the year, with a peak in early summer. Females lay up to 20 elongated, horned egg capsules per season, which are attached to algae, rocks, or other firm substrates using threads. Each egg capsule contains a developing juvenile that feeds on its yolk sac. Development can take between five and eleven months, depending on water temperature. Upon hatching, juveniles are eight to ten centimeters long and immediately independent. Sexual maturity is reached at three to five years of age, with females usually growing slightly longer and larger than males. The lifespan can reach up to 13 years.

Social Structure and Characteristics

Unlike many larger sharks, small-spotted catsharks sometimes exhibit group-oriented behavior, especially among females in hiding. Otherwise, the animals live solitary lives. Their high adaptability to different habitats and flexible diet make this shark one of the most successful and common bottom-dwelling sharks in Europe.

Current Conservation Status

The small-spotted catshark is one of the most common shark species in European waters and is currently classified as "Least Concern" by the International Union for Conservation of Nature (IUCN). Populations are considered stable throughout its entire range, and this bottom-dwelling shark is widespread along the coastal regions of the northeastern Atlantic, the Mediterranean, and parts of the Black Sea. In Germany, the species is also listed as least concern on the Red List. Nevertheless, local population fluctuations are possible, so experts recommend regular monitoring.

Fisheries and Bycatch as a Risk

The greatest threat to the small-spotted catshark is commercial fishing, particularly unintentional bycatch in bottom trawls. Even targeted catches for human consumption, for example along the Atlantic coast or in the Mediterranean, regularly capture these sharks. Additional pressures include the loss of important egg-laying areas and declines in seagrass meadows and algae beds, which are particularly important for the development of juveniles. Overall, the population remains resilient, but excessive fishing pressure could lead to local declines.

Regional Differences and Observations

In some marine areas, such as the Wadden Sea in the North Sea or parts of shallow water zones, the small-spotted catshark has almost disappeared. The reasons are varied, ranging from the loss of suitable habitats due to offshore activities to climate change. In heavily trafficked or industrially used waters, measures such as marine protected areas and bottom trawl bans are urgently needed to stabilize local populations.

Conservation Measures and Perspectives

Key conservation strategies include the establishment of areas where bottom trawling is prohibited and the targeted promotion of natural spawning sites. Research projects for population monitoring help respond early to declines and adapt protection measures. Sustainable fisheries management is crucial for the long-term protection of this shark species. Public education and recognition of the small-spotted catshark as an important part of the marine ecosystem also contribute to securing its populations.

Behavior During Encounters

The small-spotted catshark is a rather shy and calm inhabitant of the seabed. Encounters with humans are rare and usually occur without conflict. Sharks of this species show little aggressive behavior toward divers or swimmers. Rather than confront, they typically flee and retreat into hiding places. Studies have shown that the sharks’ body language is crucial in determining their reaction to humans. Maintaining a calm demeanor and respectful distance helps ensure a peaceful encounter.

Potential Risks and Protective Behavior

Attacks on humans by the small-spotted catshark are virtually unknown. The animals are too small and timid to pose a danger. Risks may only arise if humans harass the sharks or disturb them while they are feeding. In such situations, defensive behavior can be triggered, but it rarely results in serious injuries. Understanding the sharks’ signals and behaviors is crucial to avoid misunderstandings and potential risks.

Recommendations for Behavior During Encounters

Anyone encountering the small-spotted catshark should remain calm, avoid sudden movements, and give the shark plenty of space. Underwater, slow and controlled movements can help reduce the shark’s stress. If changes in behavior are observed, such as rapid tail movements or raised pectoral fins, it is advisable to slowly back away. The goal is a safe and respectful coexistence without disturbance for either party.

Humans as the Greatest Threat

While the small-spotted catshark poses little danger to humans, it is mostly humans who threaten this species. Overfishing, bycatch, and habitat destruction due to changes in coastal areas put pressure on their populations. It is therefore especially important to act responsibly in the water and to protect the natural habitat of these fascinating sharks.