Let’s learn about the Dark shyshark (Haploblepharus pictus) a shyshark in the family Scyliorhinidae. This shark is indigenous to the South African coastline preferring temperate waters. It features dark brown to black colouration, blending into rocky reefs and sandy bottom habitats. This species measures around 60 – 70 cm, with a slender body and broad head. Large, expressive eyes characterize its appearance. It is a mostly nocturnal shark, preferring to hunt in darkness. It feeds on small fish, crustaceans, and cephalopods. During the day, it seeks refuge in caves, crevices, and under ledges. This behaviour protects it from potential predators. Despite its elusive nature, the Dark shyshark plays a vital role in maintaining marine ecosystems. Cape RADD is doing its part in helping understand, defend and protect this species.
Description
It is a relatively small shark, with a length of 60 – 70 cm. It has a slender body with a broad flattened head. The dorsal surface is dark brown and black allowing it to blend effectively into its rocky reef and sandy bottom habitats. It also has scattered white spots on the dorsal surface, but not as much as the puffadder shyshark. It has large, rounded pectoral fins and pelvic fins positioned closer to the head. Its dorsal fin is relatively small and located towards the posterior part of its body. Its caudal fin, or tail fin, is asymmetrical with a longer upper lobe and a shorter lower lobe, aiding in efficient swimming and manoeuvrability.
As a bottom-dwelling shark, it has spiracles behind its eyes. Spiracles are small, slit-like openings that serve as accessory respiratory organs in some shark species. In the case of the dark shyshark, these spiracles help facilitate the intake of oxygen-rich water while the shark rests on the seafloor, as it often does during the day.
These morphological adaptations collectively contribute to the Dark Shyshark’s ability to thrive in its marine environment.
Habitat
The dark shyshark inhabits the coastal waters of South Africa, along the rocky reefs and sandy bottoms. These sharks adapt well to a variety of marine habitats, but they primarily inhabit areas with rocky outcrops, underwater caves, and crevices.
Rocky reefs provide them with numerous hiding spots and sheltered areas where they can seek refuge during the day. These sharks often retreat to caves, crevices, and under ledges to avoid predators and conserve energy. Their dark brown-to-black colouration allows them to blend seamlessly into their surroundings, making them less visible to potential threats.
Sandy bottoms are another favoured habitat, particularly areas with scattered rocks or debris where they can hide and ambush prey. Despite their preference for rocky reefs and sandy bottoms, observers have also noted dark shysharks in seagrass beds and kelp forests, demonstrating their ability to adapt to diverse environments.
The coastal waters of South Africa offer an ideal environment for the dark shyshark, providing a rich and varied habitat that supports their survival and reproduction. Understanding the habitat preferences of these sharks is crucial for conservation efforts aimed at protecting their populations and the marine ecosystems they inhabit.
Behaviour of the dark shyshark
The dark shysharks exhibit nocturnal habits, becoming more active during the night. During the day, they prefer to hide in caves, crevices, and under ledges to avoid predators. Emerging at night, they forage for small fish, crustaceans, and cephalopods. They use their keen senses, such as smell and electroreception, to locate prey. Employing a stalking approach, they move stealthily to capture their target. This behaviour enables dark shysharks to thrive in their marine environment.
Furthermore, they have been observed displaying unique defensive behaviours when threatened. In response to potential predators or disturbances, they may curl up and remain motionless on the seabed, resembling a small rock or piece of debris. This “freezing” behaviour helps them avoid detection and provides a temporary refuge until the threat passes. Additionally, dark shysharks may use their small sharp teeth and agile swimming abilities to defend themselves if confronted directly by a predator.
Another intriguing aspect of dark shyshark behaviour is their social interactions with conspecifics and other marine species. While they are generally solitary animals, dark shysharks may congregate in small groups during mating season or around abundant food sources. These aggregations provide opportunities for social interactions, communication, and potential mating encounters. Additionally, dark shysharks have been observed engaging in cooperative hunting behaviours, where individuals work together to corral and capture prey. These social dynamics contribute to the overall complexity and fascinating behaviour of dark shysharks in their marine environment.
Reproduction
Dark shysharks reproduce through a method known as oviparity, where the female lays eggs rather than giving birth to live young. After mating, the female produces eggs encased in tough, leathery egg cases called “mermaid’s purses.” These egg cases protect the developing embryos and are often deposited in hidden locations, such as crevices or under rocks, to minimize the depredation risk.
The incubation period for dark shyshark eggs can vary but generally lasts several months. During this time, the female closely guards the eggs and may occasionally move them to ensure optimal conditions for development. Once the embryos are fully developed, they hatch from the egg cases, and the juvenile sharks emerge. Dark shysharks typically reach sexual maturity at around two to three years of age, depending on environmental factors such as food availability and water temperature.
Understanding the reproductive biology of dark shysharks is crucial for conservation efforts aimed at maintaining healthy populations of these intriguing creatures in their natural habitat. Researchers conduct studies to monitor reproductive patterns, egg deposition sites, and factors influencing reproductive success. By gaining insights into the reproductive behaviour of dark shysharks, conservationists can implement targeted strategies to protect critical breeding habitats and ensure the long-term sustainability of their populations in the marine ecosystem. Cape RADD has set up a monitoring program to observe the hatching success of Dark shysharks along with other endemic shark species. Join our Marine Science Field Course to get involved.
Conservation status and efforts
The dark shyshark has been listed as least concern by the IUCN Red List. However, we must remain vigilant due to habitat degradation, bycatch in fishing gear, and overfishing. Conservation efforts focus on monitoring populations, implementing fishing regulations, and creating marine protected areas to safeguard their habitats. Additionally, public awareness campaigns educate communities about the importance of preserving marine biodiversity and the role of dark shysharks in the ecosystem. Participation in citizen science projects like Snorkel for Science, and the Cape RADD Fin Spotter initiative, encourages people to contribute valuable data on shark sightings and behaviour. By engaging in citizen science, individuals can actively contribute to conservation efforts and help protect dark shysharks and their marine environment for future generations.