small prickly dogfish of the outer shelf

Size
Length: 50–70 cm, Weight: 2–5 kg
Lifespan
15–25 years
Diet
Small crustaceans and worms. Hunts near the seafloor using a tall, triangular body. Uses its large eyes to detect prey in low light. Feeds on slow-moving bottom-dwelling invertebrates.
Habitat
Deep continental slopes and seamounts between 100 and 500 metres depth. Prefers muddy and sandy bottoms with moderate currents. Often found near the seafloor in the darker waters of the upper continental slope.
Range
Coastal waters of the South Island and southern North Island from Cook Strait to Stewart Island. Most common off the east coast of the South Island. Also found in southern Australia and Tasmania.
Endemism
Native
Main Threats
Bycatch in bottom trawl and set net fisheries. Habitat damage from bottom trawling on the continental slope. Slow reproduction makes populations vulnerable. No targeted commercial fishery exists for this unusual dogfish species.
Population
Population trends are poorly understood due to the deep-water habitat and low encounter rate. Caught occasionally as bycatch in hoki and flatfish fisheries. Quota management limits total bycatch. Better species-specific data is needed.
Conservation Status
Not Threatened
Tall and triangular, like a shark that has been squashed from the sides. A shape that makes no sense until you see where it lives. The prickly dogfish has a distinctive silhouette unlike any other shark. Large dorsal fins with prominent spines stick up from its back. Thorn-like denticles cover its body, giving it a rough, prickly texture. Run a hand along it and every bump will be felt. A shark that does not want to be touched. The defence is physical. The warning is clear. The unusual shape is an adaptation for life in the dark, still waters of the deep sea. The prickly dogfish lives on the deep continental slope between 100 and 500 metres down. It hovers near the seafloor in search of slow-moving crustaceans and worms. Large eyes detect prey in low light. A slow, energy-efficient hunting style conserves fuel. A shark built for patience. The strategy is minimal movement. The reward is steady. The energy cost is low. In New Zealand waters, prickly dogfish are found around the South Island and southern North Island from Cook Strait to Stewart Island. They are most common off the east coast of the South Island. They turn up occasionally as bycatch in bottom trawl and set net fisheries targeting hoki and flatfish. No one targets them. Too prickly. Too weird. The lack of interest is protective. The appearance is deterrent. The value is negligible. Population trends are poorly understood. That phrase again. The deep sea is vast and expensive to study, and prickly dogfish live at depths that make research difficult. Slow reproduction makes populations vulnerable to any fishing pressure. Better species-specific data is needed for accurate stock assessments. The ignorance is systemic. The management is reactive. The risk is unquantified. The gap is wide. A tall, triangular, prickly shark of the deep slope, hovering near the bottom, waiting for someone to learn more. The net drags. The prickly dogfish comes up, spines rough, shape strange. It is thrown back, if it is lucky. Most are not. The survival is accidental. The capture is incidental. The release is rare. The mortality is high. It does not know why. It was just hovering in the dark. The intent was simple. The outcome was complex. The existence is obscure. The future is uncertain. No one told it otherwise.