Rig
Fish · Last reviewed 2026-08-25
New Zealand's estuary smooth-hound — a small shark with crushing plates instead of teeth, and the fish sold there as lemon fish.
Safety: injury while handling fish — minor injury.
Catching Rig
Everything here on fishing for it. Each entry opens the page behind it.
- Ground
Rig is what New Zealand calls *Mustelus lenticulatus*, a small houndshark of shallow coastal water and estuaries around the country and the Kermadecs, with records from southern Australia. On a fishmonger's slab it is `lemon fish`; in Māori it is pioke.
It is a smooth-hound, and the name is literal: it has no cutting teeth at all. Its jaws carry flattened pavement-like plates for crushing crabs and shellfish, which makes it harmless to handle at the business end and completely unlike the sharks it is grouped with in most people's minds. It is grey to grey-brown above, pale below, and covered in the small white spots the `spotted` in its other name refers to. FishBase records 125 cm, over a depth range of 0 to 860 m but usually inside 400, and gives it low resilience.
Its life history is the reason it is managed carefully. Like the other *Mustelus* it is viviparous — the young develop internally and are born live and well-grown, in small numbers — which is a reproductive strategy that produces very few offspring per adult and recovers slowly from being fished hard. Juveniles use shallow estuaries and harbours as nursery grounds.
For an angler it is a shore and small-boat target on crab and shellfish baits fished on the bottom over sand and mud, and it fights in the dogged, unspectacular way the smooth-hounds do. It is among New Zealand's more commonly eaten fish.
How it is caught
Identification
No photograph of Rig has passed identity review yet, so none is shown. FishingHQ publishes a species photograph only once somebody has confirmed the animal in it against the species record’s own diagnostic features.
- Scientific name
- Mustelus lenticulatus
- Family
- Triakidae
- Water
- Saltwater, Brackish
- Conservation status
- Least Concern
- Regions
- New Zealand, Australia
- No cutting teeth: the jaws carry flattened pavement-like crushing plates, which is what makes it a smooth-hound.
- Grey to grey-brown above with small white spots scattered over the back and flanks, and a pale belly.
- A slim houndshark build with two similarly sized dorsal fins and a long upper tail lobe.
- FishBase records a maximum of 125 cm.
- Range is a strong separator: this is the New Zealand and Kermadec smooth-hound, with records from southern Australia.
Size
- Typical
- 2–5 kg (4.4–11 lb)
- Large
- 7–10 kg (15–22 lb)
Exceptional: FishBase records a maximum of 125 cm
Lifecycle and reproduction
Demersal and oceanodromous over a depth range of 0 to 860 m but usually inside 400 m, with shallow coastal water and estuaries used as nursery ground by juveniles. FishBase gives it LOW resilience, which for a live-bearing shark producing small litters is the expected result.
Viviparous, as the smooth-hounds are: the young develop internally and are born live and well-grown, in small numbers. That is a low-fecundity strategy — a handful of pups per adult rather than thousands of eggs — and it is the whole reason a small, abundant-looking coastal shark needs managing carefully.
Feeding and senses
Takes crabs, shellfish and other hard-shelled invertebrates from the bottom, crushing them with pavement teeth. It hunts by scent over sand and mud, which is why crab and shellfish baits fished static on the bottom are what catch it.
Scent and electroreception over soft ground, in water that is frequently turbid. Presentation matters far less than bait freshness and a well-anchored bait in a tide.
Through the year
Moves inshore into estuaries and harbours seasonally, with the shore fishery concentrated when those movements bring fish within reach. Juveniles are present in the shallow nursery grounds through the warmer months.
Distribution
Southwest Pacific: Kermadec Islands and New Zealand; reported from southern Australia
This is a biological range — where the species occurs, not a prediction that you will catch one. To browse the fishing geography FishingHQ holds, start at fishing places.
Why anglers care
A standing New Zealand shore and small-boat target, taken on crab and shellfish baits fished on the bottom over sand and mud in harbours, estuaries and shallow coastal water. It fights doggedly rather than spectacularly. It is widely eaten in New Zealand and is the fish sold there as lemon fish, which is worth knowing because most people meet the name before they meet the animal.
Handling and returning
Harmless at the mouth — it has crushing plates rather than cutting teeth — and its skin is abrasive enough to take skin off a forearm. Support it horizontally, do not lift a large one by the tail, keep it in the water where possible, and return it quickly: a live-bearing shark with small litters is worth more in the water than most fish of its size.
Safety
Injury while handling fish — Minor injury
The skin is covered in dermal denticles and is abrasive enough to graze a forearm badly when a fish thrashes against it. The mouth is not the hazard: it has no cutting teeth.
What reduces it: Handle with a wet cloth or gloves, control the fish along the body rather than letting it roll against bare skin, and support it horizontally rather than lifting it by the tail.
Where to go next
Similar and related fish
Where it lives
More fish
Not related to this page — just the rest of the section. There is little else joined to this subject yet, and a short page should still lead somewhere.
Sources and evidence
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: Family, maximum size, depth range, environment, distribution and the IUCN assessment for Mustelus lenticulatus.States this directlyPassage read and verified
- The IUCN Red List of Threatened Species — International Union for Conservation of Nature (Conservation authority)Relied on for: The Least Concern assessment for Mustelus lenticulatus, assessed 22 June 2017.States this directlyCitation checked — the work exists and is described correctly
- FAO Species Identification Guides for Fishery Purposes and the FAO Species Catalogues — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Identification, distribution, habitat and fishery description from the FAO species identification guides for fishery purposes.States this directlyCitation checked — the work exists and is described correctly
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: The widely restated practitioner account of how this species is fished — tackle, method and the ground it is taken over.Background and mechanism onlyCitation checked — the work exists and is described correctly
Why the 3 connections on this page are here, and the sources
Similar and related fish
Backed by research — 1 connection
Supported by peer-reviewed research or fisheries science. The sources are listed and can be checked.
Starry smooth-hound
Mustelus lenticulatus reaches 125 cm around New Zealand and the Kermadecs; Mustelus asterias is the north-east Atlantic species a British shore angler meets. Both carry pavement crushing plates rather than cutting teeth, both take crab baits on the bottom, and both are live-bearers with small litters.
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: The morphology, size, depth range and distribution that separate these two species from one another.States this directlyPassage read and verified
How it is caught
What experienced anglers do — 1 connection
Widely and independently recommended by experienced anglers and specialist sources. This is real angling knowledge, not proof: controlled evidence for it is limited, and FishingHQ records it as convention rather than as a demonstrated effect.
Ledgering
Taken on crab and shellfish baits fished static on the bottom over sand and mud in New Zealand harbours, estuaries and shallow coastal water. Its jaws carry pavement-like crushing plates rather than cutting teeth, which decides the bait entirely.
- FAO Species Identification Guides for Fishery Purposes and the FAO Species Catalogues — Food and Agriculture Organization of the United Nations (Scientific institute)Relied on for: Identification, distribution, habitat and fishery description from the FAO species identification guides for fishery purposes.States this directlyCitation checked — the work exists and is described correctly
- General angling website restatements of established technique — Various (Credible secondary source)Relied on for: The widely restated practitioner account of how this species is fished.Background and mechanism onlyCitation checked — the work exists and is described correctly
Where it lives
Backed by research — 1 connection
Supported by peer-reviewed research or fisheries science. The sources are listed and can be checked.
Estuary
Demersal and oceanodromous over a depth range of 0 to 860 m but usually inside 400 m, with shallow coastal water and estuaries used as nursery ground by juveniles around New Zealand and the Kermadecs.
- FishBase: a global information system on fishes — Froese, R. and D. Pauly, eds. — FishBase Consortium (Scientific institute)Relied on for: Environment, depth range, habitat association and distribution for Mustelus lenticulatus.States this directlyPassage read and verified
How FishingHQ labels evidence is explained in the evidence policy.