Spotted estuary smooth-hound

Spotted estuary smooth-hound
Scientific classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Chondrichthyes
Subclass: Elasmobranchii
Division: Selachii
Order: Carcharhiniformes
Family: Triakidae
Genus: Mustelus
Species:
M. lenticulatus
Binomial name
Mustelus lenticulatus
Phillipps, 1932

The spotted estuary smooth-hound or rig (Mustelus lenticulatus) is a houndshark of the family Triakidae, found on the continental shelves and in estuaries around New Zealand. It is closely related to the gummy shark (Mustelus antarcticus) of Australia. Males can grow up to a length of 125 cm (49 in), while females can reach a length of 151 cm (59 in). In 2025, rigs were found to be the first known sharks capable of sound production, namely, "clicks."

It is commercially fished, and is commonly served in fish and chip shops in New Zealand under the name "lemonfish". In June 2018 the New Zealand Department of Conservation classified the spotted estuary smooth-hound as "not threatened" with the qualifier "conservation dependent" under the New Zealand Threat Classification System.