Dusky smooth-hound time to induce tonic immobility in smooth dogfish was 32.5 seconds. The mean duration of the tonic immobility was 61.9 seconds. Sharks that had the “limp” response also exhibited tonic immobility. The “limp” response is a criterion for the onset of tonic immobility. Dusky smooth-hound The dusky smooth-hound ("Mustelus canis"), also called the smooth dogfish or the dog shark, is a species of houndshark in the family Triakidae. This shark is an olive grey or brown in color, and may have shades of yellow or grayish white. Females live to 16 years and males have a lifespan of 10 years.
Speckled smooth-hound by artisan fishermen using gill nets. Landings in Chile peaked in 1989 at around 1300 tons but have since dwindled to less than 200 tons a year, with fish stocks declining and a transfer of the fisheries to targeting rays. In 2001, the Peruvian authorities introduced a minimum size requirement of for tollo. The speckled smooth-hound is assessed by the IUCN as being "near threatened" on the basis of its past over-fishing. This assessment may be raised to a more-threatened category if intensive fishing resumes. Speckled smooth-hound The speckled smooth-hound ("Mustelus mento") is a houndshark of the family Triakidae. It