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.
Starry smooth-hound range and is common in the northern part of its range where its population seems to be steady. In the Mediterranean Sea, it is less common and is targeted for human consumption along with the closely related common smooth-hound ("Mustelus mustelus"). Numbers in the Mediterranean have dwindled and in this region it might qualify for "Vulnerable" status were it not plentiful elsewhere. Starry smooth-hound The starry smooth-hound ("Mustelus asterias") is a houndshark of the family Triakidae. It is found on the continental shelves of the northeast Atlantic, between latitudes 61° N and 16° N, from the surface to a depth