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.
Hound trailing the popularity of the sport led to the establishment of the "Hound Trailing Association" in 1906, this was followed by the Border Hound Trailing Association in 1933 and later the Yorkshire Hound Trailing Association and associations in County Cork and County Kerry. Trail hounds have evolved into a distinct breed or type of hound specifically bred for performance alone, they are sleek, hard muscled hounds with almost whippet like bodies. Trail hounds descend from the Fell hounds, foxhounds found in the north of England. In his "Foxes, foxhounds and fox-hunting", Richard Clapham stated "fell hounds trace their origin back to