646 
Abstract. -Eight female cunners, 
Tautogolabrus adspersus, were tagged 
externally with ultrasonic transmitters 
in Newfoundland, and their activity 
pattern was recorded. They were active 
diurnally, commencing activity, on av- 
erage, 55 minutes after sunrise and 
ceasing activity about 50 minutes af- 
ter sunset. The diurnal activity period 
was interrupted by periods of inactiv- 
ity usually lasting 5-15 minutes. Lev- 
els of activity varied daily and season- 
ally; seasonal changes were the most 
dramatic. On average, female cunners 
were active for more than 12.5 h/day 
in June-July and for only 3 h/day in 
October-November. Decrease in activ- 
ity reflected decreasing day length; as 
photoperiod became shorter, cunners 
spent a much larger portion of the day- 
light period inactive (22.9% in June- 
July compared with 71.8% in October- 
November). Decrease in cunner activ- 
ity in the fall occurred while water tem- 
perature was as high as that in June 
and July and is speculated to be con- 
trolled by an endogenous rhythm. 
Manuscript accepted 7 May 1997. 
Fishery Bulletin 95:646-652 (1997). 
Daily and seasonal activity 
patterns of female cunner, 
Tautogolabrus adspersus 
(Labridae), in Newfoundland 
Carole Bradbury 
John M. Green* 
Department of Biology 
Memorial University 
St. John's, Newfoundland, Canada A1 B 3X9 
E-mail address (for John Green): JMGREEN@morgan.ucs.mun.ca 
Michael Bruce-Lockhart 
Faculty of Engineering 
Memorial University 
St. John's, Newfoundland, Canada A 1 B 3X9 
Cunner, Tautogolabrus adspersus, 
is the most northerly distributed 
labrid fish in the western North 
Atlantic, reaching the northern ex- 
tent of its range in waters off New- 
foundland. A member of a large, es- 
sentially tropical, family, it is well 
known for its annual state of pro- 
longed physiological torpor, which 
in Newfoundland may last for more 
than 6 months (Green and Farwell, 
1971). The ability of cunners to un- 
dergo a long period of torpor is ap- 
parently one of the factors that have 
enabled this species to flourish in a 
low temperature environment (Cur- 
ran, 1992). In waters off Newfound- 
land, cunners are abundant and in- 
habit sites where summer maxi- 
mum water temperature is less 
than 11°C and the winter minimum 
is below -1°C. Newfoundland cun- 
ners enter and remain in torpor 
when seawater temperature is be- 
low about 5°C (Green and Farwell, 
1971). 
Throughout their range, Chesa- 
peake Bay to the Strait of Belle Isle, 
cunners are associated with inshore 
habitats that provide shelter dur- 
ing nocturnal quiescence (a charac- 
teristic of labrids) as well as during 
overwintering torpor (Pottle and 
Green, 1979a). Rather than migrat- 
ing to deeper, warmer water as the 
temperature declines in the fall, 
Newfoundland cunners take shelter 
under boulders and rocks at their 
summer feeding and reproductive 
sites. There they remain until the 
seawater temperature approaches 
5°C the following year, usually in 
early June (Green and Farwell, 
1971). In Conception Bay, New- 
foundland, territorial males estab- 
lish territories within a week of 
emerging from winter torpor and 
maintain them until just prior to 
reentering winter torpor, usually in 
late November or early December 
(Pottle and Green, 1979a). Spawn- 
ing commences in mid to late July, 
depending upon water temperature, 
and lasts for 2-3 weeks. All spawn- 
ing activity occurs within male ter- 
ritories (Pottle and Green, 1979b; 
Martel and Green, 1987). 
We recently reported on a home- 
range size for adult female cunners 
in Conception Bay, Newfoundland, 
that was based on telemetry data 
* Author to whom correspondence should be 
sent. 
