|Author||Curran, Mary C.||
|Location||Western North Atlantic||
|Date of Issue||1992-09||
|Description||Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy at the Massachusetts Institute of Technology and the Woods Hole Oceanographic Institution September 1992||en_US
|Description||The family Labridae, or wrasses, is one of the most speciose fish families and is
exceptional in its wide range of morphological and behavioral diversities. The cunner
Tautogolabrus adspersus is one of two temperate-dwelling Western North Atlantic
representatives of this family, and they are one of the few fishes that remain in New
England waters throughout the year. In the winter, the cunner enters a state of "torpor"
which has previously been described based solely on behavioral observations. The
present study showed that cunner undergo physiological torpor, or hibernation, based on
low oxygen consumption rates in winter, contributing to a large Q10 value of 8.5. It is
thus established as one of the few marine species that is known to hibernate.
Cunner withstood four months of starvation at 4°C. Glycogen, lipid, and protein in
the liver decreased during this period, as did the liver/body ratio, but these components
did not decrease significantly in the whole-body samples. Since liver components were
not exhausted, and body components were not significantly affected, cunner can withstand
long periods without eating. Regression analysis predicts that they can live at least 6
months given the rate of decrease of glycogen and lipid reserves, and 9 months based on
their protein reserves.
Oxygen consumption rates were monitored continuously over several days to
determine diel variations in metabolic rate. The values obtained at night were
significantly lower than the daytime values. Cunner did not maintain a diel cycle
throughout the year; the length of this cycle varied from approximately 24 hours during
warm temperatures to approximately 48 hours at temperatures generally below 8°C.
Metabolic rates were more variable at warmer temperatures, which is in agreement with
the expected increase in spontaneous activity. Two tropicallabroids, the wrasse Thalassoma bifasciatwn and the parrotfish Scarus
iserti, also had significantly higher oxygen consumption rates during the day than at night.
Both hibernation and sleep are thought to be energy conserving mechanisms in fishes.
The ability of labrids to sleep may have predisposed them to becoming established in
temperate waters by surviving cold temperatures through hibernation.||en_US
|xmlui.metadata.dc.description.sponsorship||Funding for this research came from the Ocean Ventures Fund (OVF), and from
private funding from the Mobil Co. administered by the Coastal Research Center (CRC)
at WHO!. This research was also partially the result of research sponsored by NOAA
National Sea Grant College Program Office, Dept. of Commerce, under Grant No. NA86-
AA-D-SG090, WHOI Sea Grant Project Nos. R/A-26-PD and R/B-106-PD.||en_US
|Publisher||Massachusetts Institute of Technology and Woods Hole Oceanographic Institution||en_US
|Title||The behavioral physiology of labroid fishes||en_US