Antifreeze proteins in the grubby sculpin, Myoxocephalus aenaeus and the tomcod, Microgadus tomcod: comparisons of seasonal cycles
ABSTRACT Antifreeze protein levels in the plasma of the grubby sculpin, Myoxocephalus aenaeus and the tomcod, Microgadus tomcod of Long Island coastal waters start to increase by November in anticipation of midwinter freezing conditions. Peak levels
of antifreeze, as measured by the difference in plasma melting and freezing points, were detected in January for both species.
The thermal hysteresis values reached 0.459°C in sculpin and 0.51°C in tomcod. Antifreeze peptides and glycopeptides start
to disappear when water temperatures begin to rise and are at insignificant levels by late spring. Aspects of the seasonal
cycle and the level of antifreeze activity were compared in three sympatric species (sculpin, tomcod, flounder); in two closely
related but ecologically distinct gadids (tomcod, Atlantic cod); and within the genus Myoxocephalus.
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ABSTRACT: Two species of sculpins (Cottidae), the grubby, Myoxocephalus aenaeus, and the shorthorn sculpin, M. scorpius, were studied in rocky tidepools along the coast of Maine. Fishes were captured and measured during 116 sampling trips between 1979 and 1996. Both of these species of sculpins are from the northwestern Atlantic Ocean and are present in tidepools nearly every month of the year and are the only fish species found in Maine tidepools during winter. Both sculpin species are important components of tidepool ecosystems and dominate the rocky tidepool fish communities from late autumn to early spring, a time when other fish species decline in abundance or are absent. There was no apparent relationship between sculpin abundance and salinity, but the two species of Myoxocephalus were encountered in water temperatures of 1.5 to 18.9°C, with 55.0% of the shorthorn sculpins and 57.3% of the grubbies encountered in tidepools where water temperatures ranged from 12 to 15°C. Between 1988 and 1996, 102 individuals from both species were marked. Of these, 21.3% were recaptured, some repeatedly in the same tidepools and even at specific locations within tidepools over successive tidal cycles—an indication of homing behavior.Northeastern Naturalist 01/2009; · 0.50 Impact Factor