Wiktionary(0.00 / 0 votes)Rate this definition: upthrust(Noun) an upward thrust. upthrust(Noun) buoyancy. upthrust(Noun) an upward movement of part of the Earth's crust. upthrust(Verb) to thrust something upwards.
Predators, Food and Feeding: Natural predators of winter flounder include sharks, oyster toadfish, summer flounder, striped bass, monkfish and spiny dogfish. When feeding, a winter flounder will lie motionless, partly concealed on the bottom, with its head raised off the bottom, braced by the dorsal fin.
Nothing suits a winter flounder like cold water. Unlike most local fish, winter flounder enter shallow bays and coves in midwinter to spawn and stay until the sun warms the water to temperatures above what they prefer. This habit earned these flatfish their name. It also brought them closer to humans, who found that they were fine eating.