Marine biologists have long observed that invertebrates inhabiting the abyssal plains — crustaceans, cephalopods, and polychaete worms — routinely attain body sizes dramatically exceeding those of their shallow-water relatives. Specimens of the giant isopod, for instance, can reach dimensions thirty times greater than those of intertidal isopods of comparable taxonomic affinity. For decades, the standard account attributed this abyssal gigantism to the thermodynamic properties of near-freezing water: lower temperatures, it was argued, reduce metabolic rates, and a slower metabolism was presumed to delay senescence, thereby extending the growth window and permitting organisms to accumulate biomass over longer lifespans. In fact, however, metabolic measurements conducted on abyssal amphipods over the past decade have yielded results sharply at odds with this reasoning. Rather than exhibiting uniformly depressed metabolic activity, many deep-sea species display metabolic rates that, when corrected for temperature, equal or modestly exceed those of related taxa from temperate coastal waters. Furthermore, certain abyssal forms undergo accelerated growth phases during episodic pulses of organic detritus — so-called marine snow events — that temporarily flood the benthic ecosystem with nutrients. These findings have prompted a reevaluation: some researchers now propose that gigantism in the deep ocean may represent an adaptive response to chronic caloric unpredictability rather than to temperature per se, with enlarged body size serving as a buffer against prolonged intervals of nutrient scarcity.

The highlighted portion of the passage serves primarily to

A. enumerate instances of organisms whose dimensions contradict the predictions of the thermodynamic account
B. describe the mechanism by which deep-sea organisms are thought to convert episodic nutrient influxes into sustained somatic growth
C. delineate the explanation for abyssal gigantism that held sway before recent empirical findings called its foundational assumption into question
D. provide a counterexample that illuminates why marine biologists initially dismissed the adaptive-scarcity hypothesis
E. distinguish the metabolic responses exhibited by crustaceans from those documented in cephalopods and polychaetes



According to the passage, which of the following can be inferred about the thermodynamic explanation introduced in the highlighted text?

Consider each choice separately and select all that apply.

A. It rests on a premise that direct physiological measurements have failed to corroborate.
B. It entails that gigantism should be most pronounced in those benthic species whose metabolic rates, after temperature correction, are the most subdued.
C. It predicts that the influence of near-freezing water on organism size will be exclusively beneficial.