Why is emphasizing short cooking time recommended for pouting fillets?

To maintain moisture

Pouting, like many delicate white fish species, requires judicious cooking to achieve the best texture. The general advice strongly suggests keeping the cooking time short when preparing fillets, drawing a parallel to how one might treat whiting or haddock. The primary reason for this constraint on cooking duration is specifically to maintain the inherent moisture content of the flesh. Overcooking these types of fish causes them to dry out rapidly, resulting in a less pleasant, possibly tough texture. By cooking quickly until opaque and flaky, the goal is achieved: a tender, moist result that preserves the desirable flaky characteristic noted in the culinary descriptions of edible pouting.