Linked from
The 9 pages that link to Streamlining, each with the reason it gives.
Aquatic locomotionRelated: Many fast swimmers have forms that limit pressure drag.
DragRelated: A streamlined shape delays flow separation and can lower pressure drag.
Marine mammalRelated: A streamlined body reduces drag during swimming.
Front crawlRelated: A long, aligned body position limits drag between strokes.
Earless sealRelated: The tapered body of a phocid reduces drag while swimming.
Aquatic animalRelated: A streamlined form lowers drag during sustained swimming.