dorsal fin

基本解釋

Its sail-like first dorsal fin provides stability while swimming.
帆狀的第一背鰭在游動時提供了穩(wěn)定性。
They are cobalt-blue on top and silvery-white below, with a pronounced dorsal fin and a long, lethal, spear-shaped upper jaw.
它的頂部是鈷藍色，下面和銀白色；有著明顯的背鰭，還有著長長的、能致命的矛狀上顎。
Witnesses reported seeing a dorsal fin and thrashing in the water before the sea turned red and the man vanished at the scene on Australia's west coast.
目擊者稱看到有鯊魚背鰭在水面上時隱時現(xiàn)，后來發(fā)現(xiàn)海水變成紅色，而那名男子也從澳大利來西海岸上消失了。

The star of the show is a whole rouget, served dorsal fin upward as if the fish were still swimming.
NEWYORKER: Rouge et Blanc

any unpaired median fin on the backs of fishes and some other aquatic vertebrates: maintains balance during locomotion