背鳍

Gymnarchus niloticus ; the long-based flexible dorsal fin ; undulation contour ; polynomial-fitting function ; MPF ; aquatic bio-propulsion

尼罗河魔鬼；柔性长背鳍；波动包络线；多项式拟合方程；奇鳍/对鳍推进；水下仿生推进

At least during a week after outgrowing their yolk-sacks, they are not able to survive without "Discus milk", at the expiration of this period they attain enough functionality to feed on freshly hatched brine shrimp.

在小鱼开始能自由游动后的三周里，他们靠吸收亲鱼背鳍上的分泌物&七彩奶&过活。至少，在吃完剩卵黄的一周内，他们没有&七彩奶&也不能存活。

Any of several gregarious toothed whales of the genus Phocaena and related genera, of oceanic waters, characteristically having a blunt snout and a triangular dorsal fin.

鼠海豚一种鼠海豚属小型群集齿鲸，其共同特点是生活于海洋中，生有钝圆白的吻部以及三角形的背鳍

Porpoise Any of several gregarious toothed whales of the genus Phocaena and related genera, of oceanic waters, characteristically having a blunt snout and a triangular dorsal fin.

Also called sea hog 鼠海豚：一种鼠海豚属小型群集齿鲸，其共同特点是生活于海洋中，生有钝圆白的吻部以及三角形的背鳍也作 sea hog

Large elongate scaleless oceanic fishes with sharp teeth and a long sail-like dorsal fin.

细长的大型海生无鳞鱼，有尖牙和船帆形的长背鳍。

Any of several freshwater food and game fishes of the genus Thymallus of the Northern Hemisphere, having a small mouth and large dorsal fin.

茴鱼北半球的几种茴鱼属的几种供食用钓捕用的淡水鱼类中任何一种，有小嘴和大背鳍

Any of several marine fishes of the family Trachinidae, having venomous spines on the gill cover and first dorsal fin.

龙鳖龙鳖科的多少种海鱼之一，在鳃盖和第一背鳍上的许多毒刺

It was true, however, that he once grabbled a shark by the dorsal as it swam past the boat, and that another crashed up over the side and snapped its jaws three feet from his head. He was close enough to see the serrated edges on every three-inch tooth.

不过，千真万确的是，有一次，他抓住了正游过船边一条鲨鱼的背鳍，而另一侧的船边另一条鲨鱼的嘴巴离他的头只有三英尺，近得他都能看到里面每颗牙齿。

It was true, however, that he once grabbled a shark by the dorsal as it swam past the boat, and that another crashed up over the side and snapped its jaws three feet from his head. He was close enough to see the serrated edges on every three-inch tooth.

不过，千真万确的是，有一次，他抓住了正游过船边一条鲨鱼的背鳍，而在船的另一侧，另一条鲨鱼冲过船舷，它的大腭在离他的头只有三英尺的地方一开一合，近得他都能看到里面每颗牙齿。

Guppies have been bred in various ornate strains characterized by colour or pattern and by shape and size of the tail and dorsal fins.

已经人工培育出许多绚丽多彩的品系，特点表现于颜色或花纹，尾鳍和背鳍的形状与大小也各不相同。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。