Question

あゐ

写真 2枚目の 英文のshooting apart は、jetのことなんでしょうか？
日本語訳は写真の枚数的に後半しか写せませんでした。ちなみに疑問点の和訳は赤で線を引いているところです。

Ⅱ 英文を読み、下記の問いに答えなさい。
(7)
Like a tiny submarine, the chambered nautilus speeds through the
ocean on little jets that it creates by sucking in water and spitting it
out.
However, as ways of movement go, jet propulsion is not usually a
(8)
very good use of energy. In the ocean's depths where oxygen gets
thin, the nautilus seems to be putting itself at risk by expending so
much effort on movement. Fish use far less energy by pushing at
the water with their fins. So how does it manage to jet around
unscathed in the ocean's depths?
Graham Askew, a biomechanics professor at the University of Leeds,
set out with a graduate student, Thomas Neil, to understand better
how this shellfish moves. They found that the nautilus is actually a
(9)
highly efficient jet-propelled creature, wasting much less energy than

marine organisms like squid or jellyfish that get around in a
way.
The researchers began their study, which was
similar
published Wednesday
in Royal Society Open Science, by liberally sprinkling
an aquarium
10
with minuscule floating particles of aluminum oxide. Then, one by
one, they put five chambered nautiluses into the tank, and let them
jet about.
They used high-speed cameras, a laser that lit up the particles and
software that could record the particles' movements. In the
constellation of specks, they saw the animals sucking in water, then
forcing it out in the direction they were moving away from, with the
pocket of ( 11 ) water and the nautilus shooting apart at velocities
they could readily calculate.
jetのこと?
When they ran the numbers, the researchers saw that the nautilus
was able to use 30 to 75 percent of the energy it transferred to the
water to move.
That was much higher than other similar swimmers. "Squid, they
tend to be about 40 to 50 percent efficient," said Dr. Askew.
Bell-shaped jellyfish, which pulse their bells to squirt out water, also
tend to have lower than 50 percent efficiency.

彼らはハイスピードカメラ, 粒子を照らすレーザー,粒子の動きを記録
することのできるソフトウェアを使った。 小さな点の集まりの中で、その
生物たちが水を吸い込み、それからその水を自身が離れる方向に吐き出す
と吐き出されたひとまとまりの水とオウムガイが、難なく計算できる速
度で別々の方向へさっと動いていくのを彼らは見た。
計算してみると, オウムガイは水中に送り出した30から75%のエネル
ギーを移動に使うことができることをその研究者たちは知った。
それは,水中を移動する他の似たような生物よりもずっと高かった。
「イカは約40から50%の効率になる傾向にあります」とアスキュー博士
は語った。
釣り鐘型のクラゲは自身の釣り鐘状の部分を脈動させて水を噴出するの
だが、それもまた50%を下回る効率になる傾向にある。
解説