Box jellyfish have it over the rest of the jellyfish world—they have true eyes, featuring corneas, lenses and retinas. They have a more ___1___ nervous system too. They still don’t have a real brain, but those eyes enable them to actively hunt prey. Other jellyfish just ___2___. Well, not really hope, because you can’t do that without a brain.

Anyway, it’s been long known that box jellies had eyes, 24 in fact, of four different types. But now researchers have found that four of those eyes just look up, and out of the water. The work appears in the journal Current Biology. [Anders Garm, Magnus Oskarsson and Dan-Eric Nilsson, Box Jellyfish Use Terrestrial Visual Cues for Navigation]

The studied jellies live in mangrove swamps and the studied eyes are always aimed at the tree canopy. By ___3___ the canopy the jellies can ___4___ to their preferred spots—where their favorite food, small crustaceans called copepods, are plentiful.

Their various eyes show that the jellies evolved a clever strategy. Rather than a single set of peepers that collect info for processing by a big brain, box jellies have different eye types responsible for informing different behaviors, with no brains. More evidence that it can be a mistake to ___5___ a problem.
【视听版科学小组荣誉出品】
sophisticated drift and hope tracking navigate overthink
箱水母进化出了真正的眼睛,很有特点的眼角膜,晶状体还有视网膜,简直是水母一族中中的传说啊.不仅如此,它们还拥有更为复杂的神经系统.虽然它们大脑还未真正成形,但靠眼睛就能让它们主动对猎物发起进攻.不像其它同类只能四处游荡,满心期待.也不能算是真正期待,毕竟那得用脑子啊. 人类很早就发现箱水母有四种不同类型的眼睛,一共24只.研究人员近期发现箱水母有四只眼睛是露出水面向上看的, 这项研究成果刊登在<当代生物学>期刊上. 研究人员研究了生活在红树林沼泽地带的水母,他们发现水母的眼睛总是盯着树冠.因为盯着树冠,水母们就能找到它们的乐园-----那里到处都是它们的最爱:一种桡足类的甲壳纲动物. 箱水母各式各样的眼睛表明它们进化得更聪明了.虽没有大脑,但它们不同种类的眼睛分担不同功能,而不是一整个通过大脑支配的单纯的信息收集器.所以说嘛,想太多有时候真不是好事~