海洋里艳丽的slugs

Underwater Jewels: The Ocean’s Most Colorful Slugs

When we think of slugs, most of us picture the small, grey, slimyland variety. But under the surface of the ocean lives a whole otherworld of colorful, fascinating sea slugs. They’re called nudibranchs,and they come in a stunning array of colors and shapes.

(images via: SeaWayBlog)

Nudibranchs are found all over the world, but they’re most prolificin warm, shallow sea water. Their coloration varies widely, from themuted colors of some easy-to-overlook types to the neon, clown-likeappearance of others. Likewise, their physical forms are extremelyvaried. One consistent characteristic is the “tentacles” on the headswhich allow nudibranchs to feel, smell and taste.

(images via: Raymond)

There are around a thousand species of nudibranchs, and because oftheir extremely diverse appearances it’s often not easy for divers toidentify the specific types they encounter. Many online forums havesprung up to help divers and underwater photographers identify justwhat types of nudibranches they’ve managed to spot, as well as to sharetheir finds with the nudibranch enthusiast community.

(images via: Raymond)

Nudibranchs’ unusual name comes from their distinctive breathingmethod: “naked” branchial (breathing) tubes on their backs whichresemble branches or bushes. However, not all nudibranchs sport thisunusual-looking breathing apparatus. While nudibranchs are commonlyreferred to as “sea slugs,” which is technically a valid title, itshould be noted that not all sea slugs are nudibranchs.

(images via: Nudibranch.com.au)

So why are nudibranchs so odd looking? They have probably evolved tohave very bright colors in order to warn predators away. Nudibranchs’skin is usually poisonous or at least very foul-tasting, making theminedible to most other creatures. Their strange coloration lets fishknow that they won’t enjoy a mouthful of nudibranch. Interestingly,nudibranchs are hermaphroditic (they have sex organs of both genders)but they don’t self-fertilize. These amazing jewels of the ocean can beseen around the world, so keep an eye out the next time you gosnorkeling to see if you can spot their colorful patterns.