12 of the Most Unusual and Transparent Creatures!

The world is full of intriguing animals; none more so than those animals that are transparent. They are just incredibly interesting and stunning creatures.

The other day I read an article that was fascinating. Earlier this year, a fisherman from New Zealand pulled out of the waters off New Zealand's coast a transparent marine life (photo on left). Experts say that the "creature is a type of salp, which moves through the ocean by contracting and pumping water through its gelatinous body."

There are a multitude of mind-blowing beautiful transparent animals in this world and I thought I'd share them with you. I've culled the information from several different sources. (Click on the photos to see larger images.)

1. Salps: Not to be confused with jellyfish, salps are transparent, free-floating tunicates. Their viscous bodies swim by contracting and pumping water through internal feeding filters, feasting while they move.

Salps feed on small plants in the water called phytoplankton (marine algae). They are transparent, barrel-shaped animals that can range from one to 10cm in length.

They can be found anywhere, but they are probably most common in the Southern Ocean, where they sometimes form enormous transparent swarms.

2. Phronima: Meet a parasite that can create its own mobile nursery for its young. A parasite that is thought to be the inspiration behind the chest-bursting xenomorph in the film Alien. Meet Phronima, the pram-pushing, barrel-riding parasite.

These tiny creatures are found throughout the world’s oceans, except polar regions, swimming in open water. This sets them apart from their relatives, crabs for example, which typically stick to the safe confines of the seabed. Phronima has broken free of the sea floor, taking advantage of the salp to survive in the open water. Phronima attack these vulnerable creatures and make them their hosts. Equipped with impressive front claws, Phronima carves away their insides to leave an empty barrel structure. It then climbs inside and sails the sea from within, feeding off food and water on the go. Yikes!

3. Transparent shrimp: The semi-translucent shells of these minuscule crustaceans make them nearly as transparent as the glass aquariums in which they are sometimes kept. In the wild, different species can be found in rivers and lakes throughout the world, including the central United States.

The animal is so clear in appearance that it only has color after it has eaten a colorful meal, which is typically plant-based and, therefore, usually green.

The palaemonetes pugio has a smooth carapace and abdomen, as well as three pairs of legs. The second pair is the strongest, while the third pair lacks chelae (claws). It reaches a length of around 5 cm (2.0 in), and has a life span of around one year.

4. Glass frogs: Native to Venezuela, the Glass Frogs belong to the amphibian family Centrolenidae (order Anura). While the general background coloration of most glass frogs is primarily lime green, the abdominal skin of some members of this family is transparent, so that the heart, liver, and digestive tract are visible through their translucent skin.

Glass frogs are generally small, ranging from 3 to 7.5 cm (1.2 to 3.0 in) in length. They are known to eat their own young. (Tastes like chicken.)

These types of frogs would be useful for the squeamish biology students who don't want to perform dissections.

5. Glasswing butterfly: Found in Central America, from Mexico to Panama, the Glasswing Butterfly (Greta Oto) is a brush-footed butterfly where its wings are transparent. The tissue between the veins of its wings looks like glass and it has an average wingspan of 5.6 to 6.1 cm (2.2 to 2.4 in).

This butterfly has a Spanish name, "espejitos," which means "little mirrors." If it wasn't for the opaque outline around the wings, the average observer might not see one perched on a leaf or flower.

Adult glasswing butterflies will often migrate great distances, and males of the species are known to lek, or gather in large groups for the purpose of competitive mating displays. Much like Saturday nights in the nightclubs.

6. Barreleye:  This unusual fish might be the most bizarre creature ever found lurking in the deep ocean. Sometimes called a "spookfish," no doubt because of its strange appearance, the barreleye has a completely transparent head.

The purpose of the clear head is that its eyes, which are located inside the head, can look straight up as it swims, presumably so that it can detect the silhouettes of available prey. Its eyes can rotate within the socket so that the fish can look in multiple directions, which would be impossible if not for the transparent cranium. The two "eye-like" spots above the mouth are actually its nostrils. The javelin spookfish is by far the largest species at 50 cm standard length; most other species are under 20 cm.

Check out this incredible video of a live barreleye as it swims. You can also check out Stephen Colbert's reaction to this weird fish. Hilarious!

7. Glass octopus: This unbelievable octopus is so ghostly and unusual that it occupies its own family, Vitreledonellidae. Little is known about this marine animal, but it can be found in tropical and subtropical waters around the world.

Thanks to its transparent skin, scientists know that its optic lobes have unusually long optic nerve stalks, meaning its sense of sight is acute. This fascinating animal has a mantle length of up to 11 cm and a total length of up to 45 cm in adults. The upper three pairs of arms are subequal in length; in juveniles about as long as the mantle, in adults 2-3 times the mantel. The fourth, ventral pair is slightly shorter.

The female broods her eggs, of which there are hundreds, within the mantle cavity. Each egg measures about 4 mm in length. Newborn larvae have a mantle of approximately 2.2 mm.

8. Crocodile icefish: Found in the cold waters around Antarctica and southern South America, the crocodile icefish feed on krill, copepods, and other fish. Their blood is transparent because they have no hemoglobin, the protein in blood that transports oxygen. They are the only known vertebrates in the world without hemoglobin.

Their metabolism relies only on the oxygen dissolved in the liquid blood, which is believed to be absorbed directly through the skin from the water. This works because water can dissolve the most oxygen when it is coldest. In five species, the gene for myoglobin in the muscles has also vanished, leaving them with white instead of pink hearts. 

They can survive without hemoglobin thanks to the subzero temperatures of the ocean where they live, since cold water has a much higher dissolved oxygen content than warmer water.  About 25 species of crocodile icefish are currently recognized. Icefish reach total length of 25-75 cm.

9. Transparent sea cucumber:  Recently discovered by researchers with the Census of Marine Life, this sea cucumber is so transparent that its digestive tract is on spectacular display.

Found at a depth of 2,750 meters, it is one of many unusual finds discovered by the marine census. When encountered, this cucumber was creeping forward on its many tentacles at about 2 centimeters per minute while sweeping detritus-rich sediment into its mouth.

10. Glass squid: There are about 60 different species of glass squid, so-called because many of them appear completely transparent. This transparency keeps them hidden from predators, since they spend much of their lives in partially sunlit shallow waters.

Many species are bioluminescent and possess light organs on the undersides of their eyes. Since the digestive gland can still be seen through the transparent skin, it is typically held in a vertical position to reduce its visibility.

Found on the southern hemisphere's oceans, the Glass Squid has light organs on its eyes and possesses the ability to roll into a ball, like an aquatic hedgehog. It is prey of many deep-sea fish (eg goblin sharks) as well as whales and oceanic seabirds. But can you make calamari out of them? 

11. Jellyfish:  Perhaps the most well-known types of transparent creatures are jellyfish.

Many of the free-swimming members of the phylum Cnidaria are transparent, a trait that makes them occasionally hazardous because of their sometimes deadly stings, which can surprise swimmers. Their translucent bodies also make them among the most elegant and beautiful of the ocean's creatures.

They are found in every ocean, from the surface to the deep sea. The one shown here is from the Arctapodema genus, with a size of an inch-long (2.5-centimeter-long).

12. Transparent Zebrafish: This see-through zebrafish was created in 2008 by scientists so they can study disease processes, including the spread of cancer. The transparent fish are allowing researchers at Boston Children's Hospital to directly view fish's internal organs and observe processes such as tumor growth in real-time in living organisms. 

In January 2013, Japanese scientists genetically modified a transparent zebrafish specimen to produce a visible glow during periods of intense brain activity, allowing the fish's "thoughts" to be recorded as specific regions of its brain lit up in response to external stimuli. Check out the video of the thinking fish.

Got to love science!

This concludes your science lecture for today.  Make sure you study for the upcoming test.