Thursday, January 22, 2009

Science finds 3 types of fish are really 1

In an article posted on yahoo news, Researchers believe they have solved the puzzle of three seemingly different fish, one all males, one all females and one all juveniles. They're the same fish, and undergo remarkable changes as they mature.

"You can imagine it was a pretty exciting discovery," said G. David Johnson, an ichthyologist at the Smithsonian's National Museum of Natural History. "The pieces kept falling into place."

"And it tells you how little we know about the deep sea, Johnson said in a telephone interview.

The fish live in the sparsely populated deep water thousands of feet below the surface, though as youngsters they rise to shallower levels where there is more to eat.

Cetomimidae, a type of whalefish, had been known since the 19th century, but only females had been found.

Seemingly related species called Mirapinnidae, or tapetails, and Megalomycteridae, or bignose fish, were identified in the 1950s and 1960s. Tapetails were only found as juveniles and bignoses only as males.

Although their skeletons indicated the three were related, there were so many differences no one could believe they were the same fish at different sexes or stages in life, Johnson said.

But it turns out that is the case, Johnson and colleagues report this week in Biology Letters, a journal of Britain's Royal Society.

All three will now be classified as Cetomimidae, he said.

Johnson said the researchers were able to link the fish through comparative anatomical study and, once they obtained fresh samples, by their DNA.

The larvae are called tapetails because they grow long streamers, he said. The purpose of the streamer remains unknown, but several fish larvae develop similar appendages, so it must have some value, he said. They reside within 600 feet of the surface, a region well stocked with food.

As adults, however, these fish descend thousands of feet down into the dark ocean.

There is scarce food there and the females cope by developing a large mouth — a common trait among fish living in the deepest waters — and they even develop teeth in their gill area that can serve as an additional mouth.

Even stranger, males who reach adulthood don't eat at all. Having gorged as larvae, their jaw fuses and they develop a vestigial gut that only stores shells from previous meals. That's an advantage, Johnson said, because in the deep ocean "there's not a lot of food, you're better off taking your lunch with you." The males gorge as larvae and grow a giant liver, storing energy there to live on.

"This thing was basically a set of testes looking for the female," Johnson said.

The males also develop a large nose to sense smells in the dark water.

Meanwhile, researchers had noted that females have some unusual tissue, separate from the skin, on their body. It's not luminous, so Johnson speculated that this tissue may produce a pheromone that the big-nosed male can home in on.

Co-authors of the paper were John R. Paxton of the Australian Museum, Sydney; Tracey T. Sutton of the Virginia Institute of Marine Science, Takashi P. Satoh and Mutsumi Nishida of the University of Tokyo and Tetsuya Sado and Masaki Miya of the Natural History Museum, Chiba, Japan.


jan said...

Fascinating! I guess there is a lot to learn about the life in the depths of the ocean.

(The male fish reminds me of some guys I have known)

Nyanko said...

It's amazing! It seems to be a SF story...

tom said...

I started to use Viagra I tried Cialis. I got in to a pharmacy to Buy Viagra and Buy Cialis, I intended to Buy Cialis Online or maybe Cheap Viagra I decided to Buy Levitra at Buy Cheap Levitra site. I got to an online pharmacy to Buy LipitorHydrocodone medications as Cheap Vicodin and its related Cheap Hydrocodone I will continue Buy Hydrocodone I went to the doctor to Buy Oxycodone I in a online pharmacy to Buy Oxycodone Online I'll try to Buy Vicodin Online it cost much less Buy Valium I think it as the same effect as Buy Vicodin it is easy to Buy Hydrocodone Online I can also Buy Hydrocodone No Prescription my doctor advise me Buy Vicodin Online I started a diet, and going to Buy Phentermine and Buy Phentermine Online I also Buy Acomplia and Buy Vicodin No Prescription I went in for a physical the doctor told me I can Buy soma and Buy Ultram pain medication Buy Oxycontin Online is a derivative of opium as Buy Valium Online I also have sleeping problems I tried Xanax It is better to use online pharmacy to Buy Xanax Online and Buy Xanax I'll try to Buy Ambien Online I originally take Ambien, since I used internet to Buy Ambien I recommend some sites Buy Percocet pain reliever as well as Buy Xenical also
Buy Adipex and Buy Zolpidem. also Viagra and Cialis and Levitra and Cialis last Viagra and Buy Viagra and Buy Viagra and Free Viagra good health!

tom said...

Play Roulette and Roulette also Casino finest Casinos games Slots U can play Slot experience Slots play Slot most advanced Slots card games Texas Holdem Poker and Poker Online and Online Poker and Poker and Poker world's leading Blackjack and Blackjack selection of Casinos Online sites Casinos Stop searching Online Casinos go Play Casino Online safe & secure Casino Onlinelive 24/7 Casinos sites Online Casino generous deposit bonus Blackjack join the No Deposit Casino most trusted Play Casino real money Casino Online fantastic atmosphere Online Casino feel the buzz of a live Casino Las Vegas Casino Huge jackpots Casino attractive Casinos most professional Casinos o multiplayer Casino quick cash outs Casino play 21 Blackjack all limits Slots largest tournament Casino Online sit-n-go Online Casino bet Casino Free and Play Poker also Holdem Poker and Poker Games and Casino Poker and Online Roulette and Play Roulette and Slot Machine and Free Slots and Black Jack and Black Jack and Online Blackjack also Free Poker & Play Poker Online and Poker Bonus and Casino Games and more