NEWS CATEGORIES:

NEWS ARCHIVE >>
SOFTPEDIA REVIEWS >>

Home / News / Science / Nature

Nature

Why Are Pregnant Males Such Fast Eaters? The mystery of seahorse feeding	By Stefan Anitei, Science Editor 8th of February 2007, 15:15 GMT Adjust text size:


Sea horses are famous for the fact that males assume female roles, guarding the eggs in a special abdominal pouch and taking care of the infants. Seahorses eat small crustaceans and few know that they are amongst the fastest feeding vertebrates: they can snap up a meal in 5.5 milliseconds. You could be watching it, but you won't see the fish is feeding! A team at the University of M�nster, Germany, wanted to know why seahorses can do it and other fishes can't. A mathematical analysis proved that the smaller a fish's mouth, the longer its snout and vice versa. Most ray-finned fish employ suction and jaw protrusion when feeding. But in seahorses and their parents the suction evolved to the maximum, as their snout form a tube with a tiny mouth on the tip (these fishes are named Syngnathiformes, from Syngnathus "joined jaws"). An elongated snout permits the animals to catch their prey more swiftly, by moving their heads rapidly sideways but in terms of energy costs, researchers found that these make sense only if the fish eats small prey. The researchers used high-speed cameras to observe feeding behavior on two fish species related to seahorses: razor fish, Centriscus scutatus, and greater pipefish, Syngnathus acus. Slow motion images allowed them to make a mathematical formula connecting snout size and capture speed for the two species. "Razor fish and pipefish both have long snouts, and therefore need to raise their heads only slightly to reach relatively distant prey quickly," explained Marc de Lussanet, one of the researchers. A rounder head design forces fish species to approach more their prey before the final snap, and they are therefore slower in capturing their prey. That's why the researchers wanted to know why not all carnivorous species are long snouted. They found that hunting for big prey is better without long snouts. As the mouth is located at the tip of the snout, large mouths would be placed on huge, bulky snouts. "A snout that is very large is heavy is therefore difficult to move," de Lussanet explains. A comparison made on 34 fish species revealed this link between mouth size and snout size. The team will check this formula to other animals that use rapid sideways head turns to grip their prey, such as crocodiles. "The current model would not apply directly to crocodiles because they have different head shapes to pipefish, and they are designed to hunt out of the water too, but the model could be adapted easily," said de Lussanet.

Rating:

Good (3.6/5)

6 vote(s) so far

Read by 907 user(s) | Add comment | Link to this article

Subscribe to news |

Print article |

Send to friend

© Copyright 2001-2008 Softpedia
Contact:

SEARCH THE NEWS ARCHIVE :

Today's News | Yesterday's News | News Archive

MORE RELATED ARTICLES:

Primitive Stage of White Cells Discovered in Fishes

Wild Salmons Destroyed by Fish Farms

Archerfish Tunes Its Shot Power According to the Size of the Prey

Fishes Spy on Hunting Dolphins

Bottom Trawlers Are Menacing the Fragile Deep Sea Coral Ecosystem

The Strongest Bite Ever

How Males Got Pregnant ?

Water Contamination Turns Fish Males into Hermaphrodites

Why Are Seas Swarming with Fish?

Fish That Know in Human-Like Logic

... Make Unusual Aquaculture

Sharks, Not As Dangerous As Thought

Electric Fish Explains How Our Brain Controls Our Body Movements

User opinions:

No user comments yet.

Be the first to express your opinion using the form below!

Share your opinion:

SUBMIT PROGRAM \| ADVERTISE \| GET HELP \| SEND US FEEDBACK \| RSS FEEDS \| ENTER NEWS SITE \| ENGLISH BOARD \| ROMANIAN FORUM
© 2001 - 2008 Softpedia. All rights reserved. Softpedia™ and the Softpedia™ logo are registered trademarks of SoftNews NET SRL.	Copyright Information \| Privacy Policy \| Terms of Use \| Update your software \| Archive