Distinctive body type aids long life and predation

Feb 10, 2014 by Sarah Curran-Ragan
Distinctive body type aids long life and predation
By incorporating large volumes of water into their bodies, jellyfish are able to grow to a size disproportionately larger than other animals relative to their carbon content. Credit: 达 李 

Jellyfish (Cnidarian medusa) have unique body plans that violate a universal law of biology and facilitate their longevity and their propensity to form blooms, according to an international study involving UWA scientists.

Most physiological and ecological processes in animals relate to body size and such relationships, called allometrics, predict a broad range of functions in animals.

However , exhibit allometric differences that cannot be explained solely by their unusually high water and low carbon content.

UWA Oceans Institute director and co-author Professor Carlos Duarte says, "the differences provide insights into jellyfish's evolutionary and competitive advantages conferred by their unique body plans."

He says the jellyfish's allometrics help to explain their tendency to form spectacular blooms.

The study tested differences in allometric relationships for several key parameters: rates of respiration, excretion, longevity and swimming velocity, between jellyfish and other pelagic (open sea dwelling) animals.

Jellyfish were 3.2 times larger than other pelagics of equivalent carbon content and 2.5 times larger than those of equivalent nitrogen content.

Furthermore, respiration rates were 28 times slower, excretion rates 257 times slower and jellyfish grew 3.5 times faster than other similarly sized pelagic marine animals.

"The study highlights that gelatinous marine organisms differ from other marine organisms in fundamental ways," Prof Duarte says.

"These differences are not simply a matter of high water content, but reflect consequences of their fundamentally different life histories, body plans and interactions with surrounding water flows."

By incorporating large volumes of water into their bodies, jellyfish are able to grow to a size disproportionately larger than other animals relative to their .

This offers many adaptive advantages; such as being less vulnerable to predators and being able to catch larger prey.

Prof Duarte says the most outstanding anomalies of jellyfish are differences in swimming speed with size, and the short seasonal lifespan exhibited by animals that can weigh up to 200kg.

"Jellyfish violate an almost , that the life span of species is scaled to size," he says.

"Our analyses showed that the giant jellyfish in Japan (2m in diameter and weighing a ton) lives just as long as species 1000 times smaller.

"We've shown that jellyfish are extremely efficient organisms, in terms of their metabolism, growth and motion, generating blooms even under conditions of relatively low marine production, when other zooplankton cannot form bloom."

The research is part of a broader international effort to understand the ecology of and how it affects the ocean.

Explore further: Mystery giant jellyfish washes up in Australia

More information: Pitt KA, Duarte CM, Lucas CH, Sutherland KR, Condon RH, et al. (2013). "Jellyfish Body Plans Provide Allometric Advantages beyond Low Carbon Content." PLoS ONE 8(8): e72683. DOI: 10.1371/journal.pone.0072683

add to favorites email to friend print save as pdf

Related Stories

Mystery giant jellyfish washes up in Australia

Feb 06, 2014

Scientists were on Thursday working to classify a new species of giant jellyfish that washed up on an Australian beach, describing it as a "whopper" that took their breath away.

The life cycle of a jellyfish, and a way to control it

Jan 16, 2014

Those free-swimming jellyfish in the sea don't start out in that familiar medusa form, but rather start as sessile and asexual polyps. Now, researchers reporting in the Cell Press journal Current Biology on Jan ...

'Trojan horse' effect may explain jellyfish blooms

Sep 07, 2012

(Phys.org)—Man-made structures such as harbours, tourist facilities, oil rigs and aquaculture farms provide ideal sanctuaries for jellyfish polyps to flourish and may explain an apparent increase in jellyfish ...

Unraveling jellyfish metamorphosis

Jan 27, 2014

How does one genome create two completely different body plans in one animal? This was the question Konstantin Khalturin was attempting to answer when he began working on jellyfish. The fascinating story ...

Recommended for you

Noise pollution impacts fish species differently

15 minutes ago

Acoustic disturbance has different effects on different species of fish, according to a new study from the Universities of Bristol and Exeter which tested fish anti-predator behaviour.

Invertebrate numbers nearly halve as human population doubles

15 minutes ago

Invertebrate numbers have decreased by 45% on average over a 35 year period in which the human population doubled, reports a study on the impact of humans on declining animal numbers. This decline matters because of the enormous ...

Insecticides similar to nicotine widespread in Midwest

1 hour ago

Insecticides similar to nicotine, known as neonicotinoids, were found commonly in streams throughout the Midwest, according to a new USGS study. This is the first broad-scale investigation of neonicotinoid ...

User comments : 0