Featured Research

from universities, journals, and other organizations

Wonder of the natural world: Key to Christmas Island's red crab migration discovered

Date:
August 30, 2010
Source:
University of Bristol
Summary:
One of the most spectacular migrations on Earth is that of the Christmas Island red crab. Acknowledged as one of the wonders of the natural world, every year millions of the crabs simultaneously embark on a five-kilometer breeding migration. Now, scientists have discovered the key to their remarkable athletic feat.

Christmas Island red crabs.
Credit: Mrinalini at Bangor University

One of the most spectacular migrations on Earth is that of the Christmas Island red crab (Gecarcoidea natalis). Acknowledged as one of the wonders of the natural world, every year millions of the crabs simultaneously embark on a five-kilometre breeding migration. Now, scientists have discovered the key to their remarkable athletic feat.

A three-year project conducted by a team led by the late Professor Steve Morris from the University of Bristol's School of Biological Sciences in collaboration with Professor Simon Webster from Bangor University, has discovered that hormonal changes play a significant role in enabling the crabs to make their journey.

Lucy Turner, a researcher at the University of Bristol, said: "During the wet season on the island, in November or December, and prompted by the arrival of the monsoon rains, millions of the crabs undertake an arduous breeding migration from their home on the high rainforest plateau to the ocean to reproduce. This is a journey of several kilometres -- a long way when you are a relatively small land crab (less than 20cm long).

"Scientists have long been puzzled by what mechanisms enable the necessary changes to take place in the crabs' physiology to allow this journey to take place, and how they make such a dramatic switch from hypoactivity to hyperactivity."

The results of this project have proven that it is a Crustacean Hyperglycaemic Hormone (CHH) that enables the crabs to make the most efficient use of their stored energy in the muscles (glycogen) and its conversion to glucose to fuel the migration.

Professor Webster, an endocrinologist at Bangor University, added: "Their migration is extremely energetically demanding, since the crabs must walk several kilometres over a few days. During the non-migratory period, the crabs are relatively inactive and stay in their burrows on the floor of the rain forest, only emerging for a brief period at dawn, to feed. The behaviour change reflects a fundamental change in the metabolic status of the animal.

"Surprisingly, we found that hyperglycaemic hormone levels were lower in actively migrating crabs than those that were inactive during the dry season. However, studying the crabs running and walking after giving them glucose resolved the puzzle. During the dry season, forced activity resulted in a tremendous release of hormone, within two minutes, irrespective of whether glucose had been administered. However, in the wet season, the glucose completely prevented the release of the exercise-dependent hormone, showing that they were controlled by a negative feedback loop.

"Glucose levels were clearly regulating hormone release at this time. This made sense since it ensures that during migration, glucose is only released from glycogen stores when glucose levels are low, using the crabs' precious reserves of glycogen, to ensure that they can complete the migration."

The research, funded by a Natural Environment Research Council (NERC) grant, is published in the September issue of The Journal of Experimental Biology.


Story Source:

The above story is based on materials provided by University of Bristol. Note: Materials may be edited for content and length.


Journal Reference:

  1. Morris et al. The adaptive significance of crustacean hyperglycaemic hormone (CHH) in daily and seasonal migratory activities of the Christmas Island red crab Gecarcoidea natalis. Journal of Experimental Biology, 2010; 213 (17): 3062 DOI: 10.1242/jeb.045153

Cite This Page:

University of Bristol. "Wonder of the natural world: Key to Christmas Island's red crab migration discovered." ScienceDaily. ScienceDaily, 30 August 2010. <www.sciencedaily.com/releases/2010/08/100827102549.htm>.
University of Bristol. (2010, August 30). Wonder of the natural world: Key to Christmas Island's red crab migration discovered. ScienceDaily. Retrieved September 16, 2014 from www.sciencedaily.com/releases/2010/08/100827102549.htm
University of Bristol. "Wonder of the natural world: Key to Christmas Island's red crab migration discovered." ScienceDaily. www.sciencedaily.com/releases/2010/08/100827102549.htm (accessed September 16, 2014).

Share This



More Plants & Animals News

Tuesday, September 16, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Some Tobacco Farmers Thrive Amid Challenges

Some Tobacco Farmers Thrive Amid Challenges

AP (Sep. 16, 2014) The South's tobacco country is surviving, and even thriving in some cases, as demand overseas keeps growers in the fields of one of America's oldest cash crops. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

Scientists Given Rare Glimpse of 350-Kilo Colossal Squid

AFP (Sep. 16, 2014) Scientists say a female colossal squid weighing an estimated 350 kilograms (770 lbs) and thought to be only the second intact specimen ever found was carrying eggs when discovered in the Antarctic. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

Ivorians Abandon Monkey Pets in Fear Over Ebola Virus

AFP (Sep. 16, 2014) Since the arrival of Ebola in Ivory Coast, Ivorians have been abandoning their pets, particularly monkeys, in the fear that they may transmit the virus. Duration: 00:47 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

    Environment News

      Technology News



      Save/Print:
      Share:

      Free Subscriptions


      Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

      Get Social & Mobile


      Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

      Have Feedback?


      Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
      Mobile: iPhone Android Web
      Follow: Facebook Twitter Google+
      Subscribe: RSS Feeds Email Newsletters
      Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins