Huge an­i­mals bend bi­o­log­i­cal laws

The blue whale over­comes na­ture’s lim­i­ta­tions by means of spe­cial adap­ta­tions such as a huge tail fin and an ex­cel­lent abil­ity to ox­i­dize blood. The pre­his­toric fish lizard prob­a­bly had sim­i­lar char­ac­ter­is­tics.

Science Illustrated - - NATURE PREHISTORIC ANIMALS -

WIDE HIND PART AND SLIM BODY CAUSE MA­JOR PROPULSION

PROB­LEM: Marine an­i­mals such as the blue whale and the ex­tinct fish lizard move by means of flukes. The larger the an­i­mal, the more force is re­quired to pro­duce mo­tion. If the an­i­mal keeps in­creas­ing its mass, it will be un­able to move at some point.

SO­LU­TION: The blue whale's body is slim­mer than the other whales', and its dor­sal fins are very small. This re­duces the re­sis­tance of the wa­ter. The fluke mea­sures 7 m and makes sure to force the giant for­wards at a speed of up to 30 km/h.

PRO­TEIN FORCES THE LUNGS TO WORK HARDER

PROB­LEM: The more body mass an an­i­mal has, the more oxy­gen must it ab­sorb to re­main alive. The oxy­gen re­quire­ment is eight times larger, ev­ery time the am­i­nal's size dou­bles, so the blue whale needs – and the fish lizard needed – huge quan­ti­ties.

SO­LU­TION: A blue whale's lungs weigh 1 t each and can hold 2,500 l of air. More­over, the whale can ab­sorb 90 % of the oxy­gen of the air, as com­pared to 15 % for hu­mans. This al­lows the marine an­i­mal to build a large store of oxy­gen in its mus­cles.

SEA MON­STERS SWAL­LOW PREY LIKE HUGE VAC­UUM CLEANERS

PROB­LEM: An an­i­mal must eat ac­cord­ing to its mass. This means that the food re­quire­ment in­creases eight times for ev­ery time the an­i­mal's size dou­bles. A blue whale must con­sume some 3.5 t of food a day to sur­vive.

SO­LU­TION: Blue whales feed on krill, which can oc­cur at a den­sity of 770,000 in­di­vid­u­als per m3 of ocean wa­ter. By open­ing its huge mouth in­side a shoal of krill, the whale pro­duces un­der­pres­sure, so more than 2 t of krill flow into its mouth.

SO­LU­TION A 60-m-long blue whale needs an eight times big­ger tail fin than a blue whale of 30 m to gen­er­ate suf­fi­cient propulsion.

SO­LU­TION The fish lizard prob­a­bly fed on large fish rather than krill. Ac­cord­ing to sci­en­tists, it also sucked its prey into its mouth.

SO­LU­TION A blue whale has twice as much haemoglobin in its blood as hu­mans. The pro­tein car­ries oxy­gen about the body.

Newspapers in English

Newspapers from Australia

© PressReader. All rights reserved.