Physiological adaptations in Camel #zoology 3rd sem #Unit l

Camelus dromedarius adapts itself when there is prolonged water scarcity , high temperature and non-availability of feed resources or feed quality is poor .

 Many physiological adaptations are observed in a camel to :

1. Conserve water

2.Dehydrate the blood

3.Prevent cellular damage at high temperature.

4.Regulate body temperature.

The above features are discussed below :- Conservation of water  

(1)Water turnover rate in camel is 38-76 ml/kg.It increases body temp.and also stores CO2 and glucose in the blood to reduce urine production to concentrate urine and to reduce sweating at hot arid conditions.

(2) It can survive 6-14 days without water and can tolerate 30% water loss.

(3)It drinks 1/3^rd of its body weight to rehydrate it  and stores in gut for 24 hrs to avoid rapid dilution of blood.

(4)The ratio of medulla/ cortica is 4/1 which allows high reabsorption of water in kidney thus makes the urine concentrate (3200 mOsm).

(5)      It follows bi-phasic breathing to reduce water use.

Dehydration of Blood :-

It dehydrates it's blood but blood composition, Hb function etc. remain same  by the following adaptive features :-

(1)Non – nucleated,oval-shaped erythrocytes increase twice during rehydration without any damage.

(2) The life span of erythrocyte increases during dehydration and the lifespan is :

  (a) 90-120 days if hydrated.

(b)      150 days if dehydrated at 20°C at night  &-40°C at day time.

 Prevention of cellular Damage :-

(1)High heat,and dehydration may result in oxidative stress,cellular damage and hepatic dysfunction.But a camel adapts itself by regulating AST and ALT level to prevent such malfunctions:-

                       Hot climate.        Cool climate

AST.  RF units/ml  82°71± 1.41    69.93        ±8.93

ALT   RF units/ml  10.4 ± 0.31.       9.98 ± 0.17

Regulation of body temperature:

(1)      Generally at high heat loads animals increase evaporative  heat loss to keep body temperature below a lethal level, but in such a condition a camel increases it’s body temperature 6°C --7°C to combat the problem. During this period body temperature reduces 2°C below the normal minimum to store heat in day time and dissipated at night by radiation without the use of water.

(2)      Brain cooling:

(a)       The presence  of a carotoid rete at the base of the brain in camel allows selective cooling of the brain during high temperature.

(b)      A camel also increases respiration rate 7 -80 breaths/min when body temperature increases from 35°C-41°C .This allows its brain temperature to be 1.5°C lower than the body temperature.

Thus, a camel survive in  high temperature and  at water deficit condition.