Platypus is a unique species which posses a combination of both mammalian and reptile characteristics. Its scientific name is Ornithorhynchus anatinus mainly found in Australia. Platypus reproduce by laying fertilized eggs but produce milk through their mammalian glands and suckle their young ones. Average body temperature is relatively lower than that of other mammalian animals (McCarriston & Gadawiski, 2008). Study of platypus skull and other features indicate the possibility of existence of this species during the ice age along with the dinosaurs. Physiological adaptation refers to the changes in organ function and size that are meant to assist an organism cope with the environmental setting in which it exists (Star, 2012).
Research indicates close similarity of internal anatomical features of this organism and those of human being and other mammals while other are similar to those observed in birds and reptiles with adaptation to fit the environment (McCarriston & Gadawiski, 2008). Platypus nervous system consists of a brain that has two hemispheres just as mammals and a spinal cord secured in a vertebral column. The specific parts of the CNS are adapted to coordinate functioning of various body parts. Nerve ending are highly concentrated on parts such as the bill which uses electroreceptor’s to detect their prey (Star, 2012). Due to their environment platypus do not locate food by use of sight or smell. Instead their bill evolved to detect electric field generated by muscular contraction in the prey (McCarriston & Gadawiski, 2008). This helps in discriminating animate and inanimate objects in their surrounding especially in water. This bill also serves the purpose of mechanical digestion of food before it is swallowed. Absence of teeth is compensated by hard grinding pads. These pads get worn out with time but are rapidly replaced through continuous growth (Star, 2012).
Platypus digestive system consists of one stomach, large and small intestines. Each part is physiologically adapted to its function. Small intestines are highly supplied with blood capillaries and have a thinner membrane for enhance nutrients diffusion into the body. The appendix is larger in size to filter out solid particles
Its kidney has evolved to its function of rapidly disposing water since there s no water shortage in the environmental setting. However it retains salts and ions to compensate for mineral deficit in fresh water environment since the ions are essential for metabolic reactions. Oxygen is vital for metabolism therefore platypus posse a higher concentration of hemoglobin and red blood cells. This allows prolong stay underwater approximately up to 15 minutes (Star, 2012).
The spleen and gut associated lymphoid tissues are well developed such that immune system can provide the required immune response in case of antigen infection. Other internal organs such a skeleton and muscles are comparable to those of mammals and similar to those of reptiles. Bone structure can be traced back to relation with the dinosaur family which is currently extinct. One theory explains their survival based on ability to detect food even in with minute electro stimulation and ability to survive both on land and under water. Ecological adaptation is considered key factor of evolution process (Star, 2012).
Temperature falls to extremely low levels during winter. To cope with this platypus are physiologically adapted by having an insulating layer of fat immediately below the skin. Fats are poor conductors hence allow retention of body heat such that platypus maintain average body temperature of 32 degree Celsius. The skin is coated by a two layer of fur based on their length. The first layer is short and thicker protecting the skin from direct contact with the cold water. Its waterproof nature prevents the fur from getting wet. The second layer is longer and highly sensitive aiding in transmitting information to the brain on changes in the surrounding (Star, 2012)
Since platypus spent considerable amount of time under water reliance on auditory receptor is minimal. This may explain the evolution of the ears such that they lack visible external part. The internal parts are in place on the skull similar to other mammals but are less prominent as explained by evolution law of use and disuse (McCarriston & Gadawiski, 2008).
Excretion processes are similar in both male and female platypus such that to determine sex of an individual organism would require gene- analysis. They have 26 chromosomes which is more than those of human while X and Y chromosomes are responsible for sex another pair of ZZ/ZW is similar to bird’s sex chromosomes. The male platypus has their testis inside the body different from other monotreme species that have external reproductive organs. In females only the left side ovary is fully developed for reproduction. Fertilized eggs are incubated in the body for 28 days and 10 days in an external incubation after being laid. The mother does not have defined tits therefore milk flows out of body pores for suckling the young platypus (McCarriston & Gadawiski, 2008).