Excreting carbon dioxide is different than taking in oxygen. Carbon dioxide diffuses through the ants tissues approximately 25 times faster than oxygen. Therefore the ants get rid of their carbon dioxide through the process of diffusion. Carbon dioxide simply diffuses through the tissues and out the integument. (internet source 1).

Oxygen is delivered directly to the tissues and then the cells via a tracheal system. This tracheal system connects all of the tissues of the ant with the external oxygen-containing air via openings in the body called spiracles. As the tracheal system opens up the ant to the outside air the ant must incorporate mechanisms to avoid water loss but allow gas movement into the body. To insure only one way movement the spiracles are usually modified with valves that close to help minimize water loss. This total process is referred to as passive ventilation. (Internet source 1).

Ants lack a true circulatory system, which has arteries and veins. They have what is referred to as an open circulatory system in which the organs and muscles are freely bathed in the ants blood called hemolymph. In the ants the hemolymph serves no function in gas exchange. The hemolymph cells are called hemocytes which aid in the ingestion of foreign particles, plugging wounds by coagulation, transferring of nutrients and waste products, and acting as a lubricant for organs, muscles, and their exoskeleton, and delivering water taken in from what they eat as well as from the air they take in through the tracheal system. (Internet source 1).

Ants obtain their nutrients from the prey that they kill and consume. They kill any other insect including ones that are extremely larger than they are including scorpions and earthworms. Ants consume both other animals and plants for their nutrients for their energy. Ants have a alimentary canal which is divided into three regions, the foregut, midgut, and the hindgut. (Book source 1).

The foregut is simply a tube which cares food from the mouth to the midgut. The midgut is the primary site for food digestion and absorption. In the midgut digestive enzymes are secreted and microorganisms are harbored that produce enzymes that allow the ant to digest cellulose and wax. After digestion and absorption have occurred a liver acting organ called a Fat Body removes excess nutrients and stores them for later use. The Fat Body Is capable of storing fats, glycogen, and proteins and as well helps to regulate the blood sugar level. The hindgut mostly serves to transfer undigested food from the midgut out of the ants body. It also reabsorbs almost 100% of the water in the waste as well as salts and amino acids. (Internet source 1).

Ants eliminate their wastes through the use of Malpighian tubules. The Malpighian tubules act as the ants kidneys. They are long convoluted tubes closed at the end and open at the junction of the mid and hindgut. While being bathed in the hemolymph the tubules remove water, sodium, and potassium salts. In another section of the tubules the water is reabsorbed into the hemolymgh and the rest of the waste products are then forced into the rear of the hindgut for secretion. As the wastes makes its way to the through the rectum of the ant water is further absorbed and the ant excretes uric acid. (Internet source 1).

References:

Internet source 1- Natural History of Insects Topic 4 Ants- http://entmuseum9.urc.edu/ent010/lec_04.html.

Book source 1- Army Ants, William Gotwald, Cornell University Press.

1995.

The anatomical or physiological adaptations of the ants that help adapt them to their environment are: The Tracheal system, The Fat Body, The Malpighian tubules.

Gymnura are heterotrophs, they obtain their energy in food that they eat, which contains organic molecules synthesized by other organisms. The food is then digested by enzymatic hydrolysis, and the energy containing molecules are absorbed by body cells. The cells generate ATP through the catabolic processes of cellular respiration and fermentation. The chemical energy of ATP powers cellular work, enabling organs to perform their functions and keep the gymnura alive. (Book source 1).

Gymnures diet consists of mainly insects but also includes other invertebrates, small reptiles, fruits and roots. They are resistant to snake venom and resemble hedgehogs except they lack the spines. (Internet Source 1).

The digestive system consists of alimentary canal with various accessory glands that secrete digestive juices into the alimentary canal via ducts. Upon eating the digestion of the food is begun while in the mouth when the teeth chew and grind the food into smaller pieces. It is also at this point that the salivary glands secrete saliva to lubricate both the mouth and the food but also to begin the breaking down of glucose polymers starch from plants and breaking down glycogen from animals. Then with help from the tongue the food is passed through the Pharynx down the esophagus and into the stomach.

The stomach lining secretes gastric juices that mixes with the food which disrupts the extracellular matrix that holds meat and plant cells together. The stomach also secretes pepsin that begins the breaking down of proteins. The hydrolyzed food then passes into the small intestine.

When the food enters the small intestine it is immediately mixed with other digestive fluids from the pancreas, glands in the small intestine, liver and the gallbladder. The breakdown of proteins by various enzymes result in nitrogen, sugars and phosphates.

Most absorption of nutrients occurs in the small intestine but some also occurs in the stomach and the large intestine. The nutrients are absorbed across the epithelium and then across the unicellular wall of the capillaries. Then the nutrients goes to the liver then to the heart where it is pumped to the rest of the body. Water is consumed through the mouth and is absorbed through the stomach and the small intestine, it is also reabsorbed in the large intestine. The gymnura also receives water from what it eats.

The undigested food then enters the large intestine which reabsorbs water that originally enter the alimentary canal. In the large intestine the food is contaminated by harmless bacteria and their by-products forms some vitamins which are absorbed in the large intestine. The undigested food then passes through the rectum and the anus as feces.

The Gymnura has a 4 chambered heart which pumps blood containing the absorbed nutrients to the lungs for the exchange of oxygen and carbon dioxide. The Gumnura inhales into its lungs air containing oxygen and then via capillaries surrounding the alveoli exchange the two gases by diffusion. The blood now rich in oxygen and nutrients, returns to the heart and is pumped through arteries to the rest of the body.

The arteries reduce down into very small capillaries that intermingle with every tissue and cell, therefore supplying the oxygen and the nutrients necessary to keep the gymnura alive. The blood also picks up wastes and carbon dioxide from the cells. This process occurs through interstitial fluid, which is in between the capillaries and the cells. The blood then passes through the kidneys for waste removal and then through the lungs to remove the carbon dioxide.

As the blood enters the kidneys the blood pressure forces out water, urea, salts and other waste products. The blood then moves on to pickup more nutrients and oxygen and to expel its load of carbon dioxide. The impurities then pass through a series of tubules in which water and necessary salt is reabsorbed. Leaving the kidney the urine flows through the ureters to the bladder and is then urinated out of the body. Because of the abundant amount of water available to the gymnura the animal has relatively diluted urine, therefore it has adapted shorter loops inside the kidneys. (Internet source 2).

References:

Internet source 1- www.oit.itd.umich.edu/bio108/chordata/Mammalia/

Insectivora/Erinaceidae.html- Erinaceidae Family.

Internet source 2-www.oit.itd.umich.edu/bio108/chordata/Mammalia/

Insectivora.shtml- Order Insectivora.

Book source 1- Biology 4th edition(Campbell University of California.

1996.

The three anatomical and physiological adaptations of Gymnura to its environment: 1) Teeth designed for what it eats. 2) A diverse diet.

3) Short loops in the kidneys due the amount of water in the environment. Resulting relatively dilute urine.