Potamotrygoniae: The Major Stingray Family
Potamotrygoniae
The major stingray family of the potamotrygoniae occur throughout the major rivers system of the eastern south Americas. Based on research, scientists believed that the potamotrygoniae family had indeed evolved from dasyaitude. Although there is a lot of speculation, scientists assume that the first and early ancestors of the potamotrygonids had dispersed into fresh waters therefore adapting and obtaining their name as “river rays”. This was thought to have occurred during the last marine ingression 3-5 million years ago (Daniel R. Brooks, 1992).
Predators
In the stingray’s natural environment, the stingray do in fact have a few natural predators mainly due to the large sizes of stingrays. These include sharks such as Hummerheads …show more content…
This means a stingray have the blood closed at all times within their vessels. (Akira Sakurai, 2011) In this system, blood is pumped by a heart though vessels around the body in a single circuit. This allows for the delivery of food and oxygen to body tissues. At first, the heart pumps the blood through the gills, where it can pick up oxygen and get rid of excess carbon dioxide, before circulating the newly oxygenated blood to other body tissues where it is used for function. The heat of a stingray consist of 2 chambers: atria and ventricles and their two associated structures, sinus venosus and conus arterriosis. The atrium is responsible for taking the blood from the body and the ventricle is responsible for pumping out the blood that has entered the heart. The blood from the body, which is low in oxygen enters the atrium via the sinus venosus where pacemaker cells located in the atrium can initiate contractions within the blood. When this process is completed, the blood is then pumped into the ventricle, where deoxygenated blood is pumped to the gills and oxygen from the surrounding water is given to the blood. Stngrays also use a structure called the conus arteriosus which is a conical pouch formed from the upper and left angle of the right ventricle. This structure ultimately prevents blood from flowing backwards into the heart and allows for the continuous flow of blood around the system. Due to the fact that Stingrays
The major stingray family of the potamotrygoniae occur throughout the major rivers system of the eastern south Americas. Based on research, scientists believed that the potamotrygoniae family had indeed evolved from dasyaitude. Although there is a lot of speculation, scientists assume that the first and early ancestors of the potamotrygonids had dispersed into fresh waters therefore adapting and obtaining their name as “river rays”. This was thought to have occurred during the last marine ingression 3-5 million years ago (Daniel R. Brooks, 1992).
Predators
In the stingray’s natural environment, the stingray do in fact have a few natural predators mainly due to the large sizes of stingrays. These include sharks such as Hummerheads …show more content…
This means a stingray have the blood closed at all times within their vessels. (Akira Sakurai, 2011) In this system, blood is pumped by a heart though vessels around the body in a single circuit. This allows for the delivery of food and oxygen to body tissues. At first, the heart pumps the blood through the gills, where it can pick up oxygen and get rid of excess carbon dioxide, before circulating the newly oxygenated blood to other body tissues where it is used for function. The heat of a stingray consist of 2 chambers: atria and ventricles and their two associated structures, sinus venosus and conus arterriosis. The atrium is responsible for taking the blood from the body and the ventricle is responsible for pumping out the blood that has entered the heart. The blood from the body, which is low in oxygen enters the atrium via the sinus venosus where pacemaker cells located in the atrium can initiate contractions within the blood. When this process is completed, the blood is then pumped into the ventricle, where deoxygenated blood is pumped to the gills and oxygen from the surrounding water is given to the blood. Stngrays also use a structure called the conus arteriosus which is a conical pouch formed from the upper and left angle of the right ventricle. This structure ultimately prevents blood from flowing backwards into the heart and allows for the continuous flow of blood around the system. Due to the fact that Stingrays