True sea snakes (Family Hydrophiidae) have a range of characteristics that facilitate dives of long duration. Identify FOUR such characteristics. Briefly explain the significance of each of these four characteristics. Flashcards
Explain the significance of being an excellent breath holder:
o All snakes have a single long lung- good oxygen storing capacity
o Sea snakes have muscular, rearwards extension of lung (which may help to mix air in part of lung where oxygen is absorbed)
Explain why it is beneficial to have relatively low oxygen demands and to be endothermic:
o Do not regulate their core body temperature, mammals use metabolic heat to warm core body temperature and this consumes a large amount of oxygen. In comparison to a mammal a snake has seven times less oxygen demand meaning it can spend seven times longer underwater
Explain why it is beneficial to be water-tight when engaging in dives of long duration:
o Around the mouth the scales are known to be particularly tight fitting making them much more watertight
o Nostrils open inwards with a vascular valve that can just be filled with blood in order to close it up
Explain why a cardiac shunt is beneficial in breath holding:
• Cardiac shunt (preferentially direct blood to different parts of the body)
o Gives them a bit of flexibility when the oxygen starts to run out