Daily Devotional – October 16

Biology

Sharks are coldblooded animals. These type of creatures take on the surrounding temperature. So So how do great whites, common threshers or shortfin mako sharks keep their internal core temperature some 13-48 Fahrenheit ABOVE the waters in which they swim? These sharks have their own build in heat-exchangers!

The heat created by their muscle activity is moved to vessels that flow by the gills; water can be very cold as it flows by the gills, which extract oxygen. These very small blood vessels make a mesh (rete mirabile) of capillaries causing the heated blood to flow next to the cold (oxygenated) blood. As this happens, heat is exchanged to the incoming cold blood, keeping the shark warm. Now with heated and oxygenated blood, the shark is able to swim in cold waters at high speeds. These sharks have their own built-in countercurrent heat exchangers!

We use heat exchangers in much of our technology - such as refrigeration and air conditioning. Would we say this technology happened accidentally over millions of years? Then why would we say it happened by accident in a shark? God knew sharks would have to swim fast even though some would live in cold waters. To solve the problem, He designed them with heat exchangers.

Sing unto him, sing psalms unto him: talk ye of all his wondrous works.

~ Psalm 105:2

Source: "Pearls in Paradise" by authors Bruce Malone and Jule Von Vett

References for this devotional.