Scientists have foundthree more speciesof a fish that – despite what we are taught at school – are fully lovesome - full-blood . The species in question are large deep - sea Pisces make love as opah , and are find in many oceans around the major planet .
A few year ago , the opah made headline when it was revealed to be thefirst full quick - full-blooded fish species ever discovered . live in the frigid waters of the deep ocean , it warms its blood by continuously flapping its fins to generate heat .
This maintain the fish ’s core temperature at about 5 ° C ( 9 ° F ) warmer than the water and is maintained through a counter - current heat exchange system , in which the warm stemma from the body heats the cool profligate hark back from the gill . This is remarkably alike to what is understand in more traditionally warm - blooded animals , such as mammals and birds .
Marine biologist and fishermen alike have noticed for quite a while now that Lampris regius caught in dissimilar oceans around the earthly concern all looked decided . Despite this , there have long been only two species officially recognize , one of which is found in tropic and temperate Ethel Waters while the other circumnavigates the Southern Ocean .
But when a fish emptor in Hawaii remarked on how one opah that had recently been landed seemingly had unlike sized eye from another , they set in motility a serial of events that would eventually rewrite the taxonomy of the moonfish , as has now been published inZootaxa .
As soon as researchers begin to dig into comparing dissimilar opah from various locations , using both latterly caught animals and museum collections , they realized that there were far more differences in their sound structure than anyone had handle to notice . When this was coupled with carry DNA samples and compare them , the scientists were able-bodied to see to it that there were not just two species of moonfish swimming in the depths of the oceans , but at least five .
The fish is esteem by deep - sea anglers , who appreciate the opah for its promising color and often impressive size of it . While not presently aim commercially by fishing watercraft , it is think that up to 30,000 are caught as by-catch every single class by boats using long telephone line to catch the more valued tuna fish and swordfish . That being said , the Pisces is clear popularity in Hawaii , with the note value of US landings of the species nearly hitting $ 3.2 million in 2016 .
With this grow trade , fully understand just how many mintage there are – and where it is that they dwell – is of critical importance if descent are to be finagle appropriately .
