Some of the rarest and most endangered sharks on Earth look to be influenced by lunar cycles , as they have been observed gather in tremendous numbers during the full Moon . Exactly why these Moon hangouts are taking place is something scientific discipline has yet to immobilize down , but research into the phenomenon has turned up some fascinating insights .
The greathammerhead shark(Sphyrna mokarran)was the subject of a study that set out to learn more about how these animals behave in the Central Pacific . adopt a non - invading methodological analysis , they snapped moving-picture show and measured the blockhead shark in two key part of French Polynesia : the Rangiroa atoll and the Tikehau atoll .
Large number of these usually rarefied hammerhead shark were go out here during the summer of 2020 and 2021 , and curiously they were mostly adult female . If it were a case of spawning like themass assemblage of Nassau groupersthat get together during the week of the full moon , you ’d look more of a blending of sexes , so what is it about the full Moon that gets these female sharks in the political party mood ?
The full Moon also appeal the ocellated bird of Jove ray , Aetobatus ocellatus , a fellow Moon mansion girlie the hammerheads had no misgiving champ up . Great hammerheads are get it on to migrate in tandem bicycle with food availability , and given the reliableness with which they dress up every year , this could be a eating opportunity the shark have larn to capitalize on .
“ The gathering ofA. ocellatusis thus a predictable effect that sharks could render to intercept , indicating that depredation is a likely driving constituent of the seasonal comportment of great dunce sharks , ” explain the authors . “ Few studies have been conducted onA. ocellatusin French Polynesia , however societal assemblage of schools of beam is a behavior known to be linked to reproductive memory stage in the genusAetobatus . ”
“ It would thus explain the magnetic declination in numbers of ocellated bird of Jove rays in the pass and accordingly the act of predators , as mating duad would be gentle quarry for great dunce shark inside the laguna . However , this correlativity between the number of great hammerhead sharks and ocellated eagle ray of light should be interpreted with caution as environmental and other biotic factors could drive increase and variation in the abundance of both metal money . ”
The full Moon coincides with a time known in Polynesian culture as Matari’i i ni’a , which symbolize a season of copiousness . In this first glance into hammerhead demeanour in the region , it seems that like humans , shark take advantage of Matari’i i ni’a to meet the motive of their life cycle . We may not have intercourse yet what appeal the “ shark side of the Moon ” holds for these animals , but it ’s a fascinating first glance into the demeanour of one of our ocean ’s most peculiar vulture in this part of the existence .
The discipline is publish inFrontiers in Marine Science .
