{"id":698,"date":"2020-06-01T18:10:02","date_gmt":"2020-06-02T01:10:02","guid":{"rendered":"https:\/\/sites.evergreen.edu\/animatingthesea-s20\/?p=698"},"modified":"2020-06-04T16:17:21","modified_gmt":"2020-06-04T23:17:21","slug":"the-ocean-sunfish-mola-mola","status":"publish","type":"post","link":"https:\/\/sites.evergreen.edu\/animatingthesea-s20\/the-ocean-sunfish-mola-mola\/","title":{"rendered":"The Ocean Sunfish (Mola mola<\/em>)"},"content":{"rendered":"
This illustration shows the ocean sunfish sunbathing at the surface of the ocean. Waiting for the parasites, that are attached to the surface of the sunfishes\u2019 skin during deep sea diving, to either be burned by the sun or ripped off by marine birds flying overhead. Not only is this how the sunfish likes to spend the majority of its time near the surface but it is also essential for the survival of the sunfish to create these symbiotic relationships.<\/h6>\n\n\n

The Ocean Sunfish <\/h2>\n\n\n\n

(Mola mola)<\/em><\/h2>\n\n\n

MATT WOLCH<\/p>\n

The Ocean Sunfish is one of our oceans\u2019 heaviest and laziest fish! Weighing in at over 2,000 pounds, these giant cousins of the pufferfish can often be found sunbathing at the surface of the water providing shelter or a snack to a passerby in need.<\/p>\n\n\n\n\n

The Mola Mola is the largest of all the known bony fish. Related to other fishes in the Molidae family they asise from the order tetraodontiform. Although classified as a bony fish much of the organism\u2019s endoskeleton is made out of cartilage. One strange characteristic of the sunfish is their absence of a caudal fin.  One unique characteristic to the ocean sunfish is quite similar to other fishes in the tetraodontiform order, occurs during their two distinct transitions during its larval stage into adulthood. The first of these two transition starts in the larval and juvenile stages of the ocean sunfish, described by author Hailin Pan, \u201c\u2026resembles a miniature pufferfish possessing large pectoral fins, a tail fin and body spines; and the second is a highly transformed stage during which the tail is completely absorbed\u201d, (Pan). All of these major morphological changes must occur by the time the mola mola is 15 months old and has reached adult size.<\/p>\n\n\n\n

\"\"<\/figure>\n\n\n
This is an adult Ocean sunfish showing the average size of 2 meters in length with a wingspan of close to 3 meters between its dorsal and anal fins. A sunfish can reach what is considered to be adult size at just 15 months old. This Image also shows a human diver to scale the massive size of this full-grown organism. But don\u2019t let this fool you, it is still best to avoid the sunfish in the wild as they host up to 50 different species of parasites!<\/h6>\n\n\n

One fascinating aspect about the ocean sunfish is its ability to reach such a large size so quickly. \u201cA captive sunfish gained approximately 400 kg in just 15 months with an average growth rate of 0.82 kg\/day\u201d (Pan). Growing up quickly is essential for survival in the ocean biome, the larger you are, fewer are the things that are able to eat you. In this study Pan conducts the location of the genes responsible for the fast growth rate in this species. \u201cWe examined genes involved in the growth pathway and found several fast-evolving genes and genes containing positively selected sites in the GH\/IGF1 axis\u201d (Pan). After this stage it is estimated that a sunfish can live 20-25 years however, this is not backed up by much scientific research. \u201cA growth curve derived from repeated measurements of captive specimens estimated an individual with a total length of 3 m would be about 20 years old\u201d (Pope). This can help us identify and give an estimate a possible age for wild sunfishes, which can be useful to note when researching the organism. As far as reproduction cycles go very few studies have been conducted but it\u2019s been found that their spawning period is estimated between August and October. In their lives females contain, \u201can estimated 300 million eggs\u201d (Pope).  It\u2019s also noted that females tend to be larger than males. <\/p>\n\n\n\n

\"\"<\/figure>\n\n\n
This illustration shows a mola mola in the larval stage (at 1.5 mm in length) where it shows similarities to other fish within the order, tetraodontiform. This stage of life occurs directly after hatching, they resemble a puffer fish and look almost cartoon like with massive eyes and tiny bodies.<\/h6>\n\n\n

When looking at the sunfish the first words to come\nto mind usually aren\u2019t, fast, powerful or even that great of swimmers. Lacking\na caudal fin, many wouldn\u2019t think they can really do much besides sunbathing\nnear the ocean\u2019s surface. But, thanks to accelerometer technology we are now\nable to find out how they move in the open ocean. \u201cLateral acceleration\noscillated regularly, showing that the fish stroked their dorsal and anal fins\nfrom side-to-side\u201d (Watanabe). This is where most of the muscle movement is\nhapping on the fish and what us crucial in propelling them forward in the open\nocean. \u201cThis suggests that thrust generated by the two fins during a stroke\ncycle are equal, because lift produced by a wing is proportional to the area of\nthe wing\u201d (Watanabe). Here the author of this study describes how the\nlift-based propulsion works. The author then goes on to debunk some flimflam\nspread among the scientific community, contrary to what many believe this study\nis able to highlight the fast swimming nature hidden within the mola mola.\nAlthough the sample size remained small it\u2019s clear that the sunfish has the\nability to do some powerful swimming especially when escaping things that do\nprey on them such as large marine mammals, sharks, and occasionally humans. <\/p>\n\n\n\n

\n