In the realm of marine biology, the ocean sunfish, despite its name, defies conventional expectations by boasting a colossal weight of up to two tonnes and a body riddled with parasites, including its eyeballs. Exploring the peculiarities of the Mola mola, one of the ocean’s largest fish species, host Sarika Cullis-Suzuki delves into its unique features in an episode of The Nature of Things 101.

The Mola mola’s unconventional appearance, characterized by its circular body, lack of a distinct tail, and massive fins, challenges traditional notions of fish morphology. Through a life-size model demonstration, Cullis-Suzuki showcases to co-host Anthony Morgan the often-overlooked attributes that make the ocean sunfish remarkable.

Despite their ability to traverse vast distances and depths in search of sustenance, these fish are prone to parasitic infestations due to their leisurely pace, extensive surface area, and movement across various water layers. Cullis-Suzuki highlights the pervasive presence of parasites on the Mola mola, infesting its skin, gills, fins, eyeballs, mouth, and intestines, with a staggering 73 parasite species identified on these fish and their ocean sunfish counterparts.

In addressing the challenge of parasite control, Cullis-Suzuki explains that ocean sunfish resort to breaching behavior, leaping out of the water and crashing back down, possibly to dislodge parasites. Additionally, they facilitate parasite removal by allowing smaller fish and birds to feed on the parasites.

Despite existing knowledge about the ocean sunfish, Cullis-Suzuki emphasizes the necessity for further research to unravel the mysteries surrounding this intriguing species. The quest for knowledge about the ocean sunfish remains ongoing and offers promising avenues for future scientific exploration.

For those intrigued by the ocean sunfish’s enigmatic existence, The Nature of Things 101 can be viewed on CBC Gem and The Nature of Things YouTube channel.