Our photo of the week is the Sargassum Fish, Histrio histrio, to celebrate Mission Blue’s Sargasso Sea Hope Spot and the work of the Sargasso Sea Alliance. An iconic resident of the Sargasso Sea, it’s life is typically spent adrift on tropical and warm temperate oceans among floating Sargassum Weed. Although the Sargassum Fish is capable of swimming quite rapidly, it often crawls through the Sargassum Weed, using its pectoral fins like arms.
The unique appearance of the fish features stalked, grasping, limb-like pectoral fins with small gill openings behind the base, a trapdoor-like mouth high on the head, and a “fishing lure” on the snout. The Sargasso Fish is an ambush predator and also a cannibal – one individual was found to have 16 juveniles in its stomach! It hunts by dangling its ‘fishing lure’ to attract small fish, shrimps and other invertebrates. It is able to dart forward to grab its prey by expelling water forcibly through its gill openings. It can expand its mouth to many times its original size in a fraction of a second, drawing prey in via suction, and can swallow prey larger than itself. To avoid underwater threats it can leap above the surface onto mats of weed, and can survive for some time out of water.
Feature Photo: Justin Lewis, 70 Degrees West