Microcotyle oceanica is a species of monogenean, parasitic on the gills of a marine fish.

It was first described and illustrated based on two specimens from the gills of the Mexican needlefish Tylosurus fodiator (Belonidae), off Panama.

[1] Microcotyle oceanica has the general morphology of all species of Microcotyle, with a symmetrical lanceolate body, comprising an anterior part which contains most organs and a posterior part called the haptor.

The digestive organs include an anterior, terminal mouth, an ovoid small pharynx, a long narrow oesophagus and a narrow posterior intestine with two lateral branches provided with numerous secondary branches; the intestine extends to the base of the haptor.

The reproductive organs include an anterior genital atrium, armed with numerous very spines, a medio-dorsal vagina, a single large ovary and 51 to 58 ovoid testes located in the posterior part of the body, in the intercecal area, in two rows.