RESUMO
Objectives: This study investigates the histology of the middle layer of the eye in rabbit fish Siganus javus. Methods: The eyes of twelve healthy fish were enucleated and histologic sections of 6μ were prepared. The sections were stained with Hematoxyline & Eosine (H&E) and Masson trichrom then were observed using light microscopy. Results: The middle or vascular layer consisted of the choroid and iris. The result revealed that the choroid coat was subdivided into five laminae: 1. Suprachoroid layer 2. Substina propria included choroidal gland or retemirabile, melanoid layers and connective tissue 3. Fibrouse layer 4. Choriocapillary layer 5. Separator layer. The extension of the choroid coat into the anterior compartment made the iris which mainly composed of connective tissue, blood vessels, melanocyte and a smooth muscle at the posterior part of the iris, adjacent to the pupil. The choroid coat did not continue rostrally adjacent to the cornea. Suspensory apparatus of the lens of the Siganus javus eye consisted of a dorsal suspensory ligament and a ventral retractor muscle. Conclusions: The diversity and deviation in the detail of microscopic structures in the eye of teleosts is approved through this microscopic study in middle layer of rabbit fish eye however the five differentiated parts of choroid were distinguished as in many telelost species.