start stage end stage multi-tissue structure pseudobranch ZFA:0005967 zebrafish_anatomy An epithelial structure located anterior to the gill filaments and connected to the eye via the ophthalmic artery. It arises from mandibular arch neural crest-derived mesenchyme and first pouch endodermal epithelia. The pseudobranch appears as a small bud behind the eye at 4dpf. At 17 dpf, the pseudobranch is composed of five distinct filaments that resemble the primary gill filaments, with the five filaments merging to form a single pseudobranch by adult stages (90 dpf). The pseudobranch is not exposed to the outside environment unlike the gills. The pseudobranch may regulate ocular blood pressure and/or have an endocrine function. 2024-09-20T07:10:16Z zfinf larval:day 4 adult