(A) Survivability of zebrafish at two months. Once animals had reached the defined standard length, treatments were initiated and continued until animals were sacrificed two months later. For the DMSO control group, animals were treated at 5.5 mm standard length. DMSO, dimethyl sulfoxide. EH, enclomiphene hydrochloride. CC, clomiphene citrate. *p = .02 compared to DMSO control, n = 20, experiment performed in duplicate (B) Body length at two months on pooled surviving fish, expressed as Tukey box plot. *p = .04 compared to DMSO control, n ≥ 5.

(A) Interfrontal suture morphology in pooled surviving fish. *p < .01, n ≥ 5. (B) Representative whole mount Alizarin red stain of untreated control fish indicating patent interfrontal suture (arrow). (B) Representative stain of control fish showing patent interfrontal suture. (C) Representative stain of a fish showing overlapping interfrontal suture (arrow). (D) Representative stain of a fish showing fused/absent interfrontal suture (arrow).

Representative Alizarin red stain of vertebral and rib morphology in pooled surviving fish from each treatment group. At increased magnification, no vertebral fusions are observed (inset). Bar = 1 mm.