Vertebral abnormalities in juvenile inland silversides Menidia beryllina exposed to terbufos during embryogenesis

Abstract

Embryos of the inland silverside Menidia beryllina were exposed to a nominal concentration of 50 pg terbufos I-' during the first 5 d of embryogenesis. Silversides were maintained in clean dilute seawater until 37 d after hatching. Radiographs revealed compressed and fused vertebrae and dorsal-ventral misalignment of pre- and post-zygapophyseal processes. Histopathological examination of representative individuals exposed to terbufos during embryogenesis revealed various vertebral lesions ranging from small hyperostoses to almost complete fusion of some vertebrae.