Photomicrographs of live (A) and Alcian blue-stained (B-F) larvae belonging to the ‘hammerhead-like’ group. The live larvae are characterized by a lack of tissue anterior to the eyes, as can be seen from a dorsal view (A). Hammerhead mutant larvae (A-D) are characterized by a shortened head and kinked elements. All elements are present but consist of smaller and less organized chondrocytes (B-D). The pharyngeal skeleton of pipe tail (ti265) mutant embryos (E,F) is reduced in length but appears thicker, especially the ceratohyal (E). Meckel’s cartilage is located further to the posterior, at about the level of the center of the eyes. The neurocranium is also reduced in length and the ethmoid plate is less differentiated (F). Scale bars: 200 μm (A) and 100 μm (B-F).
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