. The Biological bulletin. Biology; Zoology; Marine biology. Figure 1. Schematic cross section of Aristotle's lantern of Diadema setosum (left) and magnified view of jaw (j) with dental slides (ds), tooth (t), and tooth ligament (li). Note the extensions of the tooth coelom (tc) along the sides of the tooth. The jaw consists of two pieces connected along a suture (double arrow). glued with cyanoacrylate glue to a platform in a trough containing ASW. A load of 30 g was applied to the tooth by means of a lever. In pull tests the tooth was pulled in the same di- rection as it naturally shifts dur
. The Biological bulletin. Biology; Zoology; Marine biology. Figure 1. Schematic cross section of Aristotle's lantern of Diadema setosum (left) and magnified view of jaw (j) with dental slides (ds), tooth (t), and tooth ligament (li). Note the extensions of the tooth coelom (tc) along the sides of the tooth. The jaw consists of two pieces connected along a suture (double arrow). glued with cyanoacrylate glue to a platform in a trough containing ASW. A load of 30 g was applied to the tooth by means of a lever. In pull tests the tooth was pulled in the same di- rection as it naturally shifts during growth. In these tests the lever was connected to the tooth with a silver wire. In push tests the tooth was pushed in the opposite direction as in pull tests, and the lever was connected with a plastic holder. Displacement of the tooth was detected by a linear eddy current sensor (502-F, EMIC Corp., Tokyo, Japan) and recorded with a microcomputer. Teeth that had been pulled out of the jaw in mechanical tests, and the corresponding jaws, were examined by scanning electron microscopy. Specimens were fixed in glutaraldehyde in Mcacodylate buffer, postfixed with 1% osmium tetroxide in the same buffer, and de- hydrated in an acetone series. After an intermediate step of amyl acetate, they were dried in a critical point drying apparatus and mounted on holders. The specimens were then coated with gold and observed in a JEOL JSM-T220 scanning electron microscope. Results Anatomy The tooth ligament of Diadema setosum is morpho- logically similar to the ligament of Eucidaris tribuloides described in the preceding paper (Birenheide and Moto- kawa, 1996). The main difference is in the size of the tooth ligament. In D. setosum the tooth ligament is shorter in relation to the whole length of the jaw. The tooth coe- lom on the abradial side extends along both sides of the U-shaped tooth and narrows the tooth ligament (Fig. 1). The length of the dental slide varied with size of th
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectb, booksubjectzoology
