. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ^to "'|s G*=4. Figure 4. Ophiophragmnsfilograneus: growth stages of jaw and oral papillae. Stages numbered accord- ing to Figure 1; abbreviations as in Figure 2. The buccal tentacles (bt) are intact, and the oral plates and adoral shields are covered with integument because samples were not plasma-ashed to remove soft tissue. (A) Stage 2; mm dd, 2 AS. (B) Stage 4; mm dd, 14 AS. (C) Stages 5-8 initialized; mm dd, >35 AS. (D) Stages 5-8 complete; mm dd, >87 AS. (E) Adult; mm dd, 319 AS. oral papi
. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. ^to "'|s G*=4. Figure 4. Ophiophragmnsfilograneus: growth stages of jaw and oral papillae. Stages numbered accord- ing to Figure 1; abbreviations as in Figure 2. The buccal tentacles (bt) are intact, and the oral plates and adoral shields are covered with integument because samples were not plasma-ashed to remove soft tissue. (A) Stage 2; mm dd, 2 AS. (B) Stage 4; mm dd, 14 AS. (C) Stages 5-8 initialized; mm dd, >35 AS. (D) Stages 5-8 complete; mm dd, >87 AS. (E) Adult; mm dd, 319 AS. oral papillae are not all derived from identical struc- tures—that they are not serially homologous (sensu Roth, 1984). First, the oral papillae do not develop in a unidirectional sequence, such as proximal to distal along the jaw. Second, the anlage of each papilla is associated with a different skeletal plate. For example, as skeletal elements the adoral shields are regarded as homologues of the lateral arm plate, therefore the adoral shield spine (an oral papilla) is serially homologous with the arm spines that are attached to lateral arm plates of each arm segment (Hendler, 1978). In contrast, the association of the infradental papilla with the dental plate indicates that as a skeletal element it is homologous with dental papil- lae or teeth. Specific oral papillae of different taxa are provisionally regarded as homologous if they originate at the same site and develop, or are resorbed, in the same chronological sequence. For example, in the taxa studied the buccal scale, adoral shield spine, infradental, oral plate papilla, and accessory papilla appear in sequence and each pa- pilla forms at a characteristic site (Tables I, II). Thus, the buccal scales of all amphiurids are presumably homolo- gous as oral papillae, the adoral shield spines of all am- phiurids are presumably homologous as oral papillae, and so on. Amphiurids lacking an "oral tentacle scale" (sensu Clark,
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Keywords: ., bookauthorlilliefrankrat, booksubjectbiology, booksubjectzoology
