Pedum spondyloideum is a byssally attached scallop in the Indo-Pacific that lives in deep fan-shaped dwellings within live scleractinian and hydrozoan corals, with the ventral edges of the scallops’ valves protruding slightly from the dwellings. Juvenile scallops have rounded, oval shells and live in shallow depressions. Complete scallop dwellings are formed by the growth of the host and allometric growth of the scallop, and by chemical and physical interactions between the scallop and its host. Scallops were extracted intact from their dwellings within massive corals in the genus Porites in Thailand (7°36′32″ N, 98°21′55″ E; in May 2019) and Malaysia (2°45′17″ N, 104°13′30″ E; in November 2019) to examine the relationship between shell height (SH) and shell width (SW). The slope of the regression of SH on SW within the first 2 years of settlement was 0.79–0.9, indicating that SW increased slightly faster than SH during this period. As the scallop grew further, the slope of the SH on SW was 1.29–1.54, indicating that SH increased faster than SW. A histological study on scallop pallial tissue, including the tentacles, and SEM observations of the dwelling walls suggested that the scallop has secretions that damage coral tissue and widen the dwelling during growth. Thus, the distinctive fan-shaped dwellings of the adult scallops are caused by a combination of allometric scallop growth and erosion of the host tissue and dwelling walls.

中文翻译：

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生活在不断增长的宿主中：扇贝 Pedum spondyloideum 在大量 Porites spp 中的生长模式和栖息地形成。珊瑚

Pedum spondyloideum 是印度洋-太平洋地区的一种扇贝，生活在活石珊瑚和水生动物珊瑚内的深扇形居所中，扇贝瓣的腹侧边缘从居所中略微突出。幼年扇贝有圆形的椭圆形贝壳，生活在浅洼处。完整的扇贝栖息地是由寄主的生长和扇贝的异速生长以及扇贝与其寄主之间的化学和物理相互作用形成的。在泰国（​​北纬 7°36′32″，东经 98°21′55″；东经 2019 年 5 月）和马来西亚（北纬 2°45′17″，104° 13′30″ E；2019 年 11 月）检查壳高度 (SH) 和壳宽 (SW) 之间的关系。在定居的前 2 年内，SH 对 SW 的回归斜率为 0.79-0.9，表明在此期间 SW 的增长略快于 SH。随着扇贝的进一步生长，SW 上 SH 的斜率是 1.29-1.54，表明 SH 增加得比 SW 快。对包括触手在内的扇贝皮层组织的组织学研究以及对居住墙壁的 SEM 观察表明，扇贝的分泌物会在生长过程中损害珊瑚组织并扩大居住环境。因此，扇贝独特的扇形栖息地是由异速生长扇贝生长和宿主组织和栖息地壁的侵蚀共同引起的。表明 SH 比 SW 增加得更快。对包括触手在内的扇贝皮层组织的组织学研究以及对居住墙壁的 SEM 观察表明，扇贝的分泌物会在生长过程中损害珊瑚组织并扩大居住环境。因此，扇贝独特的扇形栖息地是由异速生长扇贝生长和宿主组织和栖息地壁的侵蚀共同引起的。表明 SH 比 SW 增加得更快。对包括触手在内的扇贝外皮组织的组织学研究以及对居住墙壁的 SEM 观察表明，扇贝的分泌物会在生长过程中损害珊瑚组织并扩大居住环境。因此，扇贝独特的扇形栖息地是由异速生长扇贝生长和宿主组织和栖息地壁的侵蚀共同引起的。