Since recently, shark’s bioluminescence has been recorded from two Squaliformes families, the Etmopteridae and Dalatiidae. Pictures of luminescence, light organ morphologies and physiology of the luminous control have been described for species of the Etmopteridae and Dalatiidae families. In 2015, a third luminous family, Somniosidae, was assumed to present a bioluminescent species, Zameus squamulosus. Up to now, confirmation of the luminous abilities of Z. squamulosus is lacking. Here, the luminescence of Z. squamulosus was in vivo recorded for the first time confirming the bioluminescence status of the third luminescent shark family. Additionally, photophore histology revealed the conservation of the light organ morphology across the luminous Squaliformes. Light transmittance analysis through the placoid scale added information on the luminescence efficiency and highlighted a new type of bioluminescent-like squamation. All these data reinforced the likelihood that the common ancestor of Dalatiidae, Etmopteridae and Somniosidae may already have been luminescent for counterillumination purpose.

中文翻译：

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第三个夜光鲨家族：确认鳞翅目鱼（Squaliformes；Somniosidae）的发光能力

从最近开始，鲨鱼的生物发光已经从两个角形目科（Etmopteridae 和 Dalatiidae）中得到记录。已经为 Etmopteridae 和 Dalatiidae 家族的物种描述了发光控制的发光、光器官形态和生理学的图片。2015 年，第三个发光科 Somniosidae 被认为是一种生物发光物种Zameus squamulosus。到目前为止，尚缺乏对鳞状孢杆菌发光能力的确认。在这里，Z. squamulosus的发光在体内首次记录确认第三发光鲨鱼家族的生物发光状态。此外，发光组织学揭示了发光的角形目中光器官形态的保守性。通过 plaoid 尺度的透光率分析增加了关于发光效率的信息，并突出了一种新型的类生物发光鳞片。所有这些数据都加强了 Dalatiidae、Etmopteridae 和 Somniosidae 的共同祖先可能已经为反照明目的而发光的可能性。