Ctenophore.

Public Domain from NOAA photo library - this page has now vanished but has been saved at Internet Archive, dated 12 Dec 2006.

Image ID: nur01002, National Undersearch Research Program (NURP) Collection
Credit: OAR/National Undersea Research Program (NURP)

The cited web page does not specifically say this is a beroid. However the very similar The Jelly Connection identifies a Beroe specimen attacking another ctenophore.

This image is in the public domain because it contains materials that originally came from the U.S. National Oceanic and Atmospheric Administration, taken or made as part of an employee's official duties. العربية ∙ čeština ∙ Deutsch ∙ Zazaki ∙ English ∙ español ∙ eesti ∙ suomi ∙ français ∙ hrvatski ∙ magyar ∙ italiano ∙ 日本語 ∙ 한국어 ∙ македонски ∙ മലയാളം ∙ Plattdüütsch ∙ Nederlands ∙ polski ∙ português ∙ română ∙ русский ∙ sicilianu ∙ slovenščina ∙ Türkçe ∙ Tiếng Việt ∙ 简体中文 ∙ 繁體中文 ∙ +/−