Mài –Shì-Jiăo-Lín-Yóu (Coffee bean scaled squid)

The Coffee Bean Scaled Squid (Pholidoteuthis massyae) is a mesopelagic cephalopod in the family Pholidoteuthidae, named for the distinctive scale-like photophores or dermal ornaments that texture its body surface and produce bioluminescent signals in the deep-sea environment. This squid inhabits the mesopelagic zone—approximately 200–1,000 metres depth—of tropical and subtropical oceanic waters, where it feeds on small fish, crustaceans, and other cephalopods. Pholidoteuthis is a genus of relatively large, muscular squids whose taxonomy is incompletely resolved due to limited specimen availability and the challenges of collecting and studying deep-sea fauna. The Coffee Bean Scaled Squid has been recorded from the southeastern Pacific, including Chilean waters, and the western Pacific around Taiwan and adjacent seas, indicating a broadly distributed but patchily documented range consistent with open-ocean mesopelagic distributions. Like many deep-sea squids, it undergoes diel vertical migration, ascending toward shallower productive layers at night to feed and descending to depth during daylight hours, thereby playing a role in the biological carbon pump by transporting organic matter downward. It is assessed as Least Concern by the IUCN based on its oceanic distribution and absence of targeted commercial exploitation.