The Pacific barreleye (Macropinna microstoma) is instantly recognisable due to its highly unusual transparent, fluid-filled head. The two black pores on the front are not actually eyes but nares, similar to our nostrils. The two bright green orbs are the lenses of its tubular eyes which can be rotated to face either forwards or straight up, looking out of its transparent head. They normally hang motionless searching for the faint silhouettes of prey overhead. Scientists theorize that it can also steal food captured in the tentacles of siphonophores.