Not valid. The original description is from specimens recovered from the Pacific Sailfish Histiophorus hescheli (= Istiophorus platycephalus) off New Zealand. The descriptions and figures resemble closely specimens of P. filosa also recorded from Pacific Sailfish (ex: off coastal Mexico, Causey 1960). The specimens of P. histiophori fall within the length and morphological variability range of most specimens of P. filosa from many different species of large pelagic scombriform fishes (Hogans 1987). Pennella histiophori is a synonym of P. filosa (Hogans 1988a); accepted as P. filosa (Walter & Boxshall 2015).