Caught in the wild and photographed nearby in an aquarium. Bell is 20–25 mm tall.
Note tall, conical aspect of the bell and the gonad extends from nearly the top of the manubrium to the mouth (just a very short section at the top of the long manubrium is without gonad).
Hyperiid amphipods (Amphipoda, Hyperiidea) of the world's oceans: By M.E. Vinogradov, A.F. Volkov and T.N. Semenora, Science Publishers, USA, 1996, 632 pp.
P. 428 Fig. 186. Phronimella elongata (Claus)
https://library.si.edu/digital-library/book/hyperiidamphipod00vino
Female with hatchlings inside a salp barel. According to sealifebase.ca, the only phronima species with Meditteranean distribution.