Solvin Zankl / Threadfin dragonfish (Echiostoma barbatum) portrait, showing a short bioluminescent barbel present beneath the lower jaw and a large triangular luminous organ positioned under the eye. A row of light...

Tony Wu / Mature lumpfish (Eumicrotremus taranetzi) with visible disk comprising modified pelvic fins used as sucker to adhere to rocks and other surfaces. Pacific Ocean, Hokkaido, Japan.

Georgette Douwma / Female Harlequin / Ornate ghostpipefish (Solenostomus paradoxus) carrying eggs in pouch formed with pelvic fins, on black background, Bali, Indonesia, Indo-Pacific.

Alex Mustard / Distinctively grey coloured female Lumpsucker (Cyclopterus lumpus) attached to a kelp frond with her sucker (modified pelvic fins) The females of this species are rarely seen in shallow water. Kinloch...

Magnus Lundgren / Monkfish (Lophius piscatorius) photographed at night, Saltstraumen, Bodö, Norway. Magnus

Georgette Douwma / Harlequin or Ornate ghostpipefish (Solenostomus paradoxus). Female carrying eggs in pouch formed with pelvic fins. Tulamben, Bali, Indonesia.