Largest seadragon

Of the three known extant species of seadragon, the common, aka weedy, seadragon (Phyllopteryx taeniolatus) grows to the largest size, with a maximum length from snout to tail tip of 45 centimetres (1 foot 5.7 inches). The common seadragon, as its name would suggest, is also the most prolific species in the family, though research indicates that their numbers are in decline. The common seadragon lives in reefs, seagrass meadows and areas of rocky seabed off southern Australia and in the waters around Tasmania, where purple-edged leaf-like appendages along its back and fins provide excellent camouflage among the seaweed.

By comparison, the maximum length of the leafy seadragon (Phycodurus eques) is around 35 cm (1 ft 1.7 in), while for the only recently discovered ruby seadragon (Phyllopteryx dewysea, first described in 2015), specimens to date have only been around 25 cm (9.8 in), though as further examples come to light, this figure may be revised.

Weedy seadragons are threatened by aquarium collectors and a traditional medicine market, which sells their dried and powdered bodies as an expensive form of aphrodisiac.