Gymnangium montagui (Billard, 1912)

Gymnangium montagui

Description: The main stems of this species bear side branches in alternating series on opposite sides of the main stem, forming a feather-like colony. The colour of living specimens is deep brown. The feeding polyps are borne in a single series along the side branches, each surrounded by three defensive polyps. This species reproduces from September through November, bearing white spherical capsules along the midrib of each plume. Typically 90 mm in height by about 20 mm across the colony.

Habitat: This is a scarce hydroid species found in clear water deeper than 10 metres, where it forms dense clumps on horizontal rock surfaces in moderate tidal streams and moderate to high levels of wave exposure.

Distribution: In the British Isles this is a southern species, with records from SW England and Wales, and the west coast of Ireland north to Rathlin Island, Co Antrim.

Similar Species: All species of Aglaophenia are similar but smaller and have their reproductive structures enclosed in corbulae.

Key Identification Features:

Distribution Map from NBN: Grid map (fast) : Interactive map (slower, requires login to view records) : National Biodiversity Network mapping facility, data for UK.

 Picton, B.E. & Morrow, C.C. (2016). Gymnangium montagui (Billard, 1912). [In] Encyclopedia of Marine Life of Britain and Ireland. Accessed on 2016-10-25

[Show species list]