colonial; fixed gonophores

The main stem is straight but not as robust as Diphasia alata, sometimes it is extended, forming a long thin tendril that divides at its apex, into two short, thickened processes. The side branches are alternate and support oppositely paired hydrothecae. The hydrothecae are attached to the side branches for approximately 1/2 of their length. They are tubular in shape and bend outwards from the side branch in 1 plane at an angle of approximately 45 degrees. The outer rim of the hydrotheca is smooth, and on the inner face there is a notch and the opercular flap adjoins this. Colonies typically 40-50mm in size. This is a smaller Diphasia species and is most likely to be confused with Diphasia rosacea or Diphasia fallax.

Arctic Ocean, Azores Exclusive Economic Zone, Belgian Exclusive Economic Zone, British Isles, Cap Gris Nez, East North Atlantic, European waters (ERMS scope), Irish Exclusive economic Zone, Mediterranean Sea, North Sea, South Coast of England, United Kingdom Exclusive Economic Zone, West Coast of England, Wimereux

Reported from scattered localities all around the British Isles, but appears to be more frequent on the south western coasts.

Depth range based on 14 specimens in 1 taxon.
Water temperature and chemistry ranges based on 5 samples.

Environmental ranges
  Depth range (m): 10 - 2500
  Temperature range (°C): 7.624 - 10.036
  Nitrate (umol/L): 2.853 - 6.121
  Salinity (PPS): 34.621 - 34.764
  Oxygen (ml/l): 5.952 - 6.351
  Phosphate (umol/l): 0.406 - 0.511
  Silicate (umol/l): 2.143 - 5.452

Graphical representation

Depth range (m): 10 - 2500

Temperature range (°C): 7.624 - 10.036

Nitrate (umol/L): 2.853 - 6.121

Salinity (PPS): 34.621 - 34.764

Oxygen (ml/l): 5.952 - 6.351

Phosphate (umol/l): 0.406 - 0.511

Silicate (umol/l): 2.143 - 5.452
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

This hydroid often grows on the stems of other hydroids, and the tendrils are probably used to help secure attachment.