Belgian Exclusive Economic Zone, British Isles, European waters (ERMS scope), Gulf of Mexico, Hinder Banks, Kwintebank, New Zealand Exclusive Economic Zone, Portuguese Exclusive Economic Zone, Spanish Exclusive Economic Zone, United Kingdom Exclusive Economic Zone, Westhinder

Hippothoa flagellum is widespread in the North Atlantic from Norway to West Africa, and has been widely reported from other regions. This species appears to be practically cosmopolitan in shallow shelf seas. In Britain, it has been recorded from Guernsey, Cornwall, south Devon, Hastings, the Isle of Man, the coast of Antrim and Shetland.

Hippothoa flagellum forms adnate runner-like colonies composed of delicate uniserial branches, closely adhering to the substrate. It is a smaller more delicate species than Hippothoa divaricata. Autozooids are slender and club-shaped with a long slender thread-like portion proximally (closest to the colony origin) and a dilated section distally. The thread-like portion (cauda) is one to four times as long as the dilated section.Branches of new autozooids are basically cruciform in the form of a ‘+’, with no more than one bud from each side of the autozooid.

Depth range based on 39 specimens in 1 taxon.
Water temperature and chemistry ranges based on 31 samples.

Environmental ranges
  Depth range (m): 15 - 3501
  Temperature range (°C): -1.323 - 12.694
  Nitrate (umol/L): 5.479 - 33.737
  Salinity (PPS): 33.315 - 35.504
  Oxygen (ml/l): 3.925 - 6.788
  Phosphate (umol/l): 0.460 - 2.401
  Silicate (umol/l): 2.685 - 142.966

Graphical representation

Depth range (m): 15 - 3501

Temperature range (°C): -1.323 - 12.694

Nitrate (umol/L): 5.479 - 33.737

Salinity (PPS): 33.315 - 35.504

Oxygen (ml/l): 3.925 - 6.788

Phosphate (umol/l): 0.460 - 2.401

Silicate (umol/l): 2.685 - 142.966
 
Note: this information has not been validated. Check this *note*. Your feedback is most welcome.

The species is particularly found on shells and other biogenic carbonates. It occurs in subtidal waters ranging from 10-275 m.