Diphasia margareta (Hassall, 1841)

Diphasia margareta

Description: The main stem of the colony is erect with alternate side branching, and occasionally secondary branching. The hydrothecae are paired oppositely and are attached to the side stem for approximately 1/2 their length. The upper half is unattached and flares outwards. The outer margin is smooth, but there is a notch in the inner margin. The male gonothecae are oval shaped and taper towards the base. There are four long spines that curve inwards towards a raised aperture. The female reproductive capsule is also ovate with four longitudinal ridges. Each ridge bears two spines, giving a total of eight. Together these spines form two rings that encircle the aperture. The top of the capsule is convex. Approximately 12cm. Synonym: Sertularia pinaster Ellis & Solander, 1786

Distribution: This hydroid occurs all round the British Isles, but is commoner in the North.

Distribution Map from NBN: Interactive map : National Biodiversity Network mapping facility, data for UK.

WoRMS: Species record : World Register of Marine Species.

 Picton, B.E. & Morrow, C.C. (2016). Diphasia margareta (Hassall, 1841). [In] Encyclopedia of Marine Life of Britain and Ireland. Accessed on 2017-09-21

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