Tubularia indivisa is a large hydroid reaching 10 to 15 cm in height. Living in
small clumps, the unbranched stems, gathered at the base, are pale horn coloured and bear a single
pale pink polyp. The tentacles form two concentric circles: those of the external circles are longer than
those of the oral one. In Spring (mostly), reddish-pink gonothecae grow between the tentacles. There is no
medusa released.
It lives attached to rocks, or sometimes among seaweeds' haptera in current-swept areas, in the
North-East Atlantic Ocean, the English Channel, the North Sea and the Norwegian Sea.
Phylum Cnidaria, class Hydrozoa, order Hydroida, family Tubulariidae, Tubularia indivisa Linnaeus, 1758.
Gonotheca: Part of the hydroid producing gametes and where eggs are incubated till the lava is released.
Tubularia indivisa Top photograph: © Wilfried Bay-Nouailhat. Published with author's kind permission.
Tubularia indivisa, Iles Glénan, South-Brittany, West of France. Depth 15 meters.
Bottom photograph: © Wilfried Bay-Nouailhat. Published with author's kind permission:
Tubularia indivisa, . Audierne, South-Brittany, West of France. Depth 17 meters.
Text: Wilfried Bay-Nouailhat © 2006-2008.
Translation: Anne Bay-Nouailhat © 2007-2008.
