Symbiosis: Protozoa - Ciliophora- (epibiont)

Ophiuroidea – Protozoa (Ciliophora)

• Ophiuroidea: Ophioplinthus gelida: host
• Protozoa: Folliculina sp: epibiont

On the surface of some samples of Ophioplinthus gelida may appear numerous specimens of ciliate Folliculina sp. Their presence on the ophiuroid is mostly in the radial shields, but they may also appear on any dorsal disc plate and on the dorsal and lateral arm plates. Their arrangement is both solitary and in groups of several individuals, Andrews (1914).

This relationship is an epibiosis, possibly facultative Wahl & Mark (1999). This inquilinism does not seem to affect the brittle star, while the protozoa are provided with food availability, with protection from potential predators and are save from being buried in the bottom sediments.

Specimens conserved in 70% ethanol, all  photographs were made in ethanol.

Collected by Pablo J. González-López. Cruiser ANTARKTIS XXIII/8  Polarstern

Identified by Rafael Martín-Ledo.
The study was made using Motic SMZ-168 TL stereo microscope.

References

Andrews E A 1914 The Bottle – animalcule, Folliculina oecological notes.  Biol Bull  26: 245-315

Koehler R (1922) Echinodermata Ophiuroidea. Adelaide: Australas Antarct Exped (1911–1914) Sci Rep Ser C Zool Bot 8:1–98

Madsen FJ (1967) Ophiuroidea. B.A.N.Z. Antarctic Research Expedition (1929–1931) under the Command of Sir Douglas Mawson Rep Ser B 9:123–145

Mortensen T (1936) Echinoidea and Ophiuroidea. Discovery Reports, National Institute of Oceanography Cambridge 12:199–348

Wahl M & Mark O (1999) The predominantly facultative nature of epibiosis: experimental and observational evidence. Mar Ecol Prog Ser Vol. 187: 59-66

July 2010