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tammy.horton

Deep%20sea%20life%20of%20Tanzania_2016_reduced.pdf?bcsi_scan_2687365ababd2c82=0&bcsi_scan_filename=Deep%20sea%20life%20of%20Tanzania_2016_reduced

- Echinodermata - Ophiuroidea -

Ophiuroidea (Brittle stars)

Echinodermata (Phylum) > Ophiuroidea (Class)

Unusual ophiuroid posture seen at

2600 m

The Ophiuroidea includes the brittle stars and basket

stars. It is the echinoderm class with the most species.

Ophiuroids have long arms projecting from a central

disc, but ophiuroid arms do not grade into the disc as the

asteroids do. Ophiuroid arms are also more flexible than

starfishes and locomotion is by means of pushing or pulling

themselves along in a motion reminiscent of rowing.

This is demonstrated by the tracks left in

the sediment by the animal in the lower of

the images on the left.

“Pink ophiuroid” at Zafarani

“White ophiuroid” showing tracks in the sediment as

it moves over the seabed

Ophiuroids demonstrate various feeding

modes including suspension feeding (notably

the basket stars, but others too), deposit

feeding, scavenging and predation.

Basket stars were not seen off Tanzania but

brittle stars were. They were most common

at the deeper sites (Zafarani and Lavani).

It is not possible to identify these small

echinoderms from video footage but two

distinct colour types were documented

at Zafarani and Lavani. The white ophiuroids,

shown at the bottom of this page

were more common than the pink animals

(upper images). (The observations probably

represent several species).

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