echiuran

A MORPHING MARINE WORM

A truly weird animal
Photography by Arthur Anker
Universidade Federal do Ceará (Brazil)

A thalassematid echiuran from Madang, Papua New Guinea, an odd animal that constantly changes its shape, is “never the same” … these 6 photos show the same individual.

Echiura - spoon worms - a class of marine Annelid worms.
Thalassematinae is a subfamily of spoon worms.

The Echiuran worms are an exclusively marine/brackish water group of round, unsegmented worms with a short, stout trunk and and a proboscis that can be shortened and lengthened (but not retracted). The proboscis has a broad groove beneath, with the mouth at its base. Many echiurans are quite large.

Read more in the Encyclopedia of Life

2

Green Spoonworm (Bonellia viridis)

…is a species of Echiruan or spoonworm found in the north-eastern Atlantic, Indian, and Pacific oceans, and the Red and Mediterranean and Red seas. Green spoonworms are highly sexually dimorphic, the females take the green form you see above, the males however are planktonic and live inside the females body. The presence/absence of the pigment bonellin determines sex. Green spoonworms are mainly detritivores and will anchor themselves to the floor with two hooks. They will also feed on small invertebrates aswell by using an extendable proboscis which is 10x their body size.

Phylogeny

Animalia-Echiura-Echiuroidea-Bonelliidae-Bonellia-viridis

Image Source(s)

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Marine Annelid Worms
Singapore Mega Marine Biodiversity Survey 2013
Photographer: Dr Arthur Anker
Date Taken: 2013-06-01

  1. Thalassematid echiuran worm dredged off S Singapore
    Animalia  >  Phylum: Annelida  >  Class: Echiura
  2. Yellow dragon worm (Phyllodoce sp)
    Also annelid worms, but of the class Polychaeta
  3. Phyllodocid worm
  4. Beautiful polychaete worm (family: Syllidae)
  5. Large parchment worm (Chaetopterus sp) extracted from its tube