acorn worm

Thus, the acorn worm breathes about the same way as fish.

Acorn worms are rarely seen by humans because of their lifestyle.

Acorn worms breathe by drawing in oxygenated water through their mouth.

Therefore, acorn worms are sometimes said to be a link between classical invertebrates and vertebrates.

Acorn worms have an open circulatory system, in which the blood flows through the tissues sinuses.

Acorn worms continually form new gill slits as they grow in size, with some older individuals having more than a hundred on each side.

In acorn worms, it seems to be primarily involved with coordinating muscular action of the body during burrowing and crawling.

In addition to these, the deuterostomes also include the Hemichordata, or acorn worms.

The blood of acorn worms is colourless and acellular.

Acorn worms are considered more highly specialised and advanced than other similarly shaped worm-like creatures.

Acorn worms have gill-like structures that they use for breathing, similar to the gills of primitive fish.

Another method that some acorn worms use to obtain food is to collect suspended particles of organic matter and microbes from the water.

Yoda is a genus of Acorn worm.

Ptychoderidae is a family of acorn worms.

Acorn worms are generally slow burrowers.

Despite the close relationship between the two groups, the larva does not resemble that of the acorn worms; they are "planula-like".

Acorn worms move only sluggishly, using ciliary action and peristalsis of the proboscis.

Like their relatives, the acorn worms, their body is divided into three parts: an anterior proboscis, a collar, and a trunk.

Acorn worms are solitary worm-shaped organisms.

Fish catches have declined, as have pearl oyster, gorgonian coral, and acorn worm populations.

There are about 70 species of acorn worm in the world, the main species for research being Saccoglossus kowaleski.

Many acorn worms are detritus feeders, eating sand or mud and extracting organic detritus.

Harrimania planktophilus is a marine acorn worm in the family Harrimaniidae.

Hemichordata (acorn worms and possibly graptolites)

Pterobranchs may be a sub-group of enteropneusts ("acorn worms").