How many species of Sipuncula are there?

How many species of Sipuncula are there?

The Sipuncula or Sipunculida (common names sipunculid worms or peanut worms) is a class containing about 162 species of unsegmented marine annelid worms. The name Sipuncula is from the genus name Sipunculus, and comes from the Latin siphunculus meaning a “small tube”.

How many Sipunculan species are hiding in our oceans?

The two monographs starkly differ in the number of recognized species: While Stephen and Edmonds [18] listed 320 species, Cutler [19] reduced the number to ~150 by assembling long lists of synonyms for many species.

What is the common name for Sipuncula?

peanut worms
Integrated Taxonomic Information System – Report

Taxonomic Rank: Phylum
Synonym(s): Sipunculoidea Sedgwick, 1898
Common Name(s): peanut worms [English]
shore worms [English]
sipunculan worms [English]

Are Sipuncula Protostomes?

Phylum Sipuncula | Lesser Protostomes | The Diversity of Animal Life.

What are the affinities of Sipuncula?

Sipunculans are marine spiralian worms with possible close affinities to the Mollusca or Annelida. Currently 147 species, 17 genera, 6 families, 4 orders and 2 classes are recognized.

Are Sipuncula protostomes or Deuterostomes?

Coelomate protostomes (e.g., Sipuncula, Echiura, Annelida, Pogonophora, Mollusca, Onychophora, Tardigrada, Pentastomida and some groups of arthropods).

Does Sipuncula have circulatory system?

Sipunculans have no circulatory or respiratory systems; the coelomic fluid transports both nutrients and oxygen to all parts of the body. Nephridia filter the coelomic fluid. Sipunculan Phylogeny and Systematics — Sipunculans are sometimes thought to be a group of annelids, and have been classified within them.

Are Sipuncula segmented?

Contrary to traditional belief, loss of segmentation may have occurred more often than commonly assumed, as exemplified in the sipunculans, which show remnants of segmentation in larval stages but are unsegmented as adults.

What is Protostomia and Deuterostomia?

Protostome and deuterostome are terms for members of major taxonomic groups of animals categorized by how they develop as embryos. In protostomes, the first opening in the embryo becomes the mouth. In deuterostomes, the first opening in the embryo becomes the anus, and the mouth develops later.

Which animals are Lophotrochozoans?

Lophotrochozoa is a monophyletic group of animals that includes annelids, molluscs, bryozoans, brachiopods, platyhelminthes, and other animals that descended from the common ancestor of these organisms. Lophotrochozoa is one of the three major clades that comprise bilateral animals, or Bilateria.

Does Sipuncula have coelom?

The body cavity, or coelom, of sipunculans is large and filled with fluid, in which are found free-floating cells known as hemerythrocytes as well as free-floating clusters of cells known as ciliary urns.

Which is an example of Chaetognatha?

Chaetognatha/Lower classifications

What is the meaning of Chaetognatha?

: a phylum of small, slender marine animals comprising the arrow worms But the absence of a definite synapomorphy between Chaetognatha and any other metazoan taxon except Bilateria itself has cast the arrowworms into an enduring isolation.—

Does Sipuncula have Coelom?

What is the difference between Protostomia and Deuterostomia?

The key difference between protostomes and deuterostomes is the fate of the blastopore during their embryonic development. The blastopore in a protostome develops into a mouth, whereas the blastopore in deuterostomes develops into an anal opening.

How do Protostomia and Deuterostomia differ?

Thus, the difference between protostomes and deuterostomes lies in the position of their organs. In deuterostomes, the blastopore transforms into an anus, and another cavity on the opposite side creates a mouth. However, in protostomes, the mouth is created from the blastopore.

Which of the following phyla are lophotrochozoans?

There are five phyla in the superphylum Lophotrochozoa (also known as the crest or wheel animals): Platyhelminthes, Rotifera, Nemertea, Mollusca, and Annelida. These phyla include animals from flatworms to squids.