What is the class of Balanoglossus?
Acorn wormBalanoglossus / ClassThe acorn worms or Enteropneusta are a hemichordate class of invertebrates consisting of one order of the same name. The closest non-hemichordate relatives of the Enteropneusta are the echinoderms. There are 111 known species of acorn worm in the world, the main species for research being Saccoglossus kowalevskii. Wikipedia
Which of the following is correct for Balanoglossus?
If we divide the balanoglossus body in different parts it is composed of the proboscis, collar, and long trunk and also contains an open circulatory system with worm-like body structure similar to animals in Non-Chordata. Hence option D is correct. Thus, the correct option is Non-Chordata (option D).
What are the salient features of Balanoglossus?
Balanoglossus is a deuterostome, and resembles the Ascidians or sea squirts, in that it possesses branchial openings, or “gill slits”. It has a notochord in the upper part of the body and has no nerve chord. It does have a stomochord, however, which is a gut chord within the collar.
How is Balanoglossus?
Balanoglossus is considered a connecting link between chordates and non chordates because it shows characteristics which are present in both the phyla. For example, Balanoglossus shows the presence of notochord and pharyngeal gill slits which is a characteristic feature of chordates.
Why is Balanoglossus a Hemichordata?
Note: Balanoglossus is an acorn worm and evolutionary link of invertebrates and vertebrates as a hemichordata. Balanoglossus is a deuterostome, which is similar to Ascidian or marine squirts in that it has branch openings or gill slits. In the upper part of the body it has notochord and has no chord of its nerve.
Why Balanoglossus is classified under Hemichordata?
Balanoglossus belongs to the phylum Hemichordata, The animals in this group are also called acorn worms. They differ from chordates by not having a post-anal tail and notochord. Balanoglossus has a length of 1.5 meters. These have modified proboscis.
Why is Balanoglossus important?
Unsourced material may be challenged and removed. Balanoglossus is an ocean-dwelling acorn worm (Enteropneusta) genus of zoological importance because, being a Hemichordate, it is an “evolutionary link” between invertebrates and vertebrates.
What are the affinities of Balanoglossus?
Affinities # Balanoglossus with Annelida:
- Vermiform body. ADVERTISEMENTS:
- Presence of coelom.
- Arrangement of blood vessels.
- Collar comparable to clitellum of Oligochaeta.
- Resemblances between Tornaria and Trochophora larva.
What do we know about the phylogeny of Balanoglossus?
Some of the views existing on this particular aspect of Balanoglossus are described below: Balanoglossus shows many structural similarities with non-chordates. Many authors like Dohrn (1875), Semper (1876) and Minot (1897) have attempted to bring Balanoglossus and Annelids on the level of a distinct phylogenetic relationship.
How many pharyngeal slits does Balanoglossus auranticus have?
The numbers of pharyngeal slits or gill-slits vary from 40 to 100 pairs in most cases but in Balanoglossus auranticus, the numbers of pharyngeal slits are 700 pairs and normally the number increases as the animal grows older. Each pharyngeal slit is a U-shaped aperture (Fig. 2.5A).
Does Balanoglossus have a gill pore?
All the species under the genus Balanoglossus have separate gill-pore for each branchial sac, but, in Balanoglossus misakiensis, the first four branchial sacs fuse with each other and open to the exterior through a common pharyngeal or gill-pore (see Fig. 2. 10A).