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 are the affinities of Hemichordata?
The name Hemichordata suggests that they are half chordates. The close affinities of Hemichordata with Echinodermata, Annelida, Pogonophora, Phoronida have led to the conclusion that they have arisen from a common ancestral stock.
What are the affinities of Cephalochordata?
Chordate Affinities: Cephalochordata (Branchiostoma) exhibits the three basic chordate features such as notochord, dorsal tubular nerve cord and pharyngeal gill-slits in the most typical manner and there is no doubt about its chordate nature.
What is meant by affinities discuss the affinities of chordates?
Affinities with Chordata There is close affinity between Hemichordata and Chordata. Their resemblance was based on the presence of the three fundamental chordate characteristics in Hemichordata, that is, (i) a notochord, (ii) a dorsal hollow nerve cord and (iii) the pharyngeal gill-slits (pharyngotremy).
What is the larva of Balanoglossus?
Balanoglossus is a hemichordate and yes, its larva is called tornaria.
What is meant by a Balanoglossus?
Definition of Balanoglossus : a genus of marine burrowing wormlike animals that because of certain vertebratelike characters are not usually classed as chordates and made with certain closely related forms (such as Dolichoglossus) to constitute an order (Enteropneusta) of the Hemichorda.
What is the scientific name of Balanoglossus?
Balanoglossus
Balanoglossus/Scientific names
What is the classification of Balanoglossus?
Acorn worm
Balanoglossus/Class
What are examples of Cephalochordates?
For instance, Pikaia gracilens species were recovered from the Burgess Shale (i.e. a fossil-bearing deposit located in the Canadian Rockies of British Columbia, Canada). They look similar to the lancelet and probably swam like the eels. Cathaymyrus species were found from the Chengjiang County, Yuman Province in China.
How many genera are found in Cephalochordata?
three genera
Acrania, or Cephalochordata, is a taxon of marine invertebrate chordates comprising 30 species belonging to three genera, Branchiostoma, Epigonichthys, and Asymmetron ( Poss and Boshung 1996 ).
What are affinities?
: a strong liking for or attraction to someone or something They had much in common and felt a close affinity. affinity.
What is the meaning of Balanoglossus?
Balanoglossus is an ocean-dwelling acorn worm genus of great zoological interest because, being a Hemichordate, it is an “evolutionary link” between invertebrates and vertebrates.
What are the different affinities of Balanoglossus?
Different affinities and systematic position of balanoglossus are given below: Earlier Zoologists like William Bateson (1885) proposed close affinities with chordates on the basis of three fundamental characters: On the basis of these similarities hemichordates have been considered as a subphylum of chordata.
Who was the first person to discover Balanoglossus?
J.F. Eschscholtz who discovered Balanoglossus in 1825 in Mashail Island described it as a worm-like holothurian. The discovery of gill-slits in this animal by Kowalewsky (1865) led to creation of a special class Enteropneusta by Gegenbaur (1870).
How are Hemichordata and Balanoglossus related?
The name “Hemichordata” is, however, retained for the group because it suggests that its members are related to chordates, i.e., they are “half or “part” chordates, a fact that is undisputed. Affinities of Balanoglossus (Enteropneusta, Hemichordata) with Chordates and Non-Chordate Phyla are as follows:
How is coelom related to amphioxus and Balanoglossus?
The enterocoelic origin of coelom in Balanoglossus and Amphioxus is also of greater phylogenetic significance than the resemblances in the gill-slits, and so-called notochord and dorsal tubular nerve cord. The chordates are metamerically segmented animals while Balanoglossus retains in adult stage, the trisegmental character of their larvae.