Entoprocta: India
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Entoprocta
Introduction
Entoprocta are pseudocoelomate organisms which are stalked or sessile with the anus opening inside the tentacular circlet. The tentacles are cilIated and nonretractile but can be folded into the vestibule forming a calyx. The systematic position of these organisms was for a long time contorversial but their embroyological evidences have undoubtedly relegated them to the pseudocoelomate group. These are bilaterally symmetrical with a U shaped alimentary canal and a flame-bulb"type of excretery system. Entoprocta have remarkable power of regeneration by budding. Some members .are hermophrodite while others are unisexual. Most of them are marine or brackish water, but the single family Umatellidae is freshwater. Not much work has been done on this group and their exact role in the freshwater ecosystem has yet to be determined.
Historical Resume
Leidy (1883) arid Keferstein (1863) have referred Urnatella and Loxosoma to the phylum Bryozoa, although they were aware of the differences between the two genera. Nitsche in 1870 proposed to divide Bryozoa into two groups, Entoprocta to include the genm Pedicellina, Uranatellq and Loxosoma and Ectoprocta to include other known Bryozoans. Presence of the anal opening inside the tentacular circlet is the chief diagnostic feature of this group. Hatschek, (1877) by his embroyological studies has shown that Entoprocta have a much lower grade of organization than Ectoprocta and raised Entoprocta to the sta~us of a phylum. Clarck (1921) recognized the non¬coelomate nature of Entoprocta, raised them to the 'status of a phylum, giving a new name Calyssozoa. All subsequent workers on the group have accepted the phylum status and preferred the name' Entoprocta due to priority rules.
Until 1947, despite the controversy, the group was treated as ~ class in phylum Bryozoa. This group was recorded in India for the first time by Sheshaiya (1944, 1947) who recorded the member of family Umatellidae, described Urnatella indica ~a new species from South India. The same species has been figured recently by Tonapi (1980).
Classification Phylum Entoprocta is mainly divided into 3 families, Loxosomatidae, Umatellidae and Pedicellinidae. The following table provides a broad classified account of this phylum with examples of common genera. Pedicellina, Myosoma christapis, Loxosomatoides, Pedicellinopis, Barenlsia, Ascapodaria, Gonypodaria, Arthopodaria.
Urnatella gracilis Urnatella indica
K. S. R.o, Dept. of Zoology, Vikram University t Ujjain. From the Indian subcontinent Annandale (1908, 1910 &1916) and Harmer (1885) have described a number of new genera and new species of Entoprocta and Sheshaiya (1944) a single species. The validity of these taxa was upheld by several later investigators abroad.
Selected References
Annandale, N. 1908. The fauna of Brackish Ponds at Port Canning, Lower Bengal, Pt.VII, Description of a new genus of Entoprocta. Rec. Ind. Mus., 2, 24-32.
Annandale, N. 1910. Fauna British India Vol. I, Fresh water Sponges, Coelenterates and Polyzoa.
Annandale, N. 1916. Zoological results of a tour of the far east. Polyzoa Entoprocta and Ctenostomata. Mem. Asiatic, Soc. Bengal, 6, 18-24.
Seshaiya, R. V 1944. A preliminary note on a freshwater Entoproctan discovered ,in Annamalainagar, S. India Curr, Sci., 13(7), 187-188.
Seshaiya, R.V. 1947. On Urnatella indica sp. nov., a fresh water Entoproctan from South India Rec. Ind. Mus., 45(4). 283-290.
