Question

describe general organization and affinities of hormiphora
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Answer 1

Answer:

Hormiphora has a pear-shaped body measuring 5-20 mm in diameter (Fig. 13.2A). They are pelagic and are found in the Mediterranean sea. Mouth is situated at the centre of the oral pole and the opposite pole is occupied by a complicated and characteristic sense organ usually designated as the aboral sense organ.

Answer 2

Answer:

General Organization and Affinities of Hormiphora

• ​Hormiphora is pear-shaped, glossy, transparent, and about 5-20 mm in diameter.
• Two long, solid tentacles project from opposite sides of the broad or aboral end.
• The tentacles have numerous side branches with attachment cells and They are fully retractable in deep pods.
• Mouth, a slit-like opening  at the narrow oral end.
• On the surface are eight equidistant, aradially arranged bands of meridians, the crest ribs or costas, or swimming plates, beginning near the aboral pole and extending about two-thirds of the way to the oral pole. These help with swimming.
• A series of transverse comb-like structures of narrow plates, frayed at their outer ends, form a comb-rib.
• Crests are formed by the fusion of rows of cilia at their proximal ends.
• The mouth leads to a flattened tube, the stomodeum, which functions as the stomach and extends  about two-thirds to the aboral pole.
• The walls of the stomodeum are provided with internal ridges.
• The stomodeum tapers to the aboral pole and opens into the infundibulum.i.e. Towards the aboral pole, the infundibulum divides into four short branches, two of which open outward as tiny excretory pores. e.g. The other two branches of the infundibulum are paired radial canals that extend outward in the transverse plane and each divide into two adradial canals that open into the meridional canal.
• Each paired radial canal gives off a stomodeal canal and a tentacular canal.
• The nervous system of Hormiphora consists of a subepithelial plexus of nerve fibers that extends over the entire body surface and consists of multipolar ganglion cells with their processes. Nerve fibers extend into the mesoglea.

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