Question

Botryoidal tissue occurs in
A) Hirudinaria
B) Lumbricus
C) Aphrodite
D) Chaetopterus

Answer 1

Hint: Two main types of pigmented tissues exist in leeches. The botryoidal tissue undergoes structural and functional changes in response to the various needs arising during the life-cycle of the animal.

Complete answer:
The botryoidal tissues are found in Hirudinaria which is a family of Annelida. The botryoidal tissue in leeches is composed of two different cell types- flattened endothelial-like cells and granular botryoidal cells, localized in the loose connective tissue between the body wall sac and the gut. The botryoidal tissue undergoes structural and functional changes in response to the needs arising during the life-cycle of the animal.

In untreated and healthy leeches, botryoidal cells are organized in clusters or cords, sometimes surrounding few, small lacunae. Conversely, in wounded animals, transition of the botryoidal tissue occurs from cluster or cord-like structures to a tubular or hollow architecture, typical of pre-vascular structures.

Large calcium storage is found in the botryoidal cell cytoplasm. The cytoplasm of botryoidal cells has granules of different size and form, containing melanin or iron, as tested by classic histochemical methods. They are involved in the defense mechanism of the body. The botryoidal tissue has a brown pigment which seems to consist of a masked iron compound, and that probably occurs in combination with the protein which forms the framework of the pigment granule; the vaso-fibrous tissue has green pigment, and does not contain iron, but reacts to the tests for bile pigments.

Hence, the correct answer is option (A).

Note: Botryoidal tissues are considered to represent kidneys of accumulation for the bile pigment and iron which probably represents the by-products of a breakdown of the blood that is used as food. Older leeches have a significantly greater amount of these tissues than in young leeches.