Q.What is botryoidal tissue?

[!TLDR] Botryoidal tissue is the spongy connective tissue filling the reduced coelom of leeches. …

[!ANSWER] Botryoidal tissue is a distinctive connective tissue found filling the reduced coelom of Hirudinea.

Unlike Polychaeta and Oligochaeta, in which the coelom remains a large, spacious, fluid-filled cavity that functions as a hydrostatic skeleton, the coelom of leeches is greatly reduced during development and becomes packed with a spongy, cellular connective tissue arranged in cluster- or grape-like masses — this tissue is called botryoidal tissue (from a root meaning "cluster of grapes", describing its characteristic appearance). Botryoidal tissue is thought to play roles connected with storage and possibly with blood-cell-related functions, in a class where the coelom itself no lon …

• Confusing botryoidal tissue with blood glands (a distinct Pheretima-specific structure covered later in the chapter). …