GENERAL HISTOLOGY

Detailed explanation-1: -Remember, sponges live attached to the seafloor. Because they are attached, they are called sessile. In order obtain food, sponges pass water through their bodies in a process known as filter-feeding. Water is drawn into the sponge through tiny holes called incurrent pores.

Detailed explanation-2: -So, the correct answer is ‘Sessile’.

Detailed explanation-3: -These pores are sometimes also referred to as ostia, and they provide openings for water, which carries planktonic food and oxygen, to enter the sponge body (Fig. 3.19). Simple vase-like sponges have a single large top opening, called the osculum through which water leaves the sponge.

Detailed explanation-4: -Sponges (Poriferans) receive (incoming) food particles with the help of collar cells (choanocytes). These collar cells or choanocytes are surrounded by microvilli which filter the incoming food particles. Therefore, sponges/Poriferans are called filter feeders.

Detailed explanation-5: -Filter Feeding in Echinoderms All echinoderm species are found in the sea. Filter feeders that collect food particles filtered from seawater, deposit feeders that sift through sediments at the ocean’s bottom to acquire food particles, predators, and scavengers are all examples of echinoderm eating.