Sponges are radially symmetrical or asymmetrical organisms with no tissue or organs. Based on the body form, the calcareous sponges can be classified into three: The simplest and least common sponge body form is asconoid. Ascon sponges have a vase-like body. Rarely do asconoid sponges exceed a diameter of 0.039 in (1 mm).

The simplest body structure in sponges is a tube or vase shape known as "asconoid", but this severely limits the size of the animal. The body structure is characterized by a stalk-like spongocoel surrounded by a single layer of choanocytes.

单沟型（Ascon type，Asconoid）是钙质海绵类沟系的最简单类型，见于 白枝海绵属 （Leucosolenia）。 所有海绵动物的 胚胎发生 初期，都可以看到这种类型的构造。 海克尔（E．Heack－el）设想的假空属厚海绵属于此型，因此也称厚海绵型（olynthus型）。 有的也将此型海绵称为Ascona－ten，把具有更复杂的构造称为Camaroten。 海绵的躯体呈简单的圆筒状或瓶状，水流从体壁的小孔由流入沟至胃腔，由胃腔壁的襟细胞进行消化、吸收、呼吸、排泄之 …

1. Asconoid Type: The asconoid type of canal system is re­garded to be the most simple and primitive grade of canal system. Asconoid type is present in these sponges whose body is vase-like and radially symmetrical. The wall is extremely thin. It encloses a large spongocoel (atrium) opening at the summit by a narrow osculum.

Give eight characteristics of sponges. 请给出海绵动物的八个特点。 3. Briefly describe asconoid, syconoid, and leuconoid body types in sponges. 请简要描述 海绵动物 中单沟型、双沟型和复沟型水沟系。 4. What sponge body type appears most efficient and makes possible the largest body size? 哪种 海绵体 型最高效，使其成为目前可能最大的动物？ 5.

4 天之前 · Water flows through the ostia/ostium into the spongocoel. The most basic body plan is called asconoid. In asconoid sponges the two major cell layers surround a fluid-filled cavity called the spongocoel, the large central cavity of sponges .

Spicules are straight (monaxons) or have three or four rays. These sponges tend to be small—10 cm or less in height—and tubular or vase shaped. They may be asconoid, syconoid, or leuconoid in structure.

2023年7月31日 · Learn about asconoid sponges, their structure, types, and the unique asconoid type canal system. Understand the role of choanocytes, pinacocytes and the functions of the canal system.

2017年11月25日 · This type of canal system is the characteristic of syconoid sponges like Scypha. Theoretically this canal system can be derived from asconoid type by horizontal folding of its walls. Also embryonic development of Scypha clearly shows the asconoid pattern being converted into syconoid pattern.

Asconoid Sponges As an incurrent pore or ostium, this opening brings water directly into the sponge.