Are sponges radial symmetry?
Although asymmetry is typically associated with being unfit, some species have evolved to be asymmetrical as an important adaptation. Many members of the phylum Porifera (sponges) have no symmetry, though some are radially symmetric.
Do you agree that all sponges are asymmetrical?
Most are sponges are asymmetrical, though some of them exhibit radial symmetry (Dawkins 2004). Sponges do not have any internal organs or a nervous system. Their skeleton is made of tiny, needle-like splinters, or a mesh of protein called spongin (2) Most of the Demospongiae are made of spongin.
What is the simplest animal to have symmetry?
sponges
The simplest animals include the sponges (Porifera) and the Cnidaria. Sponges are unsymmetrical or radially symmetrical, with many cell types but no distinct tissues; their bodies contain numerous pores and sharp protective spicules.
What is bilateral symmetry example?
Examples of animals that possess bilateral symmetry are: flatworms, common worms (“ribbon worms”), clams, snails, octopuses, crustaceans, insects, spiders, brachiopods, sea stars, sea urchins, and vertebrates. The symmetry of an animal generally fits its lifestyle. More active animals are generally bilateral.
What kind of body symmetry do sponges have?
The type of symmetry is found in some sponges (Sycon), cnidarians (e.g. Hydra jelly), and echinoderms (e.g. star fish). When the body can be divided into two similar halves by one or two vertical planes only, the radial symmetry is called biradial symmetry.
What is body symmetry do sponges possess?
Class 2: Hexactinellida They are exclusively marine animals. Body is more or less cup-shaped with radial symmetry. They are pale in color and can grow up to 10-30 cm in height. They are also called glass sponges. The body bears branched or un-branched canal system. The exoskeleton is composed of six-rayed siliceous spicules. They can live solitary.
Do squid have bilateral symmetry?
Like all other cephalopods, squid have a distinct head, bilateral symmetry, a mantle, and arms. Squid, like cuttlefish, have eight arms and two tentacles arranged in pairs.
Do sponges have radial symmetry?
Only a few animal groups display radial symmetry, while asymmetry is a unique feature of phyla Porifera (sponges). All types of symmetry are well suited to meet the unique demands of a particular animal’s lifestyle.