Is Mollusca a bilateral symmetry?

Is Mollusca a bilateral symmetry?

Mollusca can be found in freshwater, marine and terrestrial habitats. More features of molluscs include bilateral symmetry, soft or unsegmented bodies, respiration via ctenidium, ganglia/nerve comprised nervous system, haemocoel body cavity, etc.

What are the characteristics of Mollusca?

Mollusca Characteristics

• They are mostly found in marine and freshwater.
• They exhibit organ system level of organization.
• Their body has a cavity.
• The body is divided into head, visceral mass, muscular foot and mantle.
• The head comprises of tentacles and compound eyes.
• The body is covered by a calcareous shell.

How do molluscs reproduce?

HOW DO MOLLUSKS REPRODUCE? Mollusks reproduce sexually. Slugs and snails are hermaphrodites (possessing both male and female organs), but they must still mate to fertilize their eggs. Most aquatic mollusks lay eggs that hatch into small, free-swimming larvae called veliger.

What type of digestive system do mollusks have?

6. Clams (and all mollusks) have a complete digestive system. It consists of a mouth where food is ingested, a short connecting tube called the esophogus, a stomach which temporarily holds food, and an intestine where food digestion and absorption takes place.

What are the main morphological features of Mollusca?

The three most universal features defining modern molluscs are a mantle with a significant cavity used for breathing and excretion, the presence of a radula (except for bivalves), and the structure of the nervous system.

Are Mollusca Monoecious?

Molluscs are either dioecious, with separate sexes, or hermaphroditic, one individual bearing both male and female sex organs. The eggs of aquatic species of bivalves and some species of gastropods develop into trochophores, which in turn usually develop into veliger larvae.

Is phylum Mollusca dioecious?

The animals in the phylum Mollusca (e.g., clams, snails, and squid) display a diversity of reproductive behaviour. The majority of the amphineurans (chitons) and pelecypods (e.g., clams, oysters) are dioeciousi.e., individuals are either male or female.

What adaptations do Mollusca have?

The subclass Coleoidea, which includes squid, cuttlefish and octopus, have a number of other unique adaptations among the molluscs. They have highly developed eyes, a complex nervous system, ink glands and skin cells with the ability to change color (known as chromatophores)

Are Mollusca bilateral or radial?

Mollusks are generally considered a phylum of bilaterally symmetrical animals, although there are also many asymmetrical species. Bilateral symmetry means that an organism can only be divided into two equal halves if it is cut from top to bottom along the middle of the anterior-posterior (front-back) axis.

Do molluscs have bilateral?

The most general characteristic of molluscs is they are unsegmented and bilaterally symmetrical. The following are present in all modern molluscs: The dorsal part of the body wall is a mantle (or pallium) which secretes calcareous spicules, plates or shells.

Are Mollusca asymmetrical radial or bilateral?

In the phylum, Mollusca through there is bilateral symmetry, but it is lost in some forms, due to the phenomenon, called as. A. Asymmetry. B.

What symmetry is Mollusca?

bilateral symmetry

What are the characteristics of molluscs for kids?

Mollusks are invertebrates, meaning that they do not have a backbone. They have a soft body that holds the heart, liver, digestive system, and other important organs. Most mollusks have a mouth structure called a radula. The radula is sort of like a rough tongue with lots of tiny teeth.

Which one is characteristic of most molluscs?

Characteristic Features of Phylum Mollusca

• They are bilaterally symmetrical.
• They are triploblastic, which three layers.
• They show organ system grade of organisation.
• The body is soft and unsegmented.
• Body is divisible into three regions head, a visceral mass, and ventral foot.
• Body is covered by a mantle and shell.