Mollusca is a diverse and widespread phylum of invertebrate animals that includes a wide variety of species with different body forms and lifestyles. Despite this diversity, there are several key characteristics that unite mollusks: Soft Body with Mantle: Mollusks have a soft, unsegmented body that is often protected by a calcareous shell. The mantle is … Read more
Mollusk shells are protective structures that are primarily composed of calcium carbonate and are secreted by the mantle, a specialized tissue layer in mollusks. These shells serve as a form of defense against predators and environmental factors, as well as providing structural support for the animal’s body. Mollusk shells can vary greatly in size, shape, … Read more
Mollusks are a diverse phylum of invertebrate animals that exhibit a wide range of body symmetries. The symmetry of mollusks can vary depending on the specific group within the phylum. Here are some common examples: Bilateral Symmetry: Many mollusks, including gastropods (snails and slugs) and cephalopods (squids, octopuses, and cuttlefish), exhibit bilateral symmetry. This means … Read more
Molluscum contagiosum can also affect the genital area, and in this case, it is referred to as “molluscum contagiosum genital infection.” This viral skin infection can be transmitted through sexual contact, and the bumps can appear on or around the genital region, inner thighs, buttocks, and even the lower abdomen. The appearance and characteristics of … Read more
“Mollusca” in this context likely refers to Molluscum contagiosum, a viral skin infection that can cause a rash. Molluscum contagiosum is a common skin condition caused by a poxvirus. It is characterized by small, raised, flesh-colored or pearly pink bumps on the skin. These bumps often have a central indentation and can be mistaken for … Read more
Molluscs (Phylum Mollusca) The molluscs, or soft-bodied animals The molluscs are also invertebrate The molluscs having (80,000 species) The molluscs include oysters, mussels, slugs, snails, squids and cuttlefishes. Body form of Molluscs We can divide molluscs into four regions; A dorsal visceral mass which is coiled in the gastropods and in which the internal organs … Read more
Nervous system and sense-organe The most primitive nervous system occurs in the monoplacophorans and amphincurans (e.g. chitons, where it consists of a central nerve ring round the anterior oesophagus with pleurovisceral and pedal cords running back, the former encircling the margin of the mantle, the latter running down the foot, with cross connections between the … Read more
Circulatory system The heart lies within the pericardium which represents part of the much reduced coelom or body cavity. It consists of a single muscular ventricle into which open usually one pair, but in a few cases two pairs, of auricles. Contractions of the ventricle force blood into anterior and posterior aortae; it then circulates … Read more