The protostomes (mollusks, annelids and arthropods) develop in such a way that the first opening in the embryo is the mouth (protostome = first mouth). Deuterostomes (echinoderms and cordata) develop first the ■■■■ and then the mouth at the other end of the embryo.
Mollusks, annelids and arthropods are protostomers. Nails and cords are deuterostomers.
The mantle encloses the mantle cavity that houses the gills (if any), excretory spores, ■■■■ and gonadal pores. Mollusks are limited to the area around the systemic heart. The main body cavity is a hemocele. Many mollusks have a radula near the mouth which is used to scrape food.
The two plates separated about 600 million years ago. Protostomies have evolved in more than a million living species today compared to approximately 60,000 types of deuterostomes. Protostomes are divided into Ecdysozoa, for example, arthropods, Spiralia nematodes, for example, mollusks, annelids, flatworms and rotifers.
The Protosteam group includes an incredible variety of animals. The most common protostomes include tapeworms (such as tapeworms), roundworms (such as heartworms), mollusks (such as slugs and slugs), ringed animals (such as earthworms), and arthropods (spiders, insects, lobsters, ticks, feathers, and more!) .
The shell of molluscs has many functions, the main one of which is to close and protect the internal organs. The mantle leaves room in the body for the mollusk of the mantle cavity, which traps air or water and serves as a method of breathing.
Origin and development. Most animals, more complex than jellyfish and other cnidarians, are divided into two groups, protostomes and deuterostomes. Chordates (including all vertebrates) are deuterostomers. It seems likely that Kimberella, 555 million years old, was a member of the protostomies.
With over 110,000 described species, Phylum Mollusca is the second most diverse phylum after Arthropoda. Mollusks can be primitively segmented, but all but monoplacophores do not have a characteristic segmentation and have bodies that are spiral (e.g., twisted) to some degree.
Mollusks are probably most closely related to organisms from the Annelidae phylum, also known as segmented worms. However, unlike segmented worms, mollusks do not have body segmentation. The basic shape of mollusks is also usually very different.
In a deuterostomy, the first cavity formed by the blastopore ends with the ■■■■ of the organisms, while the mouth is secondarily formed on the other side. This is the next big difference between deuterostomes and protostomes: the protostomes form the mouth from the primary cavity and the second from the ■■■■.
ANSWER: Mollusks thrive on annelids because they have clear heads, better senses, and gills or lungs for breathing. Both evidence suggests that the mollusks originated from annelid worms.
Chitons are mollusks and are related to snails and slugs (snails), clams and oysters (thistles) and squid and squid (squid). Within the Mollusca tribe, chitons belong to a specific group known as Polyplacophora.
Annelider has two groups of muscles that are used to contract and stretch the body. Annelidorms are prime examples of a coelom-shaped hydrostatic skeleton in action. In earthworms, the hydrostatic skeleton or coelom is surrounded by sheaths with longitudinal and circular muscles.
Annelids are bilaterally symmetrical, triploblastic, coelomate invertebrates. They also have parapods to help you move. Annelider is considered a member of the Lophotrochozoa, a protostomeric superfilum that also includes mollusks, brachiopods, and nemerta.
Pseudocelomats originate from body cavities, partly from the endodermal tissue and partly from the mesoderm. Nematodes, not annelids, are pseudocoelomatic. Coelom is represented in Les Annélides.
Bilateria are all animals that have bilateral symmetry, that is, they have a front and a back, and an above and a below. Most Bilateria embryos have three different cotyledons called the endoderm, mesoderm, and ectoderm. From there they are called triploblastics.
The simplest animals with bilateral symmetry and triploblastic (consisting of three layers of basal cells) are flatworms, tapeworms. Planarians are free-flowing flatworms and have a much simpler life story. They live in fresh water and are carnivorous (even toothless) or carnivorous.
Body cavity type (coelom): tapeworms are Akoelome, have three cotyledons but no coelom. Nematodes are pseudocoolomatic, they have a cavity that forms between the mesoderm and the endoderm. Segmented worms are coelomates, they have a real coelom that forms in the mesoderm.