Non-Chordate Animals

Pontobdella is a genus of leeches (Hirudinea), which are highly modified annelids adapted for a parasitic lifestyle, showing significant reduction and specialization compared to other annelids.

Peripatus is a well-known member of the phylum Onychophora, often described as a living fossil. It exhibits characteristics of both Annelida (such as nephridia for excretion) and Arthropoda (such as a tracheal system).

Round worms (nematodes like Ascaris) are classic examples of endoparasites that live inside the human body. Mites and bed bugs are ectoparasites that live on the surface of the host.

Wuchereria bancrofti is a filarial nematode that is unsegmented and viviparous, meaning it gives birth to live young (microfilariae). Ascaris is oviparous, while Taenia and Fasciola are flatworms.

Planaria, liver flukes, and tapeworms all belong to the phylum Platyhelminthes, commonly known as flatworms. They are acoelomate and dorsoventrally flattened.

Botryoidal tissue is a characteristic feature found in the coelom of leeches, which are members of the phylum Annelida. It is thought to be involved in storage and excretion.

Humans contract Taenia solium infection by consuming undercooked pork containing the larval stage known as cysticercus (or bladder worm).

Flatworms like Taenia use specialized cells called flame cells (protonephridia) for osmoregulation and excretion. Malpighian bodies and green glands are found in arthropods.

Cysticercus is the larval stage of the tapeworm Taenia solium, which develops in the intermediate host (pig).

Obelia exhibits an alternation of generations (metagenesis) between the polyp stage and the medusa stage. Hydra exists only in the polyp form.

Polymorphism, the existence of different morphological forms (zooids) within a colony, is a characteristic feature of the class Hydrozoa (e.g., Physalia, Obelia).

Coelenterates (Cnidarians) are characterized by radial symmetry and a diploblastic body organization (ectoderm and endoderm).

Radial symmetry is common in sessile or sedentary animals where the body is organized around a central axis, often associated with a simple body plan where the alimentary canal has a single opening (blind sac body plan).

The bath sponge (Spongia) has a skeleton composed of spongin fibers. When the living tissue is removed and the sponge is dried, only the spongin fiber network remains.

Porocytes are specialized tubular cells in sponges that form the ostia, which are the incurrent pores allowing water to enter the body cavity.

Choanocytes (collar cells) are the defining feature of sponges, as they are unique to the phylum Porifera and are responsible for creating water currents and capturing food particles.

Corallium rubrum, commonly known as precious coral or red coral, is widely used in the jewelry industry.

Oriental sore (cutaneous leishmaniasis) is caused by the protozoan parasite Leishmania tropica.

The classification of sponges (Porifera) is primarily based on the composition and structure of their endoskeleton, which consists of spicules (calcareous or siliceous) or spongin fibers.

Trypanosoma brucei, the causative agent of African sleeping sickness, is transmitted to humans by the bite of an infected tsetse fly (Glossina).

Protozoa are classified into four main groups (Sarcodina, Mastigophora, Ciliophora, Sporozoa) primarily based on their locomotory organelles, such as pseudopodia, flagella, or cilia.

Sleeping sickness is transmitted by the tsetse fly, which belongs to the genus Glossina (e.g., Glossina palpalis).

Euglena is a unique protozoan that contains chloroplasts and can perform photosynthesis in the presence of light, making it an autotroph (or mixotroph).

Metagenesis is the alternation of generations between an asexual polyp phase and a sexual medusa phase, which is a hallmark of the life cycle of Obelia.

Trypanosoma gambiense is the causative agent of West African sleeping sickness.