Information: - In biology, moulting (British English), or molting (American English), also known as sloughing, shedding, or in many invertebrates, ecdysis, is the manner in which an animal routinely casts off a part of its body (often, but not always, an outer layer or covering), either at specific times of the year, or at specific points in its life cycle. - Spirurida is an order of spirurian nematodes. Like all nematodes, they have neither a circulatory nor a respiratory system. - Ecdysozoa is a group of protostome animals, including Arthropoda (insects, chelicerata, crustaceans, and myriapods), nematoda, and several smaller phyla. They were first defined by Aguinaldo "et al." in 1997, based mainly on phylogenetic trees constructed using 18S ribosomal RNA genes. A large study in 2008 by Dunn "et al." strongly supported the Ecdysozoa as a clade, that is, a group consisting of a common ancestor and all its descendants. - Tetrameridae is a family of spirurian nematodes . It is the smallest of the large genera making up the bulk of the superfamily Habronematoidea . Like all nematodes , they have neither a circulatory nor a respiratory system . They are parasites , chiefly of birds and cetaceans . This family contains the largest known nematode : Placentonema gigantissima is several meters long and has been found in the placenta of the Sperm Whale ( Physeter catodon ) . - In biology, an organism is any contiguous living system, such as an animal, plant, fungus, archaeon, or bacterium. All known types of organisms are capable of some degree of response to stimuli, reproduction, growth and development and homeostasis. An organism consists of one or more cells; when it has one cell it is known as a unicellular organism; and when it has more than one it is known as a multicellular organism. Most unicellular organisms are of microscopic scale and are thus loosely described as microorganisms. Humans are multicellular organisms composed of many trillions of cells grouped into specialized tissues and organs. - The respiratory system (called also respiratory apparatus, ventilatory system) is a biological system consisting of specific organs and structures used for the process of respiration in an organism. The respiratory system is involved in the intake and exchange of oxygen and carbon dioxide between an organism and the environment. - In biology, a phylum (plural: phyla) is a taxonomic rank below kingdom and above class. Traditionally, in botany the term division was used instead of "phylum", although from 1993 the International Code of Nomenclature for algae, fungi, and plants accepted the designation "phylum". Depending on definitions, the kingdom Animalia contains approximately 35 phyla, Plantae contains about 12, and Fungi contains around 7. Current research in phylogenetics is uncovering the relationships between phyla, which are contained in larger clades, like Ecdysozoa and Embryophyta. - The nematodes or roundworms constitute the phylum Nematoda. They are a diverse animal phylum inhabiting a broad range of environments. Nematode species can be difficult to distinguish, and although over 25,000 have been described, of which more than half are parasitic, the total number of nematode species has been estimated to be about 1 million. Nematodes are classified along with insects and other moulting animals in the clade Ecdysozoa, and, unlike flatworms, have tubular digestive systems with openings at both ends. - Habronematoidea is a superfamily of spirurian nematodes in the large order Spirurida. Like all nematodes, they have neither a circulatory nor a respiratory system. - Subclass Spiruria comprises mostly parasitic secernentean nematodes. In an alternate classification, they are treated as suborder Spirurina, with the orders listed here being ranked as infraorders. What is the relationship between 'tetrameridae' and 'spirurida'?
A:
parent taxon