The Naididae (including the former family Tubificidae) are a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

clitellate The Clitellata are a class of annelid worms, characterized by having a clitellum - the 'collar' that forms a reproductive cocoon during part of their life cycles. The clitellates comprise around 8,000 species. Unlike the class of Polychaeta, the ...

oligochaete Oligochaeta () is a subclass of animals in the phylum Annelida, which is made up of many types of aquatic and terrestrial worms, including all of the various earthworms. Specifically, oligochaetes comprise the terrestrial megadrile earthworms ...

worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in size from microscopic to over in length for marine polychaete wor ...

s like the sludge worm, ''

Tubifex tubifex ''Tubifex tubifex,'' also called the sludge worm, "Boogie Worm", or sewage worm, is a species of tubificid segmented worm which inhabits the sediments of lakes and rivers on several continents. ''Tubifex'' probably includes several species, but ...

''. They are key components of the

benthic The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "t ...

communities of many

freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include ...

and

marine Marine is an adjective meaning of or pertaining to the sea or ocean. Marine or marines may refer to: Ocean * Maritime (disambiguation) * Marine art * Marine biology * Marine debris * Marine habitats * Marine life * Marine pollution Military * ...

ecosystem An ecosystem (or ecological system) consists of all the organisms and the physical environment with which they interact. These biotic and abiotic components are linked together through nutrient cycles and energy flows. Energy enters the syste ...

s. In freshwater aquaria they may be referred to as detritus worms.

Description

These worms can vary in size, from centimeters to millimeters, depending on the subfamily. They are all

hermaphroditic In reproductive biology, a hermaphrodite () is an organism that has both kinds of reproductive organs and can produce both gametes associated with male and female sexes. Many taxonomic groups of animals (mostly invertebrates) do not have separ ...

and lack a larval stage.

Taxonomy

Analysis of

18S rDNA 18S ribosomal RNA (abbreviated 18S rRNA) is a part of the ribosomal RNA. The S in 18S represents Svedberg units. 18S rRNA is an SSU rRNA, a component of the eukaryotic ribosomal small subunit ( 40S). 18S rRNA is the structural RNA for the small ...

sequences revealed that the tradition family Tubificidae is not

monophyletic In cladistics for a group of organisms, monophyly is the condition of being a clade—that is, a group of taxa composed only of a common ancestor (or more precisely an ancestral population) and all of its lineal descendants. Monophyletic gro ...

, with the traditionally circumscribed Naididae nested within tubidicid taxa. To avoid

paraphyly In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In co ...

the naidid and tubificid taxa were included in a combined family, which took the name Naididae because it has priority under ''

International Code of Zoological Nomenclature The International Code of Zoological Nomenclature (ICZN) is a widely accepted convention in zoology that rules the formal scientific naming of organisms treated as animals. It is also informally known as the ICZN Code, for its publisher, the ...

'' rules as the

senior synonym The Botanical and Zoological Codes of nomenclature treat the concept of synonymy differently. * In botanical nomenclature, a synonym is a scientific name that applies to a taxon that (now) goes by a different scientific name. For example, Linnae ...

of Tubificidae. A proposal to the

International Commission on Zoological Nomenclature The International Commission on Zoological Nomenclature (ICZN) is an organization dedicated to "achieving stability and sense in the scientific naming of animals". Founded in 1895, it currently comprises 26 commissioners from 20 countries. Orga ...

to suppress Naididae, because the "tubificids" are the more well-known group of the two, was rejected. The family Naididae is divided into six subfamilies, arranged here in the presumed

phylogenetic In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...

sequence: *

Tubificinae Tubificinae is a subfamily of annelids belonging to the family Naididae. The following genera are assigned to Tubificinae: * '' Baltidrilus'' Timm, 2013 * '' Christerius'' Holmquist, 1985 * '' Clitellio'' Savigny, 1822 * '' Ilyodrilus'' Eisen, ...

Eisen, 1879, containing (among others) the genus ''

Tubifex ''Tubifex'' is a cosmopolitan genus of tubificid annelids that inhabits the sediments of lakes, rivers and occasionally sewer lines. At least 13 species of ''Tubifex'' have been identified, with the exact number not certain, as the species are ...

'' * Naidinae Ehrenberg, 1828 * Telmatodrilinae Eisen, 1879 *

Limnodriloidinae Limnodriloidinae is a subfamily of clitellate oligochaete worms. Species The following genera are currently recognized within Limnodriloidinae: * '' Doliodrilus'' Erséus, 1984 * ''Limnodriloides'' Pierantoni, 1903 * '' Parakaketio'' Erséus, ...

Erséus, 1982 *

Phallodrilinae Phallodrilinae is a subfamily of clitellate oligochaete worm Worms are many different distantly related bilateral animals that typically have a long cylindrical tube-like body, no limbs, and no eyes (though not always). Worms vary in s ...

Brinkhurst, 1971 * Pristininae Lastočkin, 1921, often included in Naidinae *

Rhyacodrilinae Rhyacodrilinae is a subfamily of clitellate oligochaete worms in the family Naididae. Species The World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative a ...

Hrabě, 1963

Presence in aquariums

In an

aquarium An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aq ...

, numbers of naididae can increase rapidly. When their population becomes high, the worms migrate toward the surface of the water for access to higher concentrations of oxygen. Although detritus worms may not cause harm to aquarium fish, their appearance is an indication of poor water quality mainly due to overfeeding and lack of good water sanitation. Improvement of water quality, filtration, gravel cleaning, and the reduction of feeding, may be performed to bring detritus worm population back to normal. Detritus worms feed on excess food and waste, thereby contributing to the ecosystem of an aquarium.

Gallery

File:Tubifex02.jpg,

in sediment File:Naididae.jpg, Naididae in sediment - subject from Muddy River, Boston File:Naididae swimming 2.jpg, Naididae swimming - subject from Muddy River, Boston File:Naididae swimming.jpg, Naididae swimming - subject from Muddy River, Boston

References

Annelid families {{annelid-stub