Maldanidae

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Maldanidae
Maldane adunca illustration.jpg
Maldane adunca
Scientific classification OOjs UI icon edit-ltr.svg
Domain: Eukaryota
Kingdom: Animalia
Phylum: Annelida
Clade: Pleistoannelida
Clade: Sedentaria
Clade: Maldanomorpha
Family: Maldanidae
Malmgren 1867
Subfamilies

Maldanidae is a family of more than 200 species of marine polychaetes commonly known as bamboo worms or maldanid worms. [1] [2] They belong to the order Capitellida, in the phylum Annelida. [3] They are most closely related to family Arenicolidae, and together form the clade Maldanomorpha. [1]

Contents

Morphology

Maldanid worms have a long and cylindrical body that usually bends at one or both ends. It can be divided into four parts: 1) a head, formed by a dorsally positioned prostomium that is fused to the peristomium, sometimes with a flattened cephalic plate; 2) a thorax, formed by the first four chaetigers (i.e. chaetae-bearing segments), usually with strong spines; 3) an abdomen, with several longer chaetigers that are often followed by a number of achaetous (i.e. without chaetae) segments; 4) a posterior end, with a pygidium that contains the anus. The maldanid pygidium takes a wide variety of forms such as conical, plate-shaped and funnel-shape. Sometimes a few prepygidial (i.e. anterior to the pygidium) segments can be observed. [2]

The parapodia are generally biramous, with elongated median chaetigers. The notochaetae appear as various forms of capillaries, while the neurochaetae appear as various forms of uncini (i.e. hook-like structures), sometimes replaced by acicular (i.e. needle-like) spines in some anterior segments. [2]

Ecology

Habitat

Species of maldanid worms are distributed in all marine regions of Earth, from the intertidal regions to deep waters. Some species inhabit estuarine areas, and some species have been seen living on hydrothermal vents. They are benthic creatures that build tubes made of mineral particles of diverse sizes and textures; these tubes are fixed to stones, shells, algal holdfasts, mud or sandbanks through a thin and transparent matrix of mucus that is produced after the end of the larval period. Several species build tubes under rocks forming horizontal galleries, or vertical galleris in sand or mud at the bottom of estuaries. [2]

Nutrition

They consume organic material, mostly composed of detritus, although diatoms and protozoans have been seen in the gut of some species. Most of them are head-down feeders that transport sediments upward from below the ocean floor surface. However some species have been observed dragging surface material down their tube into a feeding cavity. During feeding, the worms extend a papillae-covered globular proboscis through an increase of the coelomic pressure in the first four chaetigers. An enhanced bacterial growth observed within the tube wall of one species, Maldane sarsi , might also be a source of nutrition. Another species, Praxillura maculata , bears stiff particle-collecting spikes attached to the tube's end to collect algae and organic particles and transport them to the gut. [2]

Reproduction

Maldanid worms are gonochoristic and present a variety of reproductive modes. Some species spawn their gametes into seawater, where fertilization occurs; others may incubate eggs in the tube or directly until the development of larvae. [2]

They are capable of both anterior and posterior regeneration after suffering damage due to their fragile and easily fragmented bodies, and at least one species that reproduces asexually has been described. [2]

Embryonic development

Like other invertebrates in the clade Spiralia, bamboo worms undergo spiral cleavage during their early development. The larvae have a prototroch, neurotroch and telotroch, as is common in many polychaetes. The larval period is short, and the larval development is either lecithotrophic (i.e. with a yolk sac attached for nutrition) or direct (i.e. having to feed independently). [2]

Phylogeny

Maldanidae and Arenicolidae are united by the clade Maldanomorpha inside of Capitellida, an order of polychaetes in the phylum Annelida. [1] According to a phylogeny based on morphological data from 2011, several of the subfamilies inside Maldanidae are united under a clade called 'Maldanoplaca'. Members of this clade would be united by the evolution of the pygidium into an anal plate. [1]

Maldanidae

However, a molecular phylogeny in 2018 reveals that both Maldanoplaca and the subfamily Euclymeninae are paraphyletic. [4]

Maldanidae

Classification

The complete classification of bamboo worms accounts for 6 subfamilies, 38 genera and around 261 species. [2]

Related Research Articles

<i>Nereis</i> Genus of annelid worms

Nereis is a genus of polychaete worms in the family Nereididae. It comprises many species, most of which are marine. Nereis possess setae and parapodia for locomotion and gas exchange. They may have two types of setae, which are found on the parapodia. Acicular setae provide support. Locomotor setae are for crawling, and are the bristles that are visible on the exterior of the Polychaeta. They are cylindrical in shape, found not only in sandy areas, and they are adapted to burrow. They often cling to seagrass (posidonia) or other grass on rocks and sometimes gather in large groups.

<span class="mw-page-title-main">Nereididae</span> Family of annelid worms

Nereididae are a family of polychaete worms. It contains about 500 – mostly marine – species grouped into 42 genera. They may be commonly called ragworms or clam worms.

<span class="mw-page-title-main">Terebellidae</span> Family of annelid worms

The Terebellidae is a marine family of polychaete worms, of which the type taxon is Terebella, described by Carl Linnaeus in his 1767 12th edition of Systema Naturae.

<i>Eunice</i> (annelid) Genus of worms

Eunice is a genus in the polychaete family Eunicidae. Individuals grow to a length of between 0.5 and 300 cm. Their bodies have multiple segments. They have two eyes and five tentacles. They have well-developed sense organs and relatively large brains. Their color is dark purple-brown to red-brown with a white ring at the fourth segment. They are found in oceans and seas around the world. They have an evertible proboscis with distinctive mouthparts, some of which comprise two rows of maxilliary plates in a radula-like fashion.

<i>Ampharetinae</i> Subfamily of annelids

Ampharetinae are a subfamily of terebellid "bristle worm". They are the largest subfamily of the Ampharetidae, of which they contain the great majority of the described genera.

Rhodine is a genus of capitellid segmented worms in the family Maldanidae.

<i>Phyllodoce</i> (annelid) Genus of annelids

Phyllodoce is a genus of polychaete worms, which contains about 200 species. The prostomium bears eyes, two pairs of antennae and a pair of large retractile nuchal organs. The eversible proboscis is clearly divided into two parts.

<span class="mw-page-title-main">Cirratulidae</span> Family of annelid worms

Cirratulidae is a family of marine polychaete worms. Members of the family are found worldwide, mostly living in mud or rock crevices. Most are deposit feeders, but some graze on algae or are suspension feeders. Although subject to multiple revisions over time, cirratulids are among the few polychaete clades with a verified fossil record.

<span class="mw-page-title-main">Scolecida</span> Subclass of annelid worms

Scolecida is an infraclass of polychaete worms. Scolecids are mostly unselective deposit feeders on marine detritus.

<i>Diopatra</i> Genus of annelid worms

Diopatra is a genus of polychaete worms in the family Onuphidae.

<span class="mw-page-title-main">Amphinomidae</span> Family of annelids

Amphinomidae, also known as the fireworms, bristle worms or sea mice, are a family of marine polychaetes, many species of which bear chaetae mineralized with carbonate. The best-known amphinomids are the fireworms, which can cause great pain if their toxin-coated chaetae are touched or trodden on. Their relationship to other polychaete groups is somewhat poorly resolved.

<i>Cirriformia</i> Genus of annelid worms

Cirriformia is a genus of marine polychaete worms in the family Cirratulidae.

<span class="mw-page-title-main">Phyllodocidae</span> Family of annelids

Phyllodocidae is a family of polychaete worms. Worms in this family live on the seabed and may burrow under the sediment.

<i>Eulalia</i> (annelid) Genus of annelids

Eulalia is a genus of polychaete worms.

<i>Lepidonotus</i> Genus of annelids


Lepidonotus is a genus of marine annelids in the family Polynoidae. The genus occurs globally and includes 80 species, usually found in shallow waters down to about 80 metres.

Rhodininae is a subfamily of marine polychaete worms in the family Maldanidae.

Lumbriclymeninae is a subfamily of marine polychaete worms in the family Maldanidae.

Notoproctus is a genus of marine polychaete worms in the family Maldanidae. It is the only member of the subfamily Notoproctinae.

Euclymene is a genus of polychaete bamboo worms in the family Maldanidae, first described by Addison Emery Verrill in 1900. The type species is Clymene amphistoma Lamarck, 1818, currently accepted as Euclymene amphistoma. The species Euclymene amphistoma is now unused because Verrill incorrectly changed the Euclymene type species to Clymene oerstedii

References

  1. 1 2 3 4 de Assis, José Eriberto; Christoffersen, Martin Lindsey (2011). "Phylogenetic relationships within Maldanidae (Capitellida, Annelida), based on morphological characters". Systematics and Biodiversity. 9 (3): 233–245. doi:10.1080/14772000.2011.604358.
  2. 1 2 3 4 5 6 7 8 9 Purschke G, Böggemann M, Schmidt-Rhaesa A, Westheide W, eds. (2021). Handbook of Zoology: Annelida. Vol. 3: Pleistoannelida, Sedentaria III and Errantia I. Walter de Gruyter GmbH & Co KG. ISBN   9783110291483.
  3. "Maldanidae". www.gbif.org. Retrieved 6 June 2021.
  4. Kobayashi, Genki; Goto, Ryutaro; Takano, Tsuyoshi; Kojima, Shigeaki (2018). "Molecular phylogeny of Maldanidae (Annelida): Multiple losses of tube-capping plates and evolutionary shifts in habitat depth". Molecular Phylogenetics and Evolution. 127: 332–344. doi:10.1016/j.ympev.2018.04.036. ISSN   1055-7903.