Cauloramphus disjunctus

Last updated

Cauloramphus disjunctus
Scientific classification
Kingdom:
Phylum:
Class:
Order:
Suborder:
Family:
Genus:
Species:
C. disjunctus
Binomial name
Cauloramphus disjunctus
Canu & Bassler, 1929 [1]

Cauloramphus disjunctus is a species of small colonial bryozoan found encrusting rocks in shallow parts of the sea near Japan. Fossils of this species have been found that date back a million years.

Contents

Description

Colonies of Cauloramphus disjunctus encrust rocks and grow to a diameter of about 1 cm (0.4 in). Each colony consists of a number of interlinked polyps with each individual reaching a length of about 0.5 mm (0.02 in). [2] The epidermis secretes a hard exoskeleton which protects and supports the trunks of the polyps and the whole colony resembles an encrusting lichen. Each polyp has a lophophore, a feeding organ with tentacles, which is extended to feed but can be everted and drawn back inside the trunk. [3] Each polyp is surrounded by a ring of protective spines which resemble eyelashes. The specific name "disjunctus" refers to the fact that the polyps are widely spaced but joined to neighbouring polyps through tubular channels, an unusual feature for this group of bryozoans. [2]

Distribution and habitat

Cauloramphus disjunctus is found in the seas off the north east coast of Honshu, Japan, from Kushiro southwards to Sendai. It also occurs off the west coast of Honshu and Hokkaido in the Sea of Japan. It is a little-studied species and grows as dwarf mats on the underside of pebbles. There is a quarry at Kuromatsunai on Hokkaido which is a rich source of well-preserved bryozoan fossils, including this species, dating back to the Pleistocene. [2]

Biology

Cauloramphus disjunctus is a filter feeder, extending its lophophore to catch phytoplankton. These are drawn into the mouth by the creation of a current of water and trapped by the tentacles. [3]

Most bryozoans are hermaphrodites and produce large, yolky eggs. [3] The embryos of Cauloramphus disjunctus are brooded in individual chambers surrounding the polyps and are liberated into the sea when mature. These larvae settle on the seabed within a few hours to found new colonies. [2]

Evolution

Bryozoans similar to Cauloramphus disjunctus have been found dating back 100 million years. At that time short, widely spaced spines had already evolved to protect the feeding polyps from predators. Since then, the spines have gradually become more numerous and angled inwards and now present an effective grid through which most predators cannot penetrate but which still allow the polyps to feed. Another defensive mechanism that has developed over the years is avicularia, non-feeding polyps with jaws that can fight back against predators. Both the avicularia and the spines are believed to be modified polyps. As this is a colonial species, the avicularia receive their nourishment from neighbouring feeding polyps. [2] Fossils of this species one million years old are virtually identical to those animals that live today. [2] Some of these million year old fossils have been found with intact spines and avicularia. [4]

Related Research Articles

Bryozoa Phylum of marine invertebrates, moss animals

Bryozoa are a phylum of aquatic invertebrate animals, nearly all forming sedentary colonies. Typically about 0.5 millimetres long, they are filter feeders that sieve food particles out of the water using a retractable lophophore, a "crown" of tentacles lined with cilia. Most marine species live in tropical waters, but a few occur in oceanic trenches, and others are found in polar waters. One class lives only in freshwater environments, and a few members of a mostly marine class prefer brackish water. 5869 living species are known. One genus is solitary and the rest are colonial.

Entoprocta A phylum of aquatic invertebrates

Entoprocta, whose name means "rectum/anus inside", or Kamptozoa, is a phylum of mostly sessile aquatic animals, ranging from 0.1 to 7 millimetres long. Mature individuals are goblet-shaped, on relatively long stalks. They have a "crown" of solid tentacles whose cilia generate water currents that draw food particles towards the mouth, and both the mouth and anus lie inside the "crown". The superficially similar Bryozoa (Ectoprocta) have the anus outside a "crown" of hollow tentacles. Most families of entoprocts are colonial, and all but 2 of the 150 species are marine. A few solitary species can move slowly.

Anthozoa A class of cnidarians without a medusa stage

Anthozoa is a class of marine invertebrates which includes the sea anemones, stony corals and soft corals. Adult anthozoans are almost all attached to the seabed, while their larvae can disperse as part of the plankton. The basic unit of the adult is the polyp; this consists of a cylindrical column topped by a disc with a central mouth surrounded by tentacles. Sea anemones are mostly solitary, but the majority of corals are colonial, being formed by the budding of new polyps from an original, founding individual. Colonies are strengthened by calcium carbonate and other materials and take various massive, plate-like, bushy or leafy forms.

Cheilostomatida Order of moss animals

Cheilostomatida is an order of Bryozoa in the class Gymnolaemata.

<i>Membranipora membranacea</i> Species of moss animal

Membranipora membranacea is a very widely distributed species of marine bryozoan known from the Atlantic and Pacific Oceans, usually in temperate zone environments. This bryozoan is a colonial organism characterized by a thin, mat-like encrustation, white to gray in color. It may be known colloquially as the sea-mat or lacy crust bryozoan and is often abundantly found encrusting seaweeds, particularly kelps.

Cyclostomatida Order of moss animals

Cyclostomatida, or cyclostomes, are an ancient order of stenolaemate bryozoans which first appeared in the Lower Ordovician. It consists of 7+ suborders, 59+ families, 373+ genera, and 666+ species. The cyclostome bryozoans were dominant in the Mesozoic; since that era, they have decreased. Currently, cyclostomes seldom constitute more than 20% of the species recorded in regional bryozoan faunas.

Phoronid Phylum of marine animals, horseshoe worms

Phoronids are a small phylum of marine animals that filter-feed with a lophophore, and build upright tubes of chitin to support and protect their soft bodies. They live in most of the oceans and seas, including the Arctic Ocean but excluding the Antarctic Ocean, and between the intertidal zone and about 400 meters down. Most adult phoronids are 2 cm long and about 1.5 mm wide, although the largest are 50 cm long.

Brachiopod Phylum of marine animals also known as lamp shells

Brachiopods, phylum Brachiopoda, are a group of lophotrochozoan animals that have hard "valves" (shells) on the upper and lower surfaces, unlike the left and right arrangement in bivalve molluscs. Brachiopod valves are hinged at the rear end, while the front can be opened for feeding or closed for protection. Two major groups are recognized, articulate and inarticulate. The word "articulate" is used to describe the tooth-and-groove features of the valve-hinge which is present in the articulate group, and absent from the inarticulate group. This is the leading diagnostic feature (fossilizable), by which the two main groups can be readily distinguished. Articulate brachiopods have toothed hinges and simple opening and closing muscles, while inarticulate brachiopods have untoothed hinges and a more complex system of muscles used to keep the two valves aligned. In a typical brachiopod a stalk-like pedicle projects from an opening in one of the valves near the hinges, known as the pedicle valve, keeping the animal anchored to the seabed but clear of silt that would obstruct the opening.

<i>Parazoanthus axinellae</i>

Parazoanthus axinellae, commonly known as the yellow cluster anemone, is a zoanthid coral found on the southern Atlantic coasts of Europe and in the Mediterranean Sea. Zoanthids differ from true sea anemones, in having a different internal anatomy and in forming true colonies in which the individual animals (polyps) are connected by a common tissue, called the coenenchyme.

<i>Flustra foliacea</i> Species of moss animal

Flustra foliacea is a species of bryozoans found in the northern Atlantic Ocean. It is a colonial animal that is frequently mistaken for a seaweed. Colonies begin as encrusting mats, and only produce loose fronds after their first year of growth. They may reach 20 cm (8 in) long, and smell like lemons. Its microscopic structure was examined by Robert Hooke and illustrated in his 1665 work Micrographia.

Fossils of many types of water-dwelling animals from the Devonian period are found in deposits in the U.S. state of Michigan. Among the more commonly occurring specimens are bryozoans, corals, crinoids, and brachiopods. Also found, but not so commonly, are armored fish called placoderms, snails, sharks, stromatolites, trilobites and blastoids.

<i>Siderastrea radians</i>

Siderastrea radians, also known as the lesser starlet coral or the shallow-water starlet coral, is a stony coral in the family Siderastreidae. It is found in shallow parts of the western Atlantic Ocean as small, solid mounds or encrusting sheets.

Zoobotryon verticillatum, commonly known as the spaghetti bryozoan, is a species of colonial bryozoans with a bush-like structure. It is found in shallow temperate and warm waters in the western Atlantic Ocean and the Caribbean Sea and has spread worldwide as a fouling organism. It is regarded as an invasive species in some countries.

Conopeum seurati is a species of colonial bryozoan in the order Cheilostomatida. It is native to the northeastern Atlantic Ocean, the North Sea and the Mediterranean Sea. This species has been introduced to New Zealand and Florida.

<i>Electra pilosa</i> Species of moss animal

Electra pilosa is a species of colonial bryozoan in the order Cheilostomatida. It is native to the northeastern and northwestern Atlantic Ocean and is also present in Australia and New Zealand.

<i>Cryptosula pallasiana</i> Species of moss animal

Cryptosula pallasiana is a species of colonial bryozoan in the order Cheilostomatida. It is native to the Atlantic Ocean where it occurs in northwestern Europe and northern Africa, and the eastern seaboard of North America. It has been accidentally introduced to the western coast of North America and to other parts of the world.

<i>Watersipora subtorquata</i> Species of moss animal

Watersipora subtorquata, commonly known as the red-rust bryozoan, is a species of colonial bryozoan in the family Watersiporidae. It is unclear from where it originated but it is now present in many warm-water coastal regions throughout the world, and has become invasive on the west coast of North America and in Australia and New Zealand.

<i>Oxypora lacera</i>

Oxypora lacera, the ragged chalice coral or porous lettuce coral, is a species of large polyp stony corals in the family Lobophylliidae. It is a colonial coral which can be submassive, encrusting or laminar. It is native to the western Indo-Pacific.

<i>Beania magellanica</i> Species of bryozoan

Beania magellanica is a species of colonial bryozoan in the family Beaniidae. It has a cosmopolitan distribution, occurring in shallow waters in the Atlantic and Pacific Oceans and in Antarctica.

Callopora lineata is a species of colonial bryozoan in the family Calloporidae. It is found on rocky shores in the Atlantic Ocean and the Mediterranean Sea.

References

  1. Bock, P (2012). "Cauloramphus disjunctus Canu & Bassler, 1929". WoRMS. World Register of Marine Species . Retrieved 2012-12-28.
  2. 1 2 3 4 5 6 Taylor, Paul. "Cauloramphus disjunctus". Natural History Museum. Retrieved 2012-12-28.
  3. 1 2 3 Ruppert, Edward E; Fox, Richard S; Barnes, Robert D (2004). Invertebrate Zoology (7th edition). Cengage Learning. pp. 831–841. ISBN   81-315-0104-3.
  4. "Cauloramphus disjunctus: Distribution and habitat". The Natural History Museum. Retrieved 2012-12-30.