| Walkeria uva | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Bryozoa |
| Class: | Gymnolaemata |
| Order: | Ctenostomatida |
| Family: | Walkeriidae |
| Genus: | Walkeria |
| Species: | W. uva |
| Binomial name | |
| Walkeria uva | |
| Synonyms [1] | |
| |
Walkeria uva is a species of colonial bryozoan in the order Ctenostomatida. It occurs on either side of the Atlantic Ocean, in the Baltic Sea, in the Mediterranean Sea and in the Indo-Pacific region.
Walkeria uva is a colonial bryozoan that has thread-like stolons that creep across the substrate from which small clusters of zooids grow. The zooids have no stalks and are ovoid or tubular, growing direct from the stolon which seldom branches. There are up to ten zooids in each group, and the zooids are tipped by a bulge from which a pair of short lateral branches grow at right-angles. The whole colony is only about 2 to 4 cm (0.8 to 1.6 in) across. The colour is light beige or pale grey. The colonies are so small and inconspicuous that they may only be discovered by chance when the seaweed on which they are growing is examined in the laboratory. [2]
Walkeria uva occurs on either side of the Atlantic Ocean, in the Baltic Sea, the Mediterranean Sea, the Indian Ocean and the South China Sea. It is one of a number of creeping and low-growing bryozoans that are common on hard substrates in the lower tidal and shallow subtidal zones. It often grows on red or brown algae, such as Cystoseira , Corallina officinalis and Halidrys siliquosa or on other bryozoans, and is often associated with Bowerbankia spp.. There are two forms, one is more erect and is found near the tip of algal fronds in habitats where there is little sediment, and the other is more prostrate, and found on various red or brown algae fronds in muddy habitats. It is possible that these two forms are in fact different species. [2]
Like other bryozoans, Walkeria uva has a crown of eight tentacles called a lophophore which can be extended to catch phytoplankton, bacteria and other minute particles floating past. Cilia on the tentacles actively move the water around to promote feeding. The colony grows by the budding of new zooids at the tips of the stolons. The colony is hermaphrodite; male zooids liberate sperm into the water which the female zooids draw in, retaining their eggs and brooding the embryos. When sufficiently developed the larvae are discharged into the water column, and after a short planktonic phase, settle on a suitable substrate and undergo metamorphosis into primary or ancestral zooids. This bryozoan has an overwintering, spherical form that develops in the autumn, and returns to normal growth when the water warms up in the following spring. [2]
Bryozoa are a phylum of simple, aquatic invertebrate animals, nearly all living in sedentary colonies. Typically about 0.5 millimetres long, they have a special feeding structure called a lophophore, a "crown" of tentacles used for filter feeding. Most marine bryozoans live in tropical waters, but a few are found in oceanic trenches and polar waters. The bryozoans are classified as the marine bryozoans (Stenolaemata), freshwater bryozoans (Phylactolaemata), and mostly-marine bryozoans (Gymnolaemata), a few members of which prefer brackish water. 5,869 living species are known. Originally all of the crown group Bryozoa were colonial, but as an adaptation to a mesopsammal life or to deep‐sea habitats, secondarily solitary forms have since evolved. Solitary species has been described in four genera; Aethozooides, Aethozoon, Franzenella and Monobryozoon). The latter having a statocyst‐like organ with a supposed excretory function.
Entoprocta, 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.
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 coffin box, sea-mat or lacy crust bryozoan and is often abundantly found encrusting seaweeds, particularly kelps.
Cyclostomatida, or cyclostomata, 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.
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.
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.
Obelia longissima is a colonial species of hydrozoan in the order Leptomedusae. Its hydroid form grows as feathery stems resembling seaweed from a basal stolon. It is found in many temperate and cold seas world-wide but is absent from the tropics.
Perophora viridis, the honeysuckle tunicate, is a species of colonial sea squirt in the genus Perophora found in the tropical western Atlantic Ocean.
Amathia vidovici is a species of colonial bryozoans with a tree-like structure. It is found in shallow waters over a wide geographical range, being found in both the Atlantic and Pacific Oceans and adjoining seas.
Amathia verticillata, 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.
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.
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.
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.
Chorizopora brongniartii is a species of bryozoan in the family Chorizoporidae. It is an encrusting bryozoan, the colonies forming spreading patches. It has a widespread distribution in tropical and temperate seas.
Bicellariella ciliata is a species of bryozoan belonging to the family Bugulidae. It is found in shallow water on both sides of the Atlantic Ocean, the Mediterranean Sea and the Indo-Pacific region.
Crisularia plumosa is a species of bryozoan belonging to the family Bugulidae, commonly known as the feather bryozoan. It is native to the Atlantic Ocean.
Bugulina turbinata is a species of bryozoan belonging to the family Bugulidae. It is found in shallow water in the northeastern Atlantic Ocean and the Mediterranean Sea.
Bugulina flabellata is a species of bryozoan belonging to the family Bugulidae. It is found in shallow water in the northeastern Atlantic Ocean and the Mediterranean Sea.
Walkeria tuberosa is a species of colonial bryozoan in the order Ctenostomatida. It is native to the Mediterranean Sea, and has spread to the Red Sea and the Indo-Pacific region.