| Beroe gracilis | |
|---|---|
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Ctenophora |
| Class: | Nuda |
| Order: | Beroida |
| Family: | Beroidae |
| Genus: | Beroe |
| Species: | B. gracilis |
| Binomial name | |
| Beroe gracilis | |
Beroe gracilis is a species of comb jelly in the family Beroidae. It is a free-swimming species found in the North Sea, the Atlantic Ocean and the Mediterranean Sea.
Beroe gracilis is a translucent, elongated, hollow, cylindrical animal with a maximum length of about 4 cm (1.6 in). Like the other members of the family Beroidae, it has no tentacles. The anterior end, with the gaping mouth at its tip, is slightly broader than the closed, posterior end. At the posterior end there is a statocyst, a flattened structure shaped like a figure-of-eight. From this, eight rows of combs with cilia radiate and extend three-quarters of the way along the body wall; it is the beating of these cilia that drive the animal forward, and their movement creates characteristic multicoloured sparkles. The general colour of the body wall is slightly milky, sometimes bluish or pinkish. The gut and its diverticula can be seen through the body wall. [2] [3]
Beroe gracilis occurs in the northeastern Atlantic Ocean, the North Sea, and the Mediterranean Sea, its range extending from Norway to Morocco, and also periodically in the Baltic Sea. It also occurs in the northeastern Pacific Ocean and cold deep waters off the Bahamas. In 1989 and 1990, and again in 2013, specimens were collected in the southeastern Pacific Ocean, off the coast of Chile, the first records from the Southern Hemisphere. [4] This comb jelly forms part of the nekton, animals that actively swim rather than passively drift like plankton, and usually occurs in the top 100 m (330 ft) of the water column. [3]
Beroe gracilis is a voracious predator, feeding almost exclusively on other comb jellies, such as Pleurobrachia pileus . It swims rapidly with its mouth open wide, drawing prey into its pharynx, and processing it with the help of specialised cilia; digestion is extracellular and takes place in the body cavity. [3] The warty comb jelly Mnemiopsis leidyi has become invasive in European waters, and sometimes forms blooms in the North Sea and Baltic Sea; Beroe gracilis has been found to readily prey on M. leidyi, but was limited in controlling the alien species by being unable to ingest prey approaching its own size. Larger individuals of M. leidyi were sometimes partially consumed. [5]
Ctenophora comprise a phylum of invertebrate animals that live in marine waters worldwide. They are notable for the groups of cilia they use for swimming, and they are the largest animals to swim with the help of cilia. Depending on the species, adult ctenophores range from a few millimeters to 1.5 m (5 ft) in size. Only 100 to 150 species have been validated, and possibly another 25 have not been fully described and named. The textbook examples are cydippids with egg-shaped bodies and a pair of retractable tentacles fringed with tentilla that are covered with colloblasts, sticky cells that capture prey. Their bodies consist of a mass of jelly, with a layer two cells thick on the outside, and another lining the internal cavity. The phylum has a wide range of body forms, including the egg-shaped cydippids with retractable tentacles that capture prey, the flat generally combless platyctenids, and the large-mouthed beroids, which prey on other ctenophores.
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.
Beroidae is a family of ctenophores or comb jellies more commonly referred to as the beroids. It is the only family within the monotypic order Beroida and the class Nuda. They are distinguished from other comb jellies by the complete absence of tentacles, in both juvenile and adult stages. Species of the family Beroidae are found in all the world's oceans and seas and are free-swimmers that form part of the plankton.
The European sprat, also known as bristling, brisling, garvie, garvock, Russian sardine, russlet, skipper or whitebait, is a species of small marine fish in the herring family Clupeidae. Found in European waters, it has silver grey scales and white-grey flesh. Specific seas in which the species occurs include the Irish Sea, Black Sea, Baltic Sea and Sea of the Hebrides. The fish is the subject of fisheries, particularly in Scandinavia, and is made into fish meal, as well as being used for human consumption. When used for food it can be canned, salted, breaded, fried, boiled, grilled, baked, deep fried, marinated, broiled, and smoked.
Mnemiopsis leidyi, the warty comb jelly or sea walnut, is a species of tentaculate ctenophore. It is native to western Atlantic coastal waters, but has become established as an invasive species in European and western Asian regions. Three species have been named in the genus Mnemiopsis, but they are now believed to be different ecological forms of a single species M. leidyi by most zoologists.
Phacellophora camtschatica, commonly known as the fried egg jellyfish or egg-yolk jellyfish, is a very large jellyfish in the family Phacellophoridae. This species can be easily identified by the yellow coloration in the center of its body which closely resembles an egg yolk, hence how it got its common name. Some individuals can have a bell close to 60 cm (2 ft) in diameter, and most individuals have 16 clusters of up to a few dozen tentacles, each up to 6 m (20 ft) long. A smaller jellyfish, Cotylorhiza tuberculata, typically found in warmer water, particularly in the Mediterranean Sea, is also popularly called a fried egg jellyfish. Also, P. camtschatica is sometimes confused with the Lion's mane jellyfish.
Cydippida is an order of comb jellies. They are distinguished from other comb jellies by their spherical or oval bodies, and the fact their tentacles are branched, and can be retracted into pouches on either side of the pharynx. The order is not monophyletic, that is, more than one common ancestor is believed to exist.
Pleurobrachia bachei is a member of the phylum Ctenophora and is commonly referred to as a sea gooseberry. These comb jellies are often mistaken for medusoid Cnidaria, but lack stinging cells.
Mertensia ovum, also known as the Arctic comb jelly or sea nut, is a cydippid comb jelly or ctenophore first described as Beroe ovum by Johan Christian Fabricius in 1780. Unusually among ctenophores, which normally prefer warmer waters, it is found in the Arctic and adjacent polar seas, mostly in surface waters down to 50 metres (160 ft).
Neosabellaria cementarium is a species of marine tube worm in the family Sabellariidae, perhaps better known by its previous name, Sabellaria cementarium. It is found in the North Pacific Ocean.
Beroe, commonly known as the cigar comb jellies, is a genus of comb jellies in the family Beroidae. Beroe exhibits bioluminescence.
Beroe ovata is a comb jelly in the family Beroidae. It is found in the South Atlantic Ocean and the Mediterranean Sea and has been introduced into the Black Sea, the Aegean Sea, the Sea of Azov and the Caspian Sea. It was first described by the French physician and zoologist Jean Guillaume Bruguière in 1789.
Beroe cucumis is a species of comb jelly in the family Beroidae. It is found in the Atlantic Ocean. It was first described by the Danish missionary and naturalist Otto Fabricius in 1780.
Bolinopsis infundibulum, commonly known as the common northern comb jelly, is a species of comb jelly in the family Bolinopsidae. It is found in the northern Atlantic Ocean and was first described by the Danish naturalist Otto Friedrich Müller in 1776.
Pleurobrachia pileus is a species of comb jelly, commonly known as a sea gooseberry. It is found in open water in the northern Atlantic Ocean, the North Sea, the Baltic Sea and the Black Sea, and was first described by the Danish zoologist Otto Friedrich Müller in 1776.
Parasagitta setosa is a small arrow worm in the family Sagittidae, previously referred to as Sagitta setosa. It is native to the northeastern Atlantic Ocean, the North Sea and the Mediterranean Sea, and also occurs in the Baltic Sea and the Black Sea.
Edwardsiella lineata, the lined anemone, is a species of sea anemone in the family Edwardsiidae. It is native to the northwestern Atlantic Ocean where it occurs in the subtidal zone.
Coeloplana astericola, the creeping comb jelly, is a species of benthic comb jelly from the tropical western Indo-Pacific region that lives as an episymbiont on starfish such as Echinaster luzonicus.
The dispersal of invasive species by ballast water refers to the unintentional introduction of invasive species to new habitats via the ballast water carried by commercial shipping vessels. Ballast water spreads an estimated 7000 living species to new habitats across the globe. These species can affect the ecological balance of their new regions by outcompeting native species or otherwise impacting native ecosystems.
Beroe abyssicola is a beroid ctenophore, or comb jelly, in the genus Beroe. It is largely found in deep waters in the North Pacific Ocean, and is common in Japan and the Arctic Ocean. A predator, Beroe feeds mostly on other ctenophores by swallowing them whole. Like other ctenophores, B. abyssicola has a simple nervous system in the form of a nerve net, which it uses to direct its movement, feeding, and hunting behaviors.