| Kowalevskia | |
|---|---|
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Subphylum: | Tunicata |
| Class: | Appendicularia |
| Order: | Copelata |
| Family: | Kowalevskiidae Lahille, 1888 |
| Genus: | Kowalevskia Fol, 1872 |
| Synonyms | |
| |
Kowalevskia is a genus of larvacean tunicates, the only one in the family Kowalevskiidae. [1]
Kowalevskia is a small larvacean. In the adult, the body measures around 1 mm long, while the tail is 8 mm long, appearing stretched and tapered at its ends. [2] [3]
Unlike other Appendicularia species, Kowalevskia doesn't have a heart. Instead, the circulatory system is powered by the beating tail. [2]
Kowalevskia also lacks an endostyle, being replaced by a ciliated groove without glandular cells. [4] [5]
The spiracles also differ from other families, being shaped as long, narrow slits. [4]
Uniquely among larvaceans, Kowalevskia's house is ellipsoidal or toroidal in shape, 1 to 2 cm in diameter. It has a single opening, acting both as inlet and outlet. [3]
Both species of Kowalevskia have a wide distribution. K. tenuis can be found in the East Atlantic and West Pacific, as well as in the Mediterranean and Black Seas. Meanwhile, K. oceanica is found in the Mediterranean and North-East Atlantic, as well as in the Red Sea and West Indian Ocean. [3]
The monotypic Kowalevskiidae is believed to be the sister taxon to Fritillariidae, with both sharing specialized characteristics and forming a clade to the exclusion of Oikopleuridae. [4]
Larvaceans or appendicularians, class Appendicularia, are solitary, free-swimming tunicates found throughout the world's oceans. While larvaceans are filter feeders like most other tunicates, they keep their tadpole-like shape as adults, with the notochord running through the tail. They can be found in the pelagic zone, specifically in the photic zone, or sometimes deeper. They are transparent planktonic animals, usually ranging from 2 mm (0.079 in) to 8 mm (0.31 in) in body length including the tail, although giant larvaceans can reach up to 10 cm (3.9 in) in length.
Ascidiacea, commonly known as the ascidians or sea squirts, is a paraphyletic class in the subphylum Tunicata of sac-like marine invertebrate filter feeders. Ascidians are characterized by a tough outer "tunic" made of a polysaccharide.
The Atlantic tripletail, also known as the black grunt, black perch, buoy fish, buoyfish, brown triple tail, brown tripletail, conchy leaf, dusky triple-tail, dusky tripletail, flasher, sleepfish, triple tail, triple-tail, tripletail, or tripple tail is a species of marine ray-finned fish belonging to the family Lobotidae. This fish is found in tropical and subtropical waters around the world except for the eastern Pacific Ocean.
The Atlantic horse mackerel, also known as the European horse mackerel or common scad, is a species of jack mackerel in the family Carangidae, which includes the jacks, pompanos and trevallies. It is found in the eastern Atlantic Ocean off Europe and Africa and into the south-eastern Indian Ocean. It is an important species in commercial fisheries and is listed as a Vulnerable species on The IUCN Red List of Threatened Species.
The serpent eel or sand snake-eel is an eel found in the eastern Atlantic Ocean, western Mediterranean Sea, western Indian Ocean, western Pacific Ocean and the north-east and west coast of North Island in New Zealand. It is an elongated, slender fish with a length of up to 250 centimetres. It spends the day with its body immersed in the sediment, emerging into the open water at night.
The Portuguese dogfish or Portuguese shark, is a species of sleeper shark of the family Somniosidae. This globally distributed species has been reported down to a depth of 3,675 m (12,057 ft), making it the deepest-living shark known. It inhabits lower continental slopes and abyssal plains, usually staying near the bottom. Stocky and dark brown in color, the Portuguese dogfish can be distinguished from similar-looking species by the small spines in front of its dorsal fins. Its dermal denticles are also unusual, resembling the scales of a bony fish. This species typically reaches 0.9–1 m (3.0–3.3 ft) in length; sharks in the Mediterranean Sea are much smaller and have distinct depth and food preferences.
The velvet belly lanternshark is a species of dogfish shark in the family Etmopteridae. One of the most common deepwater sharks in the northeastern Atlantic Ocean, the velvet belly is found from Iceland and Norway to Gabon and South Africa at a depth of 20–2,490 m (66–8,169 ft). A small shark generally no more than 45 cm (18 in) long, the velvet belly is so named because its black underside is abruptly distinct from the brown coloration on the rest of its body. The body of this species is fairly stout, with a moderately long snout and tail, and very small gill slits. Like other lanternsharks, the velvet belly is bioluminescent, with light-emitting photophores forming a species-specific pattern over its flanks and abdomen. The ventral photophores are thought to function in counter-illumination, which camouflages the shark against predators and prey. The bioluminescent flank markings may play a role in intraspecific communication.
The slender catshark is a small species of catshark belonging to the family Scyliorhinidae. It is found on the upper continental slope off the coast of Suriname, French Guiana and northern Brazil, including the mouth of the Amazon River at depths between 72 and 450 metres. Its it can grow up to a length of 70 centimetres (28 in).
The bottlenose skate, spearnose skate, or white skate is a species of skate in the family Rajidae. It is a benthic fish native to the coastal eastern Atlantic Ocean. Due to overfishing, it has been depleted or extirpated in many parts of its former range in the northeastern Atlantic and the Mediterranean Sea, and is now endangered.
The European anchovy is a forage fish somewhat related to the herring. It is a type of anchovy; anchovies are placed in the family Engraulidae. It lives off the coasts of Europe and Africa, including in the Mediterranean Sea, the Black Sea, and the Sea of Azov. It is fished by humans throughout much of its range.
The round fantail stingray or round stingray, is a poorly known species of stingray in the family Dasyatidae. It inhabits sandy, muddy, or rocky coastal habitats in the eastern Atlantic Ocean and the southern Mediterranean Sea. This dark-colored ray typically reaches a width of 1 m (3.3 ft), and can be identified by its nearly circular pectoral fin disk, short tail, and mostly bare skin. The round fantail stingray hunts for fishes and crustaceans on the sea floor, and exhibits an aplacental viviparous mode of reproduction. The International Union for Conservation of Nature (IUCN) does not yet have sufficient information to assess the conservation status of this species.
Scyllarides latus, the Mediterranean slipper lobster, is a species of slipper lobster found in the Mediterranean Sea and in the eastern Atlantic Ocean. It is edible and highly regarded as food, but is now rare over much of its range due to overfishing. Adults may grow to 1 foot (30 cm) long, are camouflaged, and have no claws. They are nocturnal, emerging from caves and other shelters during the night to feed on molluscs. As well as being eaten by humans, S. latus is also preyed upon by a variety of bony fish. Its closest relative is S. herklotsii, which occurs off the Atlantic coast of West Africa; other species of Scyllarides occur in the western Atlantic Ocean and the Indo-Pacific. The larvae and young animals are largely unknown.
Clavularia crassa is a species of colonial soft coral in the family Clavulariidae. It is found in the eastern Atlantic Ocean and the Mediterranean Sea. It was first described in 1848 by the French zoologist Henri Milne-Edwards from a specimen collected off the coast of Algeria.
Oikopleuridae is a family of larvacean tunicates. A comparatively species-rich family, it has been especially well-researched thanks to the ubiquity of Oikopleura dioica as a model species. It comprises two subfamilies, Bathochordaeinae and Oikopleurinae, itself divided into the tribes Alabiata and Labiata.
Bathochordaeus, the giant larvaceans, is a genus of larvacean tunicates in the family Oikopleuridae. They are free-swimming filter-feeding marine animals that build mucus bubbles. They eat tiny particles of dead or drifting organic material that float through the water column, which contribute to the oceanic carbon cycle and the accelerated transfer of carbon to the deep sea.
Alloteuthis media, the midsize squid or little squid, is a species of squid in the family Loliginidae from the eastern Atlantic and the Mediterranean Sea. It is generally a by-catch species in trawl fisheries, although there is an active fishery in the western Mediterranean.
Althoffia is a monotypic genus of larvacean tunicates belonging to the family Oikopleuridae. The only species is Althoffia tumida.
Appendicularia is a genus of larvaceans in the family Fritillariidae.
Fritillaria is a genus of larvacean tunicates belonging to the family Fritillariidae.
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