Tanymastix stagnalis | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Branchiopoda |
Order: | Anostraca |
Family: | Tanymastigidae |
Genus: | Tanymastix |
Species: | T. stagnalis |
Binomial name | |
Tanymastix stagnalis | |
Synonyms | |
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Tanymastix stagnalis is a species of Anostraca (fairy shrimp) that lives in temporary pools across Europe. It may reach up to 2 cm (0.8 in) in some areas and has 11 pairs of bristly, flattened appendages. It swims upside-down and filters food particles from the water. It is the only species of Anostraca in Ireland, having been discovered in Rahasane Turlough in 1974.
Tanymastix stagnalis has a pair of stalked eyes, and 11 pairs of thoracic appendages, called phyllopodia. The abdomen bears no appendages except for the caudal furca and the external genitalia. In the male the genitalia are a pair of retractable hemipenes, while the female has a brood pouch with two spines. [1] The antennae are also sexually dimorphic, being prehensile in males. At the end of the abdomen, a caudal furca is made up of two red cercopods, [1] which are long, thin and setose. [2]
Reports of the size of Tanymastix stagnalis vary. In Spain, it is reported to reach lengths of 7–9 millimetres (0.3–0.4 in), [2] while Macedonian examples reach 8–17 mm (0.3–0.7 in), and French specimens have been reported as long as 20 mm (0.8 in). [3]
Tanymastix stagnalis can be most easy distinguished from other species in the order by the form of the males' antennae and frontal appendages. [4]
Tanymastix stagnalis survives drought as resting eggs, which are dark brown, 0.40–0.43 mm in diameter, [2] coppery-brown in colour and, characteristically for the genus Tanymastix , lentil-shaped. [1] Each ovisac produces 8–14 eggs, [2] which are laid in open water. [1] The eggs usually float, and tend to accumulate at the edges of the pool. [1]
The egg hatches into a nauplius, but that stage lasts only a few hours. Sexual maturity is reached after 7–40 days, and the animal's longevity depends on the temperature and the season, ranging from 30 days in summer to over 60 days in winter. [1]
Like other members of the Anostraca, T. stagnalis swims with the ventral side upwards by beating its flattened thoracic appendages, or phyllopodia. [4] It has been variously described as a cold stenothermal species, [2] or as a warm stenothermal species. [5] The species' temperature limits appear to vary between populations, with maxima of 16 °C (61 °F) reported for some populations, 20 °C (68 °F) for Irish populations, and up to 25 °C (77 °F) in Germany and elsewhere. [5] The optimum temperature has been quoted as 10–17 °C (50–63 °F) or 12–15 °C (54–59 °F). [5] Nauplii have been observed at temperatures of 3–12 °C (37–54 °F). [5]
In North Macedonia, T. stagnalis lives in pools only 20–60 centimetres (7.9–23.6 in) in diameter, and 10–20 cm (3.9–7.9 in) deep, containing a few litres of water each. Larger pools in the area harbour Chirocephalus diaphanus instead. [3] In Spain, its distribution is seasonal; in winter it is found in rain puddles on the plains, while in summer it can only be found in mountainous areas. In all cases, the pools overlie acidic igneous rocks, and they are usually mineral-poor and retain some moisture in the sediment when they dry out. [2]
Like all Anostraca, T. stagnalis is a filter feeder, removing microplankton, microorganisms and other organic material from suspension with its bristly phyllopodia. [1]
Tanymastix stagnalis is sensitive to changes in the intensity of light, and respond to sudden shade by swimming towards the bottom of the pool, or even burying themselves in the sediment. The main threat to them is perturbation of the habitat, in particular the introduction of predators such as the fishes Lepomis gibbosus and Gambusia affinis . [1]
Tanymastix stagnalis has a wide circum-Mediterranean distribution across Europe and Algeria, [1] stretching from the Iberian Peninsula in the west to south-western Russia in the east, and northwards through Germany [6] to Scandinavia. [3] Its distribution is scattered within this area. For example, in North Macedonia, it is present only in pools among andesite tuffs above Stracin (Страцин), [3] and in Denmark it is only known from Råbjerg Mile pools. [7]
It was originally described from a site near Uppsala, Sweden, which is near the northern limit of its range. A more northerly population was found in 1913 at an altitude of 3,500 ft (1,100 m) above Surendal, Norway. [8] The population from 1913 is probably extinct, but the species is known from three other high altitude locations in the Trollheimen mountains. [9]
Tanymastix stagnalis is the only Anostracan species to occur in Ireland, [4] and one of only two in the British Isles (the other being Chirocephalus diaphanus which occurs in a few sites in southern England). It was discovered in Rahasane Turlough in 1974, [4] and was soon discovered at six other sites, in temporary pools in fields, which may be more likely to represent the species' usual habitat. [10] [11] T. stagnalis is thought to have arrived in Ireland in mud on the legs of a migratory bird, or on the footwear of a wildfowler; various ducks such as mallard, teal and shoveller, and waders such as lapwing and curlew have been observed in Ireland after migrating from areas with T. stagnalis populations, such as Scandinavia and France. [4]
In France, T. stagnalis is found in the Forest of Fontainebleau near Paris, in the Camargue, in the Var and in the Rhône Valley. [1] It is also found on Corsica, Sardinia and Capraia. [12]
Tanymastix stagnalis was named by Carl Linnaeus in the 1758 10th edition of Systema Naturae , where it was called Cancer stagnalis. It was transferred by Simon to his new genus Tanymastix in 1886. [13]
Branchiopoda is a class of crustaceans. It comprises fairy shrimp, clam shrimp, Diplostraca, Notostraca, the Devonian Lepidocaris and possibly the Cambrian Rehbachiella. They are mostly small, freshwater animals that feed on plankton and detritus.
The order Notostraca, containing the single family Triopsidae, is a group of crustaceans known as tadpole shrimp or shield shrimp. The two genera, Triops and Lepidurus, are considered living fossils, with similar forms having existed since the end of the Devonian, around 360 million years ago. They have a broad, flat carapace, which conceals the head and bears a single pair of compound eyes. The abdomen is long, appears to be segmented and bears numerous pairs of flattened legs. The telson is flanked by a pair of long, thin caudal rami. Phenotypic plasticity within taxa makes species-level identification difficult, and is further compounded by variation in the mode of reproduction. Notostracans are omnivores living on the bottom of temporary pools and shallow lakes.
Vernal pools, also called vernal ponds or ephemeral pools, are seasonal pools of water that provide habitat for distinctive plants and animals. They are considered to be a distinctive type of wetland usually devoid of fish, and thus allow the safe development of natal amphibian and insect species unable to withstand competition or predation by fish. Certain tropical fish lineages have however adapted to this habitat specifically.
Anostraca is one of the four orders of crustaceans in the class Branchiopoda; its members are referred to as fairy shrimp. They live in vernal pools and hypersaline lakes across the world, and they have even been found in deserts, ice-covered mountain lakes, and Antarctic ice. They are usually 6–25 mm (0.24–0.98 in) long. Most species have 20 body segments, bearing 11 pairs of leaf-like phyllopodia, and the body lacks a carapace. They swim "upside-down" and feed by filtering organic particles from the water or by scraping algae from surfaces, with the exception of Branchinecta gigas, or "giant fairy shrimp", which is itself a predator of other species of anostracans. They are an important food for many birds and fish, and some are cultured and harvested for use as fish food. There are 300 species spread across 8 families.
The midvalley fairy shrimp, Branchinecta mesovallensis, is a small freshwater crustacean in the Branchinectidae family. The midvalley fairy shrimp was only recently formally described as a species in 2000 by Belk and Fugate. Midvalley fairy shrimp are endemic to shallow ephemeral pools near the middle of California's Central Valley. These vernal pool ecosystems are home to other unique organisms adapted to the ephemeral nature of the water cycle in the pools in California's mediterranean climate.
Branchinecta is a genus of fairy shrimp in family Branchinectidae. It includes around 50 species, found on all continents except Australia. Branchinecta gigas, the giant fairy shrimp, is the largest species in the order, with a length of up to 10 centimetres (4 in), and Branchinecta brushi lives at the highest altitude of any crustacean, at 5,930 metres (19,460 ft), a record it shares with the copepod Boeckella palustris. A new genus, Archaebranchinecta was established in 2011 for two species previously placed in Branchinecta.
Branchinella is a genus of crustaceans in the family Thamnocephalidae. This fairy shrimp genus is found across many parts of the world, but especially western Australia and southern Africa.
Chirocephalus is a genus of fairy shrimp in the family Chirocephalidae. It contains the following species:
Artemia salina is a species of brine shrimp – aquatic crustaceans that are more closely related to Triops and cladocerans than to true shrimp. It belongs to a lineage that does not appear to have changed much in 100 million years.
Branchinecta gigas is a species of fairy shrimp that lives in western Canada and the United States. It is the largest species of fairy shrimp, growing up to 86 mm (3.4 in) long. It is known commonly as the giant fairy shrimp.
Branchipodidae is a family of fairy shrimp, one of eight in the order Anostraca. It contains 35 extant species in five extant genera:
Chirocephalus diaphanus is a widely distributed European species of fairy shrimp that lives as far north as Great Britain, where it is the only surviving species of fairy shrimp and is protected under the Wildlife and Countryside Act 1981. It is a translucent animal, about 0.5 in (13 mm) long, with reddened tips to the abdomen and appendages. The body comprises a head, a thorax bearing 11 pairs of appendages, and a seven-segmented abdomen. In males, the antennae are enlarged to form "frontal appendages", while females have an egg pouch at the end of the thorax.
Branchinecta gaini is a species of fairy shrimp from Antarctica and Patagonia. It is the largest freshwater invertebrate in Antarctica, at 16 mm (0.63 in) long. It lives on bacteria and other organisms, surviving the winter as resting eggs.
Lepidocaris rhyniensis is an extinct species of crustacean. It is the only species known from the order Lipostraca, and is the only abundant animal in the Pragian-aged Rhynie chert deposits. It resembles modern Anostraca, to which it is probably closely related, although its relationships to other orders remain unclear. The body is 3 mm (0.12 in) long, with 23 body segments and 19 pairs of appendages, but no carapace. It occurred chiefly among charophytes, probably in alkaline temporary pools.
Parastreptocephalus is a subgenus of the fairy shrimp genus Streptocephalus, characterised by features of the male antennae and the tetrahedral shape of the eggs. It comprises six species:
Branchinecta paludosa is a species of freshwater fairy shrimp with a Holarctic distribution.
Lepidurus apus, commonly known as a tadpole shrimp, is a notostracan in the family Triopsidae, one of a lineage of shrimp-like crustaceans that have had a similar form since the Triassic period and are considered living fossils. This species is cosmopolitan, inhabiting temporary freshwater ponds over much of the world, and the most widespread of the tadpole shrimps. Like other notostracans, L. apus has a broad carapace, long segmented abdomen, and large numbers of paddle-like legs. It reproduces by a mixture of sexual reproduction and self-fertilisation of females.
Streptocephalus sirindhornae is a species of crustacean in the family Streptocephalidae; a genus of freshwater dwelling shrimp belonging to the Anostraca order of Branchiopoda. It is endemic to Thailand, and it was named after Princess Sirindhorn.
Lynceidae is a family of clam shrimp in the order Laevicaudata. There are about 5 genera and more than 20 described species in Lynceidae.
Rehbachiella is a genus of Cambrian crustacean comprising the only species Rehbachiella kinnekullensis. It is a possible branchiopod from the Orsten of Sweden.