Branchipodopsis | |
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Branchipodopsis sp., male and female, from the Western Cape, South Africa | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Class: | Branchiopoda |
Order: | Anostraca |
Family: | Branchipodidae |
Genus: | Branchipodopsis G. O. Sars, 1898 |
Synonyms | |
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Branchipodopsis is a genus of aquatic crustaceans, in the order Anostraca. It is one of several genera known as fairy shrimp . All described species are specialised for inhabiting ephemeral rock pools in situations such as mountains and deserts. [1] Though the genus is most widely known from Africa, some occur in the middle east and adjoining regions.
Species in the genus Branchipodopsis have been described mainly from the African mainland, in particular southern Africa, and among anostracan taxa the genus is among the most speciose in the sub-continent. Some species however have been reported from elsewhere, such as Branchipodopsis buettikeri, found in temporary desert ponds in the Sultanate of Oman, the first species found in the Arabian peninsula. [2] The recently described species, Branchipodopsis relictus on the main island of the Socotra archipelago, which is exceedingly remote for what it is, a continental fragment of Gondwana, isolated since the Miocene. Branchipodopsis relictus is correspondingly isolated genetically as well as geographically. [3]
All the species in this genus inhabit small, transient rock pools, mainly pools containing clear rain water after heavy, seasonal rainfall. Like most inhabitants of vernal pools Branchipodopsis are adapted to the associated unpredictability and drastically changing conditions peculiar to such environments. Rock pools of this nature occur in various regions of the Southern African subcontinent, including mountain ranges in the Drakensberg, the Western Cape and the Eastern Free State. They also occur in arid regions such as South-Eastern Botswana. [1]
The rock pools that Branchipodopsis species inhabit are notable for the water's clarity and its very low electrolytic conductivity (generally below 50μS per centimetre, commonly less than 10μS per cm). [1] Such poor conductivity reflects a very low content of soluble salts, acids or bases, in strong contrast to the conditions preferred by the related family Artemiidae, the brine shrimps. It also implies a very low content of soluble mineral materials, including mineral nutrients, from the surrounding rock.
The pools also are shallow, less than 50 cm (20 in) deep, as a rule. Their low mineral content sharply limits their buffering capacity and one result is that they are subject to major shifts in pH; a range between pH 4 and pH 11 is nothing unusual in some regions. Such variations are subject to the time of day and the water cycle variables. Water temperature in such shallow, exposed pools also varies dramatically according to evaporation, ambient air temperature and solar heating, as affected by the colour of the surrounding rock. Daily fluctuations between 10 °C and 40 °C are common.
Small mountain rock pools usually do not stay full for long; in semi-arid areas there may be several cycles of filling and drying out during a single rainy season, depending on local weather. [4] Any organisms attempting to complete their life cycle in such pools do so without any latitude; if they are late they die without issue. Branchipodopsis species excel in this respect and usually mature within a week or so after the formation of the pool. A typical clutch of dormant eggs generally numbers less than 100, but a mature female produces a new clutch nearly every day. [1]
Especially in arid regions like South-Eastern Botswana, rainfall may be so erratic that sometimes there is not enough time for growth and reproduction; about a third of the inundations in some regions end in the pools drying too soon, causing the entire hatched population to die. Species subject to such circumstances depend on the strategy of producing a large bank of dormant eggs in the detritus of the pool bed, most of those hatching only after an unpredictable number of cycles of inundation, some of them only after many years. This partial hatching (or germination) is a common strategy in both animals and plants dependent subject to ruderal conditions. In the case of fairy shrimps such as Branchipodopsis and of other organisms dependent on, in fact specialised for, such fugitive conditions, it entails inability to survive in superficially more attractive, permanent conditions, such as perennial water; the eggs require periodic desiccation for their hatching stimulus and the adults cannot compete effectively with organisms that can exploit more nutrient-rich water.
Dispersal of eggs over short distances may happen under many circumstances, for example by overflow from pools. However, long-range dispersal is comparatively rare and usually happens only in shallow pools without much vegetation. When dispersal takes place over longer distances, the vectors commonly would be favourable wind or the feet of birds, both of which are episodic and unreliable vehicles. Such constraints on dispersal provide a plausible reason for the high proportion of endemic species throughout the region; in the Drakensberg alone there are four. It also could explain the morphological variability of some widespread species, for example Branchipodopsis wolfi in Botswana. [1]
There are currently 22 species assigned to the genus. [5] [6]
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.
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 conservancy fairy shrimp is an endangered small crustacean in the family Branchinectidae. It ranges in size from about 1.25 centimetres (0.49 in) to 2.5 centimetres (0.98 in) long. This species is endemic to California in the United States.
The midvalley fairy shrimp, Branchinecta mesovallensis, is a small freshwater crustacean in the Branchinectidae family 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.
Branchinecta sandiegonensis is a rare species of crustacean in the family Branchinectidae and the order Anostraca, the fairy shrimp. Commonly known as the San Diego fairy shrimp, it is named after the vernal pools found in San Diego County, California, where this species was originally discovered. It is also a federally listed endangered species of the United States.
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.
Streptocephalus is a genus of fairy shrimp found in temporary waters in Africa, Australia, Eurasia, and Central and North America, following its ancient origin in Gondwana. It contains the following species:
Streptocephalus proboscideus, sometimes called the Sudanese fairy shrimp, is a species of fairy shrimp found in eastern Africa.
The Semowane River is a major natural watercourse in Southern Africa. Within Botswana the Semowane River forms a boundary between several governmental jurisdictions. This river is a vital source of water to the ephemeral wetlands of the Makgadikgadi, where a number of species of limited distribution thrive. Specifically the Semowane River discharges to Sua Pan.
The Nata River or Manzamnyama River is a natural watercourse in Southern Africa. It is an ephemeral river flowing in Zimbabwe and Botswana. It has a length of 330 km from its source to mouth, 210 km in Zimbabwe and 120 km in Botswana. Its total catchment area is 24,585 km2. The river originates in Sandown, a small farming town located on the Zimbabwean central watershed 50 km south west of Bulawayo and ends in the Makgadikgadi Pans in Botswana. There is no outlet from the salt pans which can be considered as the “dead sea” of the south. The upper reaches of the river are located in a commercial farming area where good environmental and farming practices have resulted in the river experiencing very little siltation/sedimentation. Impressive sedimentation starts occurring about 65 km along the river course marking the beginning of a 90 km stretch in Zimbabwe where the river passes through communal farming areas. It is on this stretch where the sand-abstraction potential of the river is realised and communities rely on the sand river water for domestic, farming and livestock purposes. Within the country of Botswana the Nata River is a source of water to the ephemeral wetlands of the Makgadikgadi Pans, where a number of species of limited distribution thrive. Specifically the Nata River discharges to Sua Pan, draining parts of eastern Botswana and southwestern Zimbabwe.
The Mosetse River is a natural watercourse in Botswana. Within the country of Botswana the Mosetse is a source of water to the ephemeral wetlands of the Makgadikgadi Pans, where a number of crustacean species of limited distribution thrive. More specifically the Mosetse River discharges to Sua Pan, draining parts of eastern Botswana.
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.
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:
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.
The fairy shrimp, Phallocryptus fahimii, is a fresh water crustacean discovered in 2017 from a seasonal lake in the Lut Desert in southeast Iran. It's a heat-resistant crustacea living in a lake with water temperatures reaching 87 °F (31 °C). It is the fifth known species to be discovered in the genus Phallocryptus. It received its name after the late Hadi Fahimii, a conservationist who took part in the expedition of the Lut Desert and died in 2018 from an airplane crash. Morphologically, this newly discovered species shows minimal differences from its relatives in the Phallocryptus genus. A distinguishing characteristic of this fairy shrimp is that it can lay its eggs in desert sand for decades while they await the rare presence of water. P. fahimii developed these unique characteristics due to its harsh environmental conditions throughout the Lut Desert, which in Persian, translates into “desert of emptiness.” Dr.Hossein Rajaei, one of the researchers that made the shrimp discovery, suggested, “they gave it this name because many people believed there was no life in this desert.”