The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine

crabs Crabs are decapod crustaceans of the infraorder Brachyura (meaning "short tailed" in Greek), which typically have a very short projecting tail-like abdomen, usually hidden entirely under the thorax. Their exoskeleton is often thickened and ha ...

in the family

Ocypodidae The Ocypodidae is a family of semiterrestrial crabs that includes ghost crabs and fiddler crabs. These crabs are found along tropical and temperate shorelines worldwide. Some genera previously classified within the Ocypodidae family have been r ...

. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly larger than their minor claw, whilst females claws are both the same size. The name fiddler crab comes from the appearance of their small and large claw together, looking similar to a fiddle. A smaller number of

ghost crab Ghost crabs are semiterrestrial crabs of the subfamily Ocypodinae. They are common shore crabs in tropical and subtropical regions throughout the world, inhabiting deep burrows in the intertidal zone. They are generalist scavengers and predator ...

and

mangrove crab Mangrove crabs are crabs that live in and around mangroves. They belong to many different species and families and have been shown to be ecologically significant by burying and consuming leaf litter. Mangrove crabs have a variety of phylogenie ...

species are also found in the family Ocypodidae. This entire group is composed of small crabs, the largest being ''Afruca tangeri'' which is slightly over two inches (5 cm) across. Fiddler crabs are found along sea beaches and brackish intertidal mud flats, lagoons, swamps, and various other types of brackish or salt-water

wetlands A wetland is a distinct semi-aquatic ecosystem whose groundcovers are flooded or saturated in water, either permanently, for years or decades, or only seasonally. Flooding results in oxygen-poor ( anoxic) processes taking place, especially ...

. Whilst fiddler crabs are currently split into two subfamilies of

Gelasiminae Gelasiminae is a subfamily that pertains to nine out of the eleven fiddler crab genera within the family Ocypodidae. Taxonomy The subfamily includes 94 species within nine genera. The genera are split into two tribes that are geographically di ...

and Ucinae, there is still phylogenetic and taxonomical debate as to whether the movement from the overall genus of ‘’Uca’’ to these subfamilies and the separate 11 genera Like all crabs, fiddler crabs shed their shells as they grow. If they have lost legs or claws during their present growth cycle, a new one will be present when they molt. If the major claw is lost, males will regenerate one on the same side after their next molt. Newly molted crabs are very vulnerable because of their soft shells. They are reclusive and hide until the new shell hardens. In a controlled laboratory setting, fiddler crabs exhibit a constant

circadian rhythm A circadian rhythm (), or circadian cycle, is a natural oscillation that repeats roughly every 24 hours. Circadian rhythms can refer to any process that originates within an organism (i.e., Endogeny (biology), endogenous) and responds to the env ...

that mimics the ebb and flow of the tides: they turn dark during the day and light at night.

Ecology and life cycle

Fiddler crabs primarily exist upon mudflats, sandy or muddy

beaches A beach is a landform alongside a body of water which consists of loose particles. The particles composing a beach are typically made from Rock (geology), rock, such as sand, gravel, shingle beach, shingle, pebbles, etc., or biological s ...

as well as salt marshes within

mangroves A mangrove is a shrub or tree that grows mainly in coastal saline or brackish water. Mangroves grow in an equatorial climate, typically along coastlines and tidal rivers. They have particular adaptations to take in extra oxygen and remove sal ...

. Fiddler crabs are found in

West Africa West Africa, also known as Western Africa, is the westernmost region of Africa. The United Nations geoscheme for Africa#Western Africa, United Nations defines Western Africa as the 16 countries of Benin, Burkina Faso, Cape Verde, The Gambia, Gha ...

, the

Western Atlantic The Atlantic Ocean is the second largest of the world's five borders of the oceans, oceanic divisions, with an area of about . It covers approximately 17% of Earth#Surface, Earth's surface and about 24% of its water surface area. During the ...

, the

Eastern Pacific The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean, or, depending on the definition, to Antarctica in the south, and is bounded by the conti ...

Indo-Pacific The Indo-Pacific is a vast biogeographic region of Earth. In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...

and

Algarve region The Algarve (, , ) is the southernmost NUTS II region of continental Portugal. It has an area of with 467,495 permanent inhabitants and incorporates 16 municipalities ( ''concelhos'' or ''municípios'' in Portuguese). The region has its admin ...

Portugal Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it share ...

. Whilst the fiddler crab is classified as an omnivore, it does present itself as an opportunist and will consume anything with nutritional value. The crab will feed through bringing a chunk of sediment to its mouth and sifting through it to extract organic material. This crab will filter out

algae Algae ( , ; : alga ) is an informal term for any organisms of a large and diverse group of photosynthesis, photosynthetic organisms that are not plants, and includes species from multiple distinct clades. Such organisms range from unicellular ...

microbes A microorganism, or microbe, is an organism of microscopic size, which may exist in its single-celled form or as a colony of cells. The possible existence of unseen microbial life was suspected from antiquity, with an early attestation in ...

fungus A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...

or any form of detritus. Once finished consuming all the organic matter from the sediment, these crabs will then deposit them as small sand balls near their burrow. Fiddler crabs are thought to potentially act as

ecosystem engineer An ecosystem engineer is any species that creates, significantly modifies, maintains or destroys a habitat. These organisms can have a large impact on species richness and landscape-level heterogeneity of an area. As a result, ecosystem engine ...

s within their habitat due to the way they rework the sediment during feeding. Whilst these crabs do rework the sediment around them, upturning the very top layer and depositing it nearby, there is still debate that exists as to whether this turnover of sediment has any proven difference regarding nutrients and aeration of the sediment. Fiddler crabs are a burrowing species, where within their territory they may possess several burrows. There are two types of

burrow file:Chipmunk-burrow (exits).jpg, An eastern chipmunk at the entrance of its burrow A burrow is a hole or tunnel excavated into the ground by an animal to construct a space suitable for habitation or temporary refuge, or as a byproduct of Animal lo ...

s that the fiddler crabs can build, either breeding burrows or temporary burrows. Temporary burrows are constructed by both males and females during high tide periods. These burrows are also constructed at night time when the crabs are no longer feeding and are hiding from predators. Breeding burrows are constructed by solely males, and will be constructed within the area that they have deemed their territory. These breeding burrows are constructed by male crabs so that the female and male crabs may copulate within the burrow, and the female may deposit and incubate her eggs within this area. Larger males who can more easily defend their territory will often have multiple suitable breeding burrows within their territory to enable them to mate with multiple female crabs. Female crabs are found to prefer to mate with males that have the widest burrows, however,

carapace A carapace is a dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the unde ...

width and claw size does correlate with the width of the burrow, so could be a potential size bias.Reaney, L. T., & Backwell, P. R. Y. (2007). Temporal constraints and female preference for burrow width in the fiddler crab, Uca mjoebergi. ''Behavioral Ecology and Sociobiology, 61'', 1515-1521
doi: 10.1007/s00265-007-0383-5
Two types of fiddler crabs are found to exist within a given territory, a wandering female or male, and territory-holding male or females. When in a wandering state, this means crabs do not currently occupy a burrow. They will wander in order to look for territory which contains a burrow, or to look for a mate. Wandering females will look for a mate to

copulate Sexual intercourse (also coitus or copulation) is a sexual activity typically involving the insertion of the erect male penis inside the female vagina and followed by thrusting motions for sexual pleasure, reproduction, or both.Sexual inte ...

with, usually preferring to mate with a male that currently possesses a burrow. The female fiddler carries her eggs in a mass on the underside of her body. She remains in her burrow during a two-week gestation period, after which she ventures out to release her eggs into the receding tide. The larvae remain

plankton Plankton are the diverse collection of organisms that drift in Hydrosphere, water (or atmosphere, air) but are unable to actively propel themselves against ocean current, currents (or wind). The individual organisms constituting plankton are ca ...

ic for a further two weeks. The mating system of fiddler crabs is thought to be mainly

polygynous Polygyny () is a form of polygamy entailing the marriage of a man to several women. The term polygyny is from Neoclassical Greek πολυγυνία (); . Incidence Polygyny is more widespread in Africa than in any other continent. Some scholar ...

, where the male crabs will mate with multiple females if they have the opportunity to, however, female fiddler crabs such as the ''Austruca lactea'' are known to also mate with multiple males. As they are a species of crustacean, they perform

ecdysis Ecdysis is the moulting of the cuticle in many invertebrates of the clade Ecdysozoa. Since the cuticle of these animals typically forms a largely inelastic exoskeleton, it is shed during growth and a new, larger covering is formed. The remnant ...

, which is the process of moulting. When crabs moult, they produce hormones which trigger the shedding of their

exoskeleton An exoskeleton () . is a skeleton that is on the exterior of an animal in the form of hardened integument, which both supports the body's shape and protects the internal organs, in contrast to an internal endoskeleton (e.g. human skeleton, that ...

and regeneration of limbs. Moulting is already an extremely stressful time for fiddler crabs, as their shell becomes extremely soft, leaving them vulnerable to predation. When undergoing this moulting cycle, crabs will frequently hide within their burrows to avoid harm. When male crabs are undergoing the moulting process, if they are exposed to other male crabs in high grouping with consistent light, their ability to regenerate limbs will be impaired. Whilst the crabs major claw does function as a tool for fighting and competition, it also plays a role in

thermoregulation Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when the surrounding temperature is very different. A thermoconforming organism, by contrast, simply adopts the surrounding temperature ...

. As the claw is so large, and these crabs live in generally hot territory, so require strategies to keep themselves cool, particularly for wandering males without burrows. The presence of the major claw upon the male helps them keep their body temperature regulated, and decreases the chance of them losing or gaining too much heat in a given time period. The large claw draws away excess body heat from the core of the fiddler crab and allows it to dissipate. Heat is found to dissipate significantly faster when male crabs are performing waving at the same time. Fiddler crabs come in many different colourations and patterns, and are known to be able to change their colour over time. Fiddler crabs such as the ''

Tubuca capricornis ''Tubuca capricornis'', the capricorn fiddler crab, is a species of fiddler crab that is found in north west and northern Australia. It was named after its occurrence near the Tropic of Capricorn. These crabs live on shaded mud flats in mangrov ...

'' are capable of changing their colour rapidly when placed under significant stress. When fiddler crabs undergo moulting, they are seen to have reduced colouration after each sequential moult. Female fiddler crabs are traditionally more colourful than male fiddler crabs. Conspicuous colouring in fiddler crabs is dangerous as it increases predation rate, however, sexual selection argues for brightly coloured crabs. Fiddler crabs have finely tuned visual systems that aid in detecting colours of importance, which aid in selecting coloured mates. When given the choice, females prefer to pick males that are more brightly coloured in comparison to dull males.

Behaviour, competition, and courtship

Fiddler crabs live rather brief lives of no more than two years (up to three years in captivity). Male fiddler crabs use many signalling techniques and performances towards females to win over a female to mate. Females choose their mate based on claw size and also quality of the waving display. It is very common for male fiddler crabs to be viewed fighting against one another. Male fiddler crabs fight primarily over females and territory. Whilst fights within fiddler crabs are commonly male against male fights, male fiddler crabs will also fight against female fiddler crabs when there is suitable territory with a burrow that the male wishes to obtain. When fighting, male fiddler crabs can often have their major claw ripped off, or have it harmed to the point where male fiddler crabs must autotomize this claw. Whilst this claw can regrow when the crab next moults, the properties of the claw will not be the same as they were previously. Whilst the size of the claw will be the same or similar to how it was before, the claw will become significantly weaker. Whilst this claw is now significantly weaker, other crabs cannot tell that this claw is weaker, so will assume the claw is at full size and strength. This is a form of dishonest signalling, where the appearance of the claw displayed to other fiddler crabs does not represent the true mechanics of the claw.Lailvaux, S. P., Reaney, L. T. & Backwell, P. R. Y. (2008). Regenerated claws dishonestly signal performance and fighting ability in the fiddler crab ''Uca mjoebergi. Functional Ecology, 23''(2), 359. In order for a male fiddler crab to help produce offspring, he must first attract a mate and convince her to mate with him. To win over females, male crabs will perform a waving display towards females. This waving display consists of raising the major claw upwards and then dropping it down towards itself in what appears as a 'come here' motion, like a beckoning sign. Male crabs will exhibit two forms of waving towards females to attempt to court them. Broadcast waving is a general wave the male crabs perform when a female crab is not within their field of view. This wave is at a slower pace, as to not use up energy reserves. Directed waving is performed by male crabs when they have spotted a female they wish to mate with. This wave is performed through the male crab facing towards the female, and increasing the pace of the wave towards the female. Uca perplexa male waving

When males are waving at females, this is usually done in

synchrony Synchrony may refer to: * Synchronization, the coordination of events to operate a system in unison * Synchrony and diachrony, viewpoints in linguistic analysis * Behavioural synchrony, coordinated action in animals and humans * Synchrony Financi ...

with other male crabs in the neighbouring area. Synchronous waving does provide a general positive benefit for male crabs attempting to attract wandering females, as a form of

cooperative behaviour Cooperation (written as co-operation in British English and, with a varied usage along time, coöperation) takes place when a group of organisms works or acts together for a collective benefit to the group as opposed to working in competition ...

. Synchrony however, does not provide an individual benefit, as females prefer to mate with the male that is leading the synchronous wave. Therefore, synchronous waving is thought to have evolved as an incidental byproduct of males competing to lead the wave. Fiddler crabs are also known to build sedimentary pillars around their burrows out of mud and sand. 49 of the total species under the family Ocypodidae will construct sedimentary pillars outside of their burrows for the purposes of courtship and defense from other crabs. These structures can be built by either male or female crabs and will be one of the six known structures constructed by fiddler crabs. Fiddler crabs can build either a chimney, hood, pillar, semidome, mudball or rim. These mud pillars have correlations with sediment type, genus and sex. Females are more likely to be attracted to a male if he has a sedimentary pillar outside of his burrow in comparison to a male crab without a pillar. When females are not actively being courted, they are more likely to move to an empty burrow which has a pillar present in comparison to an empty burrow without a pillar present. Fiddler crabs with any hood or dome formed pillar above their burrow are more likely to be shy crabs that take less risks. Female crabs will choose their mate based upon the claw size of the male, as well as the quality of the waving display, if he was the leader of the synchronous waving, and if the male currently possesses territory with a burrow for them to copulate within. Females will also prefer to mate with males who have the widest and largest burrows. Fiddler crabs such as ''

Austruca mjoebergi ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of '' Uca'', but in 2016 it was elevated in rank to genus. Species T ...

'' have been shown to bluff about their fighting ability. Upon regrowing a lost claw, a crab will occasionally regrow a weaker claw that nevertheless intimidates crabs with smaller but stronger claws. This is an example of dishonest

signalling A signal is both the process and the result of transmission of data over some media accomplished by embedding some variation. Signals are important in multiple subject fields including signal processing, information theory and biology. In ...

. The dual functionality of the major claw of fiddler crabs has presented an evolutionary conundrum in that the claw mechanics best suited for fighting do not match up with the mechanics best suited for a waving display.

Genera and species

More than 100 species of fiddler crabs make up 11 of the 13 genera in the crab family

. These were formerly members of the genus ''Uca''. In 2016, most of the subgenera of ''Uca'' were elevated to genus rank, and the fiddler crabs now occupy 11 genera making up the subfamilies

and Ucinae. * ''

Afruca ''Afruca'' is a genus of fiddler crabs belonging to the family Ocypodidae. ''Afruca tangeri'', the only species in this genus, lives along the Atlantic coasts of western Africa and southwestern Europe. Description ''Afruca tangeri'' is one of ...

'' ** '' Afruca tangeri'' (Eydoux, 1835) (West African fiddler crab) * ''

Austruca ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of ''Uca'', but in 2016 it was elevated in rank to genus. Species The ...

'' ** ''

Austruca albimana ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of ''Uca'', but in 2016 it was elevated in rank to genus. Species The ...

'' (Kossmann, 1877) (white-handed fiddler crab) ** ''

Austruca annulipes ''Austruca annulipes'' is a species of fiddler crab found along the coastline from South Africa to Somalia, Madagascar, India, China, Indonesia, Malaysia, and the Philippines. ''Austruca annulipes'' was formerly in the genus ''Uca'', but in 20 ...

'' ( H.Milne Edwards, 1837) (ring-legged fiddler crab) ** ''

Austruca bengali ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of '' Uca'', but in 2016 it was elevated in rank to genus. Species Th ...

'' (bengal fiddler crab) ** ''

Austruca citrus ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of '' Uca'', but in 2016 it was elevated in rank to genus. Species Th ...

'' (citrus fiddler crab) ** ''

Austruca cryptica ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of '' Uca'', but in 2016 it was elevated in rank to genus. Species Th ...

'' (Naderloo, Türkay & Chen, 2010) (cryptic fiddler crab) ** ''

Austruca iranica ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of '' Uca'', but in 2016 it was elevated in rank to genus. Species T ...

'' (Pretzmann, 1971) (iranian fiddler crab) ** ''

Austruca lactea ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of '' Uca'', but in 2016 it was elevated in rank to genus. Species Th ...

'' (De Haan, 1835) (milky fiddler crab) ** ''

'' (Rathbun, 1924) (banana fiddler crab) ** ''

Austruca occidentalis ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of '' Uca'', but in 2016 it was elevated in rank to genus. Species Th ...

'' (Naderloo, Schubart & Shih, 2016) (East African fiddler crab) ** ''

Austruca perplexa ''Austruca perplexa'' is a species of fiddler crab. It is found from the Ryukyu Islands, Japan to India, throughout the Malay Archipelago, along eastern Australian coasts from Queensland to New South Wales, and in various Pacific islands, includi ...

'' ( H.Milne Edwards, 1852) (perplexing fiddler crab) ** ''

Austruca sindensis ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of '' Uca'', but in 2016 it was elevated in rank to genus. Species Th ...

'' (Alcock, 1900) (indus fiddler crab) ** ''

Austruca triangularis ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of '' Uca'', but in 2016 it was elevated in rank to genus. Species Th ...

'' (A.Milne-Edwards, 1873) (triangular fiddler crab) ** ''

Austruca variegata ''Austruca'' is a genus of Indo-west Pacific fiddler crabs in the family Ocypodidae. There are about 13 described species in this genus. ''Austruca'' was formerly a subgenus of '' Uca'', but in 2016 it was elevated in rank to genus. Species Th ...

'' (Heller, 1862) (motley fiddler crab) * '' Cranuca'' ** '' Cranuca inversa'' (Hoffmann, 1874) * '' Gelasimus'' ** '' Gelasimus borealis'' ( Crane, 1975) (northern calling fiddler crab) ** '' Gelasimus dampieri'' ( Crane, 1975) (dampier's fiddler crab) ** '' Gelasimus excisa'' (eastern calling fiddler crab) ** '' Gelasimus hesperiae'' ( Crane, 1975) (western calling fiddler crab) ** '' Gelasimus jocelynae'' (Shih, Naruse & Ng, 2010) (jocelyn's fiddler crab) ** '' Gelasimus neocultrimanus'' (Bott, 1973) ** '' Gelasimus palustris'' Stimpson, 1862 ** '' Gelasimus pugilator'' Stimpson, 1862 ** '' Gelasimus rubripes'' Hombron & Jacquinot, 1846 ** '' Gelasimus subeylindricus'' Stimpson, 1862 ** '' Gelasimus tetragonon'' (Herbst, 1790) (tetragonal fiddler crab) ** '' Gelasimus vocans'' (Linnaeus, 1758) (calling fiddler crab) ** '' Gelasimus vomeris'' (McNeill, 1920) (orange-clawed fiddler crab) * ''

Leptuca ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' ** '' Leptuca batuenta'' ( Crane, 1941) (beating fiddler crab) ** ''

Leptuca beebei ''Leptuca beebei'', commonly known as Beebe's fiddler crab, is a species of fiddler crab native to the Pacific coasts of Central and South America, from El Salvador to northern Peru. Taxonomy Previously a member of the genus '' Uca'', the speci ...

'' ( Crane, 1941) (Beebe's fiddler crab) ** ''

Leptuca coloradensis ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' (Rathbun, 1893) (painted fiddler crab) ** '' Leptuca crenulata'' (Lockington, 1877) (Mexican fiddler crab) ** ''

Leptuca cumulanta ''Leptuca cumulanta'', commonly known as the heaping fiddler crab or the mangrove fiddler crab, is a species of fiddler crab native to tropical and subtropical areas of the western Atlantic. Taxonomy Previously a member of the genus '' Uca'', t ...

'' ( Crane, 1943) (heaping fiddler crab) ** '' Leptuca deichmanni'' (Rathbun, 1935) (Deichmann's fiddler crab) ** ''

Leptuca dorotheae ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' (von Hagen, 1968) (Dorothy's fiddler crab) ** ''

Leptuca festae ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' (Nobili, 1902) (Festa's fiddler crab) ** '' Leptuca helleri'' (Rathbun, 1902) (Heller's fiddler crab) ** ''

Leptuca inaequalis ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' (Rathbun, 1935) (uneven fiddler crab) ** '' Leptuca latimanus'' (Rathbun, 1893) (lateral-handed fiddler crab) ** '' Leptuca leptodactyla'' (Rathbun, 1898) (thin-fingered fiddler crab) ** ''

Leptuca limicola ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' ( Crane, 1941) (Pacific mud fiddler crab) ** ''

Leptuca musica ''Leptuca musica'', commonly known as the musical fiddler crab, is a species of fiddler crab native to Baja California and the Gulf of California in Mexico. Taxonomy Previously a member of the genus '' Uca'', the species was transferred in 2016 ...

'' (Rathbun, 1914) (musical fiddler crab) ** ''

Leptuca oerstedi ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adul ...

'' (Rathbun, 1904) (aqua fiddler crab) ** ''

Leptuca panacea ''Leptuca panacea'', commonly known as the Gulf sand fiddler crab or the Panacea sand fiddler, is a species of fiddler crab native to coastal habitats along the Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea o ...

'' (Novak & Salmon, 1974) (gulf sand fiddler crab) ** ''

Leptuca pugilator ''Leptuca pugilator'', the sand fiddler crab, Atlantic sand fiddler crab, or Calico fiddler, is a species of fiddler crab that is found from Massachusetts to the Gulf of Mexico. It lives in burrows in coastal and estuarine mud-flats, and can be ...

'' (Bosc, 1802) (Atlantic sand fiddler crab) ** ''

Leptuca pygmaea ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' ( Crane, 1941) (pygmy fiddler crab) ** '' Leptuca saltitanta'' ( Crane, 1941) (energetic fiddler crab) ** ''

Leptuca speciosa ''Leptuca speciosa'', commonly known as the brilliant fiddler crab or the longfinger fiddler crab, is a species of fiddler crab native to the southern United States, Mexico, and the Caribbean. Before 2016, the species was known as ''Uca speciosa ...

'' (Ives, 1891) (brilliant fiddler crab) ** ''

Leptuca spinicarpa ''Leptuca spinicarpa'', commonly known as the spiny-wristed fiddler crab or the spined fiddler crab, is a species of fiddler crab native to coastal habitats along the Gulf of Mexico from northwestern Florida to Mexico. Taxonomy Previously a mem ...

'' (Rathbun, 1900) (spiny-wristed fiddler crab) ** ''

Leptuca stenodactylus ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' (

Milne-Edwards Milne-Edwards is a surname. Notable people with the surname include: * Henri Milne-Edwards (1800–1885), French zoologist * Alphonse Milne-Edwards (1835–1900), French ornithologist and carcinologist, a son of Henri Milne-Edwards See also * Miln ...

& Lucas, 1843) (narrow-fingered fiddler crab) ** ''

Leptuca subcylindrica ''Leptuca subcylindrica'', commonly known as the Laguna Madre fiddler crab or the puffed fiddler crab, is a sparsely-studied species of fiddler crab native to southern Texas and northeastern Mexico in the Gulf of Mexico. Before 2016, the species ...

'' (Stimpson, 1859) (Laguna Madre fiddler crab) ** ''

Leptuca tallanica ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' (von Hagen, 1968) (Peruvian fiddler crab) ** ''

Leptuca tenuipedis ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' ( Crane, 1941) (slender-legged fiddler crab) ** ''

Leptuca terpsichores ''Leptuca terpsichores'', commonly known as the dancing fiddler crab, is a species of fiddler crab native to the eastern Pacific coast of the Americas, from Nicaragua to Peru. Taxonomy Previously a member of the genus '' Uca'', the species was ...

'' ( Crane, 1941) (dancing fiddler crab) ** ''

Leptuca thayeri ''Leptuca thayeri'', known generally as the Atlantic mangrove fiddler crab or mangrove fiddler, is a species of true crab in the family Ocypodidae. It is distributed all across the Western Atlantic. ''Leptuca thayeri'' was formerly a member of ...

'' M. J. Rathbun, 1900 (Atlantic mangrove fiddler crab) ** ''

Leptuca tomentosa ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' ( Crane, 1941) (matted fiddler crab) ** ''

Leptuca umbratila ''Leptuca'' is a genus of fiddler crabs belonging to the family Ocypodidae. The species of this genus are found on the coasts of the Americas. Description They are small- to large-sized crabs with an adult carapace width of 5–25 mm in adu ...

'' ( Crane, 1941) (Pacific mangrove fiddler crab) ** '' Leptuca uruguayensis'' (Nobili, 1901) (Uruguayan fiddler crab) * '' Minuca'' ** ''

Minuca argillicola Minuca may refer to: * ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' ( Crane, 1941) (clay fiddler crab) ** ''

Minuca brevifrons Minuca may refer to: * Minuca (crab), ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' (Stimpson, 1860) (narrow-fronted fiddler crab) ** '' Minuca burgersi'' (Holthuis, 1967) (burger's fiddler crab) ** ''

Minuca ecuadoriensis Minuca may refer to: * ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' (Maccagno, 1928) (Pacific hairback fiddler crab) ** '' Minuca galapagensis'' (galápagos fiddler crab) ** ''

Minuca herradurensis Minuca may refer to: * Minuca (crab), ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' (Bott, 1954) (la herradura fiddler crab) ** ''

Minuca longisignalis ''Minuca longisignalis'', the longwave gulf fiddler, is a species of American broad-front fiddler crab in the family Ocypodidae The Ocypodidae is a family of semiterrestrial crabs that includes ghost crabs and fiddler crabs. These crabs are f ...

'' (Salmon & Atsaides, 1968) (longwave gulf fiddler) ** ''

Minuca marguerita Minuca may refer to: * ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' (Thurman, 1981) (olmec fiddler crab) ** ''

Minuca minax ''Minuca minax'', commonly known as the red‐jointed fiddler crab or brackish-water fiddler crab, is a species of fiddler crab that is found in the United States from Massachusetts to the Gulf of Mexico. It is one of the most common macroinverte ...

'' (Le Conte, 1855) (red-jointed fiddler crab) ** ''

Minuca mordax Minuca may refer to: * ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' (Smith, 1870) (biting fiddler crab) ** ''

Minuca osa Minuca may refer to: * ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' (Landstorfer & Schubart, 2010) (osa fiddler crab) ** ''

Minuca pugnax ''Minuca pugnax'', commonly known as the Atlantic marsh fiddler crab, is a species of fiddler crab that lives on north-western shores of the Atlantic Ocean. Distribution ''Minuca pugnax'' is the most common species of fiddler crab on the east co ...

'' (S. I. Smith, 1870) (Atlantic marsh fiddler crab) ** ''

Minuca rapax ''Minuca rapax'', also known by its common name mudflat fiddler crab, is a species from the genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant tax ...

'' (Smith, 1870) (mudflat fiddler crab) ** ''

Minuca umbratila Minuca may refer to: * ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' Crane, 1941 (Pacific mangrove fiddler crab) ** ''

Minuca victoriana Minuca may refer to: * ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' (von Hagen, 1987) (victorian fiddler crab) ** ''

Minuca virens Minuca may refer to: * Minuca (crab), ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' (Salmon & Atsaides, 1968) (green-banded fiddler crab) ** ''

Minuca vocator Minuca may refer to: * Minuca (crab), ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' (Herbst, 1804) (Atlantic hairback fiddler crab) ** ''

Minuca zacae Minuca may refer to: * Minuca (crab), ''Minuca'' (crab), genus of crabs belonging to the family Ocypodidae * Minuca (footballer) (1944–2010), Hermínio Francisco de Oliveira Filho, Brazilian footballer {{disambiguation, hn ...

'' ( Crane, 1941) (lesser Mexican fiddler crab) * '' Paraleptuca'' ** '' Paraleptuca boninensis'' (Shih, Komai & Liu, 2013) (bonin islands fiddler crab) ** ''

Paraleptuca chlorophthalmus ''Paraleptuca chlorophthalmus'', is a common fiddler crab found in the mangroves of East Africa, from Somalia to South Africa, as well as Madagascar and Mauritius. Marsh fiddlers dig burrows in the muddy or sandy banks of salt marshes, which they ...

'' ( H.Milne Edwards, 1837) (green-eyed fiddler crab) ** ''

Paraleptuca crassipes ''Paraleptuca crassipes'' or the thick-legged fiddler crab is a species of fiddler crab that lives in intertidal habitats distributed across the western Pacific Ocean. ''Paraleptuca crassipes'' was formerly a member of the genus '' Uca'', but in ...

'' (White, 1847) (thick-legged fiddler crab) ** '' Paraleptuca splendida'' (Stimpson, 1858) (splendid fiddler crab) * '' Petruca'' ** '' Petruca panamensis'' Ng, Shih & Christy, 2015 * ''

Tubuca ''Tubuca'' is a genus in Ocypodidae The Ocypodidae is a family of semiterrestrial crabs that includes ghost crabs and fiddler crabs. These crabs are found along tropical and temperate shorelines worldwide. Some genera previously classified w ...

'' ** '' Tubuca acuta'' (Stimpson, 1858) (acute fiddler crab) ** ''

Tubuca alcocki ''Tubuca alcocki'' is a species of fiddler crab. Its range includes most of the northern Indian Ocean, from western Thailand (facing the Andaman Sea), through the Bay of Bengal and India, to the Red Sea. Etymology The specific name ''alcocki'' i ...

'' Shih, Chan & Ng, 2018 (alcock's fiddler crab) ** ''

Tubuca arcuata ''Tubuca arcuata'', the bowed fiddler crab, is a species of fiddler crab in the family Ocypodidae. It can be found in China, Taiwan, Korea, and Japan. Size Large carapace breadth: 25.3 mm ± 5.84 (sd), 95% range: 13.9–36.8 mm Referencs

...

'' (De Haan, 1835) (bowed fiddler crab) ** '' Tubuca australiae'' ( Crane, 1975) ** '' Tubuca bellator'' (White, 1847) (belligerent fiddler crab) ** ''

'' ( Crane, 1975) (capricorn fiddler crab) ** '' Tubuca coarctata'' ( H.Milne Edwards, 1852) (compressed fiddler crab) ** ''

Tubuca demani ''Tubuca'' is a genus in Ocypodidae The Ocypodidae is a family of semiterrestrial crabs that includes ghost crabs and fiddler crabs. These crabs are found along tropical and temperate shorelines worldwide. Some genera previously classified w ...

'' (Ortmann, 1897) (demanding fiddler crab) ** '' Tubuca dussumieri'' ( H.Milne Edwards, 1852) (dussumier's fiddler crab) ** '' Tubuca elegans'' (George & Jones, 1982) (elegant fiddler crab) ** ''

Tubuca flammula ''Tubuca flammula'', commonly known as the flame-backed fiddler crab is a species of fiddler crab that is found in the northwest of Western Australia, the northern part of the Northern Territory and the western half of Papua New Guinea ''Tubuca ...

'' ( Crane, 1975) (flame-backed fiddler crab) ** ''

Tubuca forcipata ''Tubuca'' is a genus in Ocypodidae The Ocypodidae is a family of semiterrestrial crabs that includes ghost crabs and fiddler crabs. These crabs are found along tropical and temperate shorelines worldwide. Some genera previously classified w ...

'' (Adams & White, 1849) (forceps fiddler crab) ** '' Tubuca hirsutimanus'' (George & Jones, 1982) (hairy-handed fiddler crab) ** '' Tubuca longidigitum'' (Kingsley, 1880) (long-fingered fiddler crab) ** '' Tubuca paradussumieri'' (Bott, 1973) (spined fiddler crab) ** '' Tubuca polita'' ( Crane, 1975) (polished fiddler crab) ** '' Tubuca rhizophorae'' (Tweedie, 1950) (Asian mangrove fiddler crab) ** '' Tubuca rosea'' (Tweedie, 1937) (rose fiddler crab) ** '' Tubuca seismella'' ( Crane, 1975) (shaking fiddler crab) ** ''

Tubuca signata ''Tubuca signata'', the signalling fiddler crab, is a species of fiddler crab The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their ...

'' (Hess, 1865) (signaling fiddler crab) ** '' Tubuca typhoni'' ( Crane, 1975) (typhoon fiddler crab) ** ''

Tubuca urvillei ''Tubuca urvillei'' is a species of fiddler crab. It is found in Southeastern Africa from southern Somalia to South Africa and Madagascar. ''Tubuca urvillei'' was formerly a member of the genus '' Uca'', but in 2016, it was placed in the genus ' ...

'' ( H.Milne Edwards, 1852) (d'urville's fiddler crab) * ''Uca'' ** †''

Uca antiqua The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly lar ...

'' Brito, 1972 ** ''

Uca heteropleura The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly lar ...

'' (Smith, 1870) (American Red fiddler crab) ** †''

Uca inaciobritoi The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly lar ...

'' Martins-Neto, 2001 ** ''

Uca insignis The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly lar ...

'' ( H.Milne Edwards, 1852) (distinguished fiddler crab) ** '' Uca intermedia'' von Prahl & Toro, 1985 (intermediate fiddler crab) ** ''

Uca major The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly lar ...

'' Herbst, 1782 (greater fiddler crab) ** †''

Uca marinae The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly lar ...

'' Dominguez-Alonso, 2008 ** ''

Uca maracoani The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly lar ...

'' Latreille 1803 (Brazilian fiddler crab) ** ''

Uca monilifera The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly la ...

'' Rathbun, 1914 (necklaced fiddler crab) ** †''

Uca nitida The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly lar ...

'' Desmarest, 1822 ** †''

Uca oldroydi The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly lar ...

'' Rathbun, 1926 ** ''

Uca ornata The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly lar ...

'' (Smith, 1870) (ornate fiddler crab) ** '' Uca princeps'' (Smith, 1870) (large Mexican fiddler crab) ** '' Uca stylifera'' ( H.Milne Edwards, 1852) (styled fiddler crab) ** ''

Uca subcylindrica The fiddler crab or calling crab can be one of the hundred species of semiterrestrial marine crabs in the family Ocypodidae. These crabs are well known for their extreme sexual dimorphism, where the male crabs have a major claw significantly lar ...

'' Stimpson, 1862 (Laguna Madre fiddler) * '' Xeruca'' ** '' Xeruca formosensis'' (Rathbun, 1921)

Gallery

Captivity

Fiddler crabs are occasionally kept as pets. The fiddler crabs sold in pet stores generally come from brackish water lagoons. Because they live in lower salinity water, pet stores may call them fresh-water crabs, but they cannot survive indefinitely in fresh water. Fiddler crabs have been known to attack small fish in captivity, as opposed to their natural feeding habits.

References

External links

*
Movie of two fiddler crabs (''Uca lactea lactea'') waving the enlarged claw
- University of Kyoto
Info on systematics, phylogeny and morphology of fiddlers
- Fiddlercrab.info
The colorful fiddler crabs in the mangrove forest of Borneo
- mysabah.com {{Taxonbar, from=Q1329937 Ocypodoidea Asymmetry Arthropod common names