Balian E.V., L?v?que C., Segers H., Martens K. (Eds.) Freshwater Animal Diversity Assessment

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FRESHWATER ANIMAL DIVERSITY ASSESSMENT

Global diversity of shrimps (Crustacea: Decapoda:

Caridea) in freshwater

S. De Grave Æ Y. Cai Æ A. Anker

 Springer Science+Business Media B.V. 2007

Abstract Freshwater caridean shrimps account for

approximately a quarter of all described Caridea,

numerically dominated by the Atyidae and Palaemo-

nidae. With the exception of Antarctica, freshwater

shrimp are present in all biogeographical regions.

However, the Oriental region harbours the majority

of species, whilst the Nearctic and western Palaearc-

tic are very species-poor. Many species are important

components of subsistence ﬁsheries, whilst the Giant

River Prawn forms the basis of an extensive aqua-

culture industry. A total of 13 species are threatened

or endangered, with one species formally extinct.

Keywords Caridea  Decapoda  Freshwater 

Biodiversity

Introduction

The suborder Caridea presently consists of approxi-

mately 2,500 described species in 31 families. They

occur in all aquatic habitats on the planet, from

pelagic marine species and those dwelling in anchi-

aline caves through to freshwater species. A total of

655 freshwater species (just over a quarter of all

described carideans) are presently known. Amongst

the freshwater families, the two most speciose are the

near exclusively freshwater Atyidae and the Palae-

monidae (Subfamily Palaemoninae), which also have

brackish water and marine representatives. Freshwa-

ter shrimps occur in a vast range of habitats, from

torrential mountain streams down to sluggish, oli-

gohaline waters. Freshwater stygobiont taxa are well

represented, with many more taxa occasionally found

in subterraneous habi tats (see Holthuis, 1986). Atyi-

dae are characterised by unique feeding chelipeds,

with the complex brushes on the ﬁrst and second

pereiopods (Fig. 1A) ﬁltering out suspended matter

or sweeping up microbial ﬁlms (Fryer, 1977). Mem-

bers of the Palaemonidae exhibit a wide variety in

habitus, from the unspecialised habitus of Palae-

monetes species through to the males of Macrob-

rachium, which have unusually enlarged second

chelae (Fig. 1B), used in agonistic interactions and

Guest editors: E. V. Balian, C. Le

que, H. Segers and

K. Martens

Freshwater Animal Diversity Assessment

S. De Grave (&)

Oxford University Museum of Natural History,

Parks Road, Oxford OX1 3PW, UK

e-mail: sammy.degrave@oum.ox.ac.uk

Y. Cai

Biodiversity Centre, National Parks Board,

1 Cluny Road, Singapore 259569,

Republic of Singapore

e-mail: caiyixiong@yahoo.com

A. Anker

Smithsonian Tropical Research Institute, Naos Unit 0948,

APO AA, Miami, FL 34002-0948, USA

e-mail: ankera@si.edu

123

Hydrobiologia (2008) 595:287–293

DOI 10.1007/s10750-007-9024-2

predation. Many freshwater taxa are important as

sources for artisanal ﬁsheries (Holthuis, 1980), with

one species, Macrobrachium rosenbergii (De Man),

being an important aquaculture species. Freshwater

species are also becoming increasingly popular in the

aquarium trade. Abbreviated larval development

occurs in many species of Atyidae and freshwater

Palaemoninae, with members of Neocaridi na having

completely lost larval development, hatching as post

larvae. Although abbreviated larval development

allows these species to complete their life cycle in

freshwater, many other species of both families

complete part of their larval cycle in brackish water

or even in fully marin e conditions.

Species diversity

Freshwater species of carideans belong to eight

families/subfamilies, numerically dominated by the

Atyidae, with 359 species/subspecies (Table 1).

Although this family is considered in many textbooks

as restricted to freshwater habitats, some anchialine

genera are known (e.g. Antecaridina, Halocaridina ,

Typhlatya), whilst juveniles of Atya have been found

under fully marine conditions in Atlantic waters.

Although the most speciose genus Caridina occurs in

six biogeographic regions, many genera and species

are either only known from their type locality or have

a narrow geographical distribution (e.g. Lancaris is

restricted to Sri Lanka, see Cai & Bahir, 2005). Some

species are morphologically adapted to live in fast-

ﬂowing water, such as the Caribbean Atya scabra

(Leach), which lives beneath rocks under waterfalls

and in rapids, whilst other species, such as many

Caridina species are adapted to lakeshore weed beds,

usually displaying a more gracile habitus. Cave

dwelling taxa are well represented with many exclu-

sively stygobiont genera. Of particular ecological

interest are the only two freshwater commensal

species (a widespread mode of life in marine shrimp

species): Limnocaridina iridinae Roth-Woltereck

from the mantle cavity of a unionid clam from Lake

Tanganyika (Roth-Woltereck, 1958) and a Caridina

species from Lake Towuti in Sulawesi living with

freshwater sponges (Cai, pers. obs.).

The second most speciose family is the Palaemo-

nidae (Table 1), with many more marine and brackish

Fig. 1 Habitus of (A)

Caridina weberi De Man,

and (B) Macrobrachium lar

(Fabricius)

288 Hydrobiologia (2008) 595:287–293

123

water species known than there are freshwater taxa,

all of the latter being restricted to the subfamily

Palaemoninae. The numerically dominant genus is

Macrobrachium, restricted to fresh and brackish

water except for the enigmatic, single record of an

undescribed species from Canadian waters. Other

species-rich genera are Palaemonetes, a taxonomi-

cally poorly deﬁned world-wide genus, and Palae-

mon. Some species of Palaemonetes are exclusively

freshwater, such as the North American Palaemone-

tes kadakiensis Rathbun, but several estuarine species

can tolerate fully freshwater conditions. Several

species of Palaemon have also been recorded from

marine, brackish and freshwater environments, e.g.

Palaemon concinnus Dana (see Marquet, 1991).

Fewer species are known in the near exclusively

freshwater Typhlocarididae (one species being anchi-

aline). The Typhlocarididae comprises two subfami-

lies, the monogeneric stygobiont Typhlocaridinae,

and the Euryrhynchinae with representatives in South

America and West Africa. Although the Alpheidae are

one of the most species-rich shrimp families, a few

freshwater species are known. Some members of the

genus Potamalpheops and Alpheus cyanoteles Yeo &

Ng occur in freshwater, with several other species

either tolerating seasonally fresh water or occurring in

oligohaline waters.

It is difﬁcult to estimate the true species richness

of freshwater shrimps, as ever y year new taxa

continue to be described, mainly in the two most

numerically dominant genera, Caridina and Macrob-

rachium. As a result, species discovery curves are not

ﬂattening out (Fig. 2), and it can be expected that

many more species await discovery. New genera also

continue to be erected, for instance for morpholog-

ically disparate species previously placed in Caridina

(e.g. the genera Lancaris, Sinodina, Paracaridina).

Genetic studies have only recently started in fresh-

water shrimps, with for instance the work of Baker

et al. (2004) highlighting the presence of several

cryptic lineages in Australian Paratya, some of which

may well represent true species.

Table 1 Geographical distribution of freshwater Caridea described up to December 2005

Family/Subfamily PA NA NT AT OL AU PAC ANT World

Species + subspecies

Alpheidae – – 1 1 2 – – – 4

Atyidae 31 4 19 59 209 55 13 – 359

Desmocarididae – – – 2 – – – – 2

Kakudicarididae – 1 – – – 2 – – 3

Palaemonidae 13 12 83 28 138 30 12 – 276

Euryrhynchinae – – 4 2 – – – – 6

Typhlocaridinae 3 – – – – – – – 3

Xiphocarididae – – 2 – – – – – 2

Total 47 17 109 92 349 87 25 – 655

Genera

Alpheidae – – 1 1 1 – – – 2

Atyidae 9 2 5 11 13 11 4 – 35

Desmocarididae – – – 1 – – – – 1

Kakudicarididae – 1 – – – 2 – – 3

Palaemonidae 4 2 9 2 7 2 2 – 13

Euryrhynchinae – – 1 2 – – – – 3

Typhlocaridinae 1 – – – – – – – 1

Xiphocarididae – – 1 – – – – – 1

Total 14 5 17 17 21 15 6 – 59

Note that the family Typhlocarididae is divided into two subfamilies: Typhlocaridinae and Euryrhynchinae. PA: Palaearctic, NA:

Nearctic, NT: Neotropical, AT: Afrotropical, OL: Oriental, AU: Australasian, PAC: Paciﬁc Oceanic Islands, ANT: Antarctic

Hydrobiologia (2008) 595:287–293 289

123

Phylogeny and historical processes

In common with the remainder of the Caridea, very

little can be said on the phylogeny of freshwater

shrimps, mainly due to the paucity of higher level

cladistic and genetic studies, with the study of Pereira

(1997) being the sole exception for freshwater taxa.

This study clearly highlighted the non-monophyletic

status of many of the palaemonid genera, recently

also suggested by genetic work (Murphy & Austin,

2005).

It is however evident that, at a minimum, three

invasions of freshwater must have taken place, as

palaemonoid, atyoid and alpheoid shrimps are not

closely related. Several lines of evidence, including

the occurrence of freshwater fossils of Cretaceous age

(Beurlen, 1950) testify that Atyidae are ancient

inhabitants of freshwater, having diverged early from

an ancestral marine stock (Fryer, 1977). The origin of

Macrobrachium has been suggested to be in the late

Oligocene or early Miocene (Short, 2004; Murphy &

Austin, 2005), although there are evidence that

multiple invasions of freshwater are involved (Pere-

ira, 1997; Murphy & Austin, 2005).

Present distribution and main areas

of endemicity

With the exception of Antarctica, freshwater caride-

ans shrimps are present in all the main biogeograph-

ical regions (Fig. 3). The Oriental region harbours

three times as many species as the next most species-

rich provinces: Neotropical, Afrotropical and Aus-

tralasian. Th e Nearctic region harbours the lowest

number of taxa, primarily due to the absence of

Fig. 3 Geographical

distribution of species/

subspecies and genera

described up to December

2005 (Species number/

Genus number), coded

according to the main

zoogeographic regions. PA:

Palaearctic, NA: Nearctic,

NT: Neotropical, AT:

Afrotropical, OL: Oriental,

AU: Australasian, PAC:

Paciﬁc Oceanic Islands,

ANT: Antarctic

Fig. 2 Rates of discovery for the two most species-rich genera

of freshwater shrimp, Caridina (full line) and Macrobrachium

(dotted line)

290 Hydrobiologia (2008) 595:287–293

123

Caridina and the low number of Macrobrachium

present. Although the Palaearctic region harbours 47

taxa, there is a marked discrepancy in species

composition between the western and eastern Palae-

arctic, with no overlapping species distributions.

Interestingly, the number of troglobitic taxa is

roughly similar across several of the main biogeo-

graphic regions (Table 2), although within each

region they are not uniformly distributed. Within

the Afrotropical region for instance, all except two

species (Caridina lovoensis Roth-Woltereck from

Zaire and Caridina lanzana Holthuis from Somalia)

occur in Madagascar (Holthuis, 1986).

On a family level, the Aty idae are present in ﬁve

biogeographic regions, but with very few represen-

tatives in the western Palaearctic, Neotropical or

Nearctic regions. The only representatives of this

family in the western Palaearctic are the genera

Atyaephyra, Typhl atya , Troglocaris and Dugastella,

with in addi tion Car idina nilotica occurring in Egypt.

The atyid fauna of the Nearctic is very impoverished,

with only four species in two genera (Palaemonias,

Syncaris), whilst the Neotropical fauna consists of 19

species, primarily of the genus Atya .

The family Palaemonidae also occurs in all six

biogeographic regions, but with distinct generic level

differences (Table 1). Macrobrachium exhibits its

highest diversity in the Oriental region (123 species),

with far fewer species occurring in the Neotropical

(53 species) and the Australasian regions (28 spe-

cies). Only three species occur in the Nearctic region,

whilst the eastern Palaearctic only harbours four

species and the Paciﬁc region 10.

The Desmocarididae are restricted to West Africa

(Powell, 1977), in contrast the Euryrhynchinae occur

in Brazil ( Euryrhynchus) and west Africa (Euryrhyn-

china, Euryrhynchoides) (Powell, 1976). The

Xiphocarididae are restricted to the northern part of

the Neotropical region, chieﬂy being distributed in

the Caribbean islands; whilst the Typhlocaridinae

only occur in the western Palaearctic. Perhaps the

most disjunct distribution on a family level is

exhibited by the Kakaducarididae, with one troglob-

itic species, Calathaemon holthuisi (Strenth), from

Texas, and two epigean species in Australia (Kaka-

ducaris glabra Bruce, Leptopalaemon gagudjui

Bruce & Short) (see Bruce, 1993).

The majority of genera are restricted to a single

biogeographical region, with some notable excep-

tions, primarily those genera with marine or anchi-

aline representatives. For instance, Potamalpheops

occurs worldwide, but the only freshwater represen-

tatives are found in Mexico, West Africa and

Singapore (Anker, 2005). Similarly, Typhlatya is

distributed on both sides of the Atlantic, although

freshwater species are only found in Europe (Jaume

& Bre

hier, 2005). Caridina, Macrobrachium, Neoc-

aridina and Paratya have representatives in adjacent

parts of the Afrotropical/Oriental and/or Australasian/

Paciﬁc regions. The genus Atya has representatives

on either side of the Atlantic (Hobbs & Hart, 1982),

whilst the troglobitic genus Parisia occurs in Mad-

agascar, Australia and the Philippines.

species level, few taxa are present in more

than one biogeographical region. A suite of nine

species is distributed from East Africa (Afrotropical)

across the Oriental region through to the Austral-

asian/Paciﬁc regions. However, the taxonomic status

of man y of these populations may be in doubt. In

addition, this includes species such as Palaemon

debilis Dana and P. concinnus, both also recorded

from marine and estuarine habitats (C hace & Bruce,

1993), and it remains unclear if these taxa are present

in freshwater throughout their range. In addition, two

species of Atya (Atya gabonensis Giebel, Atya

scabra) are known from both sides of the Atlantic;

Table 2 Geographical distribution of troglobitic freshwater species of Caridea described up to December 2005

Family/Subfamily PA NA NT AT OL AU PAC ANT World

Atyidae 13 2 – 10 6 11 1 – 43

Kakudicarididae – 1 ––––– – 1

Palaemonidae – 2 15 – 4 1 – – 22

Typhlocaridinae 3 – ––––– – 3

Total 16 5 15 10 10 12 1 – 69

PA: Palaearctic, NA: Nearctic, NT: Neotropical, AT: Afrotropical, OL: Oriental, AU: Australasian, PAC: Paciﬁc Oceanic Islands,

ANT: Antarctic

Hydrobiologia (2008) 595:287–293 291

123

whilst there is some species overlap between the

eastern Palaearctic and the north-eastern Oriental

region.

On a more regional scale, several biodiversity

hotspots emerge. Mada gascar harbours 26 species of

Atyidae, many of which are troglobitic; with just over

three quarters of all species being endemic to the

island. Of the 28 species of atyids reported from

Sulawesi, half of them are endemic to the island

group, with a further 14 undescribed species recently

discovered from either cave habitats or in the ancient

lakes of the Malii group. Although the Chinese fauna

can still be considered imperfectly known, 136 taxa

are known to occur, many of which are endemic to

Hunan province (Liang, 2004). As the majority of

newly described Atyidae are from China, many more

species may await discover y. Although the total

species richness of Lake Tanganyika and the Amazon

region is relatively low, both areas are rich in

endemic genera (Limnocaridina, Caridella and

Atyella in Lake Tanganyika, Pseudopalaemon and

Euryrhynchus in the Amazon).

Human related issues

Holthuis (1980) listed 16 species of Atyidae and 61

species of freshwater Palaemonidae as either of

commercial interest or forming an important compo-

nent of subsistence ﬁshing, especially in South

America, Africa, the Far East and many Paciﬁc

islands. In addition, he noted that many, unidentiﬁed

and probably mixed populations of small species of

Caridina are heavily ﬁshed in the Philippines, China,

Sulawesi, Madagascar and parts of the Ganges Delta.

In the Philippines, these are eaten fresh or salted and

made into a fermented product, called alamang.

The Giant River Prawn, Macrobrachium rosen-

bergii, is not only commercially ﬁshed within its

native range (India to northern Australia), but also

Table 3 Species afforded special protec tion by IUCN or state legislation

Species Distribution IUCN status Other

Creaseria morleyi (Creaser) Mexico – Threatened

Macrobrachium acherontium

Holthuis

Mexico – Special protection afforded

Macrobrachium villalobosi

Hobbs

Mexico – Special protection afforded

Neopalaemon nahuatlus Hobbs Mexico – In danger of extinction

Palaemonias alabamae Smalley USA Endangered Listed as endangered in the Endangered

Species Act, 1975

Palaemonias ganteri Hay USA Endangered Listed as endangered in the Endangered

Species Act, 1975

Palaemonetes antrorum Benedict USA Endangered –

Palaemonetes cummingi Chace USA Vulnerable listed as threatened in the Endangered

Species Act, 1975

Stygiocaris lancifera

Holthuis

Australia – Likely to become extinct. Listed in the Wildlife

Conservation (specially protected fauna)

Notice 2003

Syncaris pasadenae (Kingsley) USA Extinct –

Syncaris paciﬁca (Holmes) USA Endangered listed as endangered in the US Endangered

Species Act, 1975

Troglocaris anopthalmus

(Kollar)

Former Yugoslavia and Italy Vulnerable –

Troglomexicanus

perezfarfanteae

(Villalobos)

Mexico – In danger of extinction

Three subspecies of T. anopthalmus are known, which are not distinguished in the IUCN list. The other category refers to local or

state protection categories

292 Hydrobiologia (2008) 595:287–293

123

forms the basis of intensive prawn farming since the

1960s, both in its native range and outside (e.g.

Alaska, USA, Nicaragua). The annual production is

estimated to be around 200,000 tonnes, worth about a

billion dollars. Recently Chinese prawn farms have

also begun culturing Macrobrachium nipponense (De

Haan), whilst minor quantities of Macrobrachium

malcomsoni (H. Milne Edwards) are commercially

farmed in India.

Several species are now available in the freshwater

aquarium trade, some of which are being speciﬁcally

cultured for this purpose (Werner, 2003). At least 18

species of Caridina, Neocaridi na, Atya, Atyopis,

Atyoida and Macrobrachium are now regularly

offered for sale, mainly Asiatic species.

A total of 13 species have been either listed in the

IUCN Red Data Book (2004 edition) or are otherwise

afforded local or state protection (Table 3). With the

exception of Syncaris pa sadenae (Kingsley), all these

taxa are stygobionts, many only known from a single

cave or cave system, with these systems being under

threat of human encroachment and ground water

pollution. Syncaris pasadenae is the only shrimp

species presently considered as extinct. Formally it

occurred in a few streams in the Los Angeles area,

but the species has not been found since 1933, despite

extensive searches (Martin & Wicksten, 2004).

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123

FRESHWATER ANIMAL DIVERSITY ASSESSMENT

Global diversity of crayﬁsh (Astacidae, Cambaridae, and

Parastacidae––Decapoda) in freshwater

Keith A. Crandall Æ Jennifer E. Buhay

 Springer Science+Business Media B.V. 2007

Abstract The freshwater crayﬁshes are distributed

across all but the Indian and Antarctic continents with

centers of diversity in the southeastern Appalachian

Mountains in the Northern Hemisphere and in south–

east Australia in the Southe rn Hemisphere. There are

currently over 640 described species of freshwater

crayﬁshes with an average of 5–10 species still being

described each year. Freshwater crayﬁshes can serve as

keystone species in aquatic habitats, but a few species

are als o signiﬁcantly invasive and can cause impres-

sive damage to the fragile freshwater habitat.

Crayﬁshes inhabit caves, burrows, streams, lakes and

strong burrowers can even be found in terres trial

habitats where they have burrowed to the water table or

where rainfall is sufﬁciently abundant to provide the

needed moisture. The freshwater crayﬁshes, like the

habitats in which they are encountered, are generally

endangered to some degree and conservation efforts

would do well to focus on them as key elements of the

freshwater ecosystem.

Keywords Crayﬁsh  Biodiversity 

Phylogeny  Conservation

Introduction

Freshwater crayﬁshes are a highly diverse group of

decapod crustaceans (over 640 species) with two

centers of diversity, one in the Southern Appalachian

Mountains of the southeastern United States (North-

ern Hemisphere center) and one in south–east

Australia (Southern Hemisphere center). Crayﬁshes

occupy four main habi tat types; primary burrowers

(those crayﬁsh who spend their entire life cycle in

borrows – indeed, primary burrowers can burrow

down to the water table and are not restricted to

freshwater but are essentially terrestrial), stream-

dwellers, pond/lake/large river dwellers (including

secondary burrowers who do require connectivity of

burrows with freshwater), and stygobitic species

(obligate cave-dwellers). Each habitat type has dis-

tinctive morphological adaptations for those

ecosystems (Fig. 1). For example, primary burrowers

typically have a vaulted carapace to accommodate

larger gill surface area and robust pinchers for

digging and burrow protection. Stream specialists

typically have large abdomens for swimming and are

highly intolerant of low oxygen content in the water.

Cave species have the typical suite of cave-adapted

morphologies including loss of pigmentation, loss of

eyes, elongated antennae, and elongated limbs. Most

Guest editors: E. V. Balian, C. Le

que, H. Segers & K.

Martens

Freshwater Animal Diversity Assessment

K. A. Crandall (&)  J. E. Buhay

Department of Biology, Brigham Young University,

Provo, UT 84602-5181, USA

e-mail: keith_crandall@byu.edu

K. A. Crandall

Monte L. Bean Life Science Museum, Brigham Young

University, Provo, UT 84602-5181, USA

123

Hydrobiologia (2008) 595:295–301

DOI 10.1007/s10750-007-9120-3

crayﬁsh typically has a life span of about 2 years

(although some surface and cave species can live

beyond 20 years). They reproduce sexually, although

hermaphroditic specimens and even parthenogenetic

specimens are known to occur (Scholtz et al. 2003).

Freshwater crayﬁshes are omnivorous and typically

nocturnal. They are voracious eaters and can be

extremely destructive whe n introduced to non-native

habitats. A few freshwater crayﬁsh are particularly

invasive (e.g., Orconectes rusticus) and/or were

distributed in the aquaculture trade (e.g., Procamb-

arus clarkii). These introduced species wreak havoc

on natural ecosystems to which they are not native,

but the vast majority of freshwater crayﬁshes are

extremely narrow ly distributed and hence are endan-

gered due mainly to the destruction of the freshwater

ecosystems in general. In this article, we review the

freshwater crayﬁsh diversity as it is currently under-

stood and emphasize both the phylogenetic diversity

and conservation status of this interesting group of

freshwater crustaceans.

Species diversity

There are over 640 described species of freshwater

crayﬁsh worldwide (Fig. 2; Table 1). Taxonomically,

they are organized into two superfamilies, the Northern

Hemisphere Astacoidea and the Southern Hemi sphere

Parastacoidea. The Astacoidea contain two families,

the Cambaridae (with by far the most species diversity,

containing over 420 species contained within 12

genera) and the Astacidae with six genera and 39

species (Hobbs 1989). The Parastacoidea are com-

posed of a single family, Parastacidae, consisting of 15

genera and over 170 species (Table 1).

Phylogeny and historical processes

The freshwater cray ﬁsh are a monophyletic group and

a sister taxon to the clawed lobsters from the

superfamily Nephropoidea (Crandall et al. 2000) and

together the Nephropoidea, Astacoidea, and Parasta-

coidea make up the Astacide a (Fig. 3). While much

work has been done in terms of testing the monophyly

and sister relationships among the crayﬁsh and their

allies, relatively little work has been published on the

phylogenetic relationships amo ng the genera of

freshwater crayﬁsh. To a large extent, this is reﬂective

of the fact that initial studies have shown that many of

the genera (especially in the family Cambaridae) do

not form mono phyletic groups, thereby requiring

relatively complete taxonomic sampling to perform

reasonable phylogenetic analyses (Sinclair et al.

2004). This is a difﬁcult task given the large number

of species of freshwater crayﬁsh.

Given the geographic distribution of this group

(Fig. 2) and the strong support for a monophyletic

origin, the cray ﬁshes must have originated in Pangaea

by the Tria ssic period (185–225 mya). The separation

of the two crayﬁsh superfamilies represents the

splitting of Pangaea into northern (Laurasia) and

southern (Gondwana) land-masses around 185 mya.

This separation is clearly seen in the estimat es of

crayﬁsh phylogenetic relationships (Fig. 3). The

antiquity of the crayﬁshes is supported by recent

fossil evidence from Colorado and Utah with fossil

crayﬁsh and burrows associated with Permian and

Early Triassic (265 mya) deposits (Hasiotis and

Mitchell 1993). Furthermore, the phylogenic connec-

tion of the Southern Hemisphere crayﬁshes

represented in southern South America, Madagascar,

New Zealand, and Australia corresponds to the

distribution patterns of the predatory dinosaur group

Abelisauridae (Sampson et al. 1998). Thus the

crayﬁshes offer further support for the hypothesis

suggesting extended contact between these land-

masses and the antiquity of the freshwater crayﬁsh

lineage (Crandall et al. 2000; Hobbs 1988; Scholtz

and Richter 1995).

Fig. 1 Orconectes incomptus (Hobbs & Barr 1972), a cave

adapted freshwater crayﬁsh from the Cumberland Plateau

escarpment in northern Tennessee, USA (photo by Jennifer E.

Buhay



)

296 Hydrobiologia (2008) 595:295–301

123

Present distribution and areas of endemicity

The most species rich family of freshwater crayﬁsh,

the Cambaridae, are distributed in North America

east of the Rocky Mountains, north into southern

Canada and south through Mexico and, surprisingly,

in Asia (Table 1). The Asian endemic genus Cam-

baroides is a bit of an enigma both biogeographically

Table 1 Total number of described freshwater crayﬁsh species

by taxon and distribution in the geographic regions of focus.

PA: Palaearctic; NA: Nearctic; NT: Neotropical; AT:

Afrotropical; OL: Oriental; AU: Australasian; PAC: Paciﬁc

Oceanic Islands; ANT: Antarctic

Family Genus PA NA AT NT OL AU World

Astacidae 31 8 0 0 0 39

Astacus 5 0 0 0 0 5

Atlantoastacus 8 0 0 0 0 8

39 species Austropotamobius 7 0 0 0 0 7

Caspiastacus 2 0 0 0 0 2

Pacifastacus 0 8 0 0 0 8

Pontastacus 9 0 0 0 0 9

Cambaridae 7 374 0 48 0 423

Barbicambarus 0 1 0 0 0 1

Bouchardina 0 1 0 0 0 1

445 species Cambarellus 0 8 0 9 0 17

Cambaroides 7 0 0 0 0 7

Cambarus 0 97 0 0 0 95

Distocambarus 0 5 0 0 0 5

Fallicambarus 0 18 0 0 0 18

Faxonella 0 4 0 0 0 4

Hobbseus 0 7 0 0 0 7

Orconectes 0 91 0 0 0 89

Procambarus 0 140 0 39 0 177

Troglocambarus 0 2 0 0 0 2

Parastacidae 0 0 9 16 151 176

Astacoides 0 0 9 0 0 9

Astacopsis 0 0 0 0 3 3

175 species Cherax 0 0 0 0 45 45

Engaeus 0 0 0 0 39 39

Engaewa 0 0 0 0 5 5

Euastacus 0 0 0 0 43 43

Geocharax 0 0 0 0 2 2

Gramastacus 0 0 0 0 1 1

Ombrastacoides 0 0 0 0 11 11

Paranephrops 0 0 0 0 2 2

Parastacus 0 0 0 8 0 8

Samastacus 0 0 0 1 0 1

Spinastacoides 0 0 0 3 0 3

Tenuibranchiurus 0 0 0 1 0 1

Virilastacus 0 0 0 3 0 3

Total 38 382 9 64 151 638

Hydrobiologia (2008) 595:295–301 297

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