aeglidos.pdf

8/10/2019 aeglidos.pdf

1/13

Nauplius 21(2): 211-223, 2013 211

New species and records of the genusAeglaLeach, 1820 (Crustacea,Anomura, Aeglidae) from the West-Central region of Rio Grandedo Sul, Brazil

Sandro Santos, Carlos G. Jara, Marlise Ladvocat Bartholomei-Santos, Marcos Prez-Losada andKeith A. Crandall

(SS, MLB-S) Departamento de Biologia, Universidade Federal de Santa Maria, 97105-900, SantaMaria, RS, Brasil. E-mail: [email protected].(CGJ) Instituto de Zoologa, Universidad Austral de Chile, Campus Isla eja, Casilla 567, Valdivia,Chile.(MP-L) CIBIO, Centro de Investigao em Biodiversidade e Recursos Genticos, Universidade doPorto, Campus Agrrio de Vairo, 4485-661, Vairo, Portugal.(KAC, SS, MLB-S) Computational Biology Institute, George Washington University, Ashburn, VA,20147, U.S.A.

(KAC) Department of Invertebrate Zoology, National Museum of Natural History, SmithsonianInstitution, Washington DC, 20013, U.S.A.

ABSTRACT-Aeglidae are anomuran freshwater crabs found only in southernSouth America. In Brazil, the greatest species diversity occurs in hydrographicbasins of the state of Rio Grande do Sul. wo new species, Aegla georginaeandAegla ludwigi, are described from the Ibicu and Iju Rivers, respectively (UruguayRiver Basin). Te new taxa can be distinguished from other Aeglaspecies basedon both morphological and molecular characters. Te two new species have a

very restricted distribution and are categorized as endangered (A. georginae) andcritically endangered (A. ludwigi) using IUCN Red List criteria. We also sum-marize and present new records of the Aegla species occurring in the UruguayRiver Basin.

Key words: Aeglidae,Aegla, Brazil, freshwater biodiversity, molecular systematics,taxonomy

one extant genus, Aegla Leach, 1820, with asurprising diversity, compared to crayfishes of

the family Parastacidae (Crandall et al., 2000)and brachyuran crabs of the genusrichodactylus(Yeo et al., 2006), also inhabiting southernSouth America waters. Te first aeglid specieswas described in 1818 by Latreille, followedby threeAeglaspecies described by the end ofthe 19thcentury (Bond-Buckup and Buckup,1994). No new aeglids were described untilthe 1940s, when 15 species were described bySchmitt and two by Ringuelet (Bond-Buckupand Buckup, 1994). After a second period of

INTRODUCTION

Members of the family Aeglidae are unique

among the infraorder Anomura because thewhole group is entirely restricted to freshwaterenvironments and to the Neotropical regionof South America (Bond-Buckup andBuckup, 1994). Te uniqueness of some of itsmorphological characters and its distinctivephylogenetic position (Prez-Losada et al.,2002) led to the reclassification of Aeglidae in aseparate super-family, Aegloidea (McLaughlinet al., 2007).

Te family Aeglidae comprises only

Published by Brazilian Crustacean Society, Ribeiro Preto, Brazil - December 2013c


2/13

Santos et al.: New species of Aeglidae212

stagnation, from 1972 onward the number ofknown Aegla species increased significantly,mainly due the contributions of C. Jara (Chile)and L. Buckup and G. Bond-Buckup (Brazil).Currently, a total of 72 species have been

described (McLaughlin et al., 2010; Santos etal., 2012). Of these, at least 25 Aegla speciesare under threat, according to the IUCN(2001) criteria (Bond-Buckup et al., 2008),including some species recently described suchas the vulnerableA. manuinflata Bond-Buckupand Santos, 2009,A. leachi Bond-Buckup andBuckup, 2012 and A. oblata Bond-Buckupand Santos, 2012 and the critically endangeredA. renanaBond-Buckup and Santos, 2010 andA. brevipalma Bond-Buckup and Santos, 2012

(Santos et al.2009; 2010; 2012).Forty-two species are present in

Brazilian rivers and 24 are found in rivers inBrazils southernmost state, Rio Grande doSul (Bond-Buckup et al., 2008; Bond-Buckupet al., 2010; Santos et al., 2010). Tis stateincludes three hydrographic regions, with theUruguay hydrographic basin being the largestand covering an area of 126,964.24 km2(Secretaria do Meio Ambiente RS). Despite

its large size, only 11 Aeglaspecies have beendescribed in this region so far (including threespecies from the bordering southern State ofSanta Catarina).

Efforts to catalogue and describe newspecies are crucial for biodiversity conserva-tion. Tis is especially true for freshwater or-ganisms, since the knowledge of the total di-versity of fresh waters is very incomplete. Ourknowledge of the fundamental units of biodi-versity are especially lacking among inverte-brates and microbes, particularly in the tropi-cal latitudes that support most of the worldsdiversity (Dudgeon et al., 2006). Moreover,global freshwater biodiversity has declined at

higher rates than biodiversity from either ma-rine or terrestrial habitats (Sala et al., 2000;Dudgeon et al., 2006; WWF, 2012). Here weexpand our current knowledge of the freshwa-ter biodiversity ofAeglain the Uruguay hydro-graphic region by describing two new speciesand presenting new records of previously de-scribed species (ab. 1). Furthermore, we as-sess these new species for conservation usingthe IUCN Red List criteria.

SpeciesSub-basins

1 2 3 5 6 7 8 9

Aegla grisellaBond-Buckup and Buckup, 1994 X

Aegla jaraiBond-Buckup and Buckup, 1994 X

Aegla longirostriBond-Buckup and Buckup, 1994 X X

Aegla manuniataBond-Buckup and Santos, 2009 X

Aegla odebrechtiiMller, 1876 X

Aegla platensisSchmitt, 1942 X X X X X

Aegla singularisRinguelet, 1948 X X

Aegla spinosaBond-Buckup and Buckup, 1994 X

Aegla uruguayanaSchmitt, 1942 X X X

Aegla leachiBond-Buckup and Buckup, 2012 X

Aegla oblataBond-Buckup and Santos, 2012 X

Aegla brevipalmaBond-Buckup and Santos, 2012 X

Aegla georginaen.sp. X

Aegla ludwigin.sp. X

Table 1. Distribution of Aeglidae in the main Sub-basins of the Uruguay River: x = present. Sub-basins are numbered as in Figure1: 1 = Upper Uruguay, 2 = Iju, 3 = Icamaqu, 5 = Jaguari, 6 = Ibicu-Mirim, 7 = Quara, 8 = Ibirapuit and 9 = Santa Maria.


3/13

Nauplius 21(2): 211-223, 2013 213

MATERIAL ANDMETHODS

Specimens of the two putative new specieswere collected in Perau Creek, tributary of theJaguari River (Ibicu Sub-basin) and in CambarCreek, a tributary of Potiribu River (IjuSub-basin) (Fig. 1), during several samplingcampaigns. All specimens are deposited in theCollections of Crustaceans of the Departmentof Zoology - Federal University of Rio Grandedo Sul (UFRGS), Laboratrio de Carcinologia- Universidade Federal de Santa Maria (UFSM)and Museu de Zoologia - Universidade de SoPaulo (MZUSP).

Te Cambar Creek (283411S -533715W) is a third-order stream, ranging

from 5.1 to 8.5 m in width and from 20 to 50 cmin depth at the sampled section. It has a rockybottom and is surrounded by agricultural areaswith exposure to agricultural runoff. Te PerauCreek (292913S - 544242.6W), located

in Jaguari municipality, has banks with bushvegetation and cattle graze in adjacent areas.Te habitat alternates environments with calmand flowing waters, with organic detritus andsandy-rocky substrate. In the section sampled,the creek was 2 to 5 m wide and ranged from20 to 50 cm in depth.

Te description of the two new Aeglaspecies is based on the examination of thecharacters of the type-series. Te identification

Figure 1.Map of the State of Rio Grande do Sul (Brazil) showing the main hydrographic basins and rivers: (A) Uruguay Basin (gray):1 Wetland, 2 Iju, 3 Icamaqu, 4 Ibicu, 5 Jaguari, 6 Ibicu-Mirim, 7 Quara, 8 Ibirapuit, 9 Santa Maria; (B) Jacu-Guaba Basin:

10 Jacu. * species 1; # species 2.


4/13


of the other species collected at the samehydrographic basin was confirmed using thekey in Bond-Buckup and Buckup (1994).For the measurements of the specimens, themethodology of Bond-Buckup and Buckup

(1994) was adopted, with the followingabbreviations: Letter m represents males,f females, j juveniles, CL cephalothoraxlength (from the midpoint of the orbital sinusto the midpoint of the posterior margin of thecarapace), PCW precervical width (betweenthe left and right epibranchial margins), FW frontal width (between the tips of the spinesof the antero-lateral angles of the carapace),AL areola length, AW areola width, RL rostrum length (between the tip of the rostrum

and the midpoint of the orbital margin).MZUSP Museu de Zoologia da Universidadede So Paulo, So Paulo, Brazil; UFRGS Universidade Federal do Rio Grande do Sul,Porto Alegre, Brazil. UFSM UniversidadeFederal de Santa Maria.

Morphometric analysis: For thedescription of the new species the followingbody dimensions were recorded for all animalsof the type series and also for the non-paratypeanimals: CL, RL, PCW, FW, AL and AW. Temorphometric ratios CL/RL, PCW/FW, andAL/AW were calculated for all animals fromeach species.

Molecular and phylogenetic analysis: Inorder to confirm that the two putative newspecies differ from other Aeglidae previouslydescribed not only in morphology but alsoin molecular characters, we constructeda phylogeny based on the mitochondrialgene COII. otal genomic DNA from fourspecimens of each of the two newAeglaspecieswas extracted using methods described byCrandall and Fitzpatrick (1996). A segmentof the mitochondrial gene COII (568 bp) wasPCR-amplified and sequenced, using primers,sequencing conditions and protocols describedin Prez-Losada et al. (2009). Sequencesare deposited in GenBank under accessionnumbers (KC237723-KC237728). Te new

Aegla sequences were aligned together with

those in Prez-Losada et al. (2009) usingClustalW implemented in Mega5 software(amura et al., 2011). Te alignment hadno ambiguous regions. Maximum likelihood(ML) phylogenies were inferred using RAxML

(Stamakis, 2006; Stamakis et al., 2008). Onehundred searches were conducted (Stamakis etal., 2008), using the GR++I model selectedby jModeltest2 (Darriba et al., 2012). Branchsupport was assessed via the rapid bootstrapalgorithm (100 replicates) (Stamakis et al.,2008; Pattengale et al., 2010). Aegla papudoSchmitt, 1942 was used as outgroup, sincethis species was found to be the most primitiveAeglidae, based on morphology (Jara, 1992)and molecular characters (Prez-Losada et al.,2002; Prez-Losada et al., 2004).

Conservation assessment: TeInternational Union for Conservation ofNature and Natural Resources (IUCN) set fivequantitative criteria that can be applied to assessif a taxon is threatened, and to which threatencategory it should be assigned (CriticallyEndangered, Endangered or Vulnerable).Most of them include sub-criteria to justify the

assignment of a taxon within a specific category.o assess the conservation status of these newspecies, we evaluated their geographic range,which was inferred from sampling efforts indifferent streams in the surrounding region.Te landscape characteristics (land use) at theperiphery of their ranges was based on dataabout forest coverage and evaluated (FundaoSOS Mata Atlntica & Instituto de PesquisasEspaciais, 2011: http://mapas.sosma.org.br/).

RESULTS

Aegla georginaen. sp. Santos & Jara(Fig. 2)

ype-material: Holotype male, Brazil,state of Rio Grande do Sul, Perau Creek,tributary of the Jaguari Sub-basin, Jaguari, RioGrande do Sul, 292913S - 544242.6W,07-ii-2009, collected by Legramanti et al., 1male (MZUSP 27831).


5/13

Nauplius 21(2): 211-223, 2013 215

Figure 2.Aegla georginae n. sp., new species: male holotype, dorsal view: (a) precervical portion of carapace, lateral view; (b) ischiumof cheliped, ventral view; (c) third and fourth sterna, ventral view; (d) second pleomere epimeron.


6/13


Additional material - Paratypes: 4 m(UFRGS 5343), same data as holotype; 6mand 4f (UFSM 332), Perau Creek, 16.ii. 2009Legramanti et al.; 2m, 2j (UFSM 328), igreCreek, tributary of Jaguari River, Rio Grande

do Sul, 5.ii.2009, collected by Santos et al.

Diagnosis: Antero-lateral spine ofcarapace short, not reaching base of cornea;protogastric lobes present and epigastriclobes very modest; extra-orbital sinus present,U-shaped; rostrum short, carenate; chelipedmovable finger without lobe; fingers of bothchelipeds with lobular tooth in inner margin;palmar crest of chelipeds subrectangular,both modest and excavated, tending to sub-

oval on the minor cheliped; anterior angle ofventral margin of epimeron 2 with a spine;inner margin of ventral surface of ischium ofcheliped with a distal spine, with one to threescales along margin, one proximal tubercle;dorsal margin of dactyle, propod and carpus ofthe second, third and fourth pereiopods withscaliform tubercles and setae.

Description: Carapace flat, with anteriordepression from protogastric lobes; dorsalsurface scabrous, covered with punctuations.

Front wide; PCW/FW ratio 1.79 inmale holotype.

Rostrum triangular, short [CL/RL= 5.16 (holotype)]; straight and slightlydeflected, larger at base, excavated in medianportion. Sub-rostral process developed;in profile, rostrum with equal ventral anddorsal proportions. Rostral carena presentfrom epigastric lobes, with scales irregularlydistributed on median portion ending inunique arrow on distal portion with superposedscales. Rostrum lateral margins with scalesextending on margin of orbital sinus.

Orbital sinus moderately wide, not deep,C-shaped. Orbital spine present. Extra-orbitalsinus U-shaped.

Antero-lateral angle of carapace narrowerthan first hepatic lobe, anteriorly projected bya scale, not reaching base of cornea. Outermargin of antero-lateral lobe with scales; inner

margin with few scales.

First hepatic lobe delimited anteriorly bygroove, U-shaped; lateral margin with scales;second hepatic lobe also delimited anteriorlyby incision, shallow; third lobe modestlydelimited; lateral margins with sub-equal

scales.Epigastric prominences slightly

indicated. Protogastric lobes present, notelevated; anterior margin marked by irregularscales.

ransverse dorsal line little sinuous.Areola sub-rectangular, with sub-parallelmargins evident along all its extension. RatioAL/AW of 1.78 (holotype).

Epibranchial area triangular, sub-acute,with one apical spine followed by smaller

scaliform tubercles. Lateral margins of anteriorand posterior branchial area with sub-equalscaliform tubercles.

Abdome with anterior angle of ventralmargin of epimeron two armed with distalspine; ventro-lateral margin almost straight;posterior angle of ventral margin unarmed.Epimera of third to sixth segments projecting;third and fourth lateral projection ornamentedwith small apical scale.

elson divided by longitudinal suture.Anterior extremity of third sternite

tapered, projecting between coxae of exopoditesof third maxillipeds. Fourth thoracic sterniteflat, narrow anteriorly and projected by twotubercles, lateral margins elevated; antero-lateral margin projecting.

Right and left propodi of chelipeds withminor sub-rectangular and major sub-ovalwith slight depression on median portion andpresence of many spiniform scales along allextension. Minor propodus with slim aspectand sub-rectangular, also covered by scales andwith moderate depression below palmar crest.Both palmar crests sub-rectangular, excavatedand with scales on margin. Movable fingerlacks lobe. Both dactyli covered with scales.Prehensile margin of fingers with scale-shapeddenticles along entire extension and withopposing, dovetailed lobular teeth, with spacebetween fingers. Pre-dactylar lobe ornamentedwith scales and forming small step with

anterior margin of propodus. Articulation


7/13

Nauplius 21(2): 211-223, 2013 217

propodus-carpus with condyle-alveolar shape,ornamented with tubercle on carpus side.Dorsal margin of carpus scabrous, with scales;inner margin with two spines, with distalspine larger than second, followed by up to

two tubercles; spines lacking ornamentation,smooth on lateral margins. Carpal crest tippedby sets of scales parallel to inner margin, morefeatured and robust in proximal region, in bothchelipeds; ventral surface with one conicaltubercle. Dorsal margin of merus of chelipedwith elevations and scaliform tubercles.Lateral surfaces scabrous, with scales andponctuations. Inner ventral margin of meruswith distal spine, with scale on base and twoor three tubercles-shaped projections along

margin; outer ventral margin with pronounceddistal scaliform tubercle. Dorsal margin ofischium with elevation ornamented with scalesand tufts of long setae; inner margin of ventralsurface with distal spine followed by one tothree scales and proximal tubercle.

Dorsal margin of dactylus, propodus,and carpus of second, third, and fourthpereiopods with rows of setae tufts. Ondactylus and propods, tufts of setae havevelvety aspect. Carpus of second and third

pereiopods unarmed.

Measurements: Male holotype with21.66 mm CL. Paratypes with mean of 18.56mm CL ( 2.54 mm) for males, ranging from14.4 to 24.0; 18.64 mm CL ( 1.86 mm) forthe females.

Ratio CL/RL of paratypes ranging from4.87 to 6.57 with mean of 5.50 ( 0.56) formales and 5.53 ( 0.20) for females.

Ratio PCW/FW: paratypes ranging

from 1.70 to 1.87 with mean of 1.76 ( 0.05)for males and 1.77 ( 0.03) for females.Ratio AL/AW: paratypes ranging from

1.64 to 1.85, mean ratio AL/AW: 1.75 (0.07) for males and 1.66 ( 0.13) for females.

Etymology: Named in honor of our friendand colleague Dr. Georgina Bond-Buckup, anaeglid specialist who has devoted her career tothe excellent study of the biology, taxonomyand systematics of this most interesting group

of freshwater crabs.

Biology: Both records ofA. georginaewereat headwaters with preserved riparian forest.At these sites the water was well oxygenated(> 7.0 mg/L) and the conductivity was low(


8/13


present inA. georginae but absent inA. renana,(ii) extra-orbital sinus is present inA. georginaebut absent in A. renana, which is probablythe most remarkable difference between thesetwo species, and (iii) A. georginae has a wide

front (ratio PCW/FW = 1.79 male holotype),whereasA. renanahas a narrow front (PCW/FW = 1.95 male holotype).

Aegla ludwigin. sp. Santos & Jara(Fig. 3)

ype-material: Holotype male, Brazil,state of Rio Grande do Sul, Cambar Creek,a branch ofPotiribu River, tributary of RiverIju Sub-basin, Cruz Alta, 283411S -533715W, 27-iii-2009, collected by Copattiet al., 1 male (MZUSP 27832).

Additional material - Paratypes: Brazil:14 m, 3 f and 4 j (UFRGS 5344), same dataas holotype.

Diagnosis: Antero-lateral spine ofcarapace reaching base of cornea; protogastriclobes absent and epigastric lobes modest;extra-orbital sinus present, U-shaped;rostrum medium, carinate along its entirelength, recurved distally; movable finger ofcheliped without lobe; cheliped fingers withlobular tooth in inner margin; palmar crestof minor cheliped sub-disciform and majorcheliped sub-rectangular, both developed andexcavated; anterior angle of ventral margin ofepimerum 2 unarmed; inner margin of ventralsurface of ischium of cheliped with distalspine, one to three scales along margin andproximal tubercle; dorsal margin of dactylus,propodus and carpus of second, third andfourth pereiopods with scaliform tubercles andsetae.

Description: Carapace convex, area ofgastric region more elevated, dorsal surfacescabrous, covered with punctuations.

Front large; PCW/FW ratio of maleholotype 1.87 (holotype)

Rostrum triangular, long, ratio CL/RL= 3.67 (holotype), deflected on distal third.

Rostral carena beginning between epigastric

prominences, carenate through its entireextension, rostral scales present, with tworows on proximal third and only one on distalportion. Apical portion of rostrum with atubercle. Rostrum lateral margin with scales.

Sub-rostral process, in profile, with ventralportion larger than dorsal.

Orbital sinus moderately broad, deep,U-shaped. Orbital spine present. Orbitalmargin with scales.

Antero-lateral angle of carapaceprojecting anteriorly in a scale, which reachesbase of cornea. Outer and inner margin ofantero-lateral lobe with scales. First hepaticlobe delimited anteriorly by fissure, U-shaped;lateral margins with scales; second and thirdhepatic lobes not delimited, only indicated byincision; lateral margins with sub-equal scales.

Epigastric prominences moderated, low,indefinite in form. Protogastric lobes absent.

ransverse dorsal line slightly sinuous.Areola quadratic, with ratio AL/AW = 1.53(mean), sub-parallel distinctive margins alongtheir entire length.

Margins of anterior and posteriorbranchial region slightly recurved, with scales.Epibranchial area triangular with tubercle.

Anterior angle of ventral margin ofepimeron 2 unarmed; ventro-lateral marginslightly concave; posterior angle of ventralmargin unarmed. Epimera of third to sixthsegments projecting; on third and fourthsegments, lateral projection ornamented withapical scale.

elson divided by longitudinal suture.Anterior extremity of third sternite

truncated, projecting between coxae ofexopodites of third maxillipeds. Fourththoracic sternite flat, lateral margins recurved;antero-lateral margin projecting by lateraltubercle; tuft of transversal setae on anteriorpart of segment.

Right and left propodi of chelipedsunequal, larger hand sub-rectangular. Proximalouter margin of movable finger without lobe.

Molar process of fingers of chelipedpresent. Fingers covered by scales andpunctuations. Prehensile margins of fingers

with scaliform denticles on their entire length,


9/13

Nauplius 21(2): 211-223, 2013 219

Figure 3.Aegla ludwigi n. sp., new species: male holotype, dorsal view: (a) precervical portion of carapace, lateral view; (b) ischium

of cheliped, ventral view; (c) third and fourth sterna, ventral view; (d) second pleomere epimeron.


10/13


and with fitted opposed lobular teeth, withspace between fingers.

Palmar crest sub-disciform in minorcheliped and sub-rectangular in major,margins ornamented with scales and excavated

in both chelipeds. Median ventral surface ofmajor propodus with carena, ornamentedwith punctuations and setae, suggesting anelevation.

Dorsal surface of carpus scabrous, withscales; inner margin smooth with two spines,followed by tubercles or scales, without setae;inner antero-lateral angle obtuse, ornamentedonly with scales; two chelipeds with pronouncedcarpal crest, elevations ornamented with scales,

more featured in proximal portion; ventralsurface with a detached tubercle. Dorsal marginof merus of cheliped with distal tubercle andelevations with scales that decrease in sizeproximally; antero-dorsal margin with sparsescales. Lateral surfaces scabrous, with scalesand punctuations. Inner ventral margin ofmerus with four to five scaliform elevations;in outer ventral margin a distal tubercle showsup. Dorsal margin of ischium with elevationornamented with scales and tuft of setae; inner

margin of ventral surface with a distal spinefollowed by up to three scales and a proximaltubercle.

Dorsal margin of dactylus, propodus,and carpus of second, third, and fourthpereiopods with rows of setae tufts. On dactylusand propods, tufts of setae with velvety aspect.

Measurements: Male holotype with25.95 mm CL. Paratypes with mean of 21.20mm ( 5.56) CL for males (n = 14), ranging

from 11.16 to 29.78; females (n = 2) 16.20mm 0.19 CL.

Ratio CL/RL of paratypes ranging from2.10 to 3.51, with mean of 2.65 ( 0.36) formales and 3.01 ( 0.02) for females.

Ratio PCW/FW of paratypes rangingfrom 1.69 to 1.98, with mean of 1.85 ( 0.07)for males and 1.87 ( 0,01) for females.

Ratio AL/AW: paratypes ranging from1.31 to 1.75, mean ratio AL/AW: 1.56 (

0.10) for males and 1.50 ( 0.13) for females.

Etymology: Named in honor of our friendand colleague Dr. Ludwig Buckup, pioneer inresearching freshwater crustaceans in southernBrazil, especially Aeglidae and Parastacidae.

Biology: Te species lives in a second-order stream, tributary to the Potiribu River,where the stream bed alternates betweensegments with slab covering and segments withsand and rocks of different diameters. Usuallythe aeglids are found under these rocks.Although there are two other aeglid speciesliving at the same stream section, it seems thatthey occupy different micro-habitats.

Distribution: Cambar Creek, Potiribu

River, tributary of River Iju Sub-basin, RiverUruguay Basin, Brazil.

Conservation assessment: CRIICALLYENDANGERED (CR) (B1-a-biii): B1)Extent of occurrence (EO) estimated to beless than 100 km2; a) severely fragmentedand known to exist at only a single location;biii) Continuing decline in quality of habitat(IUCN, 2001). Te continuing decline can beobserved as a constant replacement of nativevegetation by pasture or farmlands, mainlyalong the creeks margins. According to themost recent report on the relics of AtlanticForest, this forest accounted originally for63% of the overall forest area in Cruz AltaMunicipality, where the occurrence area ofA. ludwigi is situated. In 2010 only 2% hadbeen left (Fundao SOS Mata Atlntica &Instituto de Pesquisas Espaciais, 2011).

Systematics: Te molecular phylogeny(Fig. 4) as well as the morphological charactersconfirms that A. ludwigi is a new aeglidspecies. Based on the COII mitochondrialgene phylogeny, A. ludwigi is placed in asubclade with the species A. obstipa Bond-Buckup and Buckup, 1994, A. planaBuckupand Rossi, 1977, A. itacolomiensis Bond-Buckup and Buckup, 1994 and A. grisella,although with low clade support. Of all thesespecies only A. grisella has been recorded inthe same hydrographic basin as A. ludwigi.

Tese five Aegla species share very few


11/13

Nauplius 21(2): 211-223, 2013 221

Figure 4. Maximum likelihood tree. Bootstrap proportions (if >50%) are indicated for each clade. Branch lengths are shown

proportional to the amount of change along the branches.


12/13


morphological characters such as the absenceof protogastric and epigastric lobes and thepresence of an outer orbital sinus, modestin A. obstipa. Te following characteristics,however, are shared between A. ludwigi and

A. grisella: convex carapace; rostrum shape,long, entire carenate and deflected; size of theocular peduncle reaching the base of cornea;large front; movable finger of cheliped lackinglobe; second abdominal epimerum unarmed.However, these two species differ in relationto the palmar crests, while in A. grisellathesestructures are rectangular, in A. ludwigi theyare sub-disciform in the minor cheliped andsub-rectangular in the major cheliped, both

excavated. Our ML tree (Figure 4) depictedA. obstipa as the sister-species to A. ludwigi,however, several morphological featuresdistinguish these two taxa: (i) rostrum medium,ligulate and lacking carena inA. obstipaversusrostrum long, styliform and carenate in itsentire length inA. ludwigi; (ii) the extra-orbitalsinus is reduced inA. obstipaand delimited byonly one scale; (iii) the fourth thoracic sterniteis flat and lacks antero-lateral projections inA. obstipa, but it has lateral projections in A.

ludwigi; (iv)A. obstipapresents a narrow front,whereasA. ludwigi presents a wide one.

Aeglidae records for the sub-basins ofRiver Uruguay

Tirteen aeglid species have beendescribed in the River Uruguay Basin (able1). Usually these species have restricteddistributions, except A. platensis Schmitt,1942 and A. uruguayana Schmitt, 1942.A.

jarai Bond-Buckup and Buckup, 1994, A.odebrechtii Mller, 1876, A. spinosa Bond-Buckup and Buckup, 1994, A. leachi, A. oblataand A. brevipalma are recorded only in theUpper Uruguay River, between the borders ofSanta Catarina and Rio Grande do Sul states.Until now, onlyA. georginaehas been recordedin the Jaguari River Sub-basin. However, thefollowing four species have been recordedin the Iju River Sub-basin: A. ludwigi, A.

singularisRinguelet, 1948,A. platensis andA.

grisella, and this is the first record of the latterspecies in the Uruguay Basin. Te two latterspecies occur in sympatry with A. ludwigi inthe Cambar Creek. Neither morphologicalfeatures nor molecular phylogenetic analyses

suggest the existence of hybrids between A.platensis and A. grisella. In the latter, samplesof A. grisella from two different localitieswere used and they appear as paraphyletic,as already indicated by Prez-Losada et al.(2004). Further studies are needed to elucidatethe taxonomic status of this species.

ACKNOWLEDGEMENTS -We thank everyone whocollaborated in the collections, particularly Rosemari

Parisi Legramanti, Jober Wanderlei Vargas Machadoand Carlos Eduardo Copatti. We also thank CNPq for apost-doctorate grant to SS (Proc. 201866/2012-9).

REFERENCESBond-Buckup, G. and Buckup, L. 1994. A famlia

Aeglidae (Crustacea, Decapoda, Anomura).Arquivosde Zoologia, 32: 159-347.

Bond-Buckup, G.; Jara, C.G.; Prez-Losada, M.;Buckup, L. and Crandall, K.A. 2008. Globaldiversity of crabs (Aeglidae: Anomura: Decapoda)in freshwater. Hydrobiologia, 595: 267-273.

Bond-Buckup, G.; Jara, C.G.; Buckup, L.; Prez-Losada, M.; Crandall, K.A. and Santos, S. 2010.New species and new records of endemic freshwatercrabs from the Atlantic forest in Southern Brazil(Anomura: Aeglidae).Journal of Crustacean Biology,30: 495-502.

Crandall, K.A. and Fitzpatrick Jr., J.F. 1996. Crayfishmolecular systematics: using a combination ofprocedures to estimate phylogeny. SystematicsBiology, 45: 1-26.

Crandall, K.A; Fetzner Jr., W. J.; Jara, C.G. and Buckup,L. 2000. On the phylogenetic position of the SouthAmerican crayfish genera (Decapoda: Parastacidae).Journal of Crustacean Biology, 20(3): 530-540.

Darriba, D.; aboada, G.L.; Doallo, R. and Posada, D.2012. jModelest 2: more models, new heuristics

and parallel computing. Nature Methods, 9: 772.Dudgeon, D.; Arthington, A.H.; Gessner, M.O.;

Kawabata, Z.I.; Knowler, D.J.; Leveque, C.;Naiman, R.J.; Prieur-Richard, A.H.; Soto, D.;Stiassny, M.L.J. and Sullivan, C.A. 2006. Freshwaterbiodiversity: importance, threats, status andconservation challenges. Biological Reviews, 81(2):163-182.

Fundao SOS Mata Atlntica e Instituto de PesquisasEspaciais. 2011. Atlas dos remanescentes florestaisda Mata Atlntica, Perodo 2008-2010: So Paulo,2011, http://mapas.sosma.org.br/.

IUCN (International Union for Conservation ofNature). 2001. IUCN Red List Categories and

Criteria, Version 3.1. IUCN, Gland, Switzerland.


13/13

Nauplius 21(2): 211-223, 2013 223

Jara, C.G. 1992. Un nuevo gnero de Aeglidae (Crust.:Decap.:Anom.)? Archivos de Biologa y MedicinaExperimentales, 24: R-194.

McLaughlin, P. A., Lemaitre, R. and Sorhannus, U.2007. Hermit crab phylogeny: A reappraisal and itsfall-out.Journal of Crustacean Biology, 27(1): 97-115.

McLaughlin, P.A.; Lemaitre, R. and Crandall, K.A.2010. Annotated checklist of anomuran decapodcrustaceans of the world (exclusive of the Kiwaoideaand families Chirostylidae and Galatheidae of theGalatheoidea) part III Aegloidea. Te RafflesBulletin of Zoology, Supplement 23: 131-137.

Pattengale, N.D.; Alipour, M.; Bininda-Emonds,O.R.P.; Moret, B.M.E. and Stamatakis, A. 2010.How many bootstraps replicates are necessary?Journal of Computational Biology, 17(3): 337-354.

Prez-Losada, M., Jara, C.G.; Bond-Buckup, G.;Porter, M.L. and Crandall. K.A. 2002. Anomuranphylogenetic relationships: on the taxonomicpositioning of Aeglidae freshwater crabs. Journal ofCrustacean Biology,22(3): 670-676.

Prez-Losada, M.; Bond-Buckup, G.; Jara, C.G. andCrandall, K.A. 2004. Molecular systematics andbiogreography of the southern South Americanfreshwater crabs Aegla (Decapoda, Anomura,Aeglidae) using multiple heuristic tree searchapproaches. Systematic Biology, 53(5): 767-780.

Prez-Losada, M.; Bond-Buckup, G.; Jara, C.G. andCrandall, K.A. 2009. Conservation assessment ofsouthern South American freshwater ecoregions onthe basis of the distribution and genetic diversity ofcrabs from the genus Aegla. Conservation Biology,23: 692-702.

Sala, O.E.; Chapin, F.S.; Armesto, J.J.; Berlow, R.;Bloomfield, J.; Dirzo, R.; Huber-Sanwald, E.;Huenneke, L.F.; Jackson, R.B.; Kinzig, A.; Leemans,R.; Lodge, D.; Mooney, H.A.; Oesterheld, M.; Poff,N.L.; Sykes, M..; Walker, B.H.; Walker, M. andWall, D.H. 2000. Global biodiversity scenarios forthe year 2100. Science, 287: 1770-1774.

Santos, S.; Bond-Buckup, G.; Prez-Losada, M.;Bartholomei-Santos, M.L. and Buckup, L. 2009.Aegla manuinflata, a new species of freshwateranomuran (Decapoda: Anomura: Aeglidae).Zootaxa, 2088: 31-40.

Santos, S.; Bond-Buckup, G.; Prez-Losada, M.; Jara,C.G.; Crandall, K.A. and Buckup, L. 2010. Newrecords and description of a new species of Aeglidae(Crustacea: Anomura) from river basins in SouthernBrazil. Nauplius, 18: 79-86.

Santos, S.; Bond-Buckup, G.; Buckup, L.; Prez-Losada,M.; Finley, M. and Crandall, K.A. 2012. Tree new

species ofAegla(Anomura) freshwater crabs from theUpper Uruguay River hydrographic basin in Brazil.Journal of Crustacean Biology, 32(4): 529-540.

Stamatakis, A. 2006. RAxML-VI-HPC: MaximumLikelihood-based phylogenetic analyses withthousands of taxa and mixed models. Bioinformatics,22: 2688-2690.

Stamatakis, A.; Hoover, P. and Rougemont, J. 2008.A rapid bootstrap algorithm for the RAxML Web-servers. Systematic Biology, 75(5): 758-771.

amura, K.; Peterson, D.; Peterson, N.; Stecher, G.;Nei, M. and Kumar, S. 2011. MEGA5: MolecularEvolutionary Genetics Analysis using MaximumLikelihood, Evolutionary Distance, and MaximumParsimony Methods. Molecular Biology andEvolution, 28: 2731-2739.

WWF. 2012. Living Planet Report 2012. WWFInternational, Gland, Switzerland.

Yeo, D.C.; Ng, J.P.K.L.; Cumberlidge, N.; Magalhes,C.; Daniels, S.R. and Campos, M.R. 2006. A globalassessment of freshwater crab diversity (Crustacea:Decapoda: Brachyura). Hydrobiologia, 595: 275-286.

Submitted 18 February 2013

aeglidos.pdf

Documents