Macrobrachium veredensis,

Rossi, Natalia, Magalhães, Célio, Mesquita, Elis R. & Mantelatto, Fernando L., 2020, Uncovering a hidden diversity: a new species of freshwater shrimp Macrobrachium (Decapoda: Caridea: Palaemonidae) from Neotropical region (Brazil) revealed by morphological review and mitochondrial genes analyses, Zootaxa 4732 (1), pp. 177-195: 182-188

publication ID

https://doi.org/10.11646/zootaxa.4732.1.9

publication LSID

lsid:zoobank.org:pub:7372BB34-A296-4A5C-A722-79FB05D9BB89

DOI

http://doi.org/10.5281/zenodo.3664237

persistent identifier

http://treatment.plazi.org/id/274A8784-FFA3-FFAA-FF0B-3F2E1DBAFC15

treatment provided by

Plazi

scientific name

Macrobrachium veredensis
status

sp. nov.

Macrobrachium veredensis  sp. nov. Rossi, Magalhães & Mantelatto

( Figs. 2View FIGURE 2 and 3View FIGURE 3)

http://zoobank.org/ urn:lsid:zoobank.org:act:D86A5A10-08BB-419F-9341-5724E8CB7723

Material examined: Holotype: Male (CL 38.67 mm), MZUSP 39527View Materials, Brazil, Minas Gerais state: Chapada Gaúcha, Grande Sertão Veredas National Park , prainha do Rio Preto (little beach of the Black river ), 15º08.97’S, 45°45.16’W, 14/vii/2011, Carvalho, F.C. & Souza-Carvalho, E.GoogleMaps 

Paratypes: Brazil, Minas Gerais state: 1 male (38.30 mm), MZUSP 39528View Materials and  5 males (CL 23.10–38.00 mm), CCDB 535View Materials, same data as holotypeGoogleMaps  .

Others: 9 males (CL 26.59–49.92 mm), 1 ovigerous female (CL 34.85 mm), CCDB 543View Materials, Chapada Gaúcha , Grande Sertão Veredas National Park near to Cariranha river, 15°07.25’S, 45°44.43’W, 13/vii/2011, Carvalho, F.C. & Souza-Carvalho, EGoogleMaps  .; 2 males (CL 27.46 mm, 31.92 mm), CCDB 464View Materials, Brazil, Chapada Gaúcha , Grande Sertão Veredas National Park, Black river, 15°10.92’S, 45°46.17’ W, 13/vii/2011, Carvalho, F.C., Jacobucci, G. & Souza- Carvalho, EGoogleMaps  .; 3 males (CL 31.90–35.10 mm), CCDB 5456View Materials, Povoado de Pandeiros , 15°30’46.0” S, 44° 45’ 12.4” W, 12/ii/2014, Bueno, AGoogleMaps  .; 3 males (CL 28.11–32.00 mm), 1 female (CL 21.29 mm), CCDB 534View Materials, Comunidade S. Joaquim, Jabuticaba river , Januária / Chapada Gaúcha, 12/vii/2011, Carvalho, F.C. & Souza-Carvalho, E  .; 2 males (CL 23.14 and 28.77 mm), CCDB 922View Materials, Córrego do Bom Jantar , Januária, 15°33.36’S, 44° 44’ 29.46’S W, 12/vii/2011, Carvalho, F.C. & Souza-Carvalho, E  .

Additional comparative material examined: Macrobrachium ferreirai  : Brazil, Amazonas state: 1 male (CL 50.85 mm), CCDB 2587View Materials, Jaú National Park, 25/xi/2000, Magalhães, C.; 2 males (CL 42.18 and 52,70 mm), CCDB 2588View Materials, Jaú National Park , 25/xi/2000, Magalhães, C.; Tocantins state: 1 male (CL 41.03 mm) and 1 ovigerous female (CL 33.67 mm), CCDB 6204View Materials, Alta Mateiros, 19/v/2013, Mantelatto, F.L. et al  .

Macrobrachium nattereri  : Brazil, Amazonas state: 1 male (CL 47.97 mm) CCDB 2130View Materials, 15/01/2005, Biotupé project  ; Tocantins state: 2 males (CL 33.69 and 36.06 mm) CCDB 5023View Materials, Ponte Alta, 19/v/2013, Mantelatto, F.L. et al  .

Diagnosis: Rostrum straight, almost reaching end of antennular peduncle and scaphocerite; upper margin with 8–10 teeth, usually 9, regularly arranged; 2–3 postorbital, usually second one on postorbital margin; lower margin of rostrum with 2–3 teeth. Antennule peduncle 3–segmented, with inner and outer flagella, outer flagellum biramous. Carapace smooth. Second pereopods (P2) similar in shape, different in size, overreaching scaphocerite with all carpus length; dactylus longer than propodus half-length. Dactylus with 1–2 large teeth, sometimes with smaller ones on cutting edges, row of small tubercles along inner margin. Propodus flattened, smooth with sparse spinules and setae on external faces. Fifth pleonal somite with rectangular pleuron and peaked lower margin. Males with endopod of second pleopod bearing appendix masculina smaller than appendix internae. Telson with posterior margin ending in distinct acute tip, bearing 2 spines with setae between them; inner pair of spines reaching or overreaching apex of telson.

Description: Fully grown male ( Fig. 2AView FIGURE 2). Body moderately robust. Rostrum straight, extending beyond or as long as antennular peduncle and almost reaching end of scaphocerite, armed dorsally with 8–10 teeth, usually 9, regularly arranged, 2–3 teeth postorbital, usually the second one on postorbital margin; lower margin of rostrum straight, not enough pronounced; lower margin of rostrum with 2–3 teeth. Rostral formula 8–10 (2–3)/2–3. Antennular spine acute, placed slightly below orbital angle, hepatic spine of similar size or smaller than antennal spine and located slightly behind and lower than antennal spine; paired hepatic spines parallel to antennal spines situated between upper first and second teeth of rostrum on carapace. Carapace smooth, some individuals with spinules sparsely scattered at anterior and ventral region. Eyes well developed. Antennule ( Fig. 3IView FIGURE 3) three-jointed protopodite bearing three multiarticulated flagella at distal end and statocyst at base. Inner flagellum of antennule unique and longer outer flagellum. Antennular peduncle almost reaching distal margin of scaphocerite. Basal segment of antennular peduncle moderately broad, lateral margin straight, with small proximal tooth, ventral edge tapering posteriorly; stylocerite short and sharp. Antenna ( Fig. 3HView FIGURE 3) with scaphocerite longer than wide, outer lateral side straight. Antennal flagellum multiarticulated, as long as body length. Mandible ( Fig. 3GView FIGURE 3) with slender, 3-articulated palp; incisor process robust, with 3 strong teeth; molar process robust, truncate distally, with four principal peripheral teeth. Maxilla ( Fig. 3DView FIGURE 3) with basal endite bearing setae on apical margin; endopodite and exopodite (scaphognathite) with numerous short setae distally; scaphognathite broad, anterior lobe large, posterior lobe moderately narrow, both lobes rounded. Maxillula ( Fig. 3EView FIGURE 3) with apical margin of endopodite weakly bilobed; coxa and basis surface with stiff setae. First maxilliped ( Fig. 3FView FIGURE 3) with setose palp, basal and coxal endites distinct, flagellum of exopod with numerous plumose setae distally, epipod deeply bilobed. Second maxilliped ( Fig. 3CView FIGURE 3) with normal endopod, flagellum with numerous setae distally, epipod simple, with well-developed podobranch. Third maxilliped ( Fig. 3BView FIGURE 3) with robust endopod, exopod with numerous plumose setae distally, reaching to distal margin of ischio-merus. First pereopod ( Fig. 3JView FIGURE 3) slender, smooth, reaching beyond scaphocerite by entire distal margin of carpus, equal in length, similar in form. Palm as long as finger, carpus 1.9 times as long as chela, merus shorter than carpus; both fingers ending in small apical claw. Second pereopod—P2 ( Fig. 2BView FIGURE 2) similar in shape, different in size, longer than total length; overreaching scaphocerite with all carpus length. P2, dactylus with 1–2 large teeth, sometimes with smaller ones on cutting edges, row of small tubercles along inner margin; gaping when fingers closed; dactylus longer than propodus half-length; propodus flattened, smooth with sparce spinules and setae on external faces; upper spinules obtuse; chela with small spines, with lower ones smaller than upper ones and bending towards legs ( Fig. 3AView FIGURE 3). Last three pereopods slender, smooth, similar in form; propodus, carpus, merus, with few setae. Pleon with second somite broad with lateral overlapping the first and third; fifth somite with rectangular pleuron and peaked lower margin; sixth somite slightly shorter than telson. Male second pleopod with appendix masculina longer, stouter than appendix internal, with numerous stiff setae. Telson ( Fig. 3CView FIGURE 3) almost three times as long as wide, mostly triangular, with posterior margin ending in distinct acute tip, bearing two pairs of spines with setae between them; inner pair of spines reaching or overreaching apex of telson.

Type locality: Brazil, Minas Gerais state, Grande Sertão Veredas National Park (PARNA—Grande Sertão Veredas), Chapada Gaúcha , prainha do Rio Preto (little beach of the Black river ), 15º08.97’S, 45°45.16’WGoogleMaps  .

Distribution: Only known from part of the middle São Francisco river basin, in the state of Minas Gerais, Brazil.

Etymology: The new species name is derived from geographical name where the holotype was collected, the Grande Sertão Veredas National Park, in Minas Gerais state, Brazil.

Molecular data. We aligned 43 sequences (23 news), with 528 base pairs (bp) to 16S rDNA, and 16 new sequences with 581bp, without pseudogenes, for COI mtDNA. The genetic distance among the sequences of specimens previously identified as M. brasiliense  ranged from 0.0 to 8.5% for 16S, and 0.0 to 12.7% for COI. When individuals were separated into two species, sequences of 16S ranged for M. brasiliense  from 0.0 to 4.3% ( Table 2) and 0.0 to 2.5% for COI. The diversity among the individuals from the São Francisco river basin in the state of Minas Gerais ( M. veredensis  sp. nov.) ranged from 0.0 to 1.70% for 16S ( Table 2) and 0.0 to 0.08% for COI. The nucleotide divergence between sequences from M. veredensis  sp. nov. and M. brasiliense  ranged from 7 to 8.5% for 16S and 11.8 to 12.5% for COI. All these individuals and congener species ( M. amazonicum  , M. aracamuni  , M. borelli  , M. ferreirai  , M. iheringi  , M. inpa  , M. potiuna  and M. nattereri  ) ranged from 6.8 to 14.3% for 16S (see details in Table 2).

Similar topologies were achieved on ML and BI analyses for 16S data set. Therefore, the final tree obtained by ML with bootstrap values and posterior probability (BI) more than 50 were added ( Fig. 4View FIGURE 4). The topologies obtained by both analyses revealed that M. veredensis  sp. nov. and M. brasiliense  represent monophyletic clades with high values to support (bootstrap 75 and posterior probability 80). Individuals herein considered as from São Francisco river system in central-western Minas Gerais, M. veredensis  sp. nov. is clustered as sister-group of M. brasiliense  . Moreover, our phylogenetic hypothesis showed distinctive phylogroups with similar morphology in M. brasiliense  , as well as in M. potiuna  , which had already considered a possible cryptic species group ( Carvalho et al. 2013).

Macrobrachium aracamuni  , M. ferreirai  and M. inpa  were positioned in another clade, which is sister-group of M. nattereri  . Macrobrachium ihering  is clustered as sister-group of M. potiuna  clade. Macrobrachium borellii  is sister-group of the clade with outgroup species. The phylogenetic tree was rooted with M. amazonicum  clade ( Fig. 4View FIGURE 4).

Fourteen haplotypes (H) with high diversity (0.98) were recognized based on the COI fragment of sixteen unambiguous sequences, with 581bp, without pseudogenes ( Table 3). Twelve haplotypes (85.71%) represented single individuals, and two (14.29%) were polymorphic. The frequencies of haplotypes in different localities were heterogeneous ( Table 3). The sixth haplotype (H6) was shared between two individuals from northern São Paulo (BR-SP). The tenth (H10) was shared between two individuals from Pará (BR-PA). Networks haplotypes were similar based on the statistical parsimony method (data not shown) and Median-Joining method ( Fig. 4View FIGURE 4).

Analysis of molecular variance (AMOVA) indicated that specimens within the M. brasiliense  populations have the lowest percentage of variation (5.4% without hierarchical structure— i.e., M. veredensis  sp. nov. included—and 3.7% with hierarchical structure), whereas the variation among populations was higher (94.6% without hierarchical structure and 12.6% with hierarchical structure). When populations were structured according to the Minas Gerais region ( M. veredensis  sp. nov.) and other Brazilian populations ( M. brasiliense  ), the variations among groups were very high (83.7%) and the values obtained by AMOVA based on haplotypes frequencies with and without hierarchical structure were significant ( Table 4).