Research Article |
Corresponding author: Fábio F. Roxo ( roxoff@hotmail.com.br ) Academic editor: Nina Bogutskaya
© 2016 Gabriel S.C. Silva, Fábio F. Roxo, Luz E. Orrego, Claudio Oliveira.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Silva GSC, Roxo FF, Luz E. Ochoa LE, Oliveira C (2016) Description of a new catfish genus (Siluriformes, Loricariidae) from the Tocantins River basin in central Brazil, with comments on the historical zoogeography of the new taxon. ZooKeys 598: 129-157. https://doi.org/10.3897/zookeys.598.7400
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This study presents the description of a new genus of the catfish subfamily Neoplecostominae from the Tocantins River basin. It can be distinguished from other neoplecostomine genera by the presence of (1) three hypertrophied bicuspid odontodes on the lateral portion of the body (character apparently present in mature males); (2) a large area without odontodes around the snout; (3) a post-dorsal ridge on the caudal peduncle; (4) a straight tooth series in the dentary and premaxillary rows; (5) the absence of abdominal plates; (6) a conspicuous series of enlarged papillae just posterior to the dentary teeth; and (7) caudal peduncle ellipsoid in cross section. We used maximum likelihood and Bayesian methods to estimate a time-calibrated tree with the published data on 116 loricariid species using one nuclear and three mitochondrial genes, and we used parametric biogeographic analyses (DEC and DECj models) to estimate ancestral geographic ranges and to infer the colonization routes of the new genus and the other neoplecostomines in the Tocantins River and the hydrographic systems of southeastern Brazil. Our phylogenetic results indicate that the new genus and species is a sister taxon of all the other members of the Neoplecostominae, originating during the Eocene at 47.5 Mya (32.7–64.5 Mya 95% HPD). The present distribution of the new genus and other neoplecostomines may be the result of a historical connection between the drainage basins of the Paraguay and Paraná rivers and the Amazon basin, mainly through headwater captures.
Molecular phylogeny, Freshwater fishes, headwater capture, catfish, taxonomy
The Loricariidae, an endemic Neotropical family of freshwater fish, is the largest group of catfish, with about 900 valid species (
The neoplecostomines are small-bodied catfishes which were, until now, restricted to southern and southeastern Brazil, where they are found in small- to medium-sized streams with clear and shallow water, of up to 1 m in depth (
Here, we recognize a new genus and species of neoplecostomine catfish based on specimens collected during a recent expedition to the Tocantins River basin in Goiás state, Brazil. The new taxon is described in detail below.
Body plate nomenclature follows
The molecular analysis included 157 specimens representing 116 loricariid species (115 species from the study of
Vouchers of the samples were those catalogued by
Total DNA was extracted from muscle samples collected from two specimens of the new genus preserved in ethanol using the protocol described by
The individual sequences of each species were initially analyzed in the BioEdit 5.0.9 software (
Maximum likelihood analyses were run in RAxML Web-Servers (
The uncorrelated relaxed (lognormal) molecular clock was calibrated using BEAST v.1.7.5. All clade-age estimates are presented as the mean and 95% highest posterior density (HPD) values. We included two calibration points to constrain the divergence dates for the 157 clades identified in our phylogenetic tree. The first calibration point was implemented as a normally-distributed prior, with an offset of 125 million years ago (Mya), and a standard deviation of 15 million years. Data from the stratigraphic record and the geographic distribution of living taxa indicate that the Siluriformes originated during the Lower Cretaceous (145–100 Mya;
The second calibration point was implemented using a log-normal prior set at 55 Mya, with a mean and standard deviation of 1 for the origin of the family Callichthyidae. The oldest known callichthyid fossil, Corydoras revelatus
Data on the geographic distribution of the species in each of the three subfamilies analyzed here (Hypoptopomatinae, Neoplecostominae and Otothyrinae) were obtained from the original species descriptions and the catalog of
We estimated the likelihood of ancestral range evolution using the Dispersal-Extinction-Cladogenesis (DEC:
Microplecostomus forestii sp. n.
The new genus and species differs from all members of the Loricariidae by having (1) three hypertrophied bicuspid odontodes on the lateral portion of the body (character apparently present only in mature males – observed in the holotype, but not present in the paratypes) (Fig.
The generic name is a combination of Greek, micro (mikrós) = small, related to the small size of the adult type-specimen, and plecostomus = a former generic name of species currently included in Loricariidae, also in reference to the small adult size of the type-species. A masculine name.
All from Brazil, Goiás state, Tocantins River basin (15 specimens).
Same as for the genus.
Morphometric and meristic data in Table
Morphometric data for Microplecostomus forestii sp. n. SD = standard deviation.
Microplecostomus forestii sp. n., 15 paratypes and the holotype | ||||
---|---|---|---|---|
Holotype | Range | Mean | SD | |
SL | 38.3 | 21.7–38.3 | 27.9 | – |
Percentage of SL | ||||
Predorsal length | 45.5 | 44.5–50.8 | 47.9 | 1.8 |
Head length | 34.9 | 34.5–39.9 | 37.4 | 1.5 |
Head-dorsal length | 12.5 | 10.0–13.5 | 11.4 | 1.1 |
Cleithral width | 32.5 | 31.2–35.2 | 33.3 | 1.0 |
Head-pectoral length | 29.7 | 22.4–32.7 | 30.1 | 2.4 |
Thorax length | 19.1 | 17.1–20.5 | 19.1 | 1.0 |
Pectoral-spine length | 19.9 | 19.2–25.3 | 21.4 | 1.7 |
Abdominal length | 21.8 | 19.4–24.3 | 21.8 | 1.2 |
Pelvic-spine length | 20.8 | 17.0–22.3 | 20.3 | 1.6 |
Post-anal length | 34.2 | 31.8–34.9 | 33.2 | 0.9 |
Anal-fin spine length | 12.2 | 10.6–13.6 | 12.1 | 0.8 |
Dorsal-pectoral distance | 25.7 | 25.3–34.5 | 28.1 | 2.2 |
Dorsal spine length | 19.4 | 18.2–23.0 | 20.9 | 1.4 |
Dorsal-pelvic distance | 20.2 | 16.8–22.3 | 20.1 | 1.6 |
Dorsal-fin base length | 18.5 | 15.1–19.4 | 17.6 | 1.2 |
Caudal peduncle depth | 9.5 | 8.1–10.5 | 9.6 | 0.6 |
Dorsal-anal distance | 13.6 | 13.6–16.8 | 15.0 | 1.0 |
Pelvic-dorsal distance | 22.5 | 20.3–25.7 | 23.2 | 1.6 |
Percentage of HL | ||||
Head-eye length | 32.3 | 30.9–36.7 | 33.9 | 1.9 |
Orbital diameter | 15.8 | 13.2–17.2 | 15.1 | 1.2 |
Snout length | 61.8 | 52.9–61.8 | 57.8 | 2.8 |
Internares width | 17.0 | 14.8–19.2 | 16.7 | 1.2 |
Interorbital width | 31.5 | 28.8–34.3 | 32.1 | 1.5 |
Head depth | 58.8 | 55.8–66.6 | 61.1 | 2.6 |
Mouth length | 55.8 | 45.6–66.9 | 58.7 | 5.8 |
Barbel length | 4.8 | 1.2–5.5 | 3.2 | 1.2 |
Dentary tooth cup length | 24.2 | 20.1–27.0 | 23.3 | 1.6 |
Premaxillary tooth cup length | 21.7 | 18.3–25.2 | 23.3 | 1.8 |
Tip of snout formed by two triangle rostral plates, without odontodes. Nasal plates almost rectangular forming medial nostril margin and contacting pre-nasals anteriorly. Nasal plates posteriorly contacting frontal bones. Lateral margin of head formed by four or five postrostral plates. Complete infraorbital plate series composed of five plates; all infraorbital plates containing latero-sensory canals; first and second infraorbitals largest and third, fourth and fifth smallest. Preopercle elongate, bearing a branch of laterosensory canal. Subocular cheek plates present ventral to preopercle plate. Top of head composed of compound pterotic, supraoccipital, prefrontal, frontal, and sphenotic (Fig.
Dorsal view of the head plates in Microplecostomus forestii sp. n., LBP 19017, 29.0 mm SL. CPT = compound pterotic; F = frontal; IO1-5 = infraorbitals; N = nasal; OP = opercle; PR1-4 postrostral plates; PF = prefrontal; PN = prenasal; POP = preopercle; R = rostral plate; SP = sphenotic; CP2 = subocular cheek plate; SOC = parieto-supraoccipital; AD = additional plates.
Lateral ethmoid exposed without odontodes in dorsal view. Lateral ethmoid strut short and broad, nasal capsule partially closed, lateral ethmoid surrounding more than 50% of nasal capsule. Compound pterotic roughly quadrangular, without posterior process, with several fenestrae non-uniform in shape and size. Parieto-supraoccipital not contributing to dorsal portion of swimbladder capsule. Metapterygoid channel present. Hyomandibular square and not sutured to compound pterotic, hyomandibular adductor palatine crest present. Quadrate triangle. Lips large; oral disk rounded and papillose. Premaxillary teeth 44–65 (mode 46). Dentary teeth 45–69 (mode 48). Teeth bicuspid. Maxillar barbel short. Upper pharyngeal tooth-plate small and triangular. Five ceratobranchials with accessory process present and long. Five teeth in ceratobranchial. Four branchiostegal rays.
Dorsal-fin rays II,7; dorsal-fin originating at vertical through posterior end of pelvic-fin base; distal margin slightly convex; dorsal-fin spinelet short and oval in shape. Pectoral-fin rays I,6; distal margin slightly convex; unbranched pectoral-fin ray reaching pelvic-fin origin; unbranched pectoral-fin ray covered with large and pointed odontodes. Pectoral girdle not exposed ventrally. Arrector fossae, partially enclosed by ventral lamina of coracoids, opening relatively large, extending laterally towards base of pectoral fin. Pelvic-fin rays I,5; distal margin of fin slightly convex; tip of adpressed pelvic-fin almost reaching anal-fin origin; unbranched pelvic-fin ray covered with conspicuously pointed, and uniformly distributed odontodes, larger at ventral portion. Pelvic girdle with slender lateropterigium. Basipterygium lacking anterior fenestrae. Anal-fin rays I,5; distal margin slightly convex. Adipose-fin absent. Caudal-fin rays I,7–7,I, truncated with ventral unbranched principal ray longer than dorsal ray.
Compound hypurals 1 and 2 almost completely fused to compound hypurals 3–5, and lower and upper halves fused to last vertebra. Upper and lower lobes of hypural plates of same length. Epural present and separated from hypural plate. Body entirely covered by bony plates, except for ventral surface of head, abdomen and region between compound pterotic and first medial plate. Dorsal series of plates 22–23, mid-dorsal 4–7, median perforated plates 22–23, mid-ventral 11, and ventral 18–20. Trunk with conspicuous, elongated, post-dorsal ridge formed by 14–15 raised, unpaired, median plates; ridge continuous posteriorly with procurrent caudal-fin rays. Six pairs of ribs associated with vertebrae 7–13. Ribs slender and poorly ossified. Total vertebrae 27.
Background color of dorsal and ventral surfaces of body yellowish tan. Dorsal surface of head dark brown. Four dark brown saddles on dorsal surface of trunk, most anterior inconspicuous and below dorsal-fin origin, second below end of dorsal-fin, third typically in adipose-fin region, and fourth at end of caudal peduncle. Lateral portion of body with inconspicuous dark stripe from head to caudal fin. Pectoral, pelvic and dorsal fins with three irregular, poorly defined bands. Caudal fin with variegated blotches (Fig.
Similar to pattern described for living individuals, but with darker brown color, and darker saddles and stripes (Fig.
Specimens lacking main sexual dimorphic characters usually present in loricariid species, particularly in Neoplecostominae members, such as (1) a papilla present posteriorly to urogenital opening; (2) an expanded flap skin on dorsal surface of first pelvic-fin ray; and (3) a larger pelvic-fin and body size (all characters present in males), but absent in females. Three hypertrophied bicuspid odontodes are present on lateral portion of body (a characteristic that may be related to mature males), however it is only present in holotype.
The specific name, forestii, is given in honor of Fausto Foresti, Professor of the university of São Paulo state “Júlio de Mesquita Filho” (Unesp) in Brazil, for his contributions to fish genetics, with more than 250 papers published in this field.
Microplecostomus forestii sp. n. is known from two localities, the Roncador Stream and the das Brancas Stream, both tributaries of the Tocantizinho River, in the Tocantins basin (Fig.
a Map showing the distribution of Microplecostomus forestii sp. n. Type locality at Roncador Stream, red star – 14°43'51.3"S, 47°32'34.0"W. Paratype locality at das Brancas Stream, red circle – 14°53'47.2"S, 47°34'58.4"W. Habitat where Microplecostomus forestii sp. n. is found at b Roncador Stream and c das Brancas Stream. These are small size streams with a depth of less than 1 m, clear water, the bottom covered with loose stones and shaded margins. Photographs: LH Roxo.
Microplecostomus forestii sp. n. was collected in shallow, clear waters of about 0.5 m in depth and fast-flowing currents, with an underlying substrate of rock, in areas of flat terrain. The fishes captured were associated with pebbles (Fig.
The sequences of all 157 specimens are shown in Suppl. material
Our results are very similar to those of of
Our time-calibrated tree estimated that the origin of the hypoptopomatine lineage was in the Paleocene, about 63.1 Mya (44.5–83.8 Mya 95% HPD), and is inferred by the DEC+J model to have been located in areas A (Atlantic Coast drainage basins) + D (Amazon and Orinoco basins) (Fig.
The results of our molecular analyses indicated that Microplecostomus forestii sp. n. is the sister-group of all the other members of the Neoplecostominae (Fig.
Another character used to distinguish Microplecostomus forestii sp. n. from other neoplecostomines is the presence of a post-dorsal ridge on the caudal peduncle.
The subfamily Neoplecostominae, as defined by
Using the DEC model to estimate ancestral species ranges,
Our ancestral range estimates found, using the DECj model and including Microplecostomus forestii sp. n. in the HNO phylogeny, that the ancestral lineages of these three subfamilies were widely distributed on the Atlantic Coast (area A) and in the Amazon and Orinoco basins (area D). While these two areas are not adjacent (i.e. they do not share an endpoint or border), a number of studies have found evidence of the historical mixing of the faunas of the headwaters of the Amazon and Paraná rivers, and the drainage basins of the Atlantic Coast. The historical connection between the Paraguay and Amazon basins has been known for more than a century (e.g.
All neoplecostomine lineages are found in southern and southeastern of South America, except Microplecostomus forestii sp. n. and Pareiorhaphis regani (Giltay, 1936), which are from the Amazon basin (area D). In a paper on the evolution of plants,
Chauliocheilos saxatilis Martins, Andrade, Rosa & Langeani, 2014: paratype,
Curculionichthys insperatus Britski & Garavello, 2003: LBP 4945, 5, 27.3−28.5 mm SL, 2 c&s, 28.2−29.9 mm SL, municipality of Botucatu, São Paulo state, Brazil, Tietê River basin.
Gymnotocinclus anosteos Carvalho, Lehmann A. & Reis, 2008: LBP 17125, 3, 18.8–33.0 mm SL, municipality of Alto Paraíso de Goiás, Goiás state, Brazil, Tocantins River basin.
Hisonotus acuen Silva, Roxo & Oliveria, 2014: holotype,
Hisonotus bocaiuva Roxo, Silva, Oliveira & Zawadzki, 2013: holotype,
Hisonotus notatus Eigenmann & Eigenmann, 1889a: LBP 18472, 7, 30.1–38.3 mm SL, municipality of Silva Jardim, Rio de Janeiro state, Brazil, coastal drainage basin.
Isbrueckerichthys alipionis (Gosline, 1947): LBP 7373, 17, 31.7–81.6 mm SL, municipality of Iporanga, São Paulo state, Brazil, Ribeira de Iguape River basin;
Kronichthys subteres
Lampiella gibbosa (Miranda Ribeiro, 1908): LBP 7430, 5, 25.6−26.1 mm SL, municipality of Jacupiranga, São Paulo state, Brazil, Ribeira de Iguape River basin.
Microlepidogaster arachas Martins, Calegari & Langeani, 2013: LBP 10882, 3, 22.8−35.3 mm SL, municipality of Araxás, Minas Gerais state, Brazil, Paraná River basin.
Nannoplecostomus eleonorae Ribeiro, Lima & Pereira, 2012: LBP 19016, 51, 19.9–25.4 mm SL, municipality of Guarani de Goiás, Goiás state, Brazil, Tocantins River basin.
Neoplecostomus microps (Steindachner, 1877a): LBP 8036, 38, 41.3–65.0 mm SL, municipality of Piquete, São Paulo state, Brazil, Paraíba do Sul River basin.
Neoplecostomus franciscoensis Langeani, 1990: LBP 6489, 50, 42.8–55.9 mm SL, municipality of São Bartolomeu, Minas Gerais state, Brazil, São Francisco River basin.
Neoplecostomus paranensis Langeani, 1990: holotype,
Otocinclus affinis (Steindachner, 1877b): 19, 19.5−28.9 mm SL, municipality of Poconé, Mato Grosso state, Brazil, Paraguay River basin.
Otocinclus vittatus Regan, 1904: 27, 18.2−21.7 mm SL, municipality of Cáceres, Mato Grosso state, Brazil, Paraguay River basin.
Otothyropsis marapoama Ribeiro, Carvalho & Melo, 2005: LBP 4698, 6, 23.9−36.3 mm SL, municipality of Marapoama, São Paulo state, Brazil, Tietê River basin.
Pareiorhaphis splendens (Bizerril, 1995): LBP 1117, 20, 32.0–100.0 mm SL, municipality of Morretes, Paraná state, Brazil, Atlantic Coast drainage basins.
Pareiorhaphis steindachneri (Miranda Ribeiro, 1918a): LBP 739, 6, 33.8–49.0 mm SL, municipality of Jaraguá do Sul, Santa Catarina state, Brazil, Atlantic Coast drainage basins.
Pareiorhina brachyrhyncha Chamon, Aranda & Buckup, 2005: LBP 12240, 50, 26.4–36.9 mm SL, municipality of Pindamonhangaba, São Paulo state, Brazil, Paraíba do Sul River basin.
Pareiorhina cepta Roxo, Silva, Mehanna & Oliveira, 2012d: holotype,
Pareiorhina rudolphi (Miranda Ribeiro, 1911): LBP 8044, 18, 31.7–48.9 mm SL, municipality of Piquete, São Paulo state, Brazil, Paraíba do Sul River basin.
Parotocinclus maculicauda (Steindachner, 1877b): LBP 2869, 15, 20.2−44.7 mm SL, municipality of Miracatu, São Paulo state, Brazil, Ribeira de Iguape River basin.
Plesioptopoma curvidens Reis, Pereira & Lehmann A, 2012: LBP 17394, 39, 26.1–81.7 mm SL, municipality of Cristiano Otoni, Minas Gerais state, Brazil, São Francisco River basin.
Pseudotocinclus juquiae Takako, Oliveira & Oyakawa, 2005: LBP1081, 2, 29.0–31.9 mm SL, municipality of Juquitiba, São Paulo state, Brazil, Atlantic Coast drainage basins.
Pseudotocinclus tietensis (Ihering, 1907): LBP 2931, 3, 38.6–62.3 mm SL, municipality of Salesópolis, São Paulo state, Brazil, Tietê River basin.
Schizolecis guntheri (Miranda Ribeiro, 1918b): LBP 14335, 18, 18.3–35.3 mm SL, municipality of São Sebastião, São Paulo state, Brazil, Atlantic Coast drainage basins.
The authors wish to thank Angela M. Zanata, Bruno F. Melo, Jefferson M. Henriques, Luiz H. Roxo, Marcelo Melo, Martin Taylor, Oswaldo T. Oyakawa, Priscila Camelier, Renato Devidé for their help during the collection of specimens, Maria Thereza P. Jorge for the review of the English text, Victor A. Tagliacollo for help with the biogeographic analysis, and Jonathan W. Armbruster for reading the manuscript and providing valuable suggestions. Furthermore, the authors would like to thank the editorial team for handle this study. This research was supported by the Brazilian agencies FAPESP (Fundação de Amparo à Pesquisa do Estado de São Paulo, proc. 2014/05051–5 and 2015/00691–9 to FFR, 2014/06853–8 to LEO and 2012/01622–2 to GSCS) and MCT/CNPq (Conselho Nacional de Desenvolvimento Científico e Tecnológico) (Edital Universal, proc. N. 441347/2014–2 coord. FFR).
Table S1
Data type: Microsoft Word document
Explanation note: Species included in the present study with voulchers and GenBank accession numbers.
Table S2
Data type: Microsoft Word document
Explanation note: Models tested to estimate distribution ranges inherited by the descending lineages at each node of the tree.