Research Article |
Corresponding author: Erick Cristofore Guimarães ( erick.ictio@yahoo.com.br ) Academic editor: Nicolas Hubert
© 2019 Pâmella Silva de Brito, Erick Cristofore Guimarães, Luis Fernando Carvalho-Costa, Felipe Polivanov Ottoni.
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:
de Brito PS, Guimarães EC, Carvalho-Costa LF, Ottoni FP (2019) A new species of Aphyocharax Günther, 1868 (Characiformes, Characidae) from the Maracaçumé river basin, eastern Amazon. Zoosystematics and Evolution 95(2): 507-516. https://doi.org/10.3897/zse.95.36788
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A new species of Aphyocharax is described from the Maracaçumé river basin, eastern Amazon, based on morphological and molecular data. The new species differs from all its congeners, mainly by possessing the upper caudal-fin lobe longer than the lower one in mature males, and other characters related to teeth counts, colour pattern, and body depth at dorsal-fin origin. In addition, the new species is corroborated by a haplotype phylogenetic analyses based on the Cytochrome B (Cytb) mitochondrial gene, where its haplotypes are grouped into an exclusive lineage, supported by maximum posterior probability value, a species delimitation method termed the Wiens and Penkrot analysis (WP).
Freshwater, integrative taxonomy, Neotropical ichthyology, sexual dimorphism
The Neotropical fish genus Aphyocharax Günther, 1868 is distributed along the river basins of the Orinoco, Amazon, and La Plata systems, as well as in the river systems drainaing the Guiana Shield (
During recent fieldwork at the Maracaçumé river basin, eastern Amazon, specimens of an additional undescribed species of Aphyocharax were collected and is herein described, based on both morphological and molecular evidence, in accordance to an integrative taxonomy perspective.
Individuals collected for this study were euthanized with a buffered solution of Tricaine methanesulfonate MS-222 at a concentration of 250 mg/L for a period of 10 min or more until opercular movements completely ceased. Specimens selected for morphological analysis were fixed in 10% formalin and left for 10 days, after which they were preserved in 70% ethanol and specimens selected for molecular analysis were fixed, and preserved in absolute ethanol.
Specimens for morphological analysis are listed in type and comparative material lists. Specimens for molecular analysis are listed in Table
List of species, specimens and their respective GenBank sequence accession numbers. Sequences made available by this study in bold.
Species | Catalog number | Genbank accession |
---|---|---|
Aphyocharacidium bolivianum | LBP9055-42219 | HQ289710 |
Aphyocharax anisitsi | LBP 25524 | JQ820081 |
Aphyocharax anisitsi | LBP3764-22190 | HQ289581 |
Aphyocharax avary | CICCAA2344-1 | MK409660 |
Aphyocharax avary | CICCAA2344-3 | MK409661 |
Aphyocharax brevicaudatus sp. nov. (female) | CICCAA02306 | MK409668 |
Aphyocharax brevicaudatus sp. nov. (male) | CICCAA02308 | MK409669 |
Aphyocharax brevicaudatus sp. nov. (male) | CICCAA02310 | MK409670 |
Aphyocharax dentatus | LBP 26163 | JQ820082 |
Aphyocharax dentatus | LBP 3604 | JQ820083 |
Aphyocharax cf. erythrurus | LBP 15819 | JQ820076 |
Aphyocharax cf. erythrurus | LBP 15820 | JQ820077 |
Aphyocharax nattereri | LBP 22345 | JQ820070 |
Aphyocharax nattereri | LBP 22132 | JQ820071 |
Aphyocharax pusillus | LBP 23546 | JQ820078 |
Aphyocharax pusillus | LBP4046-22920 | HQ289590 |
Aphyocharax rathbuni | LBP 36496 | JQ820079 |
Aphyocharax rathbuni | LBP 40434 | JQ820080 |
Aphyocharax sp. | LBP1587-11774 | HQ289533 |
Aphyocharax sp. | LBP 16349 | JQ820084 |
Prionobrama paraguayensis | LBP 19465 | JQ820073 |
Prionobrama paraguayensis | LBP 19468 | JQ820072 |
Prionobrama filigera | LBP 23664 | JQ820075 |
Prionobrama filigera | LBP 23663 | JQ820074 |
Leptagoniates steindachneri | LBP 4137-23661 | HQ289600 |
Paragoniates alburnus | LBP9208-43156 | HQ289712 |
Phenagoniates macrolepis | LBP6105-35623 | HQ289678 |
Xenagoniates bondi | LBP3074-19694 | HQ289563 |
Measurements and counts were made according to
DNA extraction was carried out with the Wizard Genomic DNA Purification kit (Promega) following manufacturer’s protocol. DNA quality was evaluated by 0.8% agarose gel electrophoresis stained with GelRed (Biotium). DNA was stored in −20 °C until further procedures. Samples (Table
Amplification reactions were performed in a total volume of 15 μl comprising 1× buffer, 1.5 mM MgCl2, 400 μM dNTP, 0.2 uM of each primer, 1 U of Taq Polymerase (Invitrogen), 100 ηg of DNA template, and ultrapure water. The amplification program consisted of a denaturation of 94 °C for 3 min, followed by 35 cycles of 94 °C for 30 s, 46–48 °C for 45 s, and 72 °C for 80 s, and an extension phase of 5 min at 72 °C. Amplicons were visualised in 1% agarose gel electrophoresis stained with GelRed (Biotium) and purified with Illustra GFX PCR DNA and Gel Purification Kit (GE Healthcare). Samples were sequenced using both forward and reverse primers and BigDye Terminator 3.1 Cycle Sequencing kit in ABI 3730 DNA Analyser (Thermo Fisher Scientific).
The dataset included the partial Cytochrome B (CytB) mitochondrial gene (754bp). Sequences were aligned using ClustalW (
A Bayesian inference-based phylogenetic (BI) tree was estimated in MrBayes (
The unified species concept is herein adopted by expressing the conceptual definition shared by all traditional species concepts, “species are (segments of) separately evolving metapopulation lineages”, disentangling operational criterion elements to delimit taxa from species concepts (
Two distinct and independent operational criteria for species delimitation, based on morphological and molecular data, were implemented here: the population aggregation analysis (
The PAA (
The WP analysis was based on CytB haplotypes, supported on the direct inspection of the haplotype tree generated by the phylogenetic analysis having as terminals at least two individuals (haplotypes) of each focal species. In this method, the term ‘exclusive’ is used instead of monophyletic, as the term monophyly is considered inapplicable below the species level (
CICCAA 02293, (male) 35.9 mm SL, Brazil, Maranhão state, Maracaçumé municipality, Maracaçumé River, 2°3'14"S, 45°57'16"W; 29 Jun 2018, E.C. Guimarães and P.S. Brito.
All from Brazil, Maranhão state: CICCAA 02294, 1 (female), 32.4 mm SL, CICCAA 02295, 35 (males), 20.9–31.7 mm SL,CICCAA 02296, 94 (females), 21–32.1 mm SL, CICCAA 02297, 30 (females) C&S, 22.2–30.8 mm SL, CICCAA 02312, 2 (males) C&S, 28.3–32.1 mm SL, UFRJ 11746, 10 (female), 24.2–30.2 mm SL; all collected with holotype.
Aphyocharax brevicaudatus sp. nov. differs from all its congeners by possessing the upper lobe of the caudal fin longer than the lower lobe in mature males (vs upper and lower lobes similar in length, see Figs
Morphometric data is presented in Table
Morphometric data (N = 141) of the holotype and paratypes of Aphyocharax brevicaudatus sp. nov. from the Maracaçumé river basin. SD: Standard deviation.
Holotype (Male) | Paratypes (Male) N = 35 | Mean | SD | Paratypes (Female) N = 105 | Mean | SD | |
---|---|---|---|---|---|---|---|
Standard length (mm) | 35.9 | 20.9–35.9 | 26.6 | – | 21.0–32.4 | 28.0 | – |
Percentages of standard length | |||||||
Depth at dorsal-fin origin (body depth) | 25.4 | 24.5–28.7 | 25.9 | 1.0 | 25.6–29.1 | 26.3 | 0.8 |
Snout to dorsal-fin origin | 53.1 | 51.9–55.6 | 52.6 | 1.1 | 51.8–54.5 | 52.1 | 0.7 |
Snout to pectoral-fin origin | 23.2 | 23.0–27.7 | 23.9 | 0.9 | 22.6–25.2 | 23.5 | 0.6 |
Snout to pelvic-fin origin | 46.3 | 45.1–49.4 | 45.2 | 0.6 | 44.2–47.1 | 44.6 | 0.9 |
Snout to anal-fin origin | 67.4 | 63.9–68.6 | 64.4 | 0.9 | 64.0–68.5 | 64.2 | 0.7 |
Caudal peduncle depth | 10.8 | 10.1–12.5 | 11.3 | 0.5 | 10.9–12.2 | 11.3 | 0.3 |
Caudal peduncle length | 13.2 | 12.2–17.2 | 14.0 | 1.2 | 12.2–14.9 | 13.1 | 0.7 |
Pectoral-fin length | 20.4 | 17.9–22.5 | 19.7 | 0.3 | 18.6–21.1 | 19.3 | 0.6 |
Pelvic-fin length | 15.9 | 14.6–20.6 | 15.6 | 0.5 | 14.0–17.1 | 15.3 | 0.7 |
Dorsal-fin base length | 11.6 | 9.5–13.4 | 11.3 | 0.5 | 10.8–13.0 | 11.8 | 0.5 |
Dorsal-fin height | 23.1 | 21.2–24.8 | 22.4 | 0.5 | 20.8–24.0 | 22.3 | 0.7 |
Anal-fin base length | 18.9 | 16.7–21.1 | 18.1 | 0.4 | 16.8–20.7 | 18.3 | 1.0 |
Eye to dorsal-fin origin | 42.6 | 40.6–54.6 | 42.1 | 0.6 | 41.4–52.4 | 41.8 | 1.9 |
Dorsal-fin origin to caudal-fin base | 47.6 | 46.5–49.5 | 46.5 | 0.7 | 46.4–49.4 | 46.5 | 0.7 |
Head length | 24.0 | 22.3–26.6 | 24.0 | 1.7 | 22.3–24.9 | 23.1 | 0.6 |
Percentages of head length | |||||||
Horizontal eye diameter | 30.2 | 28.7 –36.0 | 31.4 | 1.5 | 29.5–34.8 | 31.6 | 1.4 |
Snout length | 24.2 | 19.7 –28.8 | 23.5 | 0.6 | 22.8–29.3 | 25.4 | 1.2 |
Least interorbital width | 36.8 | 32.7 –38.9 | 34.1 | 0.1 | 32.9 –37.0 | 11.1 | 1.1 |
Upper jaw length | 34.2 | 31.9 –37.3 | 33.4 | 0.2 | 32.7–39.9 | 33.9 | 1.4 |
All teeth unicuspid or tricuspid and lateral cusps, when present, much smaller; premaxillary teeth in one rows with 6(9), 7(23) tricuspid teeth; maxilla with 11(3), 12(12), 13(14), or 14(3) unicuspid teeth; dentary with 6 (2) or 7 (30) larger tricuspid teeth followed by 6(26) or 7(6) smaller tricuspid teeth.
Scales cycloid and same size over entire body generally. Predorsal scales mostly regular, but sometimes irregular just posterior to supraoccipital and/or slightly anterior to dorsal-fin. Scales covering anterior third of caudal-fin, with up to two, three, or four scales beyond posterior margin of hypural plate. Lateral line interrupted; last scale on caudal-fin base, with 9+1(12),10+1(74), 11+1(50), or 12+1(5). Longitudinal scales series including lateral-line scales 35(3), 36(3), 37(56), 38(49), or 39(30). Longitudinal scales rows between dorsal-fin origin and lateral line 5(1), 6(93) or 7(47). Horizontal scale rows between lateral line and pelvic-fin origin 4 (141), Axillary scale present. Scales in median series between tip of supraoccipital spine and dorsal-fin origin 13+1(24),14+1(65), 15+1(26), or 16+1(26). Circumpeduncular scales 13(18), 14(115), or 15(8).
Dorsal-fin rays i+10(99) or ii+10(42). Dorsal-fin origin situated posterior to vertical through pelvic-fin insertion, near middle of body. First dorsal-fin pterygiophore main body located of 8th and 9th vertebrae. Adipose-fin present. Anal-fin i+14(20), iii+15(18), ii+16(61), iii+16(24), ii+17(10), iii+17(5), ii+18 (3). Anteriormost anal-fin pterygiophore inserting at 14th and 15th vertebrae. Anterior anal-fin margin slightly convex, with anteriormost rays more elongate and slightly more thickened than remaining rays, forming a distinct lobe. Remaining rays smaller with straight distal margin. Pectoral-fin rays i+9(8), i+10(113), or i+11(20). Tip of pectoral-fin not reaching pelvic-fin origin, when adpressed. Pelvic-fin rays i+7(120) or ii+7(21). Tip of pelvic-fin not reaching anal-fin origin, when adpressed. Caudal-fin with a sexually dimorphic pattern, described below (Fig.
Branchiostegal rays 4(32). Supraneurals 6(4) 7(27) or 8(1). Total vertebrae 31 (1), 32(30) or 33(1).
Ground colouration light brown to yellowish brown. Inconspicuous light brown to light gray stripe from humeral spot to caudal-fin base, more conspicuous on posterior half. Humeral region with one conspicuous dark brown to black humeral spot. Smaller dark brown or black chromatophores homogeneously scattered. Smaller dark brown or black chromatophores homogeneously scattered along body, except on chest. Head ground colouration similar to trunk, with dark brown chromatophores present on jaws, tip of snout, opercle, and dorsal portion of head. Dorsal, adipose, anal, caudal, pectoral, and pelvic fins hyaline to light brown.
Caudal-fin of mature males with upper lobe longer (about 2/3 longer) than lower one, while both cauldal-fin lobes have similar leght in females (Fig.
The name brevicaudatus is a contraction of the Latin words brevis meaning “short” and cauda meaning “tail”, an allusion to the shorter caudal-fin lower lobe in the mature males of the new species.
Several authors supported Aphyocharax as a monophyletic genus within Aphyocharacinae (
On the other hand, few studies focused on the intrageneric phylogenetic relationships within Aphyocharax (e.g
Aphyocharax brevicaudatus sp. nov. is described here based on two distinct criteria and assumptions (PAA and WP). As mentioned in the Diagnosis (PAA), Aphyocharax brevicaudatus sp. nov. is unique among its valid congeners possessing the upper lobe of the caudal fin longer than the lower lobe in mature males (
In our Bayesian inference phylogenetic analysis (Fig.
The closer relationship between A. brevicaudatus sp. nov. and A. avary is recovered with maximum posterior probability value. However the relationship between this clade (A. brevicaudatus sp. nov. and A. avary) and other congeners have low phylogentic resolution, and discussions related to the phylogenetic positioning of this clade would be speculative with the data at hand.
Aphyocharax avary : ANSP 39217, 1 (Holotype), Madeira River, about 200 miles east, Brazil. UFRO 018489, 3, Guajará municipality, Rondônia state, Brazil. UFRO016159, 62, Porto Velho municipality, Rondônia state, Brazil. UFRO 014317, 7, Novo Aripuanã municipality, Amazonas state, Brazil. MNRJ 10968, 11, Borba municipality, lago de Borba (Madeira River Basin), Amazonas state, Brazil. CICCAA 02394, 38, Sororó River, Marabá municipality, Pará state, Brazil. Aphyocharax anisitsi: CICCAA 00867, 14, Pontes Lacerda municipality, Mato Grosso state, Brazil. CICCAA 01267, 6 C&S, Pontes Lacerda municipality, Mato Grosso state, Brazil. CAS 59697, 1, Asuncion municipality (radiograph and photograph of holotype), Paraguay. Aphyocharax dentatus: ANSP 128718, 21, Lake Mozambique, Colombia. UFRJ 5571, 2, Rio Verde municipality, Mato Grosso do Sul state, Brazil. CAS 59722, 1, Laguna del Río Paraguay (radiograph and photograph of holotype), Asuncion municipality, Paraguay. Aphyocharax erythrurus: FMNH 53406, 1, Rockstone sandbank (photograph of paratype), Guyana. Aphyocharax nattereri: UFRJ 5783, 2, Poconé municipality, Mato Grosso state, Brazil. Aphyocharax pusillus: ANSP 178013, 4 (photographs of recently preserved specimens), Rio Napo (Amazon river basin), right bank just upstream from mouth of Mazan River, near town of Mazan, Loreto, Peru. BMNH 1867.6.13.46, 1 (syntype), Amazon river basin, Huallaga and Xeberos, Peru. BMNH 1867.6.13.58-59, 2 (syntypes), Amazon river basin, Huallaga and Xeberos, Peru. BMNH 1869.5.21.10, 1 (lectotype of Chirodon alburnus), Amazon River, Peru. BMNH 1869.5.21.11-13, 3 (paralectotypes of Chirodon alburnus), Amazon River, Peru. Aphyocharax rathbuni: CAS 76467, 1 (Radiograph and photograph of a Holotype), Paraguay basin, Arroyo Chagalalina, Paraguay. Aphyocharax yekwanae: FMNH 109278, 1 (radiograph of paratype), Bolivarian Republic, Venezuela. Aphyocharax sp.: CICCAA 00865, 11, Pontes e Lacerda municipality, Mato Grosso state, Brazil. CICCAA 00865, 4 C&S, Pontes e Lacerda municipality, Mato Grosso state, Brazil.
The authors thank James Maclaine for providing photographs, x-ray images, and information on the type material of Chirodon alburnus and A. pusillus; Harry Taylor, the photographer of C. alburnus specimens, and Kevin Webb, the photographer of A. pusillus specimens; Mark Sabaj Perez for providing photographs of the A. pusillus; Rosana Souza-Lima for providing photographs and x-ray images of A. avary; Paulo Buckup, Cristiano Moreira, James Maclaine, Carolina Doria, Wilson Costa, and Mark Sabaj Perez for allowing us to examine material in their care; Paulo Petry, Francisco Provenzano, Oscar Miguel Lasso-Alcalá, and Elias Costa Araujo Junior for providing useful literature. CAPES and FAPEMA for providing the scholarship to PSB under the process 88887.159561/2017-00. This paper benefited from suggestions provided by P. Bragança and F. Roxo. This study was supported by FAPEMA (Fundação de amparo a Pesquisa e Desenvolvimento do Estado do Maranhão) and CAPES (Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - Brasil).