Papers by Ricardo Campos da Paz
<i>Eigenmannia correntes</i>, new species Figures 1–2 <b>Holotype.</b> MN... more <i>Eigenmannia correntes</i>, new species Figures 1–2 <b>Holotype.</b> MNRJ 47046, 113.0 mm LEA, Brazil, Mato Grosso do Sul, Sonora, córrego de Baixo, left margin tributary of rio Correntes, at road MS-213, 17o42'46"S 54o21'25"W, R. Campos-da-Paz, 4 Oct 2003. <b>Paratypes.</b> All collected along with holotype. MNRJ 46334, 29, +2 c&amp;s, 14.0–118.0 mm LEA. <b>Non-type material.</b> All from Brazil. MNRJ 46335, 21, 61.0–83.0 mm LEA, Mato Grosso do Sul, Sonora, córrego de Cima, left margin tributary of rio Correntes, at road MS-213, 17o39'52"S 54o14'48"W, R. Campos-da- Paz, 4 Oct 2003; MNRJ 46336, 10, 44.0–69.0 mm LEA, Mato Grosso, Itiquira, stream at right margin of rio Correntes, near highway BR-163, 17o28'36"S 54o43'23"W, R. Campos-da-Paz, 5 Oct 2003. <b>Diagnosis.</b> Distinguished from all congeners, except those species included in the <i>Eigenmannia trilineata</i> species-group, by the presence of a conspicuous superior midlateral stripe (Fig. 1; <i>vs</i>. absence). <i>Eigenmannia correntes</i> can be differentiated from all members of the <i>Eigenmannia trilineata</i> species-group, except <i>E. vicentespelaea</i>, <i>E. waiwai</i> and <i>E</i>. <i>besouro</i>, by the mouth subterminal (Fig. 2; <i>vs</i>. terminal in remaining species of the <i>E. trilineata</i> species-group). It differs from <i>E. vicentespelaea</i> by: 1) lower number of premaxillary teeth (17–20, in three irregular rows <i>vs</i>. 25–26, in four rows); 2) lower number of dentary teeth (16–18, in two irregular rows <i>vs</i>. 38–45, in three or four rows); 3) higher number of longitudinal series of scales above lateral line (11–12 <i>vs</i>. 7–8); 4) lower number of pectoral-fin rays (ii,12–13 <i>vs</i>. ii,15–17); 5) lower total number of anal-fin rays (143–164 <i>vs</i>. 169– 191); 6) larger body width (6.4–8.1% of LEA <i>vs.</i> 3.5–5.8%); and 7) larger oral width (23.5–26.0% of HL <i>vs</i>. 9.5– 17.2%). It differs from <i>E. waiwai</i> by: 1) larger oral width (23.5–26.0% of HL <i>vs</i>. 9.5–14.6%); 2) longer snout (32.2–35.2% of [...]
Systematics and Biodiversity, Mar 17, 2022
Fig. 1. Holotype of Tembeassu marauna (MZUSP 48510), left side of head. Scale bar ~ 5 mm.
Fig. 4. Radiograph (inverted) showing a detail of the left side of the upper jaw region of the fe... more Fig. 4. Radiograph (inverted) showing a detail of the left side of the upper jaw region of the female paratype of Tembeassu marauna (MZUSP 23090). Arrow at left indicates the patch of extra teeth at the anteriorly extended "boneless" portion of snout, loosely attached to soft tissue in front of the premaxillary bones (PM). Additional abbreviations as in Figure 2 (above; both maxillary bones noticed). Scale bar ~ 5 mm.
Fig. 2. Radiograph (inverted) showing skeletal structures at the anterior portion of head of the ... more Fig. 2. Radiograph (inverted) showing skeletal structures at the anterior portion of head of the holotype of Tembeassu marauna (MZUSP 48510). Arrow at left indicates the patch of extra teeth inside the mouth (roof of the oral cavity), loosely attached to soft tissue in front of the premaxillary bones (PM). Additional abbreviations are as follows: AN = anguloarticular; DE = dentary; EN = endopterygoid; FR = frontal; LE = lateral ethmoid; ME = mesethmoid; MX = maxilla; PS = pterosphenoid; VO = vomer (ventral ethmoid). Scale bar ~ 5 mm.
Fig. 3. Radiograph (inverted) showing the left side of the anterior region of head of the male pa... more Fig. 3. Radiograph (inverted) showing the left side of the anterior region of head of the male paratype of Tembeassu marauna (MZUSP 23090), also exhibiting the conspicuous forward extension of the fleshy ("boneless") portions of the upper and lower jaws, in front of the premaxillary (PM) and dentary bones (DE), respectively. Additional abbreviations as in Figure 2. Arrow at left indicates the patch of extra teeth loosely attached to soft tissue at the roof of oral cavity, in front of the premaxillary bones, at the anteriorly extended portion of the upper jaw. Scale bar ~ 5 mm.
FIGURE 1. Hypopygus varii, MNRJ 46752, holotype, 89.0 mm LEA, Brazil, Pará, Oriximiná, igarapé Sa... more FIGURE 1. Hypopygus varii, MNRJ 46752, holotype, 89.0 mm LEA, Brazil, Pará, Oriximiná, igarapé Saracá. (a) Left lateral view of body; (b) dorsal view of same specimen, head to left. Scale bar: 10 mm.
FIGURE 4. Map of South America showing approximate type-localities of species belonging to the Ei... more FIGURE 4. Map of South America showing approximate type-localities of species belonging to the Eigenmannia trilineata species-group. Circle: Eigenmannia correntes; squares: 1 = E. antonioi; 2 = E. besouro; 3 = E. desantanai; 4 = E. guairaca; 5 = E. matintapereira; 6 = E. microstoma; 7 = E. muirapinima; 8 = E. pavulagem; 9 = E. trilineata; 10 = E. vicentespelae; 11 = E. waiwai.
FIGURE 2. Eigenmannia correntes, MNRJ 47046, holotype, 113.0 mm LEA. Head and anteriormost portio... more FIGURE 2. Eigenmannia correntes, MNRJ 47046, holotype, 113.0 mm LEA. Head and anteriormost portion of body. Scale bar: 10 mm. Arrow indicates anus position.
FIGURE 1. Eigenmannia correntes, MNRJ 47046, holotype, 113.0 mm LEA, Brazil, Mato Grosso do Sul, ... more FIGURE 1. Eigenmannia correntes, MNRJ 47046, holotype, 113.0 mm LEA, Brazil, Mato Grosso do Sul, Sonora, córrego de Baixo. Lateral view of body. Scale bar: 10 mm.
FIGURE 4. Strict consensus tree of four fundamental most parsimonious cladograms (length 55, CI =... more FIGURE 4. Strict consensus tree of four fundamental most parsimonious cladograms (length 55, CI = 0.89, RI = 0.92) showing phylogenetic relationships between Hypopygus species. See text for details and discussion.
FIGURE 3. Map of northern South America showing approximate type-localities of Hypopygus species.... more FIGURE 3. Map of northern South America showing approximate type-localities of Hypopygus species. Square: Hypopygus varii; circles: 1 = H. benoneae; 2 = H. cryptogenes; 3 = H. hoedemani; 4 = H. isbruckeri; 5 = H. lepturus; 6 = H. minissimus; 7 = H. neblinae; 8 = H. nijsseni; 9 = H. ortegai.
FIGURE 2. Hypopygus varii, MNRJ 46752, holotype, 89.0 mm LEA. Head and anteriomost portion of bod... more FIGURE 2. Hypopygus varii, MNRJ 46752, holotype, 89.0 mm LEA. Head and anteriomost portion of body. Scale bar: 10 mm. Arrow indicates anus position.
PLOS ONE, 2019
A detailed osteological study of the poorly known and critical endangered ghost knifefish, Tembea... more A detailed osteological study of the poorly known and critical endangered ghost knifefish, Tembeassu marauna, from the rio Paraná , Brazil, was conducted using X-ray microcomputed tomography (μCT scan). A redescription of the external anatomy was performed, including the unusual presence of a rostral patch of extra teeth on the region of the upper lip anterior to the premaxilla and the prominent anterior fleshy expansions in both upper and lower lips. The newly surveyed characters were included and analyzed in light of a recent morphological data matrix for Gymnotiformes. In spite of some uncertainties that remains as to phylogenetic allocation of the genus, the most probable hypothesis is that Tembeassu is the sister group of a clade that includes Megadontognathus and Apteronotus sensu stricto. The phylogenetic analysis also supports that Tembeassu is considered a valid genus of Apteronotidae. An amended diagnosis for the genus is also provided.
Ocean and Coastal Research, 2021
Zootaxa, 2018
A new Hypopygus species is described from the igarapé Saracá, a stream in the lower rio Trombetas... more A new Hypopygus species is described from the igarapé Saracá, a stream in the lower rio Trombetas system, Pará State, Brazil. It differs from congeners by a unique combination of characters (either primitive or of uncertain polarity) which includes mouth position, interocular width, snout length, postorbital length, pectoral-fin length, snout-to-occiput length, caudal-filament length, counts of pectoral-fin rays and anal-fin rays, distribution of anal-fin chomatophores, as well as a set of osteological features. A phylogenetic analysis indicates that the new species, belongs to a monophyletic subgroup in Hypopygus that includes all congeners, except H. neblinae; its relationships within that clade, however, are currently uncertain, and a brief discussion is provided. Corrections are made concerning some morphometric and meristic information furnished in recent contributions regarding Hypopygus species.
Copeia, 2019
A new species of Gymnotus is described from coastal river systems in the Pernambuco State, Brazil... more A new species of Gymnotus is described from coastal river systems in the Pernambuco State, Brazil. It is phylogenetically referred to the “Gymnotus carapo group clade” for presenting a clear patch posteriorly at anal fin, two independent pores at dorsoposterior corner of preopercle, a single row of well-developed teeth (most arrowhead-shaped) anteriorly on premaxilla, cleithrum with anterior notch, and by the relative anus to anal-fin distance, pectoral-fin length, and maxilla length. The new species is distinguished from all congeners in the “Gymnotus carapo group clade” by a unique set of characters of uncertain polarity, including the number of dark bands along the body, dark bands along body three to four times wider than pale interbands, with nearly straight margins (never broken anteriorly into irregular dark spots), and bands nearly uniform in color, number of scales above lateral line, number of lateral-line perforated scales to first ventral ramus, number of total pored lateral-line scales, head length, snout length, body depth, number of anal-fin rays, number of pectoral-fin rays, number of precaudal vertebrae, number of teeth on anterior row of premaxilla, and number of teeth along outer row of dentary. The new taxon represents the first species of Gymnotus described from localities in northeastern Brazil, north of the mouth of the rio São Francisco.
Zootaxa, Jan 3, 2017
Eigenmannia correntes, a new species belonging to the Eigenmannia trilineata species-group, is de... more Eigenmannia correntes, a new species belonging to the Eigenmannia trilineata species-group, is described from tributaries of rio Correntes, a major affluent of the rio Piquiri system, upper rio Paraguai basin (Mato Grosso and Mato Grosso do Sul states, Brazil). Eigenmannia correntes is included in the currently poorly defined sternopygid genus Eigenmannia (Ostariophysi: Gymnotiformes) by presenting characters that are either primitive or of uncertain polarity, such as eyes covered by skin, scales present over entire postcranial portion of body, teeth absent from oral valve, infraorbital bones 1+2 with enlarged posterodorsal expansion, and gill rakers short and unossified. The new species is distinguished from all congeners, except those species included in the Eigenmannia trilineata species-group, by the presence of a conspicuous superior midlateral stripe (synapomorphy of this clade). Eigenmannia correntes can be differentiated from all members of the Eigenmannia trilineata species...
Neotropical Ichthyology, 2005
Recent study of the type-material of Tembeassu marauna, a poorly-known species currently represen... more Recent study of the type-material of Tembeassu marauna, a poorly-known species currently represented in collections only by its holotype (male) and paratypes (male and female), all collected forty years ago at the Ilha Solteira reservoir area, upper Paraná river region, revealed an unique pattern of dental arrangement among members of the order Gymnotiformes. This autapomorphic condition refers to a patch of around 15 elongate conical, extra teeth associated to soft tissue, and disposed inside the mouth on a restricted area at the roof of oral cavity and located just in front of the premaxillary bones (although clearly apart from those). Besides this obvious feature, two additional conditions are recognized as possibly unique for T. marauna, which refer to the conspicuous "fleshy" (that is, not presenting subjacent bony structures) anterior elongations of the upper and lower jaws. Some additional osteological features identified on radiographs taken from the type material ...
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Papers by Ricardo Campos da Paz