Copeia, 2005(3), pp. 550–558
Pareiorhina brachyrhyncha (Loricariidae: Siluriformes): a New Species of Fish from the Paraı´ba do Sul Slope of Serra da Mantiqueira, Southeastern Brazil CARINE C. CHAMON, ARION T. ARANDA,
AND
PAULO A. BUCKUP
A new species of Pareiorhina is described from the Ribeira˜o Grande and adjacent drainages, in the left bank of the Rio Paraı´ba do Sul basin, in Sa˜o Paulo State, southeastern Brazil. Pareiorhina brachyrhyncha is uniquely diagnosed among its congeners by the reduction or absence of azygous plates in front of the nuchal plate. It also differs from its congeners by the presence of a minute lateral cusp in the teeth, wider body, anterior and lateral profile of head rounded, broad distal profile of the paired fins, and lower number of vertebrae. The species is considered to be closely related to the sympatric P. rudolphi, based on the lack of azygous dorsal plates above the caudal peduncle. Uma nova espe´cie de peixe do geˆnero Pareiorhina e´ descrita do Ribeira˜o Grande e bacias adjacentes, na margem esquerda da bacia do Rio Paraı´ba do Sul, no Estado de Sa˜o Paulo, sudeste do Brasil. Pareiorhina brachyrhyncha e´ diagnosticada de forma u´nica entre seus congeˆneres pela reduc¸a˜o ou auseˆncia de placas ´ımpares em frente a` placa nucal. Ela tambe´m difere de seus congeˆneres pela presenc¸a de minu´sculas cu´spides laterais nos dentes, corpo relativamente largo, perfil anterior e lateral da cabec¸a arredondado e porc¸a˜o distal das nadadeiras pares relativamente expandida, e menor nu´mero de ve´rtebras. A espe´cie e´ considerada como proximamente relacionada a espe´cie simpa´trica P. rudolphi, baseado no compartilhamento da auseˆncia de placas ´ımpares sobre o pedu´nculo caudal.
AREIORHINA Gosline (1947) was proposed as a monotypic genus to include Rhinelepis rudolphi Miranda Ribeiro (1911). Rhinelepis rudolphi is a substitution name for Plecostomus (Rhinelepis) microps Ihering (1907) described on the basis of a single specimen from ‘‘Piquete (Lorena), Estado de Sa˜o Paulo’’ (Ihering, 1907:26– 27), in the left bank of the Rio Paraı´ba do Sul basin. The name substitution was necessary because Plecostomus microps Ihering (1907) was preoccupied by Plecostomus microps Steindachner (1876). More recently, Bockmann and Ribeiro (2003) described Pareiorhina carrancas from a left bank tributary of the Rio Grande drainage, in the upper Parana´ River basin. Neither Gosline (1947) nor Bockmann and Ribeiro (2003) provided unique apomorphic characters to diagnose Pareiorhina, but relied on a combination of characters to separate the two species from other genera of the Neoplecostominae sensu Gosline (1947). Garavello and Santana (1998) reported the presence and provided ecological data on populations of Pareiorhina occurring at altitudes above 650 m in various rivers of the Grande, Paraı´ba do Sul, Sa˜o Francisco, and Tieteˆ River basins, but did not provide diagnostic characters for any of the species. During a survey of the fishes from the south-
P
western portion of the Serra da Mantiqueira, we found an undescribed species that closely resembles and is sympatric with Pareiorhina rudolphi, the type species of the genus. Here we present a formal description of that species and briefly discuss our reasons for including the new species in the genus Pareiorhina. MATERIALS
AND
METHODS
Measurements were made according to Pereira and Reis (2002). All measurements were made point-to-point with a Starret electronic digital 727 series caliper to 0.01 mm under a binocular stereomicroscope. Plates of paired series were counted according to Schaefer (1997). The number of plates in the dorsal series was split into plates located in front of the dorsal fin (predorsal plates), plates located lateral to the dorsal-fin base (plates lateral to dorsal), and plates located posterior to the dorsal-fin base (postdorsal plates). The number of plates in the ventral series was split into plates located between the pelvic- and anal-fin bases (preanal plates), plates located lateral to the anal-fin base (plates lateral to anal), and plates located posterior to the anal-fin base (postanal plates). All measurements and counts of bilateral structures were obtained from the left side of the speci-
䉷 2005 by the American Society of Ichthyologists and Herpetologists
CHAMON ET AL.—NEW PAREIORHINA FROM SOUTHEASTERN BRAZIL
551
Fig. 1. Pareiorhina brachyrhyncha, new species, holotype, MNRJ 25033, 41.0 mm SL. (A) Dorsal, (B) Lateral, and (C) Ventral views.
men. Vertebral counts were obtained from cleared-and-stained specimens and include the first five vertebrae modified into Weberian apparatus. The compound caudal centrum (PU1 ⫹ U1, Lundberg and Baskin, 1969) was counted as one vertebra. Specimens were cleared-and-stained (CS) according to the method described by Taylor and Van Dyke (1985). The nomenclature and homologies of cephalic sensory canal system follow Arratia and Huaquin (1995); homologies of preopercular lateral-sensory canal follow Schae-
fer (1988). Institutional abbreviations are as listed in Leviton et al. (1985). Pareiorhina brachyrhyncha, new species Figure 1, Table 1 Holotype.—MNRJ 25033, 40.95 mm SL, Brazil, State of Sa˜o Paulo, Municı´pio Pindamonhangaba, Bairro Ribeira˜o Grande, Ribeira˜o Grande (or Tetequ¨era) and adjacent tributary ditch (Rio Paraı´ba do Sul drainage), Vera Cruz farm, 22⬚46⬘14.1⬙S, 45⬚26⬘42.5⬙W, P. A. Buckup, O.
552
COPEIA, 2005, NO. 3
TABLE 1. MORPHOMETRIC DATA OF Pareiorhina brachyrhyncha. Measurements based on MNRJ 25033 (holotype), MNRJ 22267 (n ⫽ 11), MNRJ 22198 (n ⫽ 5), MNRJ 22202 (n ⫽ 1), MNRJ 23836 (n ⫽ 1), and MNRJ 35835 (n ⫽ 1). SD designates standard deviation. Holotype
Range
Mean ⫾ SD
Standard length (mm) Head length (mm)
41.0 11.4
29.8–42.1 9.6–14.4
36.1 ⫾ 3.4 11.6 ⫾ 1.1
Percents of standard length Head length Predorsal length Post-dorsal length Dorsal-fin spine length Anal-fin spine Pectoral-fin spine Pelvic-fin spine Lower caudal-fin ray Upper caudal-fin ray Trunk length Abdominal length Cleithral width Body depth at dorsal origin Body width at dorsal origin Body width at anal origin Caudal peduncle length Caudal peduncle depth
27.9 46.4 36.3 17.2 11.7 19.2 18.4 21.2 17.0 19.9 26.1 32.2 15.1 25.7 15.8 33.2 9.1
27.2–35.1 42.3–47.6 33.1–42.7 17.2–24.6 11.7–15.3 17.3–23.7 18.4–26.5 14.8–25.6 13.7–24.2 18.0–21.4 22.0–28.5 31.2–34.4 14.6–19.7 20.2–31.1 12.8–17.4 27.6–34.5 8.4–10.1
32.3 44.9 38.4 21.4 13.6 20.6 21.8 21.2 19.1 19.6 25.1 32.4 16.9 26.6 14.4 30.4 9.4
⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾
2.2 1.5 2.4 2.0 1.2 1.7 2.4 2.3 2.6 1.0 1.4 1.0 1.5 2.8 1.3 1.8 0.5
Percentage of head length Snout length Horizontal eye diameter Least interorbital length Head depth Mandibular ramus
74.1 16.3 47.7 60.1 21.1
56.6–74.1 9.4–16.7 37.3–48.4 45.3–60.1 15.0–22.2
61.8 11.9 42.5 50.1 18.7
⫾ ⫾ ⫾ ⫾ ⫾
3.9 1.9 2.7 3.6 2.1
Meristics Dorsal plate series Predorsal plates Plates lateral to dorsal Postdorsal plates Total Mid-dorsal plate series Median plate series Mid-ventral plate series
4 5 15 24 19 25 19
— — 15–16 24–25 17–20 25–26 17–19
4.0 5.0 15.3 24.3 18.5 25.3 18.5
⫾ ⫾ ⫾ ⫾ ⫾ ⫾ ⫾
0.0 0.0 0.5 0.5 0.9 0.5 0.6
Ventral plate series Preanal plates Plates lateral to anal Postanal plates Total Premaxillary teeth Dentary teeth
4 3 12 19 29 29
4–5 3–3 11–13 18–21 20–35 17–33
4.6 3.0 12.4 19.9 28.1 26.6
⫾ ⫾ ⫾ ⫾ ⫾ ⫾
0.5 0.0 0.7 0.9 4.0 3.8
Character
Moreira Filho, A. T. Aranda, C. C. Chamon, F. P. Silva, and F. A. G. Melo, 18 Nov. 2001. Paratypes.—Municı´pio de Pindamonhangaba, Ribeira˜o Grande drainage: MNRJ 22267, 2 CS, 41.14–41.58 mm SL, 11, 28.41–42.06 mm SL, collected with the holotype. MNRJ 22198, 9, 32.08–36.60 mm SL, Ribeira˜o Grande,
22⬚46⬘18⬙S, 45⬚27⬘42⬙W, O. Moreira Filho, L. Centofante, and L. H. Silva, 13 Sept. 2001. MNRJ 22202, 1, 36.19 mm SL, Ribeira˜o Grande, 22⬚46⬘18⬙S, 45⬚27⬘42⬙W, O. Moreira Filho, L. Centofante, and L. H. Silva, 13 Sept. 2001. MNRJ 23836, 1, 37.57 mm SL, Ribeira˜o Grande, Ribeira˜o Grande road at number 1909, 22⬚48⬘S, 45⬚27⬘W, P. A. Buckup, A. T. Aranda, C. C. Cha-
CHAMON ET AL.—NEW PAREIORHINA FROM SOUTHEASTERN BRAZIL
553
mon, F. P. Silva, and L. F. S. Ingenito, 1 June 2002. MZUSP 49296, 13, 22.41–38.67 mm SL, small tributary to Ribeira˜o Grande, at reservation area of Talha˜o 5, near headquarters of Sa˜o Sebastia˜o do Ribeira˜o Grande farm, 22⬚56⬘S, 45⬚28⬘W, O. T. Oyakawa and E. C. Espı´rito Santo, 19 Dec. 1995. Piagu¨i River drainage: MNRJ 23835, 2, 30.77–32.30 mm SL, Ribeira˜o dos Leme, at bridge of Bairro dos Leme, Municı´pio Guaratingueta´, 22⬚41⬘S, 45⬚15⬘W, P. A. Buckup, A. T. Aranda, C. C. Chamon, F. P. Silva, and L. F. S. Ingenito, 1 June 2002. Nontype material.—Specimens used to establish geographic range but not formally included in the morphological description are listed below, grouped by river drainage (all localities in the State of Sa˜o Paulo). Piagu¨i River drainage: MNRJ 25058, 4, 18.8–23.0 mm SL, Ribeira˜o dos Leme, at bridge of Bairro dos Leme, Municı´pio de Guaratingueta´, 22⬚41⬘S, 45⬚15⬘W, P. A. Buckup, A. T. Aranda, C. C. Chamon, F. P. Silva, and L. F. S. Igenito, 1 June 2002. Guaratingueta´ River drainage: MNRJ 22271, 33, 18.2–36.9 mm SL, Rio Guameral or Piratinga, tributary of Ribeira˜o Taquara, Municı´pio de Guaratingueta´, 22⬚45⬘24⬙S, 45⬚21⬘37⬙W, P. A. Buckup, O. Moreira Filho, A. T. Aranda, C. C. Chamon, F. P. Silva, and F. A. G. Melo, 18 Nov. 2001. Ribeira˜o Grande drainage, Municı´pio de Pindamonhangaba: MNRJ 23256, 2, 36.6–37.3 mm SL, Ribeira˜o Grande, L. H. da Silva, 8 May 2001; MNRJ 23838, 2, 16.4–19.1 mm SL, Ribeira˜o Grande at bridge on road of Ribeira˜o Grande at number 1909, 22⬚48⬘S, 45⬚27⬘W, P. A. Buckup, A. T. Aranda, C. C. Chamon, F. P. Silva, and L. F. S. Ingenito, 1 June 2002; MZUSP 48533, 5, 32.5– 35.1 mm SL, small stream tributary to Ribeira˜o Grande, at reservation area Talha˜o 5, near headquarters of Sa˜o Sebastia˜o do Ribeira˜o Grande farm, 22⬚56⬘S, 45⬚28⬘W, O. T. Oyakawa and E. C. Espı´rito Santo, 15 June 1995; MZUSP 49114, 3, 31.9–35.5 mm SL, Ribeira˜o Grande, Talha˜o 1, near headquarters of Sa˜o Sebastia˜o do Ribeira˜o Grande farm, 22⬚56⬘S, 45⬚28⬘W, E. C. Espı´rito Santo, 5 Sept. 1995; MZUSP 49132, 1, 34.9 mm SL, small stream tributary to Ribeira˜o Grande, Talha˜o 4, 4 km from headwaters of Sa˜o Sebastia˜o do Ribeira˜o Grande farm, 22⬚56⬘S, 45⬚28⬘W, E. C. Espı´rito Santo, 11 Aug. 1995; MZUSP 49280, 2, 35.5–37.6 mm SL, Ribeira˜o Grande, Talha˜o 1, near headquarters of Sa˜o Sebastia˜o do Ribeira˜o Grande farm, 22⬚56⬘S, 45⬚28⬘W, E. C. Espı´rito Santo, 1 Nov. 1995; MZUSP 49310, 2, 39.0–39.1 mm SL, small stream tributary to Ribeira˜o Grande, Talha˜o 2, near headquarters of Sa˜o Sebastia˜o do Ribeira˜o Grande farm, 22⬚56⬘S, 45⬚28⬘W, E. C. Espı´rito
Fig. 2. Pareiorhina brachyrhyncha, new species, holotype, MNRJ 25033, 41.0 mm SL, ventral view of mouth. Arrow indicates enlarged buccal papilla.
Santo, 18 Dec. 1995; MZUSP 58575, 10 of 23, 31.5–37.0 mm SL, co´rrego do Convento, tributary to Ribeira˜o Grande, in front of Sı´tio San Diego, 22⬚47⬘15⬙S, 45⬚28⬘W, O. T. Oyakawa, C. Oliveira, and M. Ghazzi, 13 Nov. 1999; MZUSP 58577, 2, 28.9–38.4 mm SL, co´rrego do Ferraz, at Sı´tio do Ferraz, 22⬚47⬘S, 45⬚28⬘W, O. T. Oyakawa, C. Oliveira, and M. Ghazzi, 16 Nov. 1999. Diagnosis.—Pareiorhina brachyrhyncha is uniquely diagnosed among its congeners by the reduction or absence of azygous plates in front of the nuchal plate. It also differs from its congeners by the presence of a minute lateral cusp in the teeth (vs. unicuspid teeth in the remaining species), wider body (cleithral width 31.2–34.4% SL in specimens greater than 25 mm SL vs. 23.9– 29.4% SL in P. rudolphi and 27.9–31.0% SL in P. carrancas), anterior and lateral profile of head rounded (vs. elliptical in remaining species), broad distal profile of the paired fins (vs. fin narrower, slightly pointed), lower number of vertebrae (30 vs. 31 in P. carrancas and P. rudolphi). It also differs from the sympatric P. rudolphi by the presence of odontodes at the tip of snout (vs. tip of snout completely naked), the presence of a conspicuous buccal papilla located immediately anterior to the buccal valve (Fig. 2), anterior regions of roof and floor of mouth immediately behind premaxillae and dentaries, respectively, covered with rounded papillae (vs. covered by longitudinal striae), only last median plate lacking pore of lateral line (vs. posteriormost 2–3 median plates without sensory pores of lateral line), lower counts of dorsal body plates (24–25 vs. 29–30 in P. rudolphi), lower counts of mid-dorsal body plates (17–20 vs. 21– 22 in P. rudolphi), lower counts of median body
554
COPEIA, 2005, NO. 3
plates (25–26 vs. 28–30 in P. rudolphi), lower counts of mid-ventral body plates (17–19 vs. 22– 23 in P. rudolphi), and lower counts of ventral body plates (18–21 vs. 23–24 in P. rudolphi). It also differs from P. carrancas by the absence of postdorsal ridge and azygous plates over the caudal peduncle (vs. postdorsal surface of trunk with a low ridge formed by 10–13 raised azygous plates), lower lip completely papillose (vs. lip with a smooth, unpapillose band just behind the toothed portions of dentaries), medial portions of premaxillae and dentaries gently sloped to almost straight (vs. strongly sloped inward), and inferior surfaces of first pectoral-, pelvic-, and anal-fin rays covered by conspicuously spatulate odontodes (vs. covered by pointed odontodes). Description.—Morphometric and meristic data summarized in Table 1. Dorsal profile convex, evenly arched between snout and dorsal-fin base; slightly concave between dorsal-fin base and caudal fin. Ventral profile almost straight between tip of snout and pelvic girdle, elevating posteriorly along anal-fin base, almost straight along caudal peduncle. Body depth greatest at dorsal-fin origin. Smallest depth of caudal peduncle at posterior end of second third of peduncle length. Body width greatest at opercular region; lateral profile almost straight between cleithrum and base of caudal fin. Dorsum with pair of keels formed by series of angulated plates, starting at fourth or fifth dorsal plate. Ventral surface of caudal peduncle flat. Caudal peduncle trapezoid in cross section; much wider ventrally. Head wide, rounded dorsally; anterior profile forming semicircle; head width about equal to distance between tip of snout and posterior tip of parieto-supraoccipital. Interorbital region slightly concave. Eyes small, 22.0–34.5% of interorbital distance, situated dorsolaterally. Iris with small dorsal flap over pupil. Ventral surface of snout almost flat. Lips large, covered with papillae; size of papillae decreasing towards posterior margin of lower lip. Maxillary barbel short; tip of barbel united to lips by membranes in some specimens, free in others. Upper lip folded over itself. Lower lip well developed, not reaching anterior margin of pectoral girdle. Medial end of premaxillary and dentary tooth series strongly curved inwards. Teeth long, pedunculated, with long crown and minute cusp located at base of main crown on lateral side. Teeth organized in single row in both jaws. Pectoral and pelvic fins large, without locking mechanism; medial portion much expanded relative to base; distal margins rounded. Anterior unbranched rays of all fins covered with
odontodes. Anterior unbranched rays of pectoral and pelvic fins conspicuously thick. Pectoral fin with one unbranched, six or seven branched rays. Tip of adpressed pectoral fin almost reaching middle of unbranched pelvic-fin ray. Tips of anterior four branched pectoral-fin rays surpassing tip of anterior unbranched pectoral-fin ray. Pelvic-fin origin below vertebral centrum 9, with one unbranched, four to five branched rays. Tip of adpressed pelvic fin reaching middle of posterior end of anal-fin base. Dorsal-fin origin over middle of pelvic-fin base; dorsal-fin base located over vertebral centra 10–15. Dorsalfin locking mechanism non-functional, spinelet absent. Dorsal fin with one unbranched, seven branched rays; spinelet present as a rudimentary plate. Anal-fin base below vertebral centra 16–19. Adipose fin absent; dorsal area of caudal peduncle slightly concave, covered by paired series of plates, without azygous medial platelets where adipose fin is usually located. Caudal fin truncated. Principal lower unbranched caudalfin ray longer than upper. Caudal fin with 7 ⫹ 7 branched rays. Body covered with plates with odontodes, except ventral surface between snout and anus, region overlaying swim bladder capsule, and areas around dorsal, pectoral, pelvic, and anal-fin insertions. Snout covered with small plates with odontodes more concentrated on nasal plates. Area of urogenital papilla flanked by plates. Azygous dorsal plates in front of nuchal plate absent or restricted to a single minute plate. A plate-like structure (modified spinelet) between nuchal plate and unbranched dorsal-fin ray. Few platelets (procurrent rays) in front of main dorsal caudal-fin ray. Total vertebrae 30. Vertebral centra 6–13 with ribs. Supraorbital sensory canals with great variation in number and position of pores. Supraorbital pores 2, 4, 5, and 7 usually absent; pore 1 located on medial portion of anterior margin of nasal plate; pore 3 located between nasal and frontal plates; pore 4, when present, located in only one side of frontal; epiphysial complex pore (s6 ⫹ s6) located at junction among parieto-supraoccipital and frontal bones, associated with medially fused supraorbital branches; supraorbital pore 8 (parietal pore) located between sphenotic and frontal, ocassionally at junction of these bones with parieto-supraoccipital. Epiphysial complex occasionally missing. Infraorbital sensory canal (io) with six pores: io1 and io2 (antorbital pore) situated at anterior region of snout; io3 located nearly on vertical midway between anterior and posterior nares; io4 located on ventral border of orbit; io5 located just below middle of ventral border of
CHAMON ET AL.—NEW PAREIORHINA FROM SOUTHEASTERN BRAZIL
555
name, treated as an adjective, refers to the shape of the snout, which is short relative to the width of the body and distinguishes the new species from its congeners. KEY
Fig. 3. Distribution of Pareiorhina brachyrhyncha, new species. Localities are represented by circles and correspond to (1) Ribeira˜o Grande drainage, (2) Guaratingueta´ drainage, and (3) Piagu¨i drainage. Each circle may represent more than one locality. Thick line represents state border between Minas Gerais (above) and Sa˜o Paulo (below).
orbit; io6 located behind posteroventral margin of orbit. Preopercular canal with at least three openings: one above preopercle, one between preopercle and cheek plate, one on anterolateral portion of check plate. Coloration in alcohol.—Background color tan to pale ochre. Ventral surface of body light with chromatophores widely separated. Dorsal and lateral surface of head and body mostly dark brown. Three round lighter areas on dorsum; anteriormost poorly defined, usually extending from supraoccipital process to middle of dorsal fin-base, occasionally forming variegated pattern; middle and posterior light areas located between dorsal and caudal fins. In some specimens narrow light area extending vertically on caudal peduncle along caudal-fin base. Pectoral, pelvic, and dorsal fins with variegated blotches corresponding approximately to three transverse bars. Caudal fin with variegated blotches usually forming two vertical bars; anterior bar usually much wider. Distribution.—Pareiorhina brachyrhyncha is known from stony piedmont tributaries of the left bank of Rio Paraı´ba do Sul, in the State of Sa˜o Paulo, southeastern Brazil (Fig. 3). These streams belong to the Ribeira˜o Grande (also known as Tetequ¨era), Guameral, and Piagu¨i sub-drainages. They drain the southeastern slope of Serra da Mantiqueira, a major mountain range that separates the Paraı´ba do Sul from the upper Parana´ River basin. Etymology.—From the Greek brachys, meaning short, and rhynchos, meaning snout, muzzle. The
TO
SPECIES
OF
Pareiorhina
1a. Postdorsal surface of trunk with a low ridge formed by 10–13 azygous plates extending between dorsal and caudal fin; lower lip with a smooth, unpapillose band just external the toothed portions of dentaries -------- P. carrancas 1b. Postdorsal surface of trunk without median ridge; lower lip entirely papillose ------------------- 2 2a. Teeth with minute lateral cusp; cleithral width more than 31% of standard length in specimens above 25 mm SL; tip of snout covered with plates ------------------------ P. brachyrhyncha 2b. Teeth unicuspid; cleithral width less than 31% of standard length in specimens above 25 mm SL; tip of snout without plates ----------------------------------------------------------------------- P. rudolphi
DISCUSSION The new species is very similar to P. rudolphi, the type species of the genus Pareiorhina. The genus was proposed by Gosline (1947) to accommodate that species within the Neoplecostominae, which he was redefining. The species was previously included in Rhinelepis, which Gosline retained as a valid genus of Neoplecostominae. Gosline (1947) listed a combination of characters in the characterization of Pareiorhina. Unfortunately that list of characters is a mixture of unique and non-unique characters. Bockmann and Ribeiro (2003) discussed those characters in connection with their description of P. carrancas, and restricted the diagnosis of Pareiorhina to a list of seven characters: (1) lateral borders of head without developed bristles; (2) teeth simple; (3) abdomen naked; (4) dorsal plates (sensu Schaefer, 1997) meeting (not fused as written in Bockmann and Ribeiro, 2003) along the mid-dorsal line between the dorsal and caudal fins; (5) adipose fin absent; (6) ventral plates (sensu Schaefer, 1997) covering midventral line; and (7) dorsal portion of body behind dorsal fin flatenned. Pareiorhina brachyrhyncha shares all of these features with P. rudolphi and P. carrancas, except the shape of the teeth. In P. brachyrhyncha the teeth have a minute lateral cusp at the base of the main cusp. The remaining six characters listed by Bockmann and Ribeiro (2003) represent a combination of plesiomorphic and apomorphic states. The first character (lack of large bristle-like odontodes in lateral borders of the head) was probably used by Bockmann and Ribeiro (2003)
556
COPEIA, 2005, NO. 3
as a comparison with the alternative state, which occurs in Hemipsilichthys and in most species of Isbrueckerichthys (Pereira and Reis, 2002; Pereira and Oyakawa, 2003). The presence of hypertrophied odontodes is a sexual character occurring in adult males of those two genera. The absence of hypertrophied odontodes is a widespread condition among loricariids and is likely to represent a plesiomorphy for Pareiorhina. As such it should not be used as a diagnostic character for the genus. Except for the flatness of the dorsal surface of the caudal peduncle, the remaining character states listed by Bockmann and Ribeiro (2003) are apomorphic within Loricariidae, but are not restricted to Pareiorhina and may be synapomorphies at higher levels of universality. They may be congruent with a hypothesis of close relationships among P. rudolphi, P. carrancas, and P. brachyrhyncha, but are insufficient as evidence of monophyly. The flatness of the dorsal surface of the caudal peduncle, on the other hand, appears to be unique among genera included in Neoplecostominae as redefined by Armbruster (2004). This feature is produced by a pair of keels formed by the plates of the dorsal series (sensu Schaefer, 1997), and the resulting morphology is often described as having a caudal peduncle rectangular in cross section. Outside the Neoplecostominae, the dorsal flatness of the caudal peduncle also occurs in Pseudotocinclus. However, Pseudotocinclus is a member of the Hypoptopomatinae, which is well-diagnosed as a monophyletic group (Schaefer, 1987). Based on current knowledge of loricariid phylogeny, it is more parsimonious to assume that dorsal flatness of the caudal peduncle has evolved independently in Pseudotocinclus and Pareiorhina. The Neoplecostominae as delimited by Armbruster (2004) is paraphyletic, but Pareiorhina is a member of a monophyletic subunit that also includes Neoplecostomus. We therefore prefer to diagnose the genus Pareiorhina as a Neoplecostominae uniquely diagnosed by the flatness of the caudal peduncle. Within Pareiorhina, P. brachyrhyncha and P. rudolphi share a synapomorphy which is unique within Neoplecostominae sensu Armbruster (2004), namely, the absence of azygous plates between the dorsal series of plates of the caudal peduncle. In the plesiomorphic condition among loricariids, the dorsal midline of the caudal peduncle is occupied by the adipose fin and associated azygous platelets. In species that have lost the adipose fin, such as P. carrancas and species of Corymbophanes, the adipose fin is replaced by a series of azygous platelets aligned along the mid-dorsal line. These platelets form
a mid-dorsal ridge that is relatively high in Corymbophanes andersoni, and in P. carrancas is represented by a low ridge in the middle of the dorsal concave space delimited by the paired dorsolateral keels. In Corymbophanes there are 13–17 azygous plates (Armbruster et al., 2000), and in P. carrancas there are 10–13 (Bockmann and Ribeiro, 2003). In P. brachyrhyncha and P. rudolphi both the adipose fin and the mid-dorsal ridge are absent. Based on the phylogenetic hypothesis of Armbruster (2004), the ridge of Corymbophanes is more parsimoniously interpreted as an independently acquired apomorphy. On the other hand, it is equally parsimonious to assume that the ridge in P. carrancas is an autapomorphy of the species or to assume that it represents an intermediate state between the plesiomorphic presence of an adipose fin and the apomorphic condition observed in P. brachyrhyncha and P. rudolphi. The latter hypothesis is favored by the interpretation that the dorsal ridge of azygous plates represents the remnants of the adipose fin. Bockmann and Ribeiro (2003) pointed out that the lack of secondary tooth cusp is either an autapomorphy of Pareiorhina or a synapomorphy for a clade including that genus. The presence of a lateral cusp in the teeth of P. brachyrhyncha is a priori congruent with a hypothesis of close relationship between P. carrancas and P. rudolphi. However, the distribution of unicuspid teeth among Neoplecotominae is at best ambiguous, while the loss of adipose fin, and azygous plates over the caudal peduncle may be provisionally regarded as unique events. This hypothesis may be further tested in a comprehensive phylogenetic analysis of all small species of Neoplecostominae sensu lato. Such a study is beyond the scope of this paper, and is currently being conducted by others (R. E. Reis, E. H. L. Pereira). A final point worth mentioning refers to the sympatry between P. brachyrhyncha and P. rudolphi. The geographic range of the former is entirely contained within the range of P. rudolphi. Both species are endemic to portions of the Paraı´ba do Sul drainage located above 600 m of altitude, but P. brachyrhyncha is restricted to the southeastern slopes of the Serra da Mantiqueira. If the hypothesis of close relationships between these species is correct, they may represent a case of local differentiation of a species followed by dispersal resulting in extensive sympatry. Speciation followed by subsequent dispersal and geographic overlap of closely related species has been hypothesized by Weitzman and Weitzman (1982) to explain distribution of subsets species of the characiform genera Nannostomus and Car-
CHAMON ET AL.—NEW PAREIORHINA FROM SOUTHEASTERN BRAZIL negiella in tropical areas of South America. The geotectonic events leading to the uplifting of the Mantiqueira range and associated filling of the Taubate´ sedimentary basin are well known for their complexity and have been implicated in various episodes of fish extinction and speciation (Malabarba, 1998). This complex history in combination with Pleistocene and pre-Pleistocene climatic fluctuations may have temporarily isolated hill-side streams at or near the Ribeira˜o Grande basin headwaters, and produced the events that subsequently led to the sympatry of P. brachyrhyncha and P. rudolphi. MATERIAL EXAMINED All specimens from Brazil, unless otherwise stated. Corymbophanes andersoni: AUM 28149, 1 CS, Guyana, Potaro River, Chenapou Cataract, 14.7 mi SW, Mende’s Landing–Kaieteur Falls Potaro-Siparuni, 5⬚0⬘5⬙N, bearing 233⬚ 59⬚37⬘33⬙W. Corymbophanes (?) sp.: MNRJ 15090, 4, 24.4–39.10 mm SL, Rio de Janeiro, Tereso´polis, Ribeira˜o Santa Rita (left bank tributary to Rio Paquequer), close to Santo Afonso farm, 22⬚18⬘55⬙S, 43⬚1⬘16⬙W. Hemipsilichthys garbei: MNRJ 13592, 1, 80.8 mm SL, Rio de Janeiro, Nova Friburgo, Ribeira˜o Santo Anto ˆ nio (left bank tributary to Rio Bonito, right margin bank of Rio Macae´); MNRJ 12839, 4, 29.7–82.7 mm SL, Rio de Janeiro, Tereso´polis, Rio Soberbo upstream of BR–116, 22⬚30⬘S, 42⬚59⬘W. Kronichthys sp.: MNRJ 24281, 3, 60.8–97.5 mm SL, Sa˜o Paulo, east of Juquia´, BR–101, Ribeira˜o Termoele´trica (Ribeira de Iguape drainage), 24⬚19⬘45⬙S, 47⬚37⬘W. Pareiohina rudolphi (all drainages are tributary to the Paraı´ba do Sul basin, except the Perequeˆ Ac¸u): Rio Preto drainage (State of Rio de Janeiro): MNRJ 13675, 2, 30.6–46.1 mm SL, Resende, 3 km from Souza’s bridge, small stream at Bagagem-Fumac¸a road, about 500 m from its mouth at Rio Preto; MNRJ 17440, 16, 21.7–50.8 mm SL, Municı´pio de Visconde de Maua´, left bank tributary to Rio Preto; MNRJ 24080, 26, 27.6–44.9 mm SL, Resende, Rio Preto, at curve downstream from Camping do Torto; MNRJ 23833, 6, 28.3–56.1 mm SL, Itatiaia, Poc¸a˜o Maromba, Rio Preto, circa 1 km upstream from Vila de Maromba, 22⬚21⬘S, 44⬚35⬘W; MNRJ 24084, 6, 27.6–61.8 mm SL, Itatiaia, Poc¸a˜o Maromba, downstream of border of Parque Nacional de Itaiaia. Pirapetinga drainage (State of Rio de Janeiro): MNRJ 16737, 1, 47.5 mm SL, Municı´pio de Resende, Rio Santo Anto ˆ nio; MNRJ 17438, 25, 19.5–46.3 mm SL, Municı´pio de Itatiaia, Rio Piratininga; MNRJ 17444, 20, 22.5–57.3 mm SL, Municı´pio de Itatiaia, Rio Piratininga; MNRJ 19328, 18 ⫹ 2 CS,
557
24.2–39.6 mm SL, Municı´pio de Itatiaia, distrito de Penedo, Rio Pirapetinga, approximately 22⬚22⬘S, 44⬚30⬘W. Piquete drainage (Sa˜o Paulo State): MNRJ 23837, 5, 31.5–48.7 mm SL, small left-bank tributary to Ribeira˜o Piquete, circa 2.3 km (straight line) from Piquete, 22⬚34⬘58⬙S, 45⬚10⬘07⬙W. Piaguı´ drainage: MNRJ 23834, 1, 31.8 mm SL, State of Sa˜o Paulo, Municı´pio de Guaratingueta´, Ribeira˜o dos Leme, at bridge of Bairro dos Leme, 22⬚41⬘S, 45⬚15⬘W. Ribeira˜o Grande drainage (State of Sa˜o Paulo, Municı´pio de Pindamonhangaba): MZUSP 47573, 4, 25.5– 44.0 mm SL, small stream tributary to Ribeira˜o Grande, fazenda Sa˜o Sebastia˜o do Ribeira˜o Grande, near plataform 4, 22⬚56⬘S, 45⬚28⬘W; MZUSP 48593, 2, 32.0–41.7 mm SL, Ribeira˜o Grande, near headquarters of Sa˜o Sebastia˜o do Ribeira˜o Grande farm, 22⬚56⬘S, 45⬚28⬘W; MZUSP 49118, 2, 33.2–37.7 mm SL, Ribeira˜o Grande, Talha˜o 1, near headquarters of Sa˜o Sebastia˜o do Ribeira˜o Grande farm, 22⬚56⬘S, 45⬚28⬘W; MZUSP 58575, 10 of 23, 30.1–35.7 mm SL, co´rrego do Convento (tributary of Ribeira˜o Grande) in front of Sı´tio San Diego, 22⬚47⬘15⬙S, 45⬚27⬘34⬙W. Bananal drainage: MNRJ 19669, 5, 26.3–41.3 mm SL, Sa˜o Paulo, Bananal, Rio Bananal, along SP 247 road, 22⬚45⬘07⬙S, 44⬚23⬘04⬙W. Perequeˆ-Ac¸u drainage (Parati, State of Rio de Janeiro): MNRJ 24915, 2, 45.9–46.0 mm SL; co´rrego da Estiva Preta, upstream of small road of Parque Nacional da Serra da Bocaina, 23⬚11⬘26⬙S, 44⬚50⬘30⬙W; MNRJ 24917, 3, 42.2–49.7 mm SL, co´rrego da Estiva Preta, upstream from secondary road of the Parque Nacional da Serra da Bocaina, 23⬚11⬘26⬙S, 44⬚ 50⬘30⬙W. Pareiorhina carrancas: MNRJ 23156, holotype, 39.7 mm SL; MNRJ 17064, paratypes, 1 CS, 35.7 mm SL, 2, 30.6–37.6 mm SL; Minas Gerais, Carrancas, co´rrego Debaixo da Serra ´ gua Limpa, (right bank tributary to co´rrego A right bank of co´rrego Beijinho), 21⬚26⬘40⬙S, 44⬚36⬘09⬙W. ACKNOWLEDGMENTS O. Moreira Filho (Universidade Federal de Sa˜o Carlos) provided the initial stimulus for the study at the Serra da Mantiqueira and was most helpful during fieldwork. For loan of specimens we are grateful to O. Oyakawa. R. Reis and E. Pereira kindly made available the cleared-andstained specimen under their care. We thank F. Bockmann, O. Oyakawa, and M. Britto for their advice and helpful suggestions. The manuscript benefited from comments by J. Armbruster. M. Melo provided assistance in clearing, staining, and dissecting specimens. Collecting permits were provided by Instituto Brasileiro do Meio
558
COPEIA, 2005, NO. 3
Ambiente e dos Recursos Naturais Renova´veisIBAMA, Portarias 068/99 and 41/2002. Collecting at Fazenda Sa˜o Sebastia˜o do Ribeira˜o Grande farm was facilitated by the Forestry Unit of VCP Celulose e Papel. The maps were prepared with the help of M. Matsumoto. This study was supported by grants from Fundac¸a˜o de Amparo a` Pesquisa do Estado de Sa˜o Paulo, FAPESP (process 2001/00713–0, with O. Moreira Filho); Conselho Nacional de Desenvolvimento Cientı´fico e Tecnolo´gico, CNPq (process 523237/95–2 to PAB, CCC; process PRONEX 661058/1997–2 to N. Menezes). LITERATURE CITED ARMBRUSTER, J. W. 2004. Phylogenetic relationships of the suckermouth armored catfishes (Loricariidae) with emphasis on the Hypostominae and the Ancistrinae. Zool. J. Linnean Soc. 141:1–80. ———, M. H. SABAJ, M. HARMAN, L. M. PAGE, AND J. H. KNOUFT. 2000. Catfish genus Corymbophanes (Loricariidae: Hypostominae) with description of one new species: Corymbophanes kaiei. Copeia 2000:997– 1006. ARRATIA, G., AND L. HUAQUIN. 1995. Morphology of the lateral line system and of the skin of diplomystid and certain primitive loricarioid catfishes and systematics and ecological considerations. Bonn. Zool. Monogr. 36:1–110. BOCKMANN, F. A., AND A. C. RIBEIRO. 2003. Description of a new suckermouth armored catfish of the genus Pareiorhina (Siluriformes: Loricariidae), from southeastern Brazil. Icthyol. Explor. Freshwaters 14:447– 458. GARAVELLO, J. C., AND I. C. SANTANA. 1998. Functional morphology, ecology and geographic distribution of the neotropical catfish genus Pareiorhina Gosline, 1947, from southeastern Brazilian rivers (Pisces, Loricariidae, Hypostominae). Verh. Internat. Verein. Limnol. 26:2240–2243. GOSLINE, W. A. 1947. Contributions to the classification of the loricariid catfishes. Arq. Mus. Nac., Rio de Janeiro 41:79–134. IHERING, R. 1907. Diversas espe´cies novas de peixes nematognathas do Brazil. Several new species of Brazilian nematognath fishes. Notas Prelim. Mus. Paulista 1:13–39. LEVITON, A. E., R. H. GIBBS, JR., E. HEAL, AND C. E. DAWSON. 1985. Standards in herpetology and ichthyology: part I. Standard symbolic codes for insti-
tutional resource collections in herpetology and ichthyology. Copeia 1985:802–832. LUNDBERG, J. G., AND J. N. BASKIN. 1969. The caudal skeleton of the catfishes, Order Siluriformes. Am. Mus. Novit. 2398:1–49. MALABARBA, M. C. S. L. 1998. Phylogeny of fossil Characiformes and paleobiogeography of the Tremembe´ Formation, Sa˜o Paulo, Brazil, p. 69–84. In: Phylogeny and Classification of Neotropical Fishes. L. R. Malabarba, R. E. Reis, R. P. Vari, Z. M. Lucena, and C. A. S. Lucena (eds.). Edipucrs, Porto Alegre, Brazil. PEREIRA, E. H. L., AND O. T. OYAKAWA. 2003. Isbruckerichthys epakmos, a new species of loricariid catfish from the rio Ribeira de Iguape basin, Brazil (Teleostei: Siluriformes). Neotrop. Ichth. 1:3–9. ———, AND R. E. REIS. 2002. Revision of the loricariid genera Hemipsilichthys and Isbruckerichthys (Teleostei: Siluriformes), with descriptions of five new species of Hemipsilichthys. Ichthyol. Explor. Freshwaters 13: 97–146. SCHAEFER, S. A. 1987. The Osteology of Hypostomus plecostomus (Linnaeus), with a phylogenetic analysis of the loricariid subfamilies (Pisces: Siluroidei). Contr. Sci. Nat. Hist. Mus. Los Angeles Co. 394:1– 31. ———. 1988. Homology and evolution of the opercular series in the loricarioid catfishes (Pisces: Siluroidei). J. Zool. London 214:81–93. ———. 1997. The Neotropical cascudinhos: Systematics and biogeography of the Otocinclus catfishes (Siluriformes: Loricariidae). Proc. Acad. Nat. Sci. Phila. 148:1–120. TAYLOR, W. R., AND G. C. VAN DYKE. 1985. Revised procedures for staining and clearing small fishes and other vertebrates for bone and cartilage study. Cybium 9:107–119. WEITZMAN, S. H., AND M. WEITZMAN. 1982. Biogeography and evolutionary diversification in neotropical freshwater fishes, with comments on the refuge theory, p. 403–422. In: Biological Diversification in the Tropics. G. T. Prance (ed.). Columbia University Press, New York.
DEPARTAMENTO DE VERTEBRADOS, MUSEU NACIONAL/UFRJ, QUINTA DA BOA VISTA, 20940–040 RIO DE JANEIRO, RJ, BRAZIL. E-mail: (PAB)
[email protected]; (ATA)
[email protected]. br; and (CCC)
[email protected]. br. Send reprint requests to PAB. Submitted: 1 Oct. 2004. Accepted: 7 April 2005. Section editor: J. W. Armbruster.
