Astyanax lacustris ( Lütken, 1875 ), Lutken, 1875

De Lucena, Carlos Alberto S. & Soares, Helena Gouvea, 2016, Review of species of the Astyanax bimaculatus “ caudal peduncle spot ” subgroup sensu Garutti & Langeani (Characiformes, Characidae) from the rio La Plata and rio São Francisco drainages and coastal systems of southern Brazil and Uruguay, Zootaxa 4072 (1), pp. 101-125: 103-114

publication ID

http://doi.org/10.11646/zootaxa.4072.1.5

publication LSID

lsid:zoobank.org:pub:FCE96B29-A4D3-4AD2-8124-6195BCABBEBD

DOI

http://doi.org/10.5281/zenodo.5618672

persistent identifier

http://treatment.plazi.org/id/BA6B87DF-FF97-0E73-FF56-F8DCA7CBFE80

treatment provided by

Plazi

scientific name

Astyanax lacustris ( Lütken, 1875 )
status

 

Astyanax lacustris ( Lütken, 1875)  

( Fig. 1 View FIGURE 1 ; Table 1 View TABLE 1 )

Tetragonopterus lacustris Lütken, 1875: 131   (type locality: Lagoa Santa [rio das Velhas, drainage of rio São Francisco]. Tetragonopterus jacuhiensis Cope, 1894: 88   (type locality: Rio Grande do Sul, restricted to the rio Jacuí, Rio Grande do Sul, by Fowler, 1906: 435). [Syn. nov.]

Astyanax (Poecilurichthys) bimaculatus paraguayensis Eigenmann, 1921: 256   (type locality: Paraguay [River] and upper Tocantins [River]). [Syn. nov.]

Astyanax bimaculatus asuncionensis Géry, 1972: 3   (name in substitution of Astyanax (Poecilurichthys) bimaculatusparaguayensis Eigenmann, 1921   , preoccupied by Bertoniolus paraguayensis Fowler, 1918   ). [Syn. nov.] Astyanax altiparanae Garutti & Britski, 2000: 67   (type locality: rio Grande, Volta Grande Dam, Miguelópolis, São Paulo, Brazil). [Syn. nov.]

Diagnosis. Astyanax lacustris   is distinguished from other species of the genus Astyanax   by presenting a horizontally oval, black humeral spot and two brown vertical bars situated in the humeral region, characteristics that include it in the Astyanax bimaculatus   group. It is distinguished from A. argyromarginatus   , A. clavitaeniatus   , A. goyacensis   , A. incaicus   , A. novae   , A. rupununi   , A. saltor   , A. siapae   , A. unitaeniatus   , and A. utiariti   by the absence of a conspicuous midlateral black stripe extending above the lateral line, from the humeral spot or just behind it (from the second vertical bar), until the caudal peduncle, continuing along the median rays of the caudal fin; the midlateral stripe continually narrows forward (vs. midlateral black stripe present), and one black spot is present on the caudal peduncle (vs. spot absent). From the other species of the same group, A. lacustris   differs from A. bimaculatus   and A. validus   by the absence of maxillary teeth (one tooth present on the left side of one of 237 examined specimens) (vs. presence). It further differs from A. validus   by the absence of horizontal lines, forming a zigzag pattern on body (vs. presence); and from A. bimaculatus   by presenting a markedly concave external surface of the second tooth of the internal series of the premaxilla, with misaligned cusps (vs. teeth having slightly concave surfaces with cusps almost aligned and on the same plane). Astyanax lacustris   differs from A. abramis   by a reduced number of perforated scales on lateral lines 30–39 (rarely 40 or 41) (vs. 42–48). See “Note on other species of the Astyanax bimaculatus   subgroup caudal peduncle spot” below for A. maculisquamis   , A. borealis   , and A. vittatus   , and “Remarks” on Astyanax lacustris   for A.orbignyanus   .

Description. Morphometric data summarized in Table 1 View TABLE 1 . Body compressed and high, with greatest body depth in around origin of pelvic fins. Dorsal profile of head straight or slightly concave from region above eye to supraoccipital spine. Dorsal body profile convex from tip of supraoccipital spine to dorsal-fin origin; straight from that point to adipose fin origin. Ventral profile of body convex from mandibular symphysis to anal fin origin and posterodorsally slanted along anal-fin base. Caudal peduncle deep, nearly straight on dorsal and ventral margins.

Snout rounded from margin of upper lip to vertical through anterior nostrils. Head somewhat pointed anteriorly in lateral profile. Mouth terminal, jaw isognathous. Maxilla extending posteriorly to vertical through anterior margin of orbit. Maxilla widened anteroposteriorly.

Two tooth rows in premaxilla; outer row with 4 (140) or 5 (3) tricuspid teeth, central cusp longer; inner row with five teeth, gradually decreasing in length from first to fifth; usually with five or six cusps on first tooth, five, six or seven cusps on second to fourth teeth and four or five cusps on fifth tooth; central cusp twice as long and broad as other cusps. Maxilla without teeth (one tricuspidate tooth present in the left side of a specimen—MCP 47854 - of 237 examined).Four anteriormost dentary large teeth with five, six or seven cusps; remaining four to seven (9 c&s)(4–12 in Garutti &Britski, 2000) teeth smaller, uni- to tricuspid ( Fig. 2 View FIGURE 2 ).

Dorsal-fin rays iii (9 c&s) (first very small), 8 (6), 9 (168) or 10 (33); second unbranched ray approximately half length of third ray. Distal margin of dorsal fin nearly straight to slightly convex. Dorsal fin origin slightly behind middle of SL. Origin of adipose fin at vertical through base of sixth, seventh or eighth last anal-fin rays. Anal-fin rays iv(6 c&s) or v(5 c&s), 21 (5), 22 (7), 23 (23), 24 (39), 25 (39), 26 (62), 27 (40), 28 (36), 29 (8), 30 (4) or 31 (1) (up to 34 in Garutti& Britski, 2000). Anal-fin profile smoothly concave. Anal fin origin posterior to vertical through base of last dorsal-fin ray. Pectoral-fin rays i, 11 (108), 12 (42), 13 (1), or 15 (2). Pectoral-fin tip reaching or slightly surpassing pelvic-fin insertion; not reaching in specimens smaller than 11.5 mm SL. Pelvic-fin rays i, 7. Pelvic-fin origin anterior to vertical through dorsal-fin origin. Pelvic-fin tip does not reach or barely reaches anal-fin origin. Caudal fin forked, lobes similar in size, with i+ 17 +i principal rays, no scales in the lobes. Dorsal procurrent caudalfin rays 7 (1), 9 (1), 10 (2), 11 (2) or 12 (2), and ventral 7 (1), 8 (1), 9 (4) or 10 (2) (8 c&s).

Lateral line complete, with 32 (1), 33 (26), 34 (38), 35 (60), 36 (65), 37 (41), 38 (10), 39 (9) or 40 (2) scales (up to 41 in Garutti & Britski, 2000). Scale rows between dorsal-fin origin and lateral line 6 (103), 7 (121), 8 (26) or 9 (2); scale rows between lateral line and pelvic-fin origin 4 (1), 5 (88), 6 (115), 7 (46), 8 (13) or 9 (2); scale rows between lateral line and anal-fin origin 5 (4), 6 (36), 7 (66), 8 (73), 9 (74) or 10 (7). Scale rows around caudal peduncle 11 (1), 12 (8), 13 (25), 14 (65), 15 (66), 16 (60), 17 (15), 18 (12) or 19 (1).

Precaudal vertebrae 16 (4), 17 (2) or 18 (1); caudal vertebrae 18 (5), 19 (1) or 20 (1); total vertebrae 34 (2), 35 (3) or 36 (2). Supraneurals 4 (5)or 5 (2). Gillrakers at first arch: upper branch 6 (7), 7 (10), 8 (47), 9 (104), 10 (75) or 11 (5); lower branch 12 (17), 13 (94), 14 (65), 15 (50), 16 (19), 17 (4) or 18 (1); total number 20 (6), 21 (29), 22 (46), 23 (71), 24 (52), 25 (33) or 26 (10).

Color in alcohol. Dorsal and dorsolateral portions of head and body dark brown. A dark oval humeral spot horizontally placed, followed by two vertical bars tenuously darkened; one exceeds the oval spot and the other remains two or three scales from it. Dark spot on caudal peduncle conspicuous, extending over median rays of caudal fin; anteriorly, it can reach the vertical through the origin of adipose fin.Body with dark spots at the posterior region of scales forming 2 to 4 horizontal stripes above lateral line and 2 to 5 below ( Figs 3 View FIGURE 3 A, B) (see Remarks). For color of living or freshly collected specimens see Desordi et al. (2011), Venere & Garutti (2011), Malabarba et al.(2013), Serra et al.(2014), and Graça & Pavanelli (2007).

Sexual dimorphism. Male specimenswith hooks on anal and ventral fins. Anal fin with hooks from last unbranched ray (can be absent) until the first five, or until the tenth branched ray; one pair per segment. Hooks are present on all branched rays of the pelvic fin. Gill fusion glands were not found macroscopically on the first gill arch. Téran et al. (2014) have found glandular cells but not fusion on the gill filaments in A. asuncionensis   (= A. lacustris   ).

Geographic variation. Variation of meristic characters showed ample overlapping after comparison between the drainages. Therefore, they were not useful in proposing diagnoses according to our criteria. This does not mean that we have not found statistically significant differences in the analysis undertaken. For example, Dunn´s method indicates significant differences in the number of total gill rakers and lower branch gill rakers between the populations of rio São Francisco and the other three populations from Paraguai, Paraná and SLPUR (Figs. 4 A, B). The last count was significantly different between the rios Paraná and Paraguai and SLPUR (Fig. 4 B). The number of gill rakers on the upper branch was significantly different between populations of the Paraná and Paraguai vs. the São Francisco and SLPUR (Fig. 4 C). Significant differences were found in the number of branched anal fin rays between the São Francisco and Paraguai and SLPUR (Fig. 4 D). The number of perforated scales of the lateral line and of scales around the caudal peduncle was significantly different between the rio São Francisco populations and those of the Paraná and Paraguai. The same occurred between the populations of SLPUR and the Paraguai (Figs. 4 D, E). The number of scales around the caudal peduncle was significantly different between SLPUR and Paraná populations (Fig. 4 F). Significant differences were found in the number of scales from the lateral line and pelvic fin origin between São Francisco and Paraguai and SLPUR; the same occurred between the Paraná and Paraguai and SLPUR (Fig. 5 A). The scale count from lateral line to anal fin origin was significantly different between therios São Francisco, Paraguai and Paraná, and SLPUR; the same count was different between the rios Paraguai and Paraná (Fig. 5 B). Significant differences were found in the number of scales from dorsal fin to lateral line between the rio Paraguai and the other three populations (Fig. 5 C).

Morphometric data analyzed did not indicate diagnostic differences ( Tab. 1 View TABLE 1 ), and in an exploratory test PCA did not reveal discriminate populations at all (Fig. 5 D).In PCA, the three first axes explained 96.26 % variation of the data, but the scree plot between axes indicated that only the first two are informative. The axis PC 1 corresponds to the axis of size with all variables showing positive loadings. Axis PC 2, however, showed the population of the Paraná partially discriminated from populations of the rios São Francisco and Paraguai, and SLPUR. The most influential variables in this discrimination in the second axis (explaining 2.892 % of variance) were diameter of the eye and interorbital width on the positive side, and pre-anal distance on the negative side. The drainages — the rios São Francisco, Paraguai and Sistema da Laguna dos Patos— did not show discrimination between them.

FIGURE 4. Astyanax lacustris   populations by river drainages.(A) Number of total gill rakers on the first gill arch in. (B) Number of gill rakers on lower branch of first gill arch. (C) Number of gill rakers on upper branch of first gill arch. (D)Number of branched anal-fin rays. (E) Number of perfored scales of lateral line. (F) Number of scales around caudal peduncle. Tukey box plots: the middle line is the median and lateral lines of the box are 25 th and 75 th respectively.

FIGURE 5. Astyanax lacustris   populations by river drainages (A) Number of scales between pelvic-fin and lateral line in. (B) Number of scales rows between anal-fin and lateral line. (C) Number of scales rows between dorsal-fin and lateral line. Tukey box plots: the lateral lines of the box are 25 th and 75 th respectively. (D) Projection of individual scores in the space of the first and second Principal Component axis for the populations of Astyanax lacustris   .

In specimens, principally from the rio São Francisco drainage, anterior prolongation of caudal spot can be more tapered (contrary to truncated, a more common form in the other drainages), reaching the vertical through nearly half the distance between origin of adipose fin and end of dorsal-fin base ( Figs. 1 View FIGURE 1 A, B). This prolongation, however, sometimes is difficult to visualize, both in its form and scope, suggesting that it may be related to fixation ( Fig. 6 View FIGURE 6 A).

Distribution. Rio La Plata and rioSão Francisco drainages, Sistema da Laguna dos Patos and rio Tramandaí drainage, and according to Garutti & Langeani (2009),in rio Araguaia (Tocantins-Araguaia drainage) ( Fig. 7 View FIGURE 7 A).

Remarks. Tetragonopterus lacustris   was described by Lütken based on specimens captured in Santa Lagoon, rio São Francisco, and taken by Reinhardt to the Zoological Museum at the University of Copenhagen. Lütken did not mention the number of specimens examined, but according to M. Krag (pers. comm.), collection manager of this museum, there are 25 specimens catalogued in that museum. Other syntypes are in the Museum für Naturkunde, Berlin, Musée National d'Histoire Naturelle, Paris, and in the Staatliches Museum für Naturkunde, Stuttgart. Photos of all specimens were examined and confirmed as belonging to the A. bimaculatus   subgroup with caudal peduncle spot (see type material examined)( Figs. 1 View FIGURE 1 C, D).

Astyanax paraguayensis   was described by Fowler (1918) as type species of the new genus Bertoniolus   . Géry (1972) synonymized Bertoniolus   with Astyanax   . To avoid a homonymy with Astyanax (Poecilurichthys) bimaculatus paraguayensis Eigenmann, 1921   , Géry proposed for this species the substitute name A. bimaculatus asuncionensis   , maintaining as such the name A. paraguayensis   for the Fowler species. Extensive series of specimens were analyzed from the rios La Plata and São Francisco drainages and SLP, as well as the syntypes ( Fig. 6 View FIGURE 6 B). In light of this analysis, and considering that the only characteristic mentioned by Eigenmann to distinguish Astyanax bimaculatus paraguayensis   from the others subspecies recognized by him ( lacustris   , novae   , vittatus   , paraguayensis   , and borealis   ) was “rows of spots along the centers of the scales”, a pattern widely observed in the populations from the studied area ( Figs. 6 View FIGURE 6 C), a synonymization is proposed for the name A. bimaculatus asuncionensis   with A. lacustris   , the oldest name (see details on coloration further below).

The diagnostic characters of A. altiparanae   ( Fig. 8 View FIGURE 8 A) presented by Garutti & Britski (2000), are: “ 33 to 41 scales on the lateral line, 10 to 17 scales on the transversal line, 22 to 34 rays on the anal fin, lower portion of body (when divided by the horizontal line that passes through the oral cleft) greater than the upper portion, 4 to 12 (frequently 6 to 8) small teeth on the dentary; large dentary teeth with five, six, or seven cusps; latero-ventral and ventral region of the trunk silvery, absence of maxillary tooth and black lateral band”. While comparing the new species with A. lacustris   , the authors affirm that it possesses “the same uniform coloration as altiparanae   on the ventral flank, differing from it by other characters, among which are the approximately equal height between the upper and lower portions of the horizontal line that passes through the oral cleft (vs. lower portion higher than the upper in A. altiparanae   ), the large teeth with five or six cusps on the dentary bone (vs. five, six, or seven cusps in A. altiparanae   ), and the lesser number of small teeth on the dentary (3 to 6) (vs. 4–12, usually 6–8 teeth in A. altiparanae   )”. The last two characters overlap between the two species, and therefore are not considered diagnostic.Regarding the number of small posterior teeth on the dentary, we found the total range of 4–7 with the following distribution: 5–7 in specimens of rio Paraná drainage ( MCP 20339 View Materials and MCP 37737 View Materials ); 4–6 in specimens of rio Paraguai drainage ( MCP 39750 View Materials ); 4–5 in specimens of SLP ( MCP 18666 View Materials ); 4–7 in specimens of rio Iguaçu drainage ( MCP 26610 View Materials ),and 4–5 in specimens of rio São Francisco drainage ( MCP 17155 View Materials and MCP 16997 View Materials ). The differences in height between the upper and lower portions of the body (considering a horizontal line that passes by the oral cleft, as per the authors) were variable in the material examined. For example, lot MCP 27862 View Materials (7, 70.0– 107.0 mm) of the rio Tietê, upper rio Paraná, in which specimens present weak dark spots on the scales that are almost imperceptible on the ventral part of the body, presents a pattern that according to Garutti & Britski (2000) is characteristic of the species A. lacustris   and A. altiparanae   . We have verified that the upper and lower portions of the body are approximately equal among all specimens, with a tendency for the upper part to be a bit larger. See also the syntypes of Tetragonopterurs lacustris   ( Figs. 1 View FIGURE 1 C, D), in which the height of the upper portion is smaller or approximately equal to the ventral portion.

Salgado (2013) indicates characters differentiating A. altiparanae   and A. lacustris   , which include shape of the distal margin of the anal fin, shape of the margin of the operculum, length of the second ramified ray of the anal fin, and number of cusps on the symphyseal tooth. None of these characters were diagnosed in this study.

Tetragonopterus jacuhiensis   was described by Cope (1894) based on various specimens collected in “Rio Grande do Sul” [locality restricted by Fowler (1906) to the rio Jacuí, Sistema da Laguna dos Patos]. In characterizing the species, Cope mentions diameter of orbit (4 times in head length) and number of anal fin rays (28) as main diagnostic characters. Examination of the holotype revealed the orbit diameter occupying 33.2 % of the head lenght (about 3 times in head length), a value within the limits of A. lacustris   . The same occurred regarding the number of anal fin rays. Although Cope did not mention spots on the scales forming horizontal stripes, examination of the holotype ( Fig. 9 View FIGURE 9 A) and some paratypes showed the presence of spots with weak intensity. The extensive material examined from the type locality, however, confirmed the presence of this character in this species, and highlighted the variability detailed above ( Fig. 9 View FIGURE 9 B).

In reference to the coloration of Astyanax lacustris   , although the concentration of chromatophores occurs in the same position on the scales, the intensity of spots and number of stripes may vary independently from the size of each specimen, or from its area of occurrence. Two color patterns are observed: (1) overall body light, silver on the lateroventral portion, with small dark spots on the posterior portion of some scales faded, forming 2 to 3 horizontal stripes above the lateral line, and 2, maximum 3, stripes below the lateral line ( Figs. 1 View FIGURE 1 A; 6 B, and 9 B); and (2) body darker, especially in the lateroventral region, with conspicuous spots, small on the posterior portion of most scales, forming in conjunction 3 to 4 horizontal stripes above the lateral line and 4, rarely 5 stripes below the lateral line ( Figs. 1 View FIGURE 1 B, 6 C, and 8 B).

Considering the results obtained in the present study and exposed above, and based on the pictures of the type material examined, we conclude that the names Tetragonopterus jacuhiensis Cope, 1894   , Astyanax asuncionensis Géry, 1972   , and A. altiparanae Garutti & Britski, 2000   , are junior synonyms of A. lacustris Lütken, 1875   ( ICNZ, 1999: art. 23).

continued.

Paraná São Francisco

Measurements Range Range Material examined. Types. Brazil: Minas Gerais state: Tetragonopterus lacustris   , lagoa Santa, all pictures. ZMUC P 241324, about 85.0 mm SL, ZMUC P 241322 - 23 and P 241325 -28, 6, about 49.0– 92.5 mm. MNHN 9580, 1, about 80.0 mm. NMW 57540 View Materials , 1, about 100 mm. ZMB 9200, 2, 98.0–99.0 mm SL. SMNS, 2, about 74.0–100.0 mm. São Paulostate: Astyanax altiparanae   , rio Grande, paratypes, MZUSP 48180, 32 (10, 63.3–112.8 mm. Rio Grande do Sul state. Tetragonopterus jachuiensis, Jacuhy   , holotype ,, ANSP 21912, 95.1 mm,same locality of holotype, paratypes, ANSP 21683 -21701, 19 (7, specimens numbers 1 (88.5 mm), 2 (69.7 mmm)and 3 ( Astyanax (Poecilurichthys) bimaculatus paraguayensis   , 67.2 mm), 4 (63.9 mm) and 5 (52.7 mmm), 7 (48.1 mm) and 14 (32.4 mm). Paraguay: rio Paraguay, syntype, CAS 38987 View Materials , 9.3 mm, pict and CAS 38998 View Materials , 70.0 mm, pict.

Non-types. Brazil: Sistema da laguna dos Patos: Rio Grande do Sul state: MCP 18666 View Materials , 47 (2, 47.6 – 65.0mmc&s) arroio on the road Candelária to Chachoeira. MCP 37927 View Materials (1, 96, 9 mm) rio das Antas. MCP 33613 View Materials , 3 (1, 89, 8 mm), rio das Antas. MCP 33584 View Materials , 4 (1, 54, 8 mm), arroio Jararaca. MCP 33587 View Materials , 7 (1, 98,1mm), arroio Trajano, rio das Antas. MCP 21459 View Materials , 12 (6, 68,1–104,9 mm), Lageado Fortaleza. MCP 38805 View Materials (1, 112 ,0 mm), rio das Antas. MCP 37919 View Materials (1, 99, 2 mm), rio das Antas. MCP 45787 View Materials (1, 66, 8 mm, arroio Corrientes. MCP 8879 (1, 75,9mm), rio Camaquã, at reservoir. MCP 21292 View Materials , 14 (1, 64,0 mm), Lageado do Gringo ca 2km da UHE Dona Francisca. MCP 9440, 153 (3, 47,7–52,5 mm), pools of rio Vacacaí. MCP 37892 View Materials (1, 58,0 mm) rio das Antas. MCP 33585 View Materials , 3 (1, 83, 2 mm), rio das Antas. MCP 8498 (1, 81, 2 mm), rio dos Sinos. MCP 8971, 2 (1, 81, 6 mm), rio dos Sinos. MCP 21219 View Materials , 5 (2, 72,2–74,3 mm), arroio on the road to UHE Dona Francisca. MCP 21259 View Materials , 10 (2, 60,9–71,7 mm), arroio da Gringa. MCP 21306 View Materials (2, 46.2–49.5 mm), arroio Corupá. MCP 21225 View Materials , 23 (1, 47, 1 mm), rio Jacuí. MCP 23847 View Materials , 17 (1, 68, 4 mm), arroio Faxinal. MCP 13711 View Materials , 5 (1, 91, 2 mm), rio Jacuí. MCP 37883 View Materials , 5 (1, 76.0 mm), rapids of Caninana. MCP 9157, 7 (1, 67, 7 mm), beach at Tapes. MCP 17320 View Materials , 13 (1 50,6 mm), arroio Martins. MCP 33641 View Materials , 2 (1 72,5 mm CP), rio Taquari, near do mouth of rio Guaporé. MCP 33616 View Materials (2, 70,2–80,0 mm), rio Taquari. MCP 21517 View Materials , 7 (1, 61.2 mm), tributary of Ingaí. MCP 20050 View Materials (1, 91, 4 mm), arroio Feitoria. Rio Uruguai drainage: Rio Grande do Sul state: MCP 26807 View Materials , 26 (9, 50.4–107.5 mm), rio Ibicuí Mirim. MCP 27596 View Materials 5 (1, 71, 9 mm),arroio Cambará. MCP 14190 View Materials (1,62,8 mm), rio Ibicui da Armada. MCP 19222 View Materials , 12 (1, 68, 6 mm), rio Alegre. MCP 13184 View Materials (1, 81, 6 mm), rio Comandaí. MCP 13263 View Materials , 3 (1, 94, 6 mm), mouth of rio Ijuí-Mirim. MCP 21611 View Materials , 15 (12, 53,1–92,1 mm) rio Uruguai. MCP 28903 View Materials (1, 115, 3 mm), rio Ibicui-Mirim. MCP 22870 View Materials , 9 (1, 94, 6 mm), rio Piraizinho. MCP 23144 View Materials , 3 (1, 76, 7 mm), rio Inhacunda. MCP 13225 View Materials , 7 (2, 96,9–124,1mm), rio Uruguai. MCP 6610, 6 (2, 74,8–86,9 mm), arroio Lageado. MCP 12715 View Materials , 103 (2, 57,8–103,5 mm), arroio Passo do Alto. MCP 12660 View Materials , 21 (2, 89,6–120,6 mm), rio Uruguai. MCP 13049 View Materials , 3 (2, 95,6–144,8 mm), rio Uruguai. MCP 13273 View Materials , 4, 71.3– 79.2 mm, mouth of rio Ijuí. MCP 27607 View Materials , 26, 49.3–102.9 mm. Arroio Caraí-Passo. MCP 13089 View Materials , 3, 113.4 – 138.2 mm, rio Comandaí. MCP 6282, 25, 51.7–77.5 mm, arroio na estrada Barra do Guarita/Pinheirinho. Santa Catarina state: MCP 18989 View Materials , 1, 120.0 mm, rio Uruguai em Itá MCP 18444 View Materials , 2, 113.4 – 113.6 mm, rio Uruguai. MCP 12039 View Materials , 8 (1, 62,2mm), rio Canoas. MCP 18582 View Materials , 4 (2, 86,6–89,9 mm), rio Jacutinga. MCP 18839 View Materials , 6 (1, 131.6 mm) rio Uruguai. MCP 20868 View Materials , 7 (1, 117 ,0 mm), arroio da Taipa. Rio Tramandaí drainage: Rio Grande do Sul state: MCP 25322 View Materials , 4, 72.2–92.6 mm, rio Três Forquilhas. MCP 10090 View Materials , 4, 68.3–86.5 mm, rio Maquiné near mouth with Lagoa dos Quadros. MCP 28277 View Materials , 5, 51.5–54.5 mm, rio Maquiné. Rio Paraná drainage: São Paulostate: LBP 3502, 36 (15, 55,4– 104.3 mm), rio Tietê. LBP 3588, 5 (1, 52, 8 mm), rio Tietê LBP 3908, 11.4–35.2 mm, rio Paranapanema. LBP 10682 View Materials , 5, 26.6–50.5 mm, rio Uberaba. LBP 9754, 15, 34.6–49.3 mm. NUP 11967 View Materials , 7 (2, 93.9– 95.4 mm), córrego Toledinho. DZSJRP 14082, 128 (2, 70.7–77.1 mm), córrego at bridge near Canavial. DZSJRP 12654, 15, (1, 82.6 mm) córrego do Tapeirão. DZSJRP 14362, 4 (1, 86.6 mm), córrego Água do Silveira. MCP 14429 View Materials , 11 (4, 84.4–97.9 mm), rio Pardo. MCP 14869 View Materials , 5 (1, 60.8 mm), lagoon at farm Santa Lúcia. MCP 27862 View Materials , 18 (8, 78.0– 104.3 mm) rio Piracicaba. MCP 44583 View Materials (1, 94.6 mm) rio Paranapanema. MCP 27863 View Materials , 5 (3, 52.9–59.7 mm), rio Preto. Paraná: NUP 11103 View Materials , 13 (5, 49.0– 71.8 mm), riacho Caracu. NUP 7950 (3, 55.3–62.7 mm), rio Paracai. MCP 14869 View Materials , 5 (1, 54.0 mm), lagoon at farm Santa Lúcia. Minas Gerais state: MCP 27871 View Materials (1, 8.8 mm), rio Quebra-Anzol. MCP 34675 View Materials (2, 70.1–81.7 mm), Ribeirão Coelhos. MCP 27867 View Materials (1, 66.9 mm), córrego Bagagem. MCP 27864 View Materials (1, 61.4 mm), córrego on the road Davinópolis/Douradoquara. MCP 27861 View Materials (1, 69.4 mm), Córrego Grande. MCP 27865 View Materials (1, 66.3 mm), ribeirão da Estiva. MCP 27869 View Materials (1, 53, 1 mm), Córrego na estrada Argenita/ Pratinha. MCP 34682 View Materials (1, 49.5 mm), Rio Jacaré. Goiás: MCP 42947 View Materials (1, 117.0 mm), Ribeirão João Leite. MCP 42987 View Materials (1, 75.9 mm CP), Córrego das Pedras. MCP 34256 View Materials , 2 (1, 70.6 mm), rio Meia-Ponte. MCP 20339 View Materials , 56 (12, 61.4–71.6 mm, 2, 59.3–60.8 mm c&s) rio Corumbá. MCP 27870 View Materials (2, 60,7–61,1 mm), rio Paranaíba. MCP 42977 View Materials (1, 56.7 mm) Córrego Barreiro. Rio Iguaçu drainage: Paraná state: MCP 25603 View Materials 18 (12, 54.1–68.4 mm) rio Iguaçú. MCP 25610 View Materials , 64 (4, 59.5–73.3 mm, 2, 58.4–63.4 mm c&s), rio Lageado Grande. MCP 25609 View Materials , 35 (6, 76.2–92.1 mm) rio Capanema. NUP 4342, 26 (2, 61.8–63.9 mm) Salto Santiago dam. NUP 1313, 19 (2, 61.2–72.9 mm), Caxias dam. NUP 1623 100 (2, 50.7–57.6 mm), reservatório Caxias. NUP 4126, 8 (2, 40.3 – 40.2 mm), Santo Osóriodam. NUP 7368, 6 (4, 54,6–85,9 mm) córrego Brasília. Rio Paraguai drainage: MatoGrosso state: CPUFMT 118, 9 (7, 50.7 –77,0 mm), flooded area on roadside betweenSanto Antonio do Leverger and Barão de Melgaço. CPUMFT 951, 1, 60.5 mm, rio Itiquira. MCP 48430 View Materials , 2, 38.0–39.0mm, rio Sangradouro. MCP 32464 View Materials (2, 50.9–59.7 mm), córrego Piraputanga. MCP 48421 View Materials (2, 53.7–74.2 mm), córregoon the road Barra dos Bugres – Cáceres. MCP 39279 View Materials , 16 (4, 57.4–66.1 mm), córrego on the transpantaneira road. MCP 48429 View Materials , 1, 49.8 mm, ribeirão Figueira. MCP 39590 View Materials , 34 (8, 50.3–72.1 mm),córrego on the road BR-070. MCP 48428 View Materials , 1, 59.8 mm, córregoon the road MT- 124. MCP 37737 View Materials , 226, 37.7–69.4mm, 42, 52.3–68.5 mm c&s),ribeirão Figueira. MCP 8338, 5 (4, 71.9–84.8 mm), rio Pixaim. MCP 39665 View Materials , 2, 56.0–65.0 mm SL, tributary of rio Caeté, drainage of rio Jauru. Rio SãoFrancisco drainage: Minas Gerais state: MCP 16935 View Materials , 21 (1, 73.7 mm), rio Poções. MCP 17154 View Materials , 150 (5, 51.7–60.7 mm), rio Verde Pequeno. MCP 16997 View Materials , 28 (10, 57.8–62.8 mm), stream near Montes Claros. MCP 16930 View Materials , 14 (4, 48.7–57.5 mm), rio Peru-Açu. MCP 17155 View Materials , 44, 30.4–81.6 mm, stream near Januária. MCP 16970 View Materials , 2, 49.9–68.7 mm, córrego at São João das Missões. MCP 27810 View Materials , 6 (2, 56.9–71.1 mm), stream near Claro de Minas. MCP 34307 View Materials , 5, 24.6–38.4 mm, córrego Olhos d´água. MCP 33748 View Materials , 5, 33.1–37.1 mm, rio Peru-Açu. MCP 27807 View Materials , 2, 19.1–52.3 mm, rio Pirapitinga. MCP 44767 View Materials (1, 82.3 mm), Ribeirão Neco. Bahia sate: MCP 16863 View Materials , 18, 43.4–56.6 mm, rio Tatu. MCP 16924 View Materials , 8 (2, 68.3–72.6 mm), Riacho Santana. MCP 17098 View Materials , 21 (1, 47.0 mm), rio da Olaria. Pernambuco state: MCP 31014 View Materials , 75 (4, 55.5 –56.0 mm), rio Pageu. MCP 31192 View Materials , 714 (1, 60.0 mm), stream on the road BR- 316. Alagoas state: MCP 31471 View Materials , 105, 37.5–62.7mm, tributary of rio Capiá.

TABLE 1. Morphometric data of Astyanax lacustris according to the drainages studied. N = number of specimens measured; SD = standard deviation.

  SLPUR       Paraguai    
Measurements Range       Range    
N Min Max Mean SD N Min Max Mean SD
Standard length (mm) 41 46.2 112.0 77.1 - 39 47.43 84.85 62.42 -
Percent of Standard Length              
Body depth 73 37.3 47.1 42.0 2.242 39 41.0 53.0 45.3 3.13
Predorsal length 73 47.9 53.9 51.1 1.347 39 49.1 56.0 53.0 1.27
Prepectoral length 73 24.8 30.4 27.2 1.212 39 26.0 30.0 27.8 0.90
Preanal length 73 59.9 68.9 65.3 1.697 39 63.3 73.1 68.2 2.44
Prepelvic length 73 41.0 51.1 47.1 1.782 39 47.1 52.6 49.5 1.25
Dorsal-fin length 72 25.2 31.2 28.2 1.534 38 23.7 32.1 28.9 1.52
Pectoral-fin length 41 18.9 28.3 22.6 1.540 39 18.1 26.4 23.3 1.35
Pelvic-fin length 41 14.1 21.5 18.4 1.543 39 13.1 23.4 17.9 1.56
Anal-fin base length 73 27.2 34.6 31.6 1.644 38 27.6 35.4 31.6 2.73
Caudal peduncle length 73 10.0 16.1 13.3 1.306 39 10.0 14.9 12.1 1.21
Caudal peduncle depth 73 10.7 13.0 12.1 0.652 39 10.6 13.0 12.0 0.62
Head length 73 23.2 28.3 25.3 1.023 39 25.8 30.3 27.7 1.03
Percent of Head Length              
Snout length 73 25.0 35.4 29.8 2.265 39 22.0 36.0 27.0 2.98
Interorbital width 73 35.4 41.8 38.6 2.682 39 27.8 37.6 34.5 2.07
Horizontal orbit iameter 73 28.3 44.7 34.2 3.831 39 28.8 43.0 36.4 2.82
Upper jaw length 73 36.0 49.6 41.5 2.323 39 32.0 44.8 38.2 2.33
MCP

Pontificia Universidade Catolica do Rio Grande do Sul

ZMUC

Zoological Museum, University of Copenhagen

MNHN

Museum National d'Histoire Naturelle

NMW

Naturhistorisches Museum, Wien

ZMB

Museum für Naturkunde Berlin (Zoological Collections)

SMNS

Staatliches Museum fuer Naturkund Stuttgart

MZUSP

Museu de Zoologia da Universidade de Sao Paulo

ANSP

Academy of Natural Sciences of Philadelphia

CAS

California Academy of Sciences

Kingdom

Animalia

Phylum

Chordata

Class

Actinopterygii

Order

Characiformes

Family

Characidae

Genus

Astyanax

Loc

Astyanax lacustris ( Lütken, 1875 )

De Lucena, Carlos Alberto S. & Soares, Helena Gouvea 2016
2016
Loc

Astyanax bimaculatus asuncionensis Géry, 1972 : 3

Garutti 2000: 67
Gery 1972: 3
1972
Loc

Astyanax (Poecilurichthys) bimaculatus paraguayensis

Eigenmann 1921: 256
1921
Loc

Tetragonopterus lacustris Lütken, 1875 : 131

Fowler 1906: 435
Cope 1894: 88
Lutken 1875: 131
1875