Australoheros facetus ( Jenyns, 1842 )

An, Old Ř Ich Ř Í Č & Kullander, Sven O., 2008, The Australoheros (Teleostei: Cichlidae) species of the Uruguay and Paraná River drainages, Zootaxa 1724, pp. 1-51 : 4-13

Australoheros facetus ( Jenyns, 1842)

Chromis facetus Jenyns, 1842: 104 . Type locality: Maldonado, Rio la Plata, Uruguay. Types in Cambridge University Museum (Darwin no. 660).

Chromys oblonga Castelnau, 1855: 14 . Type locality: Rio Tocantins, Goiás, Brazil. Holotype: MNHN A-9485. Heros autochthon Günther, 1862: 299 . Type locality: Brazil. Syntypes: (4) BMNH uncat. (1). Heros jenynsii Steindachner, 1869: 149 . Type locality: Montevideo, Uruguay. Syntypes: NMW 17324-27 (4), 58722 (1). Heros acaroides Hensel, 1870: 54 . Type locality: “Bei Porto Alegre in stagnirenden Gewässern, Brazil ”. Syntypes: ZMB

7455(2).

Material examined. NRM 33035 (2, 87.7–106.7 mm SL) Argentina, Buenos Aires, Moreno/Merlo, Río de la Reconquista, 100 m downstream from Represa La Reja (3km S of the village La Reja). NRM 33050 (1, 40.6 mm SL) Argentina, Entre Ríos, Gualeguaychú, Arroyo Ñancay, where crossing RN14. NRM 37036 (1, CS), NRM 37037 (1, CS), NRM 37038 (1, CS), NRM 37039 (1, CS), NRM 37040 (1, CS) Uruguay, Canelones, Laguna del Tronco at Salinas, 37 km from Montevideo on Ruta Nacional 1 to Atlántida, 500 m off road toward Pando. NRM 36495, (2, 45.2–63.5 mm SL), NRM 36774 (2, 53.2–56.0 mm SL), and NRM 36848 (3, 30.6–35.8 mm SL) Uruguay, Treinta y Tres, Arroyo Local at margin of Valentines. NRM 37035 (1, CS), NRM 39527 (13, 42.9–72.0 mm SL), NRM 37037 (1, CS) Uruguay, Treinta y Tres, Laguna Merín drainage, Arroyo Local at Valentines. NRM 39546 (2, CS) Uruguay, Treinta y Tres, Laguna Merín drainage, Arroyo Averías at Las Pavas, 30 km from Valentines and 8 km from Ruta Nacional 19. NRM 39552 (1, 103.5 mm SL) Uruguay, Canelones, Laguna Arenera de Carrasco at San José de Carrasco, 18 km on road Montevideo-Atlántida, 200 m off Ruta Nacional 1. NRM 48078 (39, 30.1–50.5 mm SL), NRM 47999 (20, 31.3–74.5 mm SL), and NRM 48074 (16, 41.4–114.2 mm SL) Uruguay, Canelones, El Pinar.

Character diversity in Australoheros facetus . The type specimens of A. facetus are from Uruguay, Río de la Plata drainage. The description given by Jenyns (1842) agrees well with populations form both the Uruguayan and Argentinian sides of the Río de la Plata, and these populations are fairly uniform. Ř íčan and Kullander (2006) distinguished a separate group of populations ( A. cf. facetus ) within the nominal Australoheros facetus . We provide below a more detailed analysis of the variation between the two forms from Uruguay. Tackling this variation will be crucial in order to classify Australoheros populations from the coastal drainages of Brazil. The coastal populations from Southern Brasil are most certainly different species from both A. facetus and A. cf. facetus . We have not examined enough material from these areas, but preliminary results show that these populations have a low proportion of four abdominal bars (only in 12% of the specimens) and also have a different combination of meristic characters. In this paper we use as comparative material fishes from the Río Jacui coastal drainage of Río Grande do Sul (A. sp. “Jacui”).

The two forms from Uruguay are distinguished mainly by meristic differences. We provide below a separate description of the material that we refer to as A. cf. facetus . Steindachner (1869) describes Heros facetus (Jenyns) by the following characters: the mouth is upwards directed, lower projects in front of upper jaw, modal count of 10 dorsal rays, 6 anal spines in all 6 specimens, dorsal fin scale cover only covering the last two spine bases and the base of the soft part of the fin (i.e. the shortest dorsal fin cover observed among Australoheros species), L1 scale counts 17 (18–19). The 6 anal spines and 10 dorsal rays distinguish the two forms according to the original description. A. cf. facetus is slightly different in some meristic characters from the description by Steindachner.

Description of A . cf. facetus from coastal Uruguay and southern Rio Grande do Sul, Brazil. Based on specimens over 60 mm SL with notes on smaller specimens. Meristic data are summarized in Table 1. Morphometric data are summarized in Table 2 . NRM 47999 (20); NRM 48074 (15); NRM 48078 (39); NRM 36495 (2); NRM 36774 (2); NRM 36848 (1); NRM 39527 (13); NRM 43943 (2); NRM 37035 (1 C&S); NRM 37037 (1 C&S); NRM 37039 (1 C&S).

High proportion of four abdominal bars (88.0% of the specimens), with only 7.4 % individuals without full separation of the four abdominal bars.

Scales in E0 row 23(1), 24(25), 25(18), 26(1). Upper lateral line scales 13(3), 14(2), 15(9), 16(17), 17(11), 18(2). Lower lateral line scales 6(2), 7(7), 8(19), 9(14), 10(3). Scales between lateral lines 2. Circumpeduncular scales 16 (7 dorsally + lateral line scale + 7 ventrally + lateral line scale).

D. XV,10 (3), XVI,8 (1), XVI,9 (30), XVI,10 (12), XVI,11 (1), XVII,8 (3), XVII,9 (13), XVII,10 (1). A. VI,8 (5), VI,9 (1), VII,7 (14), VII,8 (32), VII,9 (2), VIII,7(5), VIII,8(5). Anal fin pterygiophores 12(20), 13(40), 14(5). Modally two anal pterygiophores in front of the first haemal spine [1(11), 2(51), 3(3)]. Dorsal pterygiophores posteriorly of the first caudal vertebra 10(35), 11(27), 12(3). Pectoral fin with a rounded tip, extending to about third anal spine. P. 12(5), 13(34), 14(5).

Dorsal fin count frequences XIV XV XV XV XVI XVI XVI XVI XVII XVII XVII XVII XVIII 12 9 10 11 8 9 10 11 7 8 9 10 9

A. charrua 1 4 1 2

A. facetus Argentina-Uruguay 2 2 20 3 1

A. cf. facetus Uruguay 3 1 30 12 1 3 13 1

A. forquilha 2 4 3 16 6

A. sp. jacui 1 1 12 1

A. kaaygua upper R ί o Uruguay 16 13 2

R ί o Iguazu 3 1

A. guarani 1 1 3 1

A. scitulus 1 1 1 5 32 4 1

A. tembe 5

A. minuano 1 7 1

continued.

Anal fin count frequences V V VI VI VI VII VII VII VIII VIII VIII IX IX IX 8 9 7 8 9 7 8 9 6 7 8 6 7 8

A. charrua 2 5 1

A. facetus Argentina-Uruguay 2 9 13 1 3

A. cf. facetus Uruguay 5 1 14 32 2 5 5

A. forquilha 1 12 15 1 2

A. guarani 5 1

A. kaaygua upper R ί o Uruguay 2 3 17 8 1 R ί o Iguazu 1 3

A. minuano 2 4 3

A. scitulus 14 9 6 18 1

A. sp. jacui 8 3 1 2

A. tembe 4 1

continued.

vertebrae pectoral fin rays C1 gill rakers 12 12 12 13 13 13 13 14 14 14

13 14 15 12 13 14 15 12 13 14 12 13 14 15 5 6 7 8 9

A. charrua 1 6 1 1 7 1 5 2 A. facetus Argentina-Uruguay 23 5 5 11 1 2 15 A. cf. facetus Uruguay 59 6 5 34 5 13 14 A. forquilha 1 23 6 1 19 9 7 15 4 A. guarani 6 7 6 A. kaaygua upper R ί o Uruguay 29 2 11 5 4 11 1 R ί o Iguazu 1 3 4 1 2 1 A. minuano 9 6 1 1 6 1 A. scitulus 4 5 2 36 2 25 9 3 25 6 A. sp. jacui 1 14 6 2 3 5 A. tembe 6

continued.

caudal peduncle vertebrae

-2 -1.5 -1 -0.5 0 0.5 1 1.5 2 2.5 3 3.5

A. charrua 1 3 2 2

A. facetus Argentina-Uruguay 3 9 7 6

A. cf. facetus Uruguay 6 37 17 4 A. forquilha 1 5 13 6 6 A. guarani 3 3

A. kaaygua upper Río Uruguay 3 1 4 3 10 1

Río Iguazu 2 2

A. minuano 2 1 3 2 1

A. scitulus 1 27 7 6

A. sp. jacui 3 10 2 A. tembe 1 4 1

continued.

anal pterygiophores dorsal pterygiophores

11 11 12 12 13 13 13 14 14 14 15

1 2 1 2 1 2 3 1 2 3 2 9 10 11 12 A. charrua 1 3 3 1 2 5 1 A. facetus Argentina-Uruguay 3 14 1 7 1 2 19 5 A. cf. facetus Uruguay 7 13 3 34 3 1 4 35 27 3 A. forquilha 9 4 9 6 2 6 19 6 A. guarani 5 1 1 5

A. kaaygua upper Río Uruguay 1 1 7 8 3 3 1 13 9

Río Iguazu 1 1 2 3 1

A. minuano 2 5 2 1 8

A. scitulus 8 11 2 2 18 1 1 27 16 A. sp. jacui 5 5 3 2 1 12 2

A. tembe 3 1 2 6

continued.

E0 scale counts L1 scale counts L2 scale counts Gill rakers externally on first gill arch, 2 epibranchial, 1 in angle, 7(13), 8(14) ceratobranchial.

Vertebrae 13+13=26(59), 13+14=27(6). Caudal peduncle containing 0.5(6), 1(37), 1.5(17), 2(4) vertebrae.

Revised diagnosis of Australoheros facetus . Australoheros facetus is the only prognathous species (i.e. lower jaw longer than upper and mouth pointing upwards) in the genus. It also has the shortest dorsal scale cover of all Australoheros species and the least scaled dorsal and anal fins among Australoheros (together with A. tembe ). A. facetus is the only species of Australoheros with four abdominal bars, which are present in more than 80% of individuals as compared to 50% or less in all other species.

Revised description. Based on specimens over 60 mm SL with notes on smaller specimens. Meristic data are summarized in Table 1. Morphometric data are summarized in Table 2 .

A. forquilha A. sp. "Jacui" continued.

A. guarani A. minuano continued.

A. facetus A. cf. facetus continued.

A. kaaygua Brazil A. charrua Scales on head and chest not distinctly smaller than on flanks. Scales in E0 row 23(1), 24(9), 25(7). Upper lateral line scales 17(15), 18(2). Lower lateral line scales 7(1), 8(4), 9(10), 10(2). Scales between lateral lines 2. Circumpeduncular scales 16 (7 dorsally + lateral line scale + 7 ventrally + lateral line scale). Cheek scale rows 2(1), 3 (12), 4(4).

D. XV,11 (2), XVI,9 (2), XVI,10 (20), XVI,11 (3), XVII,10 (1). A. VI,7 (2), VI,8 (9), VI,9 (13), VII,7 (1), VII,8 (3). Anal fin pterygiophores 12(15), 13(8). Modally one anal pterygiophore in front of the first haemal spine [1(21), 2(2)]. Dorsal pterygiophores posteriorly of the first caudal vertebra 10(2), 11(19), 12(5). P. 13(5), 14(11), 15(1).

Gill rakers externally on first gill arch, 2 epibranchial, 1 in angle, 7(2), 8(15) ceratobranchial.

Vertebrae 13+13=26(23), 13+14=27(5). Caudal peduncle containing -1(3), 0(9), 0.5(7), 1(6) vertebrae.

Color pattern in alcohol. Color pattern composed of vertical bars, a midlateral blotch in a longitudinal stripe and a caudal fin blotch, as in all other Australoheros species. A. facetus (together with A. cf. facetus ; see below) is the only Australoheros species known to have as a rule four abdominal bars. Four abdominal bars present in more than 80% of individuals (84.2% based on our material), but 87% of specimens do not have the bars completely separated, producing interconnected bars unique to A. facetus . Most other species have only three, or four in less than 50% of individuals. The midlateral blotch is small, usually not prominent outside the borders of the longitudinal midlateral stripe.

Color in life. Ground color is greyish, not yellow as in A. cf. facetus , A. kaaygua , A. minuano , or A. scitulus . Breeding coloration with the typical Australoheros autapomorphy of interrupted dorsal portions of abdominal bars (Ř íčan & Kullander, 2006).

Distribution. Australoheros facetus as currently conceived is a catch-all taxon, including several undescribed species apart from those described in this work (see below). The distribution limits thus currently include the large area of the Atlantic coast drainages of Brazil and Uruguay plus populations from Argentina west from the Uruguay River drainage. Geographical distribution of A. facetus s. str. is shown on Fig. 1 .

Notes. A. facetus is most similar to A. cf. facetus , A. guarani and A. minuano . It can be distinguished from A. cf. facetus by 6 anal fin spines (vs. 7), 10 dorsal fin rays, by being more deep bodied, with a shorter caudal peduncle and a longer snout and preorbital distance (refer to Table 3 for exact values and additional separating characters).

facetus cf. facetus Body depth 49.1±2.1 44.5±1.5 Caudal peduncle depth 39.1±3.7 48.1±3.5 Caudal peduncle vertebrae 0.26±0.6 1.16±0.4 Anal fin spines 6.1±0.3 7.1±0.5

Ventral fin length 33.3±5.1 28.2±1.4 Dorsal fin rays 10.1±0.5 9.2±0.6

snout length in head length 30.6±3.1 26.3±3.9 Pectoral fin rays 13.5±0.7 13.0±0.5 Interorbital width in head length 36.5±3.8 31.1±2.5 Anal fin rays 8.4±0.6 7.8±0.5

Ceratobranchial 1 gill rakers 7.9±0.7 7.5±0.5

L1scales 16.8±0.6 15.8±1.2 Preorbital distance in head length 20.3±2.4 16.0±2.5 From the very similar A. guarani and A. minuano , it can be distinguished by a shorter dorsal fin scale cover, covering only the bases of the last 2–3 spines (vs. 7–8), in being slightly more deep-bodied with an upturned mouth. Additionally distinguished from A. guarani in the proportion of four abdominal bars (in ca 84% vs. none), by a longer head, shorter preorbital and interorbital distance, more scales between the anterior end of dorsal fin and upper lateral line (3 ½ scales vs. 2 ½), and more C1 gill rakers and L2 scales (refer to Table 4 for exact values).

TABLE 4. Significantly different values in characters in A. facetus and A. guarani (P <0.05; decreasing order of significance; mean values±SD, proportional measurements in percent).

facetus guarani Head length 34.5±1.5 32.4±0.7 Interorbital width in head length 36.5±3.8 38.7±1.9 Preorbital distance in head length 20.3±2.4 25.6±1.4 Ceratobranchial 1 gill rakers 7.9±0.7 7.0±0.0 L2 scales 8.6±0.7 7.5±1.0 Additionally distinguished from A. minuano by more C1 gill rakers, more pectoral fin rays and by a smaller orbit (refer to Table 5 for exact values).

Australoheros cf. facetus is unique among all Australoheros species in having always four fully developed abdominal bars. It is most similar to A. facetus , A. guarani and A. minuano , from which it can be distinguished in having more than 7 anal spines (vs. 6) and 16–17 dorsal fin spines. Further distinguished from A. facetus by 10 dorsal fin rays, in being less deep-bodied, with a longer caudal peduncle and a shorter snout and preorbital distance (refer to Table 3 for exact values and additional separating characters).

Additionally distinguished from both A. guarani and A. minuano by a shorter dorsal fin scale cover, covering only 2–3 last spines (vs. 7–8). Additionally distinguished from A. guarani by more scales between the anterior end of dorsal fin and upper lateral line (3 ½ scales vs. 2 ½), by a much shorter preorbital distance, by a slightly longer head and narrower interorbital distance and in being less deep-bodied (refer to Table 7 for exact values).

facetus minuano Ceratobranchial 1 gill rakers 7.9±0.7 6.0±0.5

Pectoral fin rays 13.5±0.7 12.1±0.4 Obrit diameter in head length 30.3±2.4 35.0±1.6 Body depth 49.1±2.1 46.9±1.2 cf. facetus minuano Caudal peduncle vertebrae 1.16±0.4 -0.06±0.7 Caudal peduncle depth 48.1±3.5 41.6±3.1 Ceratobranchial 1 gill rakers 7.5±0.5 6.0±0.5

Pectoral fin rays 13.0±0.5 12.1±0.4 Body depth 44.5±1.5 46.9±1.2 Anal fin spines 7.1±0.5 6.3±0.5

Anal fin rays 7.8±0.5 8.4¡À0.5 Head width in head length 54.2±2.3 52.4±1.3 Dorsal fin rays 9.2±0.6 9.8±0.4 Additionally distinguished from A. minuano in being less deep-bodied with a longer caudal peduncle, 6 C1 gill rakers (vs. more than 7), 12 pectoral fin rays (vs. 13)(refer to Table 6 for exact values and additional separating characters).

Ř íčan and Kullander (2006) further distinguished a population from the Yacui drainage (A. sp. “Jacui”), Atlantic Ocean drainage, Brazil, Rio Grande do Sul. A. sp. “Jacui” is distinct by several characters, as also expressed in the RDA and phylogenetic analyses (Ř íčan & Kullander, 2006), and clearly represents a separate species. Pending an analysis of Australoheros material from the coastal drainages of Brazil, we currently treat it as undescribed.

Australoheros scitulus (Ř í č an & Kullander, 2003)

Cichlasoma scitulum Ř íčan and Kullander, 2003: 795, fig. 1 (Type locality: Uruguay, arroyo Colla, Río Rosario drainage, Río de la Plata basin, upstream Paso Arballo (34°19'7"S 59°20'13"W). Holotype NRM 36647). Ř íčan and Kullander (2003) provide a detailed description of Australoheros scitulus and compared it with A. facetus from Uruguay. Only additional observation on life coloration and distribution are given here.

Color in life. Ground color is yellowish as in e.g. A. cf. facetus , A. kaaygua or A. minuano . Breeding coloration with the typical Australoheros autapomorphy of interrupted dorsal portions of abdominal bars (Ř íčan & Kullander, 2006). Life specimens have been photographed by Körber and Stawikowski (1999) and Staeck (2003, p. 63 upper left). Some northern populations do not distinctly develop the A. scitulus apomorphic spotted patterns (e.g. Staeck, 2003 p. 63 upper left), but are still distinguishable as A. scitulus using meristic characters, some coloration characters as the posterior part of the midlateral stripe and mouth/head shape. Breeding animals are deep yellow in dorsal interbar spaces, but ventral portion of the body is almost evenly black. The iris is red. This is in contrast to A. kaaygua , where breeding animals have yellow interbar spaces also on the belly (i.e. bars clearly demarcated all the way from dorsal fin base to anal fin base).

Distribution. Australoheros scitulus is distributed in the tributaries of the Lower and Middle Río Uruguay in Uruguay, Argentina, and the State of Rio Grande do Sul, Brazil ( Fig. 2 ).

cf. facetus guarani Preorbital distance in head length 16.0±2.5 25.6±1.4 Head length 35.8±1.0 32.4±0.7 Interorbital width in head length 31.1±2.5 38.7±1.9 Body depth 44.5±1.5 48.1± 1.6 Anal fin spines 7.1±0.5 6.2±0.4

Figures

FIGURE 1. Collecting localities of Australoheros guarani and A. facetus (the facetus group). A symbol may cover more than one collecting site.

FIGURE 2. Collecting localities of Australoheros charrua and A. scitulus (the scitulus group). A symbol may cover more than one collecting site.

Tables

TABLE 2. Morphometry of Australoheros.

	N Min-Max	Mean±SD	N Min-Max	Mean±SD
Head length	30 31.5-39.1	35.3±2	17 32.1-35.5	33.8±1
Snout length	30 7.6-17.7	13.1±2.9	17 10.1-14.3	12.3±1.3
Body depth	30 40.9-47.8	45.1±1.7	17 44.2-48.4	45.8±1.2
Orbital diameter	30 9.3-13.8	11.3±1	17 9.0-12.7	10.1±1
Head width	30 15.6-19.1	17.5±0.9	17 16.5-18.2	17.4±0.4
Interorbital width	30 8.7-11.5	9.7±0.7	17 10.4-12.4	11.3±0.6
Preorbital distance	30 6.4-10.8	8.8±1.1	17 5.3-8.3	7.4±0.7
Caudal peduncle depth	30 15.8-18.8	17.4±0.8	17 16.3-18.6	17.2±0.6
Caudal peduncle length	30 8.4-11.1	9.9±0.7	17 7.9-10.1	9.0±0.7
Pectoral fin length	30 25.7-32.6	28.9±2	17 25.1-29.0	26.5±1.1
Ventral fin length	30 22.1-34.1	28.7±2.6	17 28.2-32.2	30.0±1.1
Last D spine length	30 10.4-17.6	14.0±1.7	13 11.3-18.0	14.6±1.6