Crenicichla ploegi, Varella & Loeb & Lima & Kullander, 2018

Varella, Henrique R., Loeb, Marina V., Lima, Flávio C. T. & Kullander, Sven O., 2018, Crenicichla ploegi, a new species of pike-cichlid of the C. saxatilis group from the Rio Juruena and upper Rio Paraguai basins in Brazil, with an updated diagnosis and biogeographical comments on the group (Teleostei: Cichlidae), Zootaxa 4377 (3), pp. 361-386 : 364-377

Crenicichla ploegi , new species

( Figs. 1 , 2 , 3a–c , 4 , 5 , 6a , 8 and 10b ; Tab. 2 )

Holotype. MZUSP 120714 , male, 89.8 mm SL, Sapezal, Rio Papagaio, large river pool in the Fazenda Savocal (near road to Brasnorte) , 12°46'04"S 58°23'05"W, 8–9 Oct 2006, F. A. Machado, F. C. T. Lima, C. M. C. Leite & N. E. Silva.

Paratypes. Brazil. Mato Grosso. Rio Tapajós basin (168 specimens: 27.0– 190.4 mm SL). LBP 7953, 4, 38.3–68.8 mm SL, Nova Mutum, Rio dos Patos, 13°48'03"S 056°01'38"W, 23 Jan 2009, C. Oliveira et al. LBP 7966, 2, 58.4–59.4 mm SL, Nova Mutum, tributary of Rio dos Patos, 13°48'13"S 56°09'25"W, 23 Jan 2009, C. Oliveira et al. LBP 7979, 12, 35.6–107.1 mm SL, Nova Mutum, tributary of Rio dos Patos, 13°49'08"S 56°10'53"W, 23 Jan 2009, C. Oliveira et al. LBP 7999, 1, 85.5 mm SL, Nova Mutum, Rio Igarapé, 14°08'14"S 56°05'48"W, 24 Jan 2009, C. Oliveira et al. LBP 13259, 5, 52.9–117.3 mm SL, Diamantino, riacho Alegre, 13°59'04"S 057°04'01"W, 10 Aug 2011, I. Camaragibe & J. Pacheco. LBP 19604, 4, 43.6–63.0 mm SL, Campo Novo dos Parecis, Rio Verde, 13°37'11"S 58°00'49"W, 21 Jun 2009, R. Devidé et al. MCP 30282, 2, 27.3–44.9 mm SL, São José do Rio Claro, stream near the road MT-010, Rio Arinos basin, 13°37'23"S 056°29'18"W, 17 Jan 2002, R. E. Reis et al. MCP 30295, 1, 59.0 mm SL, São José do Rio Claro, Rio Claro or Rio Água Verde, 12 km Southeast from São José do Rio Claro, road MT-010, 13°30'12"S 056°37'08"W, 17 Jan 2002, R. E. Reis et al. MCP 30311, 1, 87.5 mm SL (measured and counted), Tapurah, stream at road MT-338, 46 km North from Tapurah, 12°23'14"S 56°41'54"W, 19 Jan 2002, R. E. Reis et al. MCP 38400, 1, 41.2 mm SL, Sapezal, córrego Água Quente, road between Sapezal and Rio Papagaio, 13°32'25"S 058°43'32"W, 13 Jul 2004, R. E. Reis et al. MCP 38423, 3, 47.4–52.5 mm SL, Campos de Júlio, Rio Juruena, at road from Campos de Júlio to Sapezal, 13°33'05"S 059°02'03"W, 13 Jul 2004, R. E. Reis et al. MCP 39528, 1, 69.4 mm SL (measured and counted), Sapezal, upstream dam in Rio Sauê-Uiná, road BR-364 toward Sapezal, 13°32'22"S 058°50'48"W, 13 Jul 2004, P. Lehmann et al. MCP 39559, 1, 61.3 mm SL (measured and counted), Sapezal, Rio Sauê-Uiná dam, at road BR-364, 13°32'26"S 058°50'47"W, 13 Jul 2004, P. Lehmann et al. MCP 42678, 2, 32.6–32.8 mm SL, Sapezal, Rio Sacre, 13°36'52"S 058°05'38"W, 3 Aug 2007, V. Lampert & M. Teixeira. MCP 42680, 33, 19.4–23.6 mm SL, Sapezal, Rio Verde, 13°38'34"S 58°01'04"W, 8 Mar 2007, V. Lampert & M. Teixeira. MCP 42771, 1, 77.6 mm SL, Rio Sacre, 13°36'52"S 058°05'40"W, 7 Jun 2007, V. Lampert. MCP 42673, 2, 40.3–49.4 mm SL (1 measured and counted: 49.4 mm SL), Sapezal, Rio Sacre, 13°36'52"S 058°05'38"W, 3 Aug 2007, V. Lampert & M. Teixeira. MZUSP 61081, 2, 82.4–86.5 mm SL (measured and counted), Nova Mutum, Fazenda Buriti, unnamed stream of the Rio Arinos basin, 13°51'52"S 56°11'36"W, 16 Feb 2000, F.C.T. Lima et al. MZUSP 61099, 2, 37.1–53.6 mm SL (measured and counted), Nova Mutum, Rio Criquiri, tributary of Rio dos Patos, 13°48'10"S 56°09'29"W, 19 Feb 2000, F. C.T. Lima et al. MZUSP 82075, 1, 55.8 mm SL, Brasnorte, hydroelectric dam Bocaíva, Rio Cravari, tributary of Rio do Sangue, 3 Jan 2003, K. de Silimon. MZUSP 93548, 6, 39.3–94.8 mm SL (4 measured and counted: 34.7–94.8 mm SL), Sapezal, Rio Papagaio and at the mouth of the Rio Buriti, close of the bridge at the road between Sapezal and Brasnorte, 12°47'06"S 58°23'05"W, 7–9 Oct 2006, F. A. Machado et al. MZUSP 93697, 4, 65.5–118.7 mm SL (measured and counted), collected with holotype. MZUSP 108368, 1, 43.5 mm SL, Sapezal, Rio Juruena, upstream hydroelectric dam Santa Lúcia, 13°39'18"S 59°01'12"W, 24 Sep 2006, K. de Silimon. MZUSP 108369, 1, 27.6 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Segredo, 13°14'54"S 59°01'43"W, 3 Sep 2006, K. de Silimon. MZUSP 108370, 2, 48.9–67.6 mm SL (1 measured and counted, 67.6 mm SL), Sapezal, Rio Juruena, downstream hydroelectric dam Santa Lúcia, 13°32'37"S 59°01'48"W, 25 Sep 2006, K. de Silimon. MZUSP 108371, 2, 29.7–66.2 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Telegráfica, 12°41'22"S 58°56'47"W, 15 Sep 2006, K. de Silimon. MZUSP 108372, 4, 24.6–62.5 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Rondon, 12°53'38"S 58°55'11"W, 20 Sep 2006, K. de Silimon. MZUSP 108373, 1, 41.6 mm SL, Campos de Júlio, Rio Juruena, Fazenda Tiroleza, 14°16'38"S 59°05'22"W, 19 Sep 2006, K. de Silimon. MZUSP 108374, 2, 49.8–61.4 mm SL, Campos de Júlio, Rio Juruena, Fazenda Tiroleza, 14°16'38"S 59°05'22"W, 19 Sep 2006, K. de Silimon. MZUSP 108375, 2, 45.9–46.0 mm SL, Campos de Júlio, pool between Rio Juruena and riacho Cabeceira, near road BR-364, 14°39'43"S 59°06'27"W, 18 Sep 2006, K. de Silimon. MZUSP 108376, 1, 47.2 mm SL, Campos de Júlio, Rio Juruena, near road BR-364, 14°39'40"S 59°06'27"W, 18 Sep 2006, K. de Silimon. MZUSP 108377, 3, 27.6–77.7 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Telegráfica, 12°37'32"S 58°55'36"W, 14 Sep 2007, K. de Silimon. MZUSP 108380, 4, 27.0– 57.3 mm SL, 3 c&s, 59.2–67.7 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Ilha Comprida, 13°11'32"S 58°58'51"W, 27 Sep 2006, K. de Silimon. MZUSP 108381, 1, 69.4 mm SL (measured and counted), Campos de Júlio, Rio Juruena, downstream bridge at the road BR-364, 14°39'40"S 59°06'27"W, 18 Sep 2006, K. de Silimon. MZUSP 108382, 1, 43.8 mm SL, Sapezal, Rio Juruena, upstream hydroelectric dam Santa Lúcia, left margin, 13°37'55"S 59°03'03"W, 24 Sep 2006, K. de Silimon. MZUSP 108383, 1, 53.3 mm SL, Campos de Júlio, Rio Juruena, Fazenda Tiroleza, upstream airport, 14°15'47"S 59°05'25"W, 19 Sep 2006, K. de Silimon. MZUSP 108384, 1, 43.3 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Segredo, 13°13'47"S 59°01'59"W, 27 Sep 2006, K. de Silimon. MZUSP 108385, 1, 49.4 mm SL, Campos de Júlio, tributary of the Rio Juruena, near road BR-364, 14°39'40"S 59°06'27"W, 18 Sep 2006, K. de Silimon. MZUSP 108386, 1, 50.5 mm SL, Campos de Júlio, Rio Juruena, near road BR-364, 14°39'00"S 59°06'00"W, 17 Sep 2006, K. de Silimon. MZUSP 108387, 1, 56.4 mm SL, Sapezal, Rio Juruena, upstream hydroelectric dam Sapezal, right margin, 13°16'06"S 59°01'27"W, 22 Sep 2006, K. de Silimon. MZUSP 108388, 1, 50.3 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Ilha Comprida, 13°12'06"S 58°59'03"W, 26 Sep 2006, K. de Silimon. MZUSP 108389, 2, 37.2– 41.9 mm SL, Sapezal, Rio Juruena, upstream hydroelectric dam Santa Lúcia, 13°34'49"S 59°01'48"W, 24 Sep 2006, K. de Silimon. MZUSP 108390, 1, 30.5 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Sapezal, right margin, 13°14'47"S 59°00'52"W, 22 Sep 2006, K. de Silimon. MZUSP 108391, 2, 27.4–28.1 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Telegráfica, 12°41'05"S 58°56'29"W, 14 Sep 2006, K. de Silimon. MZUSP 108392, 1, 27.6 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Rondon, 12°53'38"S 58°55'11"W, 20 Sep 2006, K. de Silimon. MZUSP 108393, 1, 31.5 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Telegráfica, 12°39'51"S 58°55'53"W, 14 Sep 2006, K. de Silimon. MZUSP 108395, 1, 24.6 mm SL, Sapezal, Rio Juruena, downstream hydroelectric dam Telegráfica, 12°41'02"S 58°56'26"W, 14 Sep 2006, K. de Silimon. MZUSP 115689, 6, 45.8–62.3 mm SL, Campos de Júlio, Rio Juína, road between Comodoro and Campos de Júlio, 13°47'41.2"S 59°27'19.6"W, 29 Sep 2013, O. T. Oyakawa et al. NRM 16872, 1, 52.0 mm SL, Rio Capitao Elio, tributary to Rio do Sangue, where crossed by MT-170 road North of Brasnorte, 12 Oct 1989, S. O. Kullander et al. NRM 26098. 3, 54.1–84.6 mm SL, Rio Juruena at ferry crossing 60 km East of Juína, 11°30'S 58°40'W, 14 Oct 1989, S. O. Kullander et al. NUP 11630, 2, 62.0– 101.2 mm SL (measured and counted), Diamantino, Rio Preto, tributary of the Rio Arinos 14°07'46.6"S 56°42'15.3"W, 15 Sep 2010, C. H. Zawadzki. ZUEC 10053, 8, 43.2–146.1 mm SL (4 measured and counted: 96.9–146.1 mm SL), São José do Rio Claro, Rio Claro, above road MT-235, 13°52'S 56°41'W, 4–12 May 2007, I. M. Fernandes & G. M. Alencar. ZUEC 10091, 1, 116.3 mm SL, São José do Rio Claro, Rio Claro, below road MT-235, 13°53'30"S 56°41'1"W, 4–5 May 2007, I. M. Fernandes & G. M. Alencar. ZUEC 10103, 2, 124.3– 164.4 mm SL (measured and counted), São José do Rio Claro, Rio Claro, below road MT-235, 13°47'38"S 56°42'10"W, 11 May 2007, I. M. Fernandes & G. M. Alencar. ZUEC 10144, 4, 41.4–190.4 mm SL (3 measured and counted: 115.9–190.4 mm SL), São José do Rio Claro, Rio Claro, below road MT-235, 13°50'43"S 56°41'46"W, 8–11 May 2007, I. M. Fernandes & G. M. Alencar. ZUEC 10179, 2, 34.1–123.7 mm SL (1 measured and counted: 123.7 mm SL), São José do Rio Claro, Rio Claro, above road MT- 235, 13°51'23"S 56°41'11"W, 4–6 May 2007, I. M. Fernandes & G. M. Alencar. ZUEC 10181, 3, 55.6–142.0 mm SL, São José do Rio Claro, Rio Claro, below road MT-235, 13°48'20"S, 56°41'34"W, 4–10 May 2007, I. M. Fernandes & G. M. Alencar. ZUEC 10244, 6, 41.7–97.3 mm SL, São José do Rio Claro, Rio Claro, below road MT- 235, 13°47'57"S 56°41'50"W, 10–15 May 2007, I. M. Fernandes & G. M. Alencar. ZUEC 10290, 1, 69.8 mm SL, São José do Rio Claro, córrego da Sucuri, tributary of the Rio Claro, 13°50'53"S 56°41'51"W, 8–9 May 2007, I. M. Fernandes & G. M. Alencar. Rio Paraguai basin (11 specimens: 48.4–127.2 mm SL). LBP 7540, 5, 52.7–86.7 mm SL (measured and counted), Campo Novo dos Parecis, Rio Verde, 14°33'24"S 57°48'43"W, 16 Jul 2008, W.P. Troy. MZUSP 78721, 1, 48.4 mm SL (measured and counted), Reserva do Cabaçal, Rio Juba, at the confluence with Rio São José, 14°48'16"S 58°17'56"W, 7 Mar 2002, F.C.T. Lima et al. MZUSP 78847, 1, 76.4 mm SL (measured and counted), Jauru, Rio Jauru, Fazenda do Sr. Salu, upstream of Salto da Fumaça, 15°11'04"S 58°43'43"W, 3–4 Mar 2002, F. A. Machado et al. MZUSP 78884, 3, 105.2– 127.2 mm SL (measured and counted), Tangará da Serra, lake in the Rio Juba, 14°45'S 58°3'W, 18 May 1996, G. Borges. MZUSP 82067, 1, 88.3 mm SL (measured and counted), Arapatinga, Rio Jauru, downstream hydroelectric dam Alto Jauru, ca. 15°18'S 58°42'W, 11 Dec 2002, K. de Silimon.

Diagnosis. Crenicichla ploegi is placed in the C. saxatilis species group as diagnosed here (see Discussion) by having a humeral blotch even in the smallest specimens observed, less than 80 scales in the E1 row (58–71), dimorphic males with many light dots scattered on the flank ( Fig. 5 ), and infraorbital series with very slender lacrimal bone and five separate post-lacrimal tubular infraorbitals ( Fig. 6a ).

It is distinguished from all other species of the C. saxatilis group by the presence of dark spots and vermiculations on snout, interorbital area and dorsally on head in many adults up to 146.6 mm SL ( Fig. 3b, c ) vs. dark markings absent or present only in juveniles but absent in adults (head uniformly dark gray in adults from 80 mm SL; Fig. 3e ), and by the presence of a deep and strongly pigmented lateral band present in both juveniles and adults, occupying a depth of 4–6 horizontal scale rows vs. lateral band narrower, occupying a depth of 2–3 horizontal scale rows, and conspicuous only in juveniles and smaller specimens, faded or absent in larger specimens. In addition, Crenicichla ploegi is more elongate (body depth 17.8–21.7% SL) and has more scales in the E1 row (58–71 scales) than C. brasiliensis , C. britskii , C. frenata , C. isbrueckeri , C. labrina , C. lepidota , C.

proteus , C. santosi , C. saxatilis and C. semicincta (body depth more than 21% SL [ Table 3, Fig. 9 ], and fewer than 56 scales in the E1 row). Crenicichla ploegi differs from C. alta , C. albopunctata , C. anthurus , C. coppenamensis , C. pydanielae and C. sipaliwini by having the humeral blotch situated almost entirely below the anterior branch of the lateral line ( Fig. 10b ) vs. humeral blotch with center on the level of the anterior branch of the lateral line ( Fig. 10c ).

Description. Largest male 190.4 mm SL, largest female 115.9 mm SL. Refer to Figs. 1 , 2 , 4 and 5 for general aspect. Morphometric data in Table 2 .

Head slightly deeper than wide. Caudal peduncle longer than deep, or with approximately equal length and depth (caudal peduncle depth 61.0–98.2% caudal peduncle length). Snout short, rounded in dorsal view, pointed in lateral view. Lower jaw prognathous, its articulation with quadrate posterior to middle of orbit, reaching vertical through posterior margin of orbit in some specimens; posterior rear of maxilla almost reaching vertical through anterior margin of orbit. Ascending premaxillary processes reaching to about one-half the orbit diameter.

Lower lip folds separate anteriorly, folds of upper lip discontinuous, with a symphyseal thickening. Postlabial skin fold margin truncate. Orbit supralateral, visible from below, entirely in anterior half of head. Interorbital area flat, narrower than mouth. Nostril dorsolateral, closer to anterior margin of orbit than to tip of postlabial skin fold, with small tubular margin exposed, but no anterior marginal membranaceous skin flap. Posterior margin of preopercle regularly serrated or with projections on its superior portion in larger specimens. Posterior margin of supracleithrum smooth. Lateralis pores on head simple.

Infraorbital series with one lacrimal (interpreted as lacrimals 1+2), with four pores, and five tubular postlacrimal infraorbitals (3–7); lacrimal slender (length 26.4–28.9% depth); infraorbital 7 curved posteriorly ( Fig. 6a ).

Flank scales ctenoid. Scales cycloid on head, on dorsum above anterior half of upper lateral line, along dorsalfin base, on chest, and on belly below line from lower edge of pectoral-fin base to anal-fin origin. Predorsal scales small, embedded in skin, extending forward to transverse frontal lateralis canal; prepelvic scales smaller than predorsal ones. Cheek completely scaled, about 9–10 horizontal scale rows below orbit, superficially embedded in skin. Preopercle naked; interopercle naked or with a patch of 1–3 scales posteriorly, embedded in skin.

Scales in E1 row 59 (1), 60*(2), 61 (3), 62 (2), 63 (3), 64 (2), 65 (3), 66 (7), 67 (2), 68 (6) or 71 (1) in specimens from Rio Juruena, 58 (1), 60 (4), 61 (1), 62 (3), 63 (1) or 65 (1) in specimens from upper Rio Paraguai. Transverse scale row 14–15+1+5. Circumpeduncular scale rows 11–13 dorsally, 11–13 ventrally (24–28 including lateral lines).

Lateral-line scales 20/13 (2), 20/14 (2), 20/15 (1), 21/11 (2), 21/12 (2), 21/13 (3), 21/14 (3), 22/11 (2), 22/12 (2), 22/13 (4), 23/11* (4), 23/12 (4), 25/11 (1) in specimens from Rio Juruena, 21/12 (1), 22/10 (1), 22/11 (2), 22/ 12(1), 23/13 (1), 24/10 (2), 24/11 (3) or in specimens from upper Rio Paraguai, and 2–3 scales continuing lower line onto caudal fin. Upper and lower branches of lateral line not overlapping. Scales between upper lateral line and first dorsal-fin spine 9–11; scales between upper lateral line and last dorsal-fin spine 4–5; horizontal scale rows between branches of lateral line 3–4. Lateral-line scales larger and more elongate than scales of adjacent rows; each scale of upper branch of lateral line impinging 2–3 scales of ventrally-adjacent row, each scale of lower branch of lateral line impinging 2 (rarely 3) scales of dorsally-adjacent row.

Dorsal, anal, pectoral and pelvic fins without scales. Caudal-fin squamation extending to about one third of fin length, posterior margin of scaled area concave.

First dorsal-fin spine about one-fourth the length of last; spines subequal in length from 11th spine. Posterior edge of soft part of dorsal fin pointed, longest ray (10th) slightly beyond base of caudal fin, extending to approximately one-half the length of caudal fin in some specimens. Dorsal-fin count XVIII.13 (1), XVIII.14 (3), XVIII.15 (2), XVIII.16 (3), XIX.13 (1), XIX.14* (9), XIX.15 (6), XX.13 (2) or XX.14 (5) in specimens from rio Juruena, XVIII.14 (1), XVIII.15 (1), XIX.14 (5), XIX.15 (1), XX.14 (3) in specimens from upper rio Paraguai.

Posterior edge of soft anal fin pointed, 7th or 8th ray longest, reaching caudal fin base or extending to approximately one-fifth the length of caudal fin. Anal fin count III.9 (2), III.10 *(11), III.11 (17), III.12 (2) in specimens from rio Juruena, III.9 (3), III.10 (8) in specimens from upper rio Paraguai. Caudal fin rounded with 8 principal and 6–7 procurrent rays on each lobe. Pectoral fin rounded, 7th or 8th ray longest, not reaching halfway from its base to first anal-fin spine. Pectoral-fin rays 15 (7), 16 (23), 17*(2) in specimens from rio Juruena, 15 (1), 16 (8), 17 (2) in specimens from upper rio Paraguai. Pelvic fin rounded and nearly symmetrical, inserted slightly posterior to pectoral axilla at vertical through dorsal-fin spine III; 2th pelvic-fin ray longest, reaching halfway from its base to spinous anal fin, very far from genital papillae.

All oral teeth conical, recurved. Teeth arranged in one outer row and 2–3 inner rows in dentary and premaxilla, with at least one of inner rows extending posteriorly almost as long as outer row and other rows more or less restricted to symphyseal portion. Teeth in outer row movable, but larger and slightly more fixed than teeth in inner rows, depressible; outer-row teeth near symphysis of dentary and premaxilla larger than posterior ones. Outer row with 22–30 teeth on right, 25–28 on left premaxilla; 27–33 on right, 25–30 on left dentary (counted in three c&s specimens, 59.2–67.7 mm SL).

First gill arch of specimens from rio Juruena with 1 (6) or 2*(24) gill rakers externally on epibranchial and 8*(4), 9 (18), 10 (8), 11 (1) on ceratobranchial. Specimens from rio Paraguai with 1 (1), 2 (10) gill rakers on first epibranchial and 8 (2), 9 (5), 10 (4) on first ceratobranchial. Occasionally, one of the ceratobranchial gill rakers can be situated at angle between epi- and ceratobranchial instead of on ceratobranchial. Gill rakers on lower pharyngeal tooth plate 6 (1), 8*(4), 9 (8), 10 (7), 11 (1), 12 (5) in specimens from Rio Juruena and 8 (3), 9 (2),10 (2), 11 (1), 12 (1) in specimens from upper Rio Paraguai. No tooth plates on any ceratobranchials. Single concavity in frayed zone of posterior margin pharyngobranchial 4. Microbranchiospines present externally on second, third and fourth gill arches.

Lower pharyngeal tooth-plate (dissected from three specimens: MZUSP 108380, 67.7 mm SL; ZUEC 10181, 142.0 mm SL; and ZUEC 10053, 146.1 mm SL, Fig. 8 ) strongly depressed in lateral view, with long posterior and anterior processes; tooth-plate length 76.7–82.7% of plate width; dentigerous-area length 42.0–63.5% of plate width, dentigerous-area width 72.0% plate width; 18 teeth in posterior row, 7–8 teeth in admedian rows. Medioposterior teeth largest and more robust, teeth gradually decreasing in height and becoming more slender rostrally and laterally. Teeth of posterior and admedian rows and on central dentigerous area bicuspid and compressed laterally, with main cusp antrorse; lateral and rostral teeth unicuspid, nearly conical.

Vertebrae (abdominal + caudal= total vertebrae): 18+13= 31 (1), 18+14=32 (1), 19+13=32 (1), 19+16=35 (2), 18+18=36 (1); with 6 vertebrae contained in caudal peduncle.

Coloration in alcohol. Juveniles up to approximately 28 mm SL ( Fig. 1d ) with ground color yellowish pale, slightly darker and grayish dorsally than ventrally; dark markings brownish or blackish. Lateral-line scales uniformly pigmented with same color of adjacent ones. Preorbital stripe dark brown, from tip of lower jaw, continuing dorsally on upper lip, then running caudad below level of nostrils to anterior margin of orbit. Postorbital stripe aligned with preorbital one, from posterior margin of orbit to opercular angle. Dark brown, narrow stripe dorsally parallel to postorbital stripe, running from dorsoposterior margin of orbit to vertical through posterior preopercular margin; another dark, rounded blotch in extrascapular area. In dorsal view, dark brown, single median stripe runs from vertical through nostrils to vertical through middle of orbit on interorbital area, duplicating afterwards in two paired, irregular stripes running from area corresponding to frontal-supraoccipital crests posteriorly along dorsum close to base of dorsal fin. Paired stripes slightly fragmented into about five portions, first one close to origin of dorsal fin and last at end of fin. Dark blackish midlateral band very evident from just behind opercle to end of caudal fin, occupying depth of 4–5 horizontal scale rows up to caudal-fin flexure, becoming narrower and fainter from it to end of caudal fin. Humeral blotch rounded, appearing to be a darker portion of midlateral blotch ventrally but distinct from midlateral band dorsally, situated entirely below upper branch of lateral line. Pectoral and pelvic fins hyaline. Dorsal fin dusky, darker on distal half of spinous portion and on submarginal and marginal areas of its soft portion. Anal fin dusky, with darker margin. Caudal fin with blackish rounded blotch tangent to fin flexure and between rays D 3–V 2, and some dark grayish pigmentation on its submarginal area of dorsal and ventral distal corners.

Most of color pattern elements (dark markings) of subadults from 34 to around 65 mm SL ( Fig. 2c, d ) correspond to those of juveniles, but with some differences as highlighted below. Ground color on dorsal half of body is distinctively darker and more brownish, mainly due to posteroventral extension of dorsal blotches (from juveniles) forming 5–7 dark bars on dorsum; first bar oblique, running posteroventrally from dorsal fin origin to humeral area; last bar at end of dorsal fin, often extending more posteriorly onto caudal peduncle. Anterior to first vertical bar, viewed from above, a median dark stripe runs from snout to vertical through middle of orbit on interorbital area, duplicating afterwards into two irregularly-edged stripes caudally on posttemporal area. Bars on dorsum separated from midlateral band by a paler region following dorsally the midlateral band in many specimens and, in some of them, these bars also divided in two portions by paler pigmentation on scales of upper branch of lateral line. Specimens from 34 mm SL already showing some melanophores concentrated below eye, but dark marking which may be interpreted as a triangular suborbital blotch only distinguishable in specimens larger than 45 mm SL. A rounded conspicuous humeral blotch, its dorsal part distinct from midlateral band and surrounded by light, whitish pigmentation; in some specimens, light pigmentation extends posteriorly as series of whitish dots accompanying dorsally the midlateral band. Caudal blotch surrounded by lighter pigmentation, often with some whitish spots around it; posteriorly to caudal blotch, at least three vertical pale stripes contrast with the darker caudal-fin background and a very dark, blackish blotch at the end of fin. Dorsal fin more widely smoky and darker than in juveniles, with one or two rows of lighter spots on its spinous portion and at least three rows of lighter spots on its soft portion. Anal fin dusky as dorsal fin, with darker margin and three series of lighter dots on soft portion.

Female with 69.4 mm SL ( Fig. 1c ) showing signals of sexual maturity and considered smallest adult specimen observed. Thus, specimens over 69 mm SL interpreted as possessing adult color pattern ( Fig. 1a–c ; Fig. 2a, b ). Dark suborbital marking more evident and extended ventrally than in subadults, triangular shape distinct. With increasing of size, dark markings dorsally on snout and nape become more fragmented, forming coarse pattern of dark spots and vermiculations; this pattern observed in many male and female specimens, including specimens up to 146.6 mm SL. Bars on dorsum extending more ventrally, reaching midlateral area, often connecting with midlateral band. Rounded humeral blotch larger and very conspicuous, distinct from midlateral band, both dorsally and ventrally, by white ring surrounding entire blotch; black blotch on pectoral axilla present. Midlateral band still conspicuous and deep, occupying depth of five to six horizontal scale rows. Females showing more homogeneous color pattern, with dark markings (except humeral blotch) fainter than in males; in same way, dorsal, anal and caudal fins of females homogeneous dark pigmented, only with a darker blackish margin and lacking the lighter spots present in most subadults (and adult males); caudal-fin blotch in mature females lacking light ring. Males exhibiting more pronounced midlateral band and vertical bars. Besides a conspicuous white ring bordering humeral blotch (as in females), mature males showing numerous white dots scattered along midlateral area, on dorsum, caudal peduncle, eventually also onto basal portion of caudal fin and around caudal-fin blotch. Dorsal, anal and caudal fins smoky, without darker margin; numerous small, light (hyaline) spots scattered on spinous and soft portion of dorsal fin, on soft portion of anal fin and on caudal fin.

Some specimens, mainly larger ones, with dark markings (head stripes and spots, midlateral band) much faded, except the humeral blotch. This variation may be due to preservation conditions or induced by stress during capture and/or subsequent fixation.

Life colors. Description based on pictures of fishes in nature, as Fig. 4 taken in the Rio Verde, a tributary of the Rio Juruena, and on pictures of live fishes photographed in aquarium just after capture, as Fig. 5 , taken of individual from the Rio Juba, upper Rio Paraguai basin. Ground color greenish-yellow dorsally and on dorsal, anal and caudal fins; ventral body pale to silvery; pectoral fin hyaline to yellowish. Melanin-based color pattern elements (e.g. head stripes and vermiculations, humeral and caudal blotches, and midlateral band) grayish to blackish, as described for preserved specimens. Iris red and two dark blotches laterally, forming what may be interpreted as a continuation from pre- to postorbital stripes. Suborbital triangular blotch brownish to yellowish. Iridescent regions around suborbital blotch and ventrally on postorbital area. White ring surrounding humeral blotch both in males and females. In males, same kind of white pigmentation forming dots scattered along midlateral area, on dorsum, and caudal peduncle; greenish and iridescent dots on caudal, dorsal and anal fins; dorsal-fin margin and margin of dorsal lobe of caudal fin red. In females, dorsal, anal and caudal fins uniform, dots absent; dorsal fin and dorsal margin of caudal fin with red submarginal stripe and blue margin.

Morphometric comparisons. The proportion body depth/standard length of Crenicichla ploegi is of 17.8– 21.7% SL, mean 19.7%. For the morphometric comparisons, the body depth was analyzed in function of the SL, firstly with data of the material encompassing juveniles and adults of all valid species of the Crenicichla saxatilis group. Graphically, there are two clouds of scattered points that corresponds to slender ( Fig. 9 green and blue) and deep-bodied species ( Fig. 9 : red). ANCOVA analysis showed non-significant differences between the body depth of these two putative subsets (p-value 0.592). The hypothesis of homogeneity of slopes was rejected, indicating that body depth increases at different rates in the two subsets, with individuals becoming more different as standard length increases. To control for allometry, a second analysis was performed with adult specimens only ( Fig. 9 ). Adults were defined as the specimens> 69 mm SL, as this is the standard length of the smallest specimen of Crenicichla ploegi with signals of sexual maturity. The second analysis showed significant difference between the body depth of the two subsets (p-value 0.039). The hypothesis of homogeneity of slopes was reject again i.e. body depth increases at different rates in the two subsets.

Distribution ( Fig. 11 ). Crenicichla ploegi is known both from the upper Rio Paraguai basin (upper reaches of Jauru, Cabaçal, and Sepotuba rivers), and from tributaries of the upper Rio Juruena (Papagaio, Sangue, Arinos rivers, and Rio Juruena itself), in Mato Grosso state, Brazil.

Etymology. Crenicichla ploegi is named in honor of the Dutch ichthyologist Alex Ploeg, whose PhD thesis dealt with the taxonomic revision, biogeography and phylogeny of Crenicichla , and who published papers on systematics of the genus from 1986 to 1991, describing a total of 23 species, 18 of which still considered to be valid. Since then, he worked as interlocutor between the ornamental fish industry and other institutions worldwide.

Unfortunately, Dr. Ploeg perished with his wife and son in the Malaysia Airlines 17 (MH17) airplane attack in Ukraine on 17 July 2014.

Habitat and ecological notes. Crenicichla ploegi has been collected in a variety of aquatic habitats, but mostly in streams and mid-sized rivers. The type locality is actually an exception, being a large river pool, more than 100 meters wide. Streams and rivers inhabited by C. ploegi possess clear water, a moderate to fast water flow, and rocky bottoms, usually with well-developed riparian forest, although the species has also been collected in rivers with highly disturbed or suppressed riparian forest.

Figures

FIGURE 2. Crenicichla ploegi: a) MZUSP 78884, paratype, 127.2 mm SL, Rio Juba, upper Rio Paraguai basin; b) LBP 7540, paratype, 85.1 mm SL; c) LBP 7540, paratype, 66.0 mm SL; and d) LBP 7540, 52.7 mm SL, Campo Novo dos Parecis, upper Rio Paraguai basin.

FIGURE 3. Schematic drawing of dorsal view of the body in Crenicichla ploegi and Crenicichla aff. lepidota Tapajós, showing the dark markings in fishes with different sizes. a) Crenicichla ploegi, MCP 42680, 23.0 mm SL; b) Crenicichla ploegi, LBP 7540, 52.7 mm SL; c) Crenicichla ploegi, ZUEC 10053, 143.3 mm SL; d) Crenicichla aff.lepidota Tapajós, LBP 8008, juvenile, 21.6 mm SL; e) Crenicichla aff. lepidota Tapajós, LBP 8020, 92.4 mm SL.

FIGURE 4. Crenicichla ploegi, a male (left) and a female (right) photographed alive in the Rio Verde, tributary of the Rio Papagaio, Mato Grosso, Brazil. Photo by Marcelo Krause.

FIGURE 5. Crenicichla ploegi, uncatalogued, 60.0 mm SL, from the Rio Juba above the waterfall of Cachoeira do Juba, tributary of the Rio Sepotuba basin, upper Rio Paraguai, Tangará da Serra, Mato Grosso, Brazil (field number SACIB2016100103).Photographed alive in aquarium just after capture by Fernando Dagosta.

FIGURE 6. Infraorbital series:a) Crenicichla ploegi, MZUSP 108380, 67.7 mm SL; b) Crenicichla macrophthalma, MZUSP 105713, 117.0 mm SL, c) Crenicichla saxatilis MZUSP 101130, 102.8 mm SL, d) Crenicichla missioneira, MCP 18926, 129.9 mm SL; e) Crenicichla jupiaensis, MZUSP 16048, 62.0 mm SL; f) Teleocichla preta, NRM 65527, 63.3 mm SL;g)Crenicichla chicha, MZUSP 93683, 70.2 mm SL.

FIGURE 8. Crenicichla ploegi, lower pharyngeal tooth plate in dorsal view, from ZUEC 10053, 146.1 mm SL. Posteromedial tooth,extracted during preparationof material, shown in lateral view.

FIGURE 10. Schematic drawings illustrating the correlation between general body shape and the position of the humeral blotch in relation to the anterior branch of lateral line: a) Crenicichla lepidota, lectotype NMW 33101, 157.8 mm SL—deepbodied species with humeral blotch below anterior branch of lateral line; b) Crenicichla ploegi, holotype MZUSP 93697, 89.8 mm SL—slender species with humeral blotch below anterior branch of lateral line; and c) Crenicichla alta, SU 78954, 115.4 mm SL—slender species with humeral blotch displaced dorsally, with its center on the anterior branch of lateral line.

FIGURE 11. Distribution map of Crenicichla ploegi. Type locality as black star, collecting sites of paratypes as white circles.

FIGURE1. Crenicichla ploegi: a)ZUEC 10053,paratype, adultmale, 143.3mm SL, Rio Claro, Rio Juruena basin;b) MZUSP 93697, holotype, adult male, 89.8 mm SL, Rio Papagaio, Rio Juruena basin; c) MCP 39528, adult female, 69.4 mm SL, Brazil, Rio Sauê-Uiná, Rio Juruena basin; d) MCP 42680, juvenile, 23.0 mm SL, Rio Verde, Rio Juruena basin.

FIGURE9. Bi-plotsof bodydepth vs.SL with linear regressions of the23 species of the Crenicichla saxatilisgroup,including C. ploegi, considering only adult specimens (> 69 cm SL). Species considered as deep-bodied taxa are shown in red; slender species are represented in green and blue.

Tables

TABLE2. Stanđarđlength in millimeters anđproportional measurementsof theholotype (HT), ofallthespecimens of Crenicichla ploegi,anđ of thespecimens of the RioTapajós anđRio Paraguaibasins separately. Holotypemeasurements incluđeđ in the range of allspecimens anđof the samplefrom Rio Tapajósbasin ( n ,numberof specimens measuređ;SD, stanđarđ đeviation).* measurementstaken from teninsteađ of eleven specimens.

			All specimens (n=43)					Rio Tapajós (n=32)			Rio Paraguai (n=11)
	HT	Range	Mean	SD	y	R²	p	Range	Mean	SD	Range	Mean	SD
Stanđarđ length (mm)	89.8	34.7̅127.2	-	-	-	-	-	34.7̅190.4	-	-	48.4̅127.2	-	-
									Percent of stanđarđ length
Bođy đepth	21.1	17.8̅21.7	19.7	1.0	0.21x - 0.76	0.99	0.04	17.8̅21.2	19.5	0.9	18.4̅21.7	20.1	1.1
Heađ length	31.8	28.4̅33.4	30.9	1.2	0.32x - 0.83	0.99	0.05	28.4̅33.4	30.7	1.2	29.1̅33.0	31.2	1.3
Heađ đepth	13.9	11.8̅15.4	13.5	0.8	0.14x - 0.61	0.98	0.04	11.8̅15.4	13.3	0.8	13.1̅14.9	13.9	0.6
Orbital điameter	8.0	6.0̅11.9	8.3	1.4	0.05x + 2.57	0.97	-	6.0̅11.9	8.3	1.6	6.7̅10.2	8.2	1.1
Interorbital wiđth	5.8	4.1̅7.7	5.7	1.0	0.08x - 1.86	0.97	-	4.1̅7.7	5.5	1.0	5.0̅7.6	6.1	0.9
Snout length	7.9	5.4̅11.0	8.1	1.4	0.12x - 2.79	0.97	-	5.4̅11.0	8.0	1.6	6.0̅10.0	8.2	1.1
Upper jaw length Lower jaw length	11.3 16.1	7.5̅13.1 12.7̅18.0	10.3 15.3	1.5 1.3	0.14x - 2.74 0.18x - 1.81	0.98 0.98	- -	7.5̅13.1 12.7̅17.6	10.3 15.2	1.6 1.3	8.1̅12.9 13.4̅18.0	10.4 15.7	1.3 1.3
Cauđal peđuncle đepth	10.1	8.2̅10.4	9.3	0.4	0.09x + 0.16	0.99	-	8.2̅10.1	9.3	0.4	9.0̅10.4	9.5	0.4
Cauđal peđuncle length	13.1	9.9̅15.2	13.5	0.9	0.13x + 0.59	0.98	0.02	9.9̅15.2	13.5	1.0	12.9̅13.8	13.4	0.4
Last đorsal-fin spine length	10.5	8.2̅12.8	10.3	0.9	0.11x - 0.20	0.97	-	8.2̅12.3	10.2	0.8	9.1̅12.8*	10.4	1.2
Pectoral-fin length	18.2	15.7̅20.5	18.4	1.2	0.16x + 1.52	0.98	0.00	15.7̅20.5	18.1	1.1	18.3̅20.4*	19.4	0.7