A New Species of Hypostomus (Siluriformes: Loricariidae) from the Upper Rio Paraguay Basin, Brazil

A new small Loricariidae, Hypostomus careopinnatus, is described from the Rio Taquari drainage, upper Rio Paraguay basin, Mato Grosso, Brazil. The new species can be easily distinguished from all congeners, except Hypostomus kids, by the absence of adipose fin. Hypostomus careopinnatus is distinguished from H. levis mainly by the presence of slender bifid teeth, with mesial cusp large and rounded, and lateral cusp small and pointed (vs. spoon-shaped teeth). The new species described herein completely lacks the adipose fin and also lacks the median pre-adipose plates in almost all specimens examined. The absence of adipose fin is probably an independent acquisition for Hypostomus careopinnatus and Hypostomus levis.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo [2009/11873-0, 2009/15075-0]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq) [306.988/2008-9]America Latina Logistica (ALL)Ferronorte S/ATetraplan Consultoria e Planejament

New species of miniature fish from Marajó Island, Pará, Brazil, with comments on its relationships (Characiformes: Characidae)

A new miniature species of the family Characidae from Marajó Island, Pará State, Brazil is described and assigned to the genus Tyttobrycon. The new species can be distinguished from its congeners primarily by having multicuspid teeth on jaws, and additionally by having the combination of 5-7 premaxillary teeth, dorsal fin only with scattered melanophores and the presence of an adipose fin

Reconciling more than 150 years of taxonomic confusion: the true identity of Moenkhausia lepidura, with a key to the species of the M. lepidura group (Characiformes: Characidae)

Marinho, Manoela M. F., Langeani, Francisco (2016): Reconciling more than 150 years of taxonomic confusion: the true identity of Moenkhausia lepidura, with a key to the species of the M. lepidura group (Characiformes: Characidae). Zootaxa 4107 (3): 338-352, DOI: 10.11646/zootaxa.4107.3.

Moenkhausia mikia Marinho & Langeani, 2010, new species

<i>Moenkhausia mikia</i>, new species <p>(Fig. 1–6; Table 1)</p> <p> <b>Holotype.</b> MZUSP 85166 (1, 49.6 mm SL), rio Tiquié, rio Negro drainage, igapó at Jabuti village, Amazonas, Brazil, 0°16’31.9”N 69°53’36.4”W, F. C. T. Lima, 30 Jun 2004.</p> <p> <b>Paratypes. Brazil, Amazonas State, rio Negro drainage:</b> DZSJRP 12673 (10, 34.9 <i>–</i> 42.9 mm SL), INPA 34346 (5, 34.8 <i>–</i> 48.2 mm SL), MCP 45680 (5, 36.5 <i>–</i> 42.07 mm SL), MPEG 18978 (5, 35.3 <i>–</i> 41.5 mm SL), MNRJ 37425 (5, 32.8 <i>–</i> 40.5 mm SL), MZUSP 81198 (296, 23.0 <i>–</i> 49.0 mm SL, 1 c&s, 46.7 mm SL), rio Tiquié, sand beaches downstream waterfall, Caruru village, F. C. T. Lima <i>et al</i>., 0°16’29”N 69°54’54”W, 20 <i>–</i> 21 Oct 2002. MZUSP 85062 (5, 52.0 <i>–</i> 57.7 mm SL), igarapé Açaí, tributary of rio Tiquié, near São Pedro village, 0°15’N 69°58’W, F. C. T. Lima, 21 Jun 2004. MZUSP 81219 (36, 32.9 <i>–</i> 49.0 mm SL, 2 c&s 33.7 and 37.0 mm SL), rio Tiquié, port between São Domingos Sávio and Jabuti village, 0°04’59”N 68°25’00”W, F. C. T. Lima <i>et al.</i>, 0 7 Nov 2002. MZUSP 85168 (1, 53.4 mm SL), rio Tiquié, port at Santa Rosa village, F. C. T. Lima, 30 Jun 2004. MZUSP 85116 (4, 46.2 <i>–</i> 50.3 mm SL), rio Tiquié at Cachoeira Comprida, 0°15’N 70°01’W, F. C. T. Lima, 26 Jun 2004. MZUSP 85172 (2, 47.0 <i>–</i> 49.4 mm SL), Igarapé Onça, Assunção village, 0°13’51.6”N 69°51’04.7”W, F. C. T. Lima, 0 1 Jul 2004.</p> <p> <b>Non-type specimens. Brazil, Amazonas State, rio Negro drainage:</b> MZUSP 65687 (1, 41.9 mm SL), rio Tiquié, beach before waterfall in Cachoeira Comprida village, 0°15’44”N 70°1’5”W, F. C. T. Lima <i>et al</i>., 20 Oct 2000. MZUSP 65768 (5, 49.3 <i>–</i> 53.3 mm SL), rio Tiquié, Caruru village, 0°16’27”N 69°54’56”W, Tukano indians, May 2000. MZUSP 65771 (2, 34.1 <i>–</i> 37.0 mm SL), rio Tiquié, Caururu village, pool downstream Caruru waterfall, 0°16’27”N 65°54’56”W, F. C. T. Lima <i>et al</i>., 21 Oct 2000. MZUSP 66136 (18, 33.5 <i>–</i> 41.3 mm SL), rio Tiquié, Caruru village, pool downstream Caruru waterfall, 0°16’27”N 69°54’56”W, F. C. T. Lima, 24 Oct 2000. MZUSP 81182 (20, 34.8 <i>–</i> 47.7 mm SL), rio Tiquié, Boca do Sal village, 0°16’22” N 69°54’3”W, N. P. Marques (Tukano), 25 Oct 2002. MZUSP 81277 (3, 34.5 <i>–</i> 37.4 mm SL), rio Tiquié, port at Boca do Sal village, 0°16’22”N 69°54’3”W, F. C. T. Lima <i>et al.</i>, 0 7 Nov 2002. MZUSP 81283 (9, 34.4 <i>–</i> 38.8 mm SL), rio Tiquié, beach below Caruru waterfall, Caruru Village, 0°16’29”N 69°54’54”W, F. C. T. Lima <i>et al.</i>, 0 7 Nov 2002. MZUSP 81314 (2, 28.6 <i>–</i> 33.0 mm SL), rio Tiquié, marginal lagoon below São Pedro village, 0°16’21”N 69°56’25”W, F. C. T. Lima <i>et al.</i>, 24 Oct 2002. MZUSP 81338 (1, 39.7 mm SL), igarapé Umari Norte, tributary of rio Tiquié, 0°16’0”N 69°58’0”W, F. C. T. Lima <i>et al.</i>, 2002. MZUSP 81362 (3, 30.3 <i>–</i> 37.3 mm SL), rio Tiquié, Traíra lake, São Pedro village, 0°16’00”N 69°58’0”W, students of Tuyuka school, 26 Oct 2002. MZUSP 81378 (6, 37.1 <i>–</i> 56.3 mm SL), igarapé Onça, tributary of rio Tiquié, Onça Igarapé village, 0°13’52”N 69°51’5”W, F. C. T. Lima <i>et al.</i>, 0 6 Nov 2002. MZUSP 81456 (29, 27.3 <i>–</i> 44.1 mm SL), rio Tiquié, marginal lagoon at below São Pedro village, 0°16’0”N 69°56’0”W, F. C. T. Lima <i>et al.</i>, 24 Oct 2002. MZUSP 81460 (1, 35.4 mm SL), igarapé Cabari, tributary of rio Tiquié, waterfall before Coração de Maria village, 0°16’26”N 69°60’24”W, F. C. T. Lima <i>et al.</i>, 0 8 Nov 2002. MZUSP 81468 (1, 41.5 mm SL), igarapé Açaí, near São Pedro village, 0°15’55”N 69°58’16”W, students of Tuyuka school, 26 Oct 2002. 85051 (1, 51.5 mm SL), igarapé tributary of rio Tiquié, Fronteira village, 0°15’N 70°02’W, F. C. T. Lima, 24 Jun 2004. MZUSP 85095 (1, 49.8 mm SL), rio Tiquié, Pedra Curta waterfall, 0°16’N 69°58’W, F. C. T. Lima, 26 Jun 2004. MZUSP 85141 (3, 50.2 <i>–</i> 59.4), rio Tiquié, between waterfall of Cauru and port at Boca do Sal village, 0°16’N 69°54’W, F. C. T. Lima, 26 Jun 2004. MZUSP 91550 (2, 46.7 <i>–</i> 49.1 mm SL), igarapé Sirinau, right margin of rio Cuieiras, about 25 km of mouth, 02°42’00”S 60°20’00”W, Alpha Helix Amazon Expedition, 30 Jan 1977. MZUSP 92143 (10, 33.6 <i>–</i> 37.6 mm SL), igarapé tributary of rio Tiquié, Serra do Mucura village, 0°10’07”N 69°07’46”W, F. C. T. Lima <i>et al.</i>, 10 Sep 2006. MZUSP 92255 (06, 31.8 <i>–</i> 39.7 mm SL), rio Tiquié, between ports of São José “do meio” and Floresta village, 0°13’00”N 69°36’00”W, F. C. T. Lima <i>et al.</i>, 28 Aug <i>–</i> 1 Sep 2006. MZUSP 92502 (3, 27.9 <i>–</i> 30.0 mm SL), near mouth of igarapé Castanha, tributary of rio Tiquié, 0°12’00”N 69°35’00”W, F. C. T. Lima <i>et al.</i>, Aug 2006. MZUSP 92590 (1, 33.1 mm SL), igarapé Castanha, tributary of rio Tiquié, beach below Santa Rosa village, 0°05’00”N 69°39’00”W, F. C. T. Lima <i>et al.</i>, 0 3 Sep 2006. MZUSP 93303 (3, 33.2 <i>–</i> 35.9 mm SL), igarapé Canuri (or Mucucu), oposite margin of port of São José II village, 0°13’N 69°36’W, F. C. T. Lima <i>et al.</i>, 16 Nov 2006. MZUSP 100251 (1, 40.5 mm SL), sand beach downstream falls, rio Tiquié, Caruru village, 0°16’29”N 69°54’54”W, F. C. T. Lima <i>et al.</i>, 21 Oct 2002. <b>Brazil, Amazonas State, rio Solimões drainage:</b> MPEG 18013 (12, 37.7–44.3 mm SL), Igarapé Tartaruga, rio Urucu drainage, Coari, 04°53’4.3”S 65°20’6.5”W, B. F. Prudente, 0 6 Sep 2009. MPEG 18014 (1, 50.2 mm SL), Igarapé Tartaruga, rio Urucu drainage, Coari, 04°53’2.7”S 65°19’02”W, W. B. Wosiacki, 0 4 Apr 2007. <b>Brazil, rio Madeira drainage:</b> MZUSP 30283 (123, 40.3 <i>–</i> 56.1 mm SL), igarapé tributary of rio Madeira, 15 km of Humaitá, 07°28’00”S 62°55’00”W, M. Golding, 0 7 Aug 1984. MCP 39791 (6, 27.8 <i>–</i> 49.7 mm SL), small tributary of right margin of rio Machado, near Km 280 of BR-364, Rondônia State, 11°21’29”S 61°50’59”W, P. A. Buckup, V. Bertaco & F. Langeani, 15 Jul 2004. MCP 39801 (5, 32.2 <i>–</i> 40.6 mm SL), igarapé, ca. 27 km south from Humaiatá in the road BR-319, Amazonas State, 07°43’54”S 63°06’47”W, R. Reis, F. Langeani, E. Pereira & A. Cardoso, 28 Jul 2004. MCP 39957 (98, 35.3 <i>–</i> 47.6 mm SL), igarapé Vinte e Dois, Recanto do Sanari, 20 km of W de Humaiatá, Amazonas State, 07°35’36”S 63°10’27”W, P. Buckup, P. Lehmann, F. C. T. Lima & V. Bertaco, 27 Jul 2004. <b>Brazil, Amazonas State, Rio Preto da Eva drainage:</b> MZUSP 87375 (2, 45.1 <i>–</i> 50.9 mm SL), tributary of rio Preto da Eva at Recanto da Mata, 02°38’25.8”S 59°44’06”W, Exc. MZUSP / USP, 0 3 Jul 2003. MZUSP 87376 (2, 35.5 <i>–</i> 44.1 mm SL), at recanto do Buriti, near bridge in town, 02°41’58”S 59°42’11”W, Toledo-Piza <i>et al.</i>, 0 4 Jul 2003. MZUSP 87377 (1, 40.7 mm SL), igarapé Cândido, Balneário Gonzagão, 02°41’13”S 59°42’33”W, Toledo-Piza <i>et al.</i>, 0 4 Jul 2003. MZUSP 87378 (1, 31.4 mm SL), flooded forest at Pousada do Paraíso, near igarapé Tauari, 02°47’25.2”S 59°38’11”W, Toledo-Piza <i>et al.</i>, 0 7 Jul 2003. MZUSP 87379 (29, 33.8 <i>–</i> 63.4 mm SL), logo ao lado esquerdo da praia do balneário, 02°41’58”S 59°42’11”W, Toledo-Piza <i>et al.</i>, 0 7 Jul 2003. MZUSP 87380 (6, 54.8 <i>–</i> 58.5 mm SL), below Encanto da Mata, 02°38' 58”S 59°43’50”W, Toledo-Piza <i>et al.</i>, 0 9 Jul 2003. MZUSP 87381 (1, 38.8 mm SL), above town, 2°41’S 59°42’W, Toledo-Piza <i>et al.</i>, 0 8 Jul 2003. <b>Brazil, Amazonas State, rio Sanabani drainage:</b> MZUSP 7433 (2, 46.7 <i>–</i> 52.9 mm SL), rio Sanabani, Silves, Brasil, 02°07’00”S 58°20’00”W, Expedição Permanente da Amazônia, 0 7 Dec 1967. MZUSP 7464 (5, 42.2 <i>–</i> 53.9 mm SL), igarapé tributary of Sanabani, Silves, 02°45’00”S 58°20’00”W, Expedição Permanente da Amazônia, 0 7 Dec 1967. <b>Brazil, Pará State, rio Trombetas:</b> MPEG 14435 (3, 44.8 <i>–</i> 78.3 mm SL), rio Saracá, W. B. Wosiacki, 18 Oct, 2007. MZUSP 17192 (2, 40.2 <i>–</i> 47.2 mm SL), Jacaré lake, 01°20’00”S 56°51’00”W, Museu Emilio Goeldi staff, 0 3 Oct 1965. <b>Brazil, Pará State, rio Amazonas:</b> MPEG 9295 (1, 58.2 mm SL), headwater of Igarapé Juruti Grande, Juruti, 02°34’36”S 56°24’03”W W. B. Wosiacki, 0 4 Aug 2004. <b>Brazil, Pará State, Tapajós drainage:</b> MPEG 15010 (1, 55.4 mm SL), rio Jamanxim, Itaituba, 06°33’44.8”S 55°40’9.2”W, F. B. N. Ribeiro, 18 May 2008. <b>Brazil, Pará State, Xingu drainage:</b> MZUSP 73397 (25, 39.4 <i>–</i> 42.2 mm SL), igarapé Atuviá, Belo Monte, 03°07’00”S 51°42’00”W, M. Golding, 29 Aug 1983. <b>Peru, Ucayali drainage:</b> MZUSP 85609 (2, 52.5 <i>–</i> 49.4 mm SL), Quebrada Copal, 15 km L. de Jenaro Herrera at road to Angamos village, Requena, Loreto, 4°55.4’S 073°32.6’W, H. Ortega, W. Crampton, R. Reis & F. C. T, Lima, 10 Jan 2004. <b>Venezuela, Orinoco drainage:</b> MZUSP 96513 (8, 33.9 <i>–</i> 39.2 mm SL), rio Parguaza, Puente Parhueña community, Bolivar, Cedeño, 05°53’30”N 67°24’14”W, M. C. C. de Pinna & C. Oliveira, 17 Jul 2004.</p> <p> <b>Diagnosis.</b> <i>Moenkhausia mikia</i> can be distinguished from all congeners, except species of the <i>Moenkhausia lepidura</i> group (<i>sensu</i> Géry, 1992), by presenting a dark spot on the upper caudal-fin lobe, and the lower caudal-fin lobe without spot or with a faint one (vs. both caudal lobes hyaline or both with a black blotch equally dark). The new species can be distinguished from <i>Moenkhausia hysterosticta</i>, <i>M. inrai</i>, <i>M. lata</i>, and <i>M. loweae</i>, by the number of branched anal-fin rays 18 <i>–</i> 21 (vs. 23 or more), from <i>M. hasemani</i> by the larger inner premaxillary teeth pentacuspid (vs. heptacuspid), from <i>M. lepidura</i> by having the predorsal scales arranged in one medial series (vs. two series anteriorly and one series posteriorly), and from <i>M. gracilima</i> and <i>M. icae</i> by presenting the upper caudal-fin lobe spot intense black (vs. faint blotch). Additionally, the presence of a conspicuous, relatively small and circular humeral spot distinguishes the new species from <i>Moenkhausia hysterosticta</i>, <i>M. inrai</i>, <i>M. lata</i>, and <i>M. loweae</i> (humeral spot larger and vertically elongated) and <i>M. gracilima</i> (humeral spot faint); and the middle caudal-fin rays hyaline distinguish <i>M. mikia</i> from <i>M. hasemani</i> and <i>M. lepidura</i> (vs. middle caudal-fin rays dark). The presence of conspicuous dark chromatophores concentrated around the lateral-line pores helps to differentiate the new species from the remaining species of the <i>Moenkhausia lepidura</i> group (chromatophores absent or few, not conspicuous, around the lateral-line pores). Also, <i>Moenkhausia mikia</i> can be distinguished from any other known Characidae species by having a unique combination of two large-sized bony hooks on the anal-fin rays and tiny spines on the distal portion of all fins in mature males.</p> <p> <b>Description.</b> Morphometrics of types and non-type specimens presented in Table 1. Largest specimen analyzed 63.4 mm SL. Body compressed, greatest body depth at vertical through dorsal-fin origin. Dorsal profile of body convex from upper lip to vertical through anterior nostril pore; straight from anterior nostril to tip of supraoccipital spine; convex from supraoccipital spine to dorsal-fin origin; straight and posteroventrally inclined along dorsal-fin base; straight to slightly convex from posterior terminus of dorsal-fin base to adipose-fin origin; slightly concave along caudal peduncle. Ventral profile of body convex from tip of lower jaw to pelvic-fin origin; straight from pelvic-fin origin to anal-fin origin; straight and posterodorsally inclined along anal-fin base and slightly concave along caudal peduncle.</p> <p> Jaws vertically aligned, mouth terminal. Premaxillary teeth in two rows, outer with 3 (12), 4* (40), or 5 (8) tricuspid teeth, inner with 5 tri- pentacuspid teeth. Maxilla extending posterior to anterior margin of eye, with 0 (8), 1* (49), or 2 (3) tricuspid teeth. Dentary with 4 pentacuspid teeth, followed by a smaller tricuspid and a series of 5 <i>–</i> 7 small conical teeth (Fig. 2)</p> <p>Dorsal-fin rays ii, 8 (1) or 9* (59). First unbranched dorsal-fin ray smaller than half length of second unbranched ray. Dorsal-fin origin slightly behind midbody, at vertical through pelvic-fin origin, and base of last dorsal-fin ray at vertical through anus. First dorsal-fin pterygiophore behind neural spine of 9th (1) or 10th (2) vertebrae. Adipose-fin origin approximately at vertical through base of 15th or 16th branched anal-fin rays. Pectoral-fin rays i, 11 (3), 12* (31), 13 (24), or 14 (2); tip of adpressed longest rays reaching pelvic-fin origin in mature males, not reaching in immatures and females. Pelvic-fin rays i, 7, tip of adpressed longest rays reaching anal-fin origin in mature males, not reaching anal fin in immature and females. Anal-fin rays iv (3), 18 (14), 19* (29), 20 (14), or 21 (3); last unbranched anal-fin ray and first four or five branched anal-fin rays longer than remaining rays. Principal caudal-fin rays i, 9+8, i. Caudal fin forked, both lobes similar in size, with small scales along first third of upper lobe and first half of lower lobe. Dorsal procurrent caudal-fin rays 11 (2) or 12 (1), ventral procurrent caudal-fin rays 9 (2) or 10 (1).</p> <p> Lateral line complete, slightly curved anteriorly, with 33 (1), 34 (19), 35* (25), or 36 (8) perforated scales. Longitudinal scale rows between dorsal-fin origin and lateral line 5; longitudinal scale rows between lateral line and pelvic-fin origin 3 (41) or 4* (11), and between lateral line and anal-fin origin 3 (12) or 4* (46). Predorsal scale row with 9 (2), 10 (42), or 11* (16) scales, arranged in a medial series. Single row of 3 <i>–</i> 6 scales overlying base of anteriormost anal-fin rays. Scales around caudal peduncle 14. Axillary scale present, without any spines.</p> <p>Supraneurals 4 (2) or 5 (1), with bony lamellae on upper portion; first supraneural “I-shaped”; remaining “Y-shaped ”.Vertebrae 34 (2) or 35 (1). Branchiostegal rays 4. First gill arch with 23 (1) or 24 (2) gill rakers: 7 or 8 on epibranchial, 1 on intermediate cartilage, 11 or 12 on ceratobranchial, and 3 on hypobranchial. Gill rakers with small denticles on proximal portion.</p> <p> <b>Color in alcohol.</b> Ground color pale yellow. Snout, lower jaw, maxilla and top of head with small dark chromatophores. Larger chromatophores spread at opercle. Infraorbitals, gular and opercular areas silvery. Scales on two or three dorsalmost longitudinal body scale rows with small chromatophores concentrated at posterior half, becoming hyaline towards posterior border, forming slightly reticulated pattern. Conspicuous chromatophores concentrated around lateral line pores, extending at least to vertical through dorsal-fin origin; generally, first half of lateral line easily visible through naked eye; in most pigmented specimens, lateral line completely visible. Small, conspicuous, circular humeral spot, horizontally over third and fourth lateral-line scales and vertically over one, sometimes two, rows above lateral line. Ventral half of humeral spot often longitudinally crossed by a clear horizontal line. Longitudinal dark stripe from humeral spot to end of caudal peduncle, narrow anteriorly, wider from vertical through posterior third of dorsal-fin base; more superficial chromatophores spread over longitudinal stripe. Pectoral, pelvic, dorsal, anal, and adipose fins with scattered dark chromatophores.</p> <p>H n Paratypes mean n Non-types mean range range</p> <p>Upper caudal-fin lobe with a black spot of variable size (Fig. 3 a, 3c and 3d), contrasting with the whitish basal portion. When black spot is restricted to median portion of upper caudal-fin lobe, the distal region is dark or hyaline. Lower caudal-fin lobe with scattered dark chromatophores (Fig. 1 and 3 b, c, d), or with a dark spot, however never as dark as the one on the upper lobe (Fig. 3 a). Middle caudal-fin rays hyaline or with dark tips.</p> <p> <b>Color in life.</b> Dorsolateral portion of body yellowish and ventrolateral portion silvery. Midlateral band silvery with bright blue iridescence. Top of head, upper and lower jaws and eyes yellowish. Infraorbital and opercular areas silvery. Tip of first anal-fin rays white. Proximal portion of dorsal-fin rays, adipose fin, base of upper caudal-fin lobe ranging from intense yellow to orange. Base of lower caudal-fin lobe yellowish (Fig. 4).</p> <p> <b>Sexual dimorphism.</b> Mature males with two large, dorsally curved bony hooks on anal-fin rays, larger on fifth or sixth proximal segment of last unbranched ray, smaller on sixth proximal segment of first branched ray; both encircled by well developed thick mass of tissue (Fig. 5). Larger hooks always more proximally positionated than smaller. Twenty males, mature (with two large and well-developed anal-fin hooks) and apparently in maturation, with bony hooks starting to develop (generally just one small hook on first unbranched anal-fin ray) were collected from May to September, and December to January, ranging from 40.3 <i>–</i> 58.5 mm SL.</p> <p>Tiny bony spines distributed on distal portion of all branched dorsal-, anal-, pectoral-, pelvic- and caudalfin rays of mature males, increasing in concentration toward tips, more numerous and eventually becoming larger on pelvic and anal-fin rays. Distal portion of longer unbranched dorsal-, pelvic-, and anal-fin rays also with tiny spines. Very abundant tiny spines on fin rays observed in only two mature males collected in December and January (MZUSP 7433 and MZUSP 91550 respectively); remaining males with fewer tiny spines on fins.</p> <p>Males generally with dorsal, pectoral and pelvic fins longer than in females of same SL (Fig

Redescription of Astyanax guaporensis Eigenmann, 1911 (Characiformes: Characidae), a small characid from the rio Madeira basin

Marinho, Manoela M. F., Ohara, Willian M. (2013): Redescription of Astyanax guaporensis Eigenmann, 1911 (Characiformes: Characidae), a small characid from the rio Madeira basin. Zootaxa 3652 (4): 475-484, DOI: 10.11646/zootaxa.3652.4.

A new species of Knodus Eigenmann (Characiformes: Characidae: Stevardiinae) with comments on nuptial tubercles and gill gland in characiform fishes.

Knodus nuptialis n. sp. is described from the Rio Curuá drainage, Rio Xingu basin, Brazil. It can be diagnosed from its congeners by having dentary teeth decreasing gradually in size posteriorly, outer premaxillary teeth row with five cusps, 12-15 branched anal-fin rays and a single humeral spot. The species presents notable sexual dimorphism consisting of densely concentrated nuptial tubercles on head, body, and fins, gill-gland, and bony hooks in the anal fin of mature males. It was found that these sexually dimorphic features are useful and functional in males of the new species only during the reproductive season and after this period, they become atrophied, and eventually disappear. The list of characiform species presenting breeding tubercles is updated and nine species and two genera of the Characidae, Deuterodon and Bryconacidnus, are for the first time reported to have breeding tubercles

Taxonomic review of Copella (Characiformes: Lebiasinidae) with an identification key for the species.

A taxonomic review of Copella is presented based on the analysis of the type material of all nominal species and extensive material from South American drainages. Six out of ten nominal species are recognized as valid: Copella arnoldi, C. callolepis, C. compta, C. eigenmanni, C. nattereri, and C. vilmae. Copella carsevennensis is a junior synonym of C. arnoldi, C. nigrofasciata and 'Nannostomus' stigmasemion are junior synonyms of C. callolepis, C. metae is junior synonym of C. eigenmanni, and C. meinkeni is junior synonym of C. nattereri. Species of Copella occur in the rio Amazonas and Orinoco basins, and coastal drainages of Guyana, French Guiana, Surinam, and Venezuela. An identification key is provided