Hypostomus myersi ( Gosline, 1947 )

Garavello, Julio César, Britski, Heraldo Antônio & Zawadzki, Claudio Henrique, 2012, The cascudos of the genus Hypostomus Lacépède (Ostariophysi: Loricariidae) from the rio Iguaçu basin, Neotropical Ichthyology 10 (2), pp. 263-283 : 273-277

Hypostomus myersi ( Gosline, 1947)

Figs. 5 , 6

Plecostomus myersi Gosline, 1947:116 , pl. 5; figs. 9-10 (Type locality: Porto União da Vitória , actual Municipality of União da Vitória, rio Iguaçu, Paraná, Brazil).

Hypostomus myersi : Isbrucker, 1980:28 (new comb.); Gomes et al., 1990:139 (description and biological data); López & Miquelarena, 1991:35 (redescription); Severi & Cordeiro, 1994:87 (rio Iguaçu, Porto União); Garavello et al., 1997:79 (rio Iguaçu); Zawadzki et al., 1999:96 (allozymes and morphometrics); Zawadzki et al., 2001:914 (isozymes); Weber, 2003:360 (ref.); Baungartner et al., 2006:3 (Salto Osório reservoir, rio Iguaçu; check list); Carvalho & Bockmann, 2007:93 (rio Iguaçu).

Material examined. All from Brazil. Paraná State. MNRJ 4251 , holotype , 174.0 mm SL, Porto União, rio Iguaçu , 21-25 Apr 1944, G. S. Myers & A. L. Carvalho . MNRJ 4252 , paratypes , 2, 124.5-200.0 mm SL, same locality and collectors as holotype . LISDEBE 2657 , 14 , 116.0-164.0 mm SL, Salto Segredo reservoir, rio Iguaçu, Municipality of Mangueirinha , 25°48’S 52°09’W, Apr 1993, Nupélia .

LISDEBE 2658 , 10 , 117.0-215.0 mm SL, rio Iguaçu, Municipality of Porto Lupion , 1979-1980, J. C. Garavello & Surehma . LISDEBE 2659 , 5 , 116.0-192.0 mm SL, downstream Salto Osório reservoir, rio Iguaçu, Municipality of Quedas do Iguaçu , 25°32’S 53°01’W, 19 Jan 1990, J. C. Garavello et al . LISDEBE 2660 , 2 , 126.0-157.0 mm SL, rio Iguaçu, Municipality of União da Vitória , 26°13’S 53°06’W, 6 March 1979, J. C. Garavello & Surehma . MHNCI 6049 , 2 , 123.3 - 146.1 mm SL, Salto Osório reservoir, Municipality of Quedas do Iguaçu , 25°33’S 52°56’W, 20 Aug 1991, Hicson et al . MHNCI 7082 , 13 , 77.2 -182.0 mm SL, rio Guarani, Municipality of Três Barras , 25°25’08”S 53°10’50”W, Feb 1993, E. T. Grando et al . MHNCI 7093 , 12 , 119.0- 182.8 mm SL, rio Guarani, Municipality of Três Barras , 25°25’08”S 53°10’50”W, Feb 1993, E. T. Grando et al . MHNCI 7104 , 14 , 125.1 -185.0 mm SL, rio Guarani, Municipality of Três Barras , 25°25’08”S 53°10’50”W, Feb 1993, E. T. Grando et al . MHNCI 7105 , 11 , 115.7 - 172.9 mm SL, rio Guarani, Municipality of Três Barras , 25°25’08”S 53°10’50”W, Feb 1993, E. T. Grando et al . MHNCI 7107 , 1 , 87.1 mm SL, rio Guarani, Municipality of Três Barras , 25°25’08”S 53°10’50”W, Feb 1993, E. T. Grando et al . MHNCI 7108 , 2 , 141.2 - 144.1 mm SL, rio Guarani, Municipality of Três Barras , 25°25’08”S 53°10’50”W, Feb 1993, E. T. Grando et al . MHNCI 7116 , 9 , 130.6 - 175.4 mm SL, rio Guarani, Municipality of Três Barras , 25°25’08”S 53°10’50”W, Feb 1993, E. T. Grando et al . MHNCI 7133 , 5 , 173.0-200.0 mm SL, rio Iguaçu, Municipality of Nova Prata do Iguaçu , 53º20’48”S 25º37’57”W, Mar 1993, E. T. Grando et al . MHNCI 7140 , 2 , 198.7 - 203.8 mm SL, rio Iguaçu, Municipality of Nova Prata do Iguaçu , 53º20’48”S 25º37’57”W, Mar 1993, E. T. Grando et al . MHNCI 7160 , 4 , 198.7 - 203.8 mm SL, rio Cotegipe, Municipality of Nova Prata do Iguaçu , 53º20’48”S 25º37’57”W, Mar 1993, E. T. Grando et al . MHNCI 7162 , 13 , 99.3- 169.2 mm SL, rio Iguaçu, Municipality of Nova Prata do Iguaçu , 53º20’48”S 25º37’57”W, Mar 1993, E. T. Grando et al . MHNCI 7163 , 9 , 157.6 -200.0 mm SL, rio Iguaçu, Municipality of Nova Prata do Iguaçu , 53º20’48”S 25º37’57”W, Mar 1993, E. T. Grando et al . MHNCI 7164 , 13 , 99.3-169.2 mm SL, rio Iguaçu, Municipality of Nova Prata do Iguaçu , 53º20’48”S 25º37’57”W, Mar 1993, E. T. Grando et al . MHNCI 7165 , 15 , 78.3 -184.0 mm SL, rio Iguaçu, Municipality of Nova Prata do Iguaçu , 53º20’48”S 25º37’57”W, Mar 1993, E. T. Grando et al . MHNCI 7427 , 1 , 23.3 mm SL, mouth of córrego da Divisa, Municipality of Pinhão , 9 Apr 1992, W.B. Wosiacki & P. R.A. Pagliosa . MHNCI 7480 , 3 , 67.0-77.0 mm SL, downstream Lutscher reservoir, rio Jordão, Municipality of Pinhão , 24 Oct 1991, W.B. Wosiacki et al . MHNCI 7529 , 1 , 80.0 mm SL, mouth of córrego Bragança, Municipality of Pinhão , 10 Nov 1991, W. B. Wosiacki & E. T. Grando . MHNCI 7633 , 1, 116.4 mm SL, rio Jordão, upstream Vaca Branca waterfall, Municipality of Pinhão / Guarapuava , 23 Oct 1991, W. B. Wosiacki et al . MHNCI 7650 , 1 , 87.5 mm SL, rio Jordão, Municipality of Jordão / Guarapuava , 22 Oct 1991, W. B. Wosiacki et al . MHNCI 7732 , 5 , 76.5-115.2 mm SL, rio Jordão, downstream Lutscher reservoir, Municipality of Jordão / Guarapuava , 24 Oct 1991, W. B. Wosiacki et al . MHNCI 7762 , 1, 159.3 mm SL, rio Jordão, downstream Lutscher reservoir, Municipality of Jordão / Guarapuava , 24 Oct 1991, W. B. Wosiacki et al . MHNCI 8161 , 1 , 143.0 mm SL, Salto Osório reservoir, rio Iguaçu, Municipality of Quedas do Iguaçu , 25º34’S 52º59’W, 13 Feb 1990, W. Severi et al . MHNCI 8348 , 1, 185.4 mm SL, Bento Munhoz da Rocha Neto reservoir, rio Iguaçu , Municipality of Pinhão , 26º00’S 51º37’W, 16 Nov 1980, F. E. Freitas . MHNCI 8841 , 8 , 158.6 - 190.2 mm SL, mouth of rio Bragança, Municipality of Pinhão , 10 Sep 1992, W. B. Wosiacki . MHNCI 10270 , 11 , 90.7-153.1 mm SL, rio Cavernoso, Municipality of Pinhão , 25º29’02”S 52º12’58”W, 17 Feb 2004, L. P. Bastos & D. P.A. Filho . MHNCI 10382 , 2 , 136.5 - 155.1 mm SL, rio Andrada, Municipality of Capitão Leônidas Marques , 25º31’04”S 53º31’33”W, 6 Apr 2004, L. P. Bastos & D. P.A. Filho . MHNCI 10708 , 3 , 161.0-187,5 mm SL, rio Iguaçu, Municipality of São Mateus do Sul , 25º47’34”S 50º11’57”W, 12 Oct 2002, L. F. Duboc et al . MHNCI 10716 , 1 , 180.0 mm SL, rio Iguaçu, Municipality of São Mateus do Sul , 25°47’34”S 50°11’57”W, 12 Oct 2002, L. F. Duboc et al . MHNCI 11739 , 1 , 167.0 mm SL, rio Guarani, Três Barras do Paraná, 25°25’08”S 53°10’50”W, 23 Feb 1993, E. T. Grando et al . MHNCI 11744 , 1 , 151.0 mm SL, Salto Caxias reservoir, 15 Aug 1994, E. T. Grando et al . MHNCI 11746 , 3 , 109.2 -120.0 mm SL, downstream Lutscher reservoir, rio Jordão, tributary of rio Iguaçu , Municipality of Pinhão , 27 Oct 1991, W. B. Wosiacki et al . MHNCI 11754 , 1 , 125.0 mm SL, Salto Santiago reservoir, Municipality of Quedas do Iguaçu , 25º32’S 52º37’11”W, 30 Jun 1989, W. Severi et al . NUP 150 , 1, 252.7 mm SL, Chopim reservoir, rio Chopim, Municipality of Cruzeiro do Iguaçu , 25º34’S 53º06’W, 6 Aug 1999, A.A. Agostinho . NUP 557 , 1, 131.6 mm SL, Cavernoso reservoir, rio Cavernoso, Municipality of Candói , 25º29’30”S 52º12’52”W, 23-24 Aug 1999, Copel . NUP 680 , 3 , 93.0- 175.4 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 7 Oct 2000, Nupélia . NUP 1625 , 8 , 86.7-127.3 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 31 Oct 1999, Nupélia . NUP 1675 , 15 , 71.8-163.1 mm SL, Jordão reservoir, rio Jordão, Municipality of Foz do Jordão / Reserva do Iguaçu , 25º45’13”S 53º05’09”W, 28 May 1996, Nupélia . NUP 1789 , 19 , 69.6-188.6 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 20 Jan 1999, Nupélia . NUP 1805 , 5 , 167.5 - 205.4 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 20 Jan 1999, Nupélia . NUP 1829 , 2 , 209.2 - 245.6 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 20 Jan 1999, Nupélia . NUP 1835 , 5 , 154.8 - 182.9 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 20 Jan 1999, Nupélia . NUP 2959 , 5 , 115.2 -158.0 mm SL, Foz do Areia reservoir, rio Areia, Municipality of Cruz Machado / Bituruna , 26º00’S 51º37’W, 1 Jan 2003, Copel . NUP 3009 , 7 , 103.3 - 145.2 mm SL, Salto Segredo reservoir, rio Iguaçu, Municipality of Mangueirinha / Reserva do Iguaçu , 25º45’S 52º05’W, 17 Jan 2002, Copel . NUP 5748 , 1, 139.1 mm SL, Foz do Areia reservoir, rio Areia, Municipality of Cruz Machado / Bituruna , 26º00’S 51º37’W, 23 May 2000, Copel . NUP 5749 , 1, 140.1 mm SL, Foz do Areia reservoir, rio Areia, Municipality of Cruz Machado / Bituruna , 26º00’S 51º37’W, 11 Sep 2001, Copel . NUP 5750 , 2 , 106.4 - 134.7 mm SL, Foz do Areia reservoir, rio Areia, Municipality of Cruz Machado / Bituruna , 26º00’S 51º37’W, 13 Jan 2002, Copel . NUP 5751 , 2 , 142.2 - 156.8 mm SL, Foz do Areia reservoir, rio Areia, Municipality of Cruz Machado / Bituruna , 26º00’S 51º37’W, 29 Jan 2002, Copel . NUP 5752 , 5 , 98.2-126.8 mm SL, Foz do Areia reservoir, rio Areia, Municipality of Cruz Machado / Bituruna , 26º00’S 51º37’W, 10 Apr 2002, Copel . NUP 5753 , 2 , 125.5 - 178.6 mm SL, Foz do Areia reservoir, rio Areia, Municipality of Cruz Machado / Bituruna , 26º00’S 51º37’W, 9 Oct 2002, Copel . NUP 5754 , 2 , 151.1 - 159.4 mm SL, Foz do Areia reservoir, rio Areia, Municipality of Cruz Machado / Bituruna , 26º00’S / 51º37’W, 1 Apr 2003, Copel . NUP 5755 , 1, 142.8 mm SL, Foz do Areia reservoir, rio Areia, Municipality of Cruz Machado / Bituruna , 26º00’S 51º37’W, 1 Jul 2003, Copel . NUP 5892 , 8 , 22.1-134.9 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 21 Jan 1999, Nupélia . NUP 5924 , 12 , 81.5- 161.8 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 24 Jan 1999, Nupélia . NUP 5925 , 3 , 135.7 -142.0 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12"S 53º29’11”W, 19 Jul 1999, Nupélia . NUP 5932 , 2 , 108.0- 161.3 mm SL, Salto Segredo reservoir, rio Iguaçu, Municipality of Mangueirinha / Reserva do Iguaçu , 25º45’S 52º05’W, 5 Jun 2001, Copel . NUP 5933 , 1, 150.2 mm SL, Salto Segredo reservoir, rio Iguaçu, Municipality of Mangueirinha / Reserva do Iguaçu , 25º45’S 52º05’W, Mar 2003, Copel . NUP 5951 , 1, 119.1 mm SL, rio Iguaçu, Municipality of Araucária , 25º36’55”S 53º07’55”W, 29 Jul 2000, A. A. Agostinho . NUP 5952 , 2 , 149.5 - 158.5 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 9 Oct 1997, Nupélia . NUP 5953 , 3 , 154.1 - 176.2 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 30 Apr 1999, Nupélia . NUP 5954 , 1 , 68.4 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 10 Jan 2001, Nupélia . NUP 5955 , 2 , 114.1 - 174.8 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 9 Sep 2000, Nupélia . NUP 5958 , 3 , 94.7- 137.3 mm SL, Salto Segredo reservoir, rio Iguaçu, Municipality of Mangueirinha / Reserva do Iguaçu , 25º45’S 52º05’W, 22 May 1993, Nupélia . NUP 5960 , 3 , 106.2 - 117.3 mm SL, Jordão reservoir, rio Jordão, Municipality of Foz do Jordão / Reserva do Iguaçu , 25°45’13”S 52°05’09”W, 11 Dec 1995, Nupélia . NUP 6093 , 3 , 29.2-200.2 mm SL, Salto Segredo reservoir, rio Iguaçu, Municipality of Mangueirinha / Reserva do Iguaçu , 25º45’S 52º05’W, 22 May 1993, Nupélia . NUP 6239 , 2, 168.4 mm SL, Salto Osório reservoir, rio Iguaçu, Municipality of Quedas do Iguaçu , 25º32’32”S 53º01’48”W, 10 Sep 2005, Gerpel . NUP 6244 , 3 , 125.0-149.0 mm SL, Salto Santiago reservoir, rio Iguaçu, Municipality of Quedas do Iguaçu , 25º37’32”S 52º37’13”W, 7 Dec 2004, Gerpel . NUP 6368 , 3 , 29.4-202.5 mm SL, Salto Segredo reservoir, rio Iguaçu, Municipality of Mangueirinha / Reserva do Iguaçu , 25º45’S 52º05’W, Mar 1995, Nupélia . NUP 7074 , 148.0 mm SL, Foz do Areia reservoir, rio Areia, Municipality of Cruz Machado / Bituruna , 26º00’S 51º37’W, 14 Nov 2000, Copel .

Diagnosis. Hypostomus myersi can be distinguished from the species of the H. cochliodon group, except H. hemicochliodon , by having bifid not spoon-shaped teeth and with the lateral cups not fused to the mesial one (vs. spoon-shaped teeth with lateral cups usually fused to the mesial one). Hypostomus myersi is distinguished from all remaining congeners except H. alatus , H. albopunctatus , H. chrysostiktos , H. faveolus , H. francisci , H. lexi , H. luteus , H. luteofrenatus , H.margaritifer , H. microstomus , H. multidens , H. regani , H. roseopunctatus , H. strigaticeps , H. tietensis , and H. variipictus by having pale spots or pale vermiculations over body and fins (vs. dark spots over body and fins). From H. microstomus , H. margaritifer , H. roseopunctatus , H. tietensis , and H. variipictus by having 64-90 teeth on each mandibular ramus (vs. 9-16 in H. microstomus , 18-32 in H. margaritifer and in H. variipictus , 6-16 in H. roseopunctatus , and 45-54 in H. tietensis ). From H. alatus , H. francisci , H. luteofrenatus , H. luteus , and H. regani by having depressed head and eye dorsally placed (vs. compressed head and eye laterally placed).From H. meleagris and H. strigaticeps by having scapular bridge totally covered by gross skin and with dense covering of odontodes on small platelets (vs. scapular bridge usually naked). From H. albopunctatus by pelvic-fin unbranched ray smaller than pectoral-fin unbranched ray (vs. pelvic-fin unbranched ray equal to larger than pectoral-fin unbranched ray). From H. chrysostiktos by having seven branched ray on dorsal fin (vs. eight). From H. multidens by having asymmetric bicuspid teeth (vs. symmetric).

Description. Dorsal profile of head from tip of snout to dorsal-fin insertion slightly concave and elevated at supraoccipital region. Head broad and depressed, totally covered by large dermal bones with fine odontodes; rows of dense odontodes on posterior region of orbit and on median supraoccipital, forming a slightly depression between this bone and orbit. Snout broad and depressed. Mesethmoid forming an inconspicuous bulge from snout tip to upper region of orbit. Orbit narrow, almost dorsal; orbital diameter 14.6-21.7% in head length. Posterior region of head between supraoccipital and dorsal-fin insertion covered by three unpaired and narrowed pre-dorsal plates with a dense series of odontodes in median region forming a divergent keel from supraoccipital. A small platelet on first dorsal-fin ray. Nares narrow, nearly four times in intranasal distance. Body profile slightly straight from dorsal-fin insertion to caudal peduncle. Adipose fin elevated and inserted five plates after dorsal-fin posterior insertion. Caudal peduncle with longitudinal series of odontodes at median region of each plate; upper region of caudal peduncle slightly concave and lower region almost straight. Maximum body width at pectoral-fin insertion, gradually decreasing from this point to base of caudal fin. Unpaired nuchal plate in front of dorsal-fin insertion elevated.Dorsal fin II,7; its origin little ahead vertical through pelvic-fin insertion; almost reaching adipose-fin spine when adpressed; its distal border slightly convex. Pectoral fin I,6; unbranched pectoral fin ray elongate, reaching median portion of pelvic fin and covered by numerous large odontodes; its distal border slightly convex. Pelvic fin i,5; not to just reaching anal-fin insertion; its distal border straight to slightly convex. Anal fin, i,5; distal border slightly rounded. Caudal fin i,14,i, slightly notched; lower unbranched ray longer than upper.

Body covered by five series of longitudinal plates; median series with origin at posterior region of scapular bridge and with a salient keel of odontodes decreasing in size on posterior plates of series. Some rows of odontodes running at median region of all plates on first and second dorsal series of plates; becoming inconspicuous on posterior plates of caudal peduncle. Rostral margin of snout in ventral view aciculate. Tip of snout formed by upper lip in part; snout tip with a naked area without odontodes. Irregular series of small bones between upper snout and orbit running to posterior limits of supraoccipital and pterotic-supracleithrum. Scapular bridge totally covered by gross skin and with dense covering of odontodes on small plates. Numerous small plates and platelets in juveniles covering scapular bridge to pelvic-fin insertion and almost whole abdomen.Abdomen almost totally covered by minute plates, with minute odontodes, leaving naked areas at anterior region of pelvic-fin insertion, around anus and in front of anal-fin insertion; region between anal fin and anus covered only by skin. Twenty six plates in lateral line. Lip gross, ovate and with numerous small papillae; labial barbel short and broad, with no membrane between barbel and lip. Premaxilla with 65-89 and dentary with 64-90 thin and elongate teeth; internal cusp of each tooth shorter than external.

Color pattern. Ground color of head, trunk and fins dark brown uniform; light brown in lower abdomen. Head, trunk and fins spotted with minute pale spots mainly along plates and interradial membranes; series of pale spots also on median region of each trunk plate, in some specimens forming rows of pale spots more conspicuous on caudal peduncle base. All fins dark brown; branched rays of pectoral, pelvic and lower lobe of caudal fin light brown; distal region of caudal fin bounded with pale brown pigment.

Distribution. Known from rio Iguaçu, Paraná State, Brazil. Hypostomus myersi is widely distributed along the rio Iguaçu and it is also found in tributaries flowing into this river as the rio Areia, Cavernoso, Cotegipe, Guarani, Jordão, córrego da divisa, among others. However, it was not usually found in the small headwater streams as is the case of H. derbyi .

Figures

Fig. 5. Holotype of Hypostomus myersi MNRJ 4251, 174.0 mm SL, Porto União, rio Iguaçu, Paraná, Brazil.

Fig. 6. Hypostomus myersi, NUP 680, 146.2 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques/Nova Prata do Iguaçu, Paraná, Brazil.