Hypostomus albopunctatus ( Regan, 1908 )

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 : 265-267

Hypostomus albopunctatus ( Regan, 1908) Fig. 1

Plecostomus albopunctatus Regan, 1908:797-798 , fig. 206, pl. 49, fig.1 (type locality: rio Piracicaba, São Paulo, Brazil); Eigenmann, 1910:407 (ref.); Miranda Ribeiro, 1918:714 (Salto de Pirassununga, rio Mogi-Guaçu; rio Paraná; Piracicaba); Gosline, 1945:81 (ref.); Fowler, 1954:175 (rio Paraná, São Paulo).

Hypostomus albopunctatus : Isbrucker, 1980:18; Gomez & Somay, 1989:726 (rio Iguazu, Argentina); López & Miquelarena, 1991:18 (redesc.); Garavello et al., 1997:78 (rio Iguaçu); Weber, 1987: 279 lectotype designation, BMNH 1907.7.6.15 (seen); Weber, 2003:355 (ref.); Zawadzki et al., 2005:272 (upper rio Paraná - allozymes); Baumgartner et al., 2006:2 (Salto Osório reservoir, rio Iguaçu; check list); Carvalho & Bockmann, 2007:92 (upper rio Paraná).

Material examined. All from Brazil: São Paulo State: BMNH 1907.7 .6.15, 2, 134.1-169.0 mm SL, syntypes, rio Piracicaba . Paraná State: LISDEBE 2649 , 4 , 108.0-230.0 mm SL, rio Iguaçu, Salto Segredo reservoir, Municipality of Mangueirinha , Apr 1993, Nupélia . LISDEBE 2650 , 11 , 95.0- 110.2 mm SL, rio Iguaçu, downstream Salto Santiago reservoir, Municipality of Laranjeiras do Sul , 25º38’S 52º37’W, 11 Nov 1990, J. C. Garavello et al . MHNCI 7177, 260.5 mm SL, rio Iguaçu, Municipality of Nova Prata do Iguaçu , 53º20’48”S 25º37’57”W, Mar 1993, E. T. Grando et al . MHNCI 11737 , 4 , 127.2 - 180.5 mm SL, rio Três Barras, Municipality of Três Barras do Paraná , 25 Feb 1993, E. T. Grando et al . MHNCI 11738 , 2 , 182.0- 202.6 mm SL, rio Guarani, Municipality of Três Barras do Paraná , 25°25’08”S 53°10’50”W, 23 Feb 1993, E. T. Grando et al . MHNCI 11741 , 1 , 194.0 mm SL, rio Iguaçu, Municipality of Nova Prata do Iguaçu , 25º37’57”S 53º20’48”W, 22 Mar 1993, E. T. Grando et al . MHNCI 11742 , 1 , 166.0 mm SL, rio Iguaçu, Municipality of Nova Prata do Iguaçu , 53º20’48”S 25º37’57”W, 22 Mar 1993, E. T. Grando et al . MHNCI 11745 , 1, 183.7 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º30’S 53º24’W, 15 Aug 1994, E. T. Grando et al . NUP 593 , 2 , 82.2-180.2 mm SL, córrego Passo do Aterrado, tributary of rio Jordão, Municipality of Foz do Jordão , 25º45’S 52º10’W; 14 Oct 1995, Copel . NUP 681 , 6 , 252.0-310.0 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º37’57”S 53º20’48”W, Feb 1997, Nupélia . NUP 684 , 10 , 88.3-227.3 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 2 Sep 1997, Nupélia . NUP 1785 , 8 , 127.8 - 220.2 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25°32’12”S 53°29’11”W, 20 Jan 1999, Nupélia . NUP 1830 , 2 , 81.7-225.3 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25°32’12”S 53°29’11”W, 21-22 Apr 1996, Nupélia . NUP 4309 , 17 , 56.0- 102.4 mm SL, riacho São João, Parque Nacional do Iguaçu, downstream Iguaçu waterfalls, rio Iguaçu , Municipality of Foz do Iguaçu , 12 Nov 2001, V. P. Margarido . NUP 4316 , 21 , 53.2-157.6 mm SL, riacho São João, Parque Nacional do Iguaçu, downstream Iguaçu waterfalls, rio Iguaçu , Municipality of Foz do Iguaçu , 1 Jun 2001, V. P. Margarido . NUP 5431 , 1 , 136.0 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25°32’12”S 53°29’11”W, 5 Mar 1997, Nupélia . NUP 5432 , 2 , 224.3 - 235.1 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25°32’12”S 53°29’11”W, Oct 1998, Nupélia . NUP 5786 , 2 , 167.7 - 198.6 mm SL, downstream Jordão reservoir, rio Jordão, tributary of rio Iguaçu , Municipality of Foz do Jordão / Reserva do Iguaçu , 25º45’51”S 52º05’23”W, 1 Jan 1998, Copel . NUP 5921 , 1, 119.8 mm SL, downstream Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25º32’12”S 53º29’11”W, 3 Jul 1997, Nupélia . NUP 5931 , 1, 116.8 mm SL, Salto Caxias reservoir, rio Iguaçu, Municipality of Capitão Leônidas Marques / Nova Prata do Iguaçu , 25°32’12”S 53°29’11”W, 5 Mar 1997, Nupélia . Santa Catarina State: LISDEBE 2651 , 1 , 114.0 mm SL, rio Timbó, tributary of rio Iguaçu, colônia São Pedro , Municipality of Porto União , 26º26’13”S 50º 49’59”W, 18-19 Nov 1986, J. C. Garavello & Surehma .

Diagnosis. Hypostomus albopunctatus can be distinguished from all other congeners except H. heraldoi by the pelvic-fin unbranched ray length equal to or greater than pectoral-fin unbranched ray (vs. pelvic-fin unbranched ray shorter than pectoral-fin unbranched ray). From H. heraldoi it is distinguished by having pale dots over body and fins (vs. dark dots over body and fins).

Description. Dorsal profile of head from tip of snout to beginning of supraoccipital almost straight; supraoccipital elevated; anterior plates of dorsal-fin insertion slightly concave. Head wide and depressed, totally covered by dermal bones with fine odontodes; a keel with origin at anterior nare, running over orbit and continuing back through pterotic-supracleithrum region and line of profuse odontodes along these keels. Snout wide and depressed. Mesethmoid forming inconspicuous keel from snout tip to upper region of orbit. Orbit narrow, almost dorsally positioned, 11.2-16.1% in head length. Posterior region of head between supraoccipital and dorsal-fin insertion formed by three unpaired and narrow pre-dorsal plates; odontodes densely covering those plates not forming keels in posterior region of head.

Body profile almost straight from dorsal-fin insertion to caudal peduncle. Six interdorsal plates between dorsal fin and adipose fin.Adipose fin elevated and posteriorly curved inward. Upper region of caudal peduncle concave and lower region almost straight. Maximum body width at pectoral-fin insertion, gradually decreasing in a straight line to caudal fin.An unpaired nuchal plate in front of dorsal-fin insertion. Dorsal fin II,7; its origin slightly anterior to vertical through pelvic-fin insertion; far from reaching adipose-fin spine when adpressed; its distal border slightly convex. Pectoral fin I,6; first ray short, but reaching pelvic-fin insertion; covered by odontodes slightly larger than that of body covering; its distal border almost straight. Pelvic fin i,5; first ray elongate, surpassing half of anal fin in females; shorter in males; its distal border straight. Anal fin, i,5; distal border slightly rounded. Caudal fin i,14,i; forked, lower unbranched ray longer than upper.

Body covered by five longitudinal series of elongate plates; median series with origin at posterior region of scapular bridge and with inconspicuous keel running to caudal peduncle. Dorsal, mid-dorsal, middle and ventral series of plates without conspicuous keels. Mid-ventral series of plates angled just to pelvic-fin insertion region. Rostral margin of snout aciculate with dense irregular series of odontodes; tip of snout with a naked area at ventral region; irregular series of small dermal bones covering the snout from anterior region of orbit to limits of supraoccipital and pterotic-supracleithrum. Scapular bridge totally covered by skin; dense covering of small plates with odontodes on almost whole abdomen, even on juveniles; only a narrow naked area in front of anal opening; an unpaired plate between anus and the anal-fin insertion. Twenty eight plates in the lateral line. Lips gross and with dense papillae; a membrane joining the short and wide labial barbel to labial border. Premaxilla with 26 to 51, and dentary with 26 to 44 moderate to robust teeth; internal cusps shorter than external ones.

Color pattern. Ground color of head and trunk uniformly dark brown; head, trunk and fins with pale spots. Some specimens having spots on each lateral plate and on interradial membranes of all fins. Pale vermiculate spots on head and trunk forming conspicuous longitudinal rows along body and caudal peduncle in some specimens. Abdominal region light brown with dark brown spots or vermiculate on whole abdomen. Fins uniformly dark brown; unbranched rays of pelvic, anal and lower caudal fin light brown.

Distribution. Known from rio Paraná-Paraguay basin including rio Iguaçu. In the rio Iguaçu basin H. albopunctatus is found mainly in the main channel of the rio Iguaçu, from its upper stretches to the lower ones, including a population below Iguaçu Falls. It was also found in a few tributaries of the rio Iguaçu as the rio Três Barras and rio Guarani in the municipality of Três Barras; in the córrego Passo do Aterrado and rio Jordão at its mouth, both in the municipality of Foz do Jordão; and in the rio Timbó in the municipality of Porto União.

Figures

Fig. 1. Hypostomus albopunctatus, NUP 593, 108.2 mm SL, córrego Passo doAterrado, tributary of rio Jordão, Municipality of Foz do Jordão, Paraná, Brazil.