Proloricaria lentiginosa (Isbrücker, 1979)

Proloricaria lentiginosa (Isbrücker, 1979)

( Figs. 2–3)

Loricaria prolixa lentiginosa Isbrücker, 1979:97 (original description, type-locality: Volta Grande Reservoir, Grande River).

Loricaria lentiginosa. ―Ferraris, 2003:337 (catalogue of Neotropical freshwater fish). ―Ghazzi, Oyakawa, 2007:89 (catalogue, freshwater fishes of Brazil). ―Perez-Junior, Garavello, 2007:331 (Mogi-Guaçu River basin). ―Meschiatti, Arcifa, 2009:141 (literature compilation). ―Oliveira et al., 2009:493 (Mogi-Guaçu River basin). ―Oliveira et al., 2015:5 (list of species Sapucaí-Mirim River). ―Froehlich et al., 2017:8 (upper Paraná River). ― Thereza, Langeani, 2019: 50 (diagnosis; Grande River). ― Ribeiro et al., 2019:138 (Uberaba River).

Loricaria macrodon (non Kner, 1853). ―Miranda-Ribeiro, 1918: 718 ( part, list of species, Mogi-Guaçu River). ― Fowler, 1954:96 (part, catalogue, Mogi Guaçu River). ―Schubart, 1962 (list of species, Mogi-Guaçu River). ―Schubart, 1964 (list of Loricariidae from Mogi-Guaçu River).

Loricaria prolixa. ― Isbrücker & Nijssen, 1978: 189–94 (part; non paratypes; Mogi Guaçu and Grande rivers). ― Meschiatti, Arcifa, 2009:141 (literature compilation). ―Covain et al. (2016):498 (molecular phylogeny, Mogi-Guaçu River).

Proloricaria lentiginosa. ―Isbrücker et al., 2001:21 (diagnosis of Proloricaria). ―Isbrücker, 2001:31 (list of Loricariidae species). ―Ferraris, 2007: 286 ( catalogue of Siluriformes). ― Dagosta et al., 2024:23 (geographic distribution).

Proloricaria prolixa. ―Pereira et al. ( 2013): additional file 1 (DNA barcode, Mogi-Guaçu River). ― Thereza, Langeani, 2019:51 (catalogue, Grande River basin). ― Ribeiro et al., 2019: 139 (list of species, Uberaba River).

Diagnosis. Proloricaria lentiginosa is distinguished from P. prolixa by color pattern, with numerous well-defined rounded grayish-brown dots and spots on the dorsal region of head and body, smaller and more numerous on head, greater and less numerous on body ( vs. dorsal surface of head with ill-defined or absent dots, a dark transverse bar between the nostrils and the anterior margin of the orbits followed by another clear bar, positioned over the orbits; and body with irregular pigmentation, in P. prolixa ). Additionally, P. lentiginosa possesses two small plates anterior to the series of predorsal plates, in contact on each side of parieto-supraoccipital (rarely on just one side, or none) ( vs. none, rarely one or two small anterior plates, in P. prolixa ) ( Fig. 4). The parieto-supraoccipital typically has a single row of well-developed odontodes in P. lentiginosa ( vs. one or two rows in P. prolixa ). The quantity and arrangement of abdominal plates is highly variable in both species and not useful to distinguish them.

Description. Morphometric data are summarized in Tab. 3. Standard length of specimens examined 128–420 mm. Body elongate, dorsoventrally depressed, widest in cleithrum. Dorsal profile of body slightly convex from tip of snout to dorsal-fin origin. Ventral profile slightly convex, mostly flat. Greatest body depth at dorsal-fin origin. Head triangular in dorsal view, with round snout and slightly convex lateral margins from snout tip to operculum. Head dorsal profile straight and inclined from tip of snout to anterodorsal margin of orbit, slightly inclined to posterior elevated margin of parieto-supraoccipital. Eye small, maximum orbital diameter 10.4–17.0% in HL. Post orbital notch absent.

Ventral mouth, thin lips with small, thin, simple or bifid barbels. Upper lip barbels longer than lower lip, more numerous, and distributed over entire surface. Rictal barbel long, occasionally reaching gill openings, branched, with simple or bifid secondary barbels similar to those on upper lip. Lower lip broad, with smaller and more dispersed barbels relative to those on upper lip. Posterior edge of lower lip rounded, with shallow median notch; barbels more elongated than others on its surface. Teeth in both maxillae. Each tooth with a small lateral cusp and longer main cusp, with rounded tips. Premaxillary teeth one to four (modally three) on each side; curved towards the inside of mouth. Dentary teeth four to seven (modally six) on each side; less than half the length of premaxillary teeth and shorter cusps.

Body completely covered with dermal plates, except ventral surface of head, portions of thorax and abdomen, around bases of pectoral and ventral fins, and areas lateral and posterior to the anus. Abdomen with small and minute bony plates, partially naked in young specimens. One pair of small plates laterally positioned to the parieto-supraoccipital and anterior to the first pair of predorsal plates ( Fig. 4). Crests of odontodes in the posterior portion of parieto-supraoccipital and predorsal plates. Each dorsolateral and lateral plates with one crest of odontodes.

Dorsal-fin rays I,7, with posterior margin straight; reaching the fourth or fifth posterior dorsal plate when adpressed. Pectoral-fin rays I,6, with distal margin curved or slightly convex; the spine, when adpressed, surpassing the half-length of pelvic-fin spine. Pelvic-fin rays I,5, with convex distal margin; spine much longer than the branched rays, surpassing the anal-fin base when adpressed. Anal-fin rays I,5, reaching the fifth or sixtieth postanal plate when adpressed, with distal margin convex. Principal caudal-fin rays I,10,I; posterior margin of fin deeply concave; upper unbranched ray produced into long trailing filament with at least half of standard length (broken in most specimens examined).

Coloration in alcohol. Ground color of dorsal region of the head and body greyish tan to pale yellow. Head with several rounded grayish-brown dots, smaller than pupil and more numerous on snout, greater on posterior part of head. Dark spots (almost size of eye) on dorsum of body (more numerous and conspicuous in pre dorsal region), sometimes irregular or ill-defined. Dark blotches posterior to dorsal fin sometimes longitudinally aligned, forming three to four lines of blotches in specimens with more than 250 mm SL. Dark grey transverse bars on the dorsum of the body conspicuous in small (up to 200 mm SL) specimens, but pale or absent in larger specimens. Ventral regions of head and body whitish to pale yellow.

Dorsal-fin brownish, with dark spots on spine and branched rays arranged in oblique irregular bands. Pectoral-fin dark brownish, with irregular dark spots in spine, branched rays and membranes, forming irregular bands on its entire surface; darker on its proximal portion. Pelvic-fin pale, with dark spots on spine and branched rays. Anal-fin pale, with faint spots on spine, and inconspicuous spots on distal half of the branched rays. Caudal-fin brownish, with dark spots on rays arranged in vertical irregular bands. The same color pattern is observed in living and recently collected specimens, but the dark pigmentation is more conspicuous than in older specimens examined.

Sexual dimorphism. Dissection of seven specimens (LISDEBE 3476, female,

323 mm SL; LISDEBE 4337, two females, 294–351 mm SL; LISDEBE 7883, female,

354 mm SL; LISDEBE 3476, male, 347 mm SL; LISDEBE 6345, male, 420 mm SL;

LISDEBE 7883, male, 350 mm SL) revealed some traits previously observed in other members of the Loricariini tribe (Isbrücker, 1981; Thomas, Rapp Py-Daniel, 2008).

Adult males have slightly shorter barbels and more numerous and well developed round papilae in the lower lip; dentary teeth tend to be rounded, with main cuspid shorter than those observed in adult females.

Geographical distribution. Proloricaria lentiginosa is distributed in the Grande and Paranaíba river basins, in the states of São Paulo, Minas Gerais and Goiás ( Fig. 5). It occurs in small to large riverine habitats with sandy and rocky bottom .

Material examined. All from Brazil. São Paulo: MZUSP 13188 View Materials , holotype of Loricaria prolixa lentiginosa , 297.0 mm SL; MZUSP 13190 View Materials , paratype, 261.0 mm SL; MZUSP 13187 View Materials , paratype, 265.0 mm SL; MZUSP 85885 View Materials , 2 View Materials , 166.0–167.0 mm SL; MZUSP 2932 View Materials , 1 View Materials , 327.0 mm SL; MZUSP 25694 View Materials , 2 View Materials , 190.2 View Materials –319.0 mm SL; LISDEBE 4337, 5, 294.0–351.0 mm SL; LISDEBE, 4102, 2, 276.0–320.0 mm SL; LISDEBE 6345, 4, 365.0–420.0 mm SL; LISDEBE 5782, 5, 284.0–368.0 mm SL; LISDEBE 7570, 1, 276.0 mm SL; LISDEBE 7883, 2, 350.0–354.0 mm SL; LISDEBE 7885, 3, 228.0–261.0 mm SL; LISDEBE 7887, 1, 228.0 mm SL; LISDEBE 4376, 7, 284.0–369.0 mm SL; LISDEBE 4312, 1, 332.0 mm SL; LISDEBE 5054, 2, 328.0–350.0 mm SL; LISDEBE 7888, 1, 260.0 mm SL; LISDEBE 7889, 1, 339.0 mm SL; LISDEBE 7890, 2, 320.0– 330.0 mm SL; DZSJRP 8423 , 1 , 379.0 mm SL; LIRP 202 View Materials , 1 View Materials , 326.0 mm SL; LIRP 15030 View Materials , 1 View Materials , 325.0 mm SL; LIRP 14886 View Materials , 1 View Materials , 144.0 mm SL. Goiás: DZSJRP 15969, 1, 220.0 mm SL; DZSJRP 16057 , 4 , 214.0–217.0 mm SL. Minas Gerais: MZUSP 24778 View Materials , 1 View Materials , 318.0 mm SL; LISDEBE 5410, 7, 223.0–329.0 mm SL; LISDEBE 5322, 2, 253.0–268.0 mm SL; LISDEBE 5403, 1, 272.0 mm SL; LISDEBE 5222, 1, 236.0 mm SL; LISDEBE 6033, 2, 267.0–302.0 mm SL; DZSJRP 16102 , 2 , 128.0–132.0 mm SL .