Corumbataia liliai, Silva & Roxo & Souza & Oliveira, 2018

Silva, Gabriel S. C., Roxo, Fabio F., Souza, Camila S. & Oliveira, Claudio, 2018, Two new species of Corumbataia (Hypoptopomatinae: Loricariidae) from Rio Corrente, upper Rio Paraná basin, Brazil, Zootaxa 4483 (2), pp. 317-330 : 323-326

Corumbataia liliai , new species

Figs. 7 , 4b . Tab.1

Holotype. MZUSP 123826, female, 24.7 mm SL, Goiás state, municipality of Aporé, Córrego da Cachoeira, Rio Corrente drainage, upper Rio Paraná basin, 18°34’50.8”S 52°05’52.8” W, November 2017, B.F. Melo, C. Arraya, G.S.C. Silva, R. Devidé.

Paratypes. AUM 71029, 3 (19.4–21.4 mm SL), collected with the holotype. LBP 9577 , 2 (18.4–23.2 mm SL), Goiás state, municipality of Aporé, Córrego da Cachoeira, Rio Corrente drainage, upper Rio Paraná basin, 18°34’50.8”S 52°05’52.8” W, 0 6 July 2010, R. Devidé, M.F. Pazian, L.H. Pereira, J.M. Henriques . LBP 25544, 2 (18.2–24.7 mm SL), 1 c&s (21.0 mm SL), collected with holotype . MZUSP 123827, 2 (21.6– 21.5 mm SL), collected with the holotype.

Diagnosis. Corumbataia liliai differs from all congeners, except C. lucianoi by presence of a broad naked area without plates or odontodes on dorsal portion of snout (vs. absence of naked area on dorsal portion of the snout) (see Fig. 2 ). Additionally, the new species C. liliai differs from C. cuestae , C. lucianoi and C. veadeiros by having four infraorbitals plate series (vs. five infraorbitals plate series); from C. lucianoi and C. britskii by having only two rounded hyaline area on caudal fin (vs. presence of four rounded hyaline area on caudal fin, more evident in large male specimens); from C. veadeiros by presence of a conspicuous tuft of enlarged odontodes on the tip of parietosupraoccipital (vs. absence of a tuft of enlarged odontodes on the tip of parieto-supraoccipital); and by absence of two platelets at typical adipose-fin region (vs. presence). Moreover, Corumbataia liliai is distinguished from C. lucianoi by a deeper caudal peduncle, 9.0–10.3% in SL (vs. 6.8–8.1% of SL) and a greater predorsal length, 45.1– 50.6% of SL (vs. 41.5–44.6% of SL); from C. cuestae by a shorter cleithral width (23.9–26.5% of SL vs. 26.7– 29.3% of SL); and from C. tocantinensis and C. lucianoi by greater snout opercle length, 27.4–30.7% of SL (vs. 17.4–26.7% of SL and 17.9–27.3% of SL, respectively).

Description. Morphometric and meristic data summarized in Table 1. Small-size loricariid (18.2–24.7% of SL). Head and snout slightly rounded, snout tip pointed. Area around snout tip without odontodes. Snout elongated (53.8–57.8% of HL); anterior region slightly depressed. Nostril small, almost reaching same diameter of eyes. Dorsal profile of head ascending approximately 45° to parieto-supraoccipital; slightly concavity between nostrils. Eyes relatively small (13.2–19.3% of SL), dorsolaterally positioned, just posterior of mid-point of head. Iris operculum present, almost covering half of eye. Superior margin of orbits not elevated. Presence of inconspicuous odontodes on suboperculum. Mouth moderate in size; oral disk ellipsoid with papillae randomly distributed. Lips without odontodes; lower lip larger than upper lip, not reaching cleithrum; its border fringed; lower lip inner surface covered with small papillae, similar in size. Maxillary barbel adnate to lower lip. Teeth slander with two symmetrical cusps; central cusp larger than lateral cusps. Premaxillary teeth 22–29 (mode 23). Dentary teeth 19–25 (mode 19).

Lower surface of head naked. Head lacking ridges. Parieto-supraoccipital process elevated and with conspicuous tuft of odontodes in specimens of all size. Predorsal region without ridges. In dorsal view, body elongated and slightly depressed on caudal peduncle. Greatest body width at cleithral region (23.9–26.5% of SL), progressively narrowing towards snout tip and caudal-fin insertion. Dorsal profile of head and trunk covered by dermal plates, except on area at base of dorsal-fin insertion. In lateral view, body depressed. Body convex from snout tip to posterior margin of parieto-supraoccipital; slight concave from that point to dorsal-fin origin; slightly concave and descending from dorsal-fin origin to first upper procurrent caudal-fin ray origin, elevating posteriorly to insertion of caudal fin. Greatest body depth at unbranched dorsal-fin ray insertion. Cleithrum and coracoid exposed in ventral view, covered by odontodes. Arrector fossa almost completely enclosed by ventral lamina of coracoid.

Ventral profile of body straight and descending from snout tip to opercular region; convex from opercular region to anal-fin origin; slightly concave from that point to lower procurrent caudal-fin ray origin. Lateral surface of body entirely covered by plates; mid-dorsal plate series truncated (17 plates) not reaching posterior end of caudal peduncle; lateral plates series formed by 21–22 plates (mode 21). Lateral line incomplete, with gap in line of pores along mid-length of body. Mid-ventral series of lateral plates developed and almost reaching middle of caudal peduncle (18 plates). Body plates covered with minute odontodes. Ventral portion of body totally covered by plates, except on ventral part of head, small area around pectoral- and pelvic fins insertions, and at urogenital opening. Abdomen in adult specimens partially covered by small rounded platelets.

Dorsal-fin rays ii,7; dorsal-fin origin slightly posterior through pelvic-fin origin. Dorsal-fin unbranched ray slightly convex. Tip of adpressed dorsal-fin ray suprassing anal-fin unbranched ray insertion. Dorsal-fin spinelet small and rectangular. Pectoral-fin rays i,6; its tip reaching adpressed pelvic-fin ray. Pectoral-fin axillary slit small, but present above pectoral-fin insertion. Pelvic-fin rays i,5; its distal margin straight to slightly convex; tip of adpressed pelvic fin reaching anal-fin origin in males, but not in females. Absent of adipose fin. Anal-fin rays i,5; distal margin slightly convex. Caudal-fin rays i,7–7,i; slightly emarginated; unbranched rays of same size. Rays of all fins covered with pointed odontodes. Least body depth at caudal peduncle. Caudal peduncle ellipsoid in cross section, rounded dorsally and ventrally. Compound hypurals1–2 completely fused to compound hypurals 3–5. Total vertebrae 27.

Neurocranium presented in figure 2. In dorsal view ( Fig. 2e ), parieto-supraoccipital (soc) octagonal, bordered by compound pterotic (cpt) and sphenotic (sp) laterally and by frontal (f) anteriorly. Snout composed by two rostral triangular-shaped plates (r); ten prenasal rounded-shape plates (pn) between nares, and two nasal bones (n). Upper region of neurocranium composed by largest three bones of head: compound pterotic (cpt), parieto-supraoccipital (soc) and frontals (f).

In lateral view ( Fig. 2f ), three posterior rostrum plates, pr1 smallest, triangular-shaped, pr2 largest, triangularshaped, pr3 median size, triangular-shaped. Infraorbital plate series incomplete (io1-io4), io1, io2 and io3 largest; io4 smallest, forming inferior orbital margin of eyes. Opercular series complete, preopercle (pop), rectangularshaped, covered by laterosensory canal; opercle (op) rounded; one subocular cheek plates (cp1), triangular shaped; bordering preopercle (pop) and opercle (op), forming posterior lateral margin of head.

Color in alcohol. Background color of dorsal region of head and trunk yellow. Four dark brown saddles along dorsal portion of body: first at dorsal-fin origin, second at end of dorsal-fin base, third at middle of caudal peduncle, and fourth reaching anteriormost caudal procurrent ray. Mid-lateral dark brown stripe extending from tip of snout to caudal peduncle. Ventral portion of body entirely yellowish, except for dark, randomly distributed chromatophores and for a concentration of chromatophores at anal-fin origin. Dorsal, pectoral, and pelvic fins with dark, irregularly distributed chromatophores. Caudal-fin brown, with two rounded hyaline area in middle portion ( Fig. 3 ).

Color in life. Similar pattern described for alcohol individuals ( Fig. 4b ), with lighter background.

Sexual dimorphism. Adult males with papilla covering urogenital opening, long pelvic fin that extends beyond anal-fin origin, and unbranched pelvic-fin ray supporting dermal flap along its dorsal surface. All these features absent in all analyzed females.

Distribution and habitat. The new species Corumbataia liliai is known from the Córrego da Cachoeira, tributary of Rio Corrente, upper Rio Paraná basin ( Fig. 5b ). The new species is found to be associated with margin vegetation (see Fig. 6 for the habitat where the new species lives).

Etymology. The specific name “ Liliai ” is in honor of Lilian Maria Costa e Silva, GSC Silva’s sister.

Figures

FIGURE 2. Neurocranium. Yellow color indicates the naked areas around the snout plates. Corumbataia britskii, LBP 9590, a) dorsal view, b) lateral view. Corumbataia lucianoi, LBP 25543., paratype, c) dorsal view, d) lateral view. Corumbataia liliai, LBP 25544., paratype, e) dorsal view, f) lateral view.

FIGURE 3. a) C. lucianoi, MZUSP 123824., 24.0 mm SL; b) C. cuestae, LBP 8114, 27.3 mm SL; c) C. liliai, MZUSP 123826., 24.7 mm SL; d) C. veadeiros, LBP 19470, 32.6 mm SL; e) C. britskii, LBP 9590, 25.5 mm SL; f) C. tocantinensis, LBP 1653, 24.6 mm SL.

FIGURE 4. Live specimens: a) Corumbataia lucianoi, holotype, MZUSP 123824., 24.0 mm SL, female. b) Corumbataia liliai, holotype, MZUSP 123826., 24.7 mm SL, female.

FIGURE 5. Map showing the distribution of C. lucianoi at Rio Corrente (triangle = type locality) and at Rio Formoso (star = paratype locality), and Corumbataia liliai at Córrego da Cachoeira (circle = type locality).

FIGURE 6. Upper picture showing the habitat of the type locality where the species Corumbataia lucianoi lives at Rio Corrente, 18°30’50.57”S 52°05’34.89”W. Lower picture showing the habitat of the type locality where the species C. liliai lives at Córrego da Cachoeira, 18°34’50.8”S 52°05’52.8” W. Both species were found associated with marginal vegetation.

FIGURE 7. Corumbataia liliai, MZUSP 123826., 24.7 mm SL, female, holotype, from Goiás state, municipality of Aporé, Córrego da Cachoeira, tributary of Rio Corrente, upper Rio Paraná basin, 18°34’50.8”S 52°05’52.8” W.