Odontesthes perugiae

description

Description. Morphometric and meristic data in Tables 1 — 2. Body elongate and slender; dorsal profile slightly convex to nearly straight from snout tip to caudal peduncle. Ventral body profile slightly convex from tip of snout to origin of anal fin; straight and ascending along anal fin and concave near end of caudal peduncle. Caudal peduncle longer than deep. Head relatively large (16.2 — 25.1 % of SL); dorsal profile straight from snout to posterior tip of supraoccipital; ventral profile of head straight or slightly concave from snout through region below anterior portion of eye. Snout pointed in dorsal view and lateral view (Fig. 5 a). Mouth terminal, protractile with large gape lying vertically at level of center of eye. Eyes rounded and well developed from lateral view, diameter smaller than snout length. Pectoral-fin rays i + 11 — 13 (i + 11); unbranched and 1 st to 4 th branched rays longer than remaining rays, its tip not reaching posterior to vertical through pelvic-fin origin. Pelvic-fin rays i + 5 (i + 5); unbranched ray half-length of first branched ray, not reaching anal-fin origin. Pelvic fins insertion close to each other, with interpelvic membrane uniting them at b

Review of the Odontesthes perugiae species group from Río de La Plata drainage, with the description of a new species (Atherinomorpha: Atherinopsidae)

diagnosis

Diagnosis. Odontesthes perugiae is distinguished from congeners, with the exception of the species included in the O. perugiae species-group (O. bicudo, O. ledae, O. mirinensis, O. piquava and O. yucuman) by the possession of the following combination of characters: teeth of the outer row on dentary and premaxilla shorter than those in the inner row (vs. teeth of outer row larger than those of inner row or teeth of outer and inner rows of equal size), origin of dorsal fin positioned over or posterior to anus (vs. anterior to anus), less than 30 gill rakers on lower branch, and 7 to 9 longitudinal scale rows above left and right lateral bands. Odontesthes perugiae is distinguished from O. ledae, O. mirinensis, O. piquava and O. yucuman by the dermosphenotic with medial flange large, covering its whole extension (Fig. 4; vs. dermosphenotic with medial flange covering only its dorsal portion in O. ledae and O. mirinensis and narrow in O. piquava and O. yucuman). Odontesthes perugiae is distinguished from O. bicudo by the dermosphenotic sensory canal open (vs. dermosphenotic sensory canal closed), the basisphenoid with two posterior projections (vs. basisphenoid with four posterior pro

Review of the Odontesthes perugiae species group from Río de La Plata drainage, with the description of a new species (Atherinomorpha: Atherinopsidae)

distribution

Distribution and type locality notes. Odontesthes perugiae was described based on a single specimen (USNM 55572) collected by John W. Titcomb during an expedition in Argentina between 1903 and 1904. Evermann & Kendall (1906) mentioned the type-locality in the original description as “ Argentina, locality label lost, probably from fresh water ”. Evermann & Kendall (1906) mentioned that the freshwater fishes reported by them came from “ (…) Rio Primero in the Province of Cordoba, and from the headwaters of the Rio Negro, chiefly Lakes Nahuel Huapi and Traful and tributary or neighboring waters (…). ” and that “ (…) unfortunately when received some of the labels had become partly effaced, making some of the localities uncertain (…) ”. However, some notes by Titcomb cited in Evermann & Kendall (1906) provided valuable information about the freshwater environments explored by him. Among those, the region where the holotype of O. perugiae was most likely collected is described as “ streams flowing south from the Sierras in the Province of Buenos Aires ”. These “ Sierras ” commented by Titcomb likely are the western mountains in the Córdoba Province and their southern tributaries probably

Review of the Odontesthes perugiae species group from Río de La Plata drainage, with the description of a new species (Atherinomorpha: Atherinopsidae)

materials_examined

Material examined. USNM 55572, holotype of O. perugiae (xr), 110.3 mm SL, J. W. Titcomb col., probably from freshwater, Argentina. MHNM 1808, holotype of O. orientalis, 104.4 mm SL, reservoir Rincón del Bonete, río Negro, Uruguay. Argentina. CAS 69625, 1 (xr), 120.1 mm SL, Buenos Aires, 34 ° 40 ’ 18 ” S 58 ° 18 ’ 08 ” W. MACN 5091, 14, 86.9 — 125.8 mm SL, río Paraná, Santa Fé, Rosário. MACN 6922, 19, 92.1 — 122.2 mm SL, río Colastiné, Santa Fé. MACN 8801, 16, 87.2 — 137.5 mm SL, río Uruguay at Embalse La Península, Entre Ríos, Concordia. MCP 33627, 3, 146.1 — 154.7 mm SL, río Paraná, Misiones, Posadas, 27 ° 27 ’ 01 ” S 55 ° 50 ” W. UMMZ 218473, 1 (xr), 91 mm SL, playa La Balandra, Buenos Aires, La Plata, 34 ° 55 ’ 43 ” S 57 ° 43 ’ 01 ” W. UMMZ 231982, 2 (xr), 114.8 — 131 mm SL, río Gualeguaycito at Salto Grande dam, Entre Ríos, 31 ° 06 ’ 34 ” S 58 ° 04 ’ 13 ” W. Brazil. All from Rio Grande do Sul State. FMNH 88228, 1, 79.7 mm SL, rio Uruguai, Uruguaiana. MCP 16198, 16 (1 c & s), 43.8 — 55.2 mm SL, rio Santa Maria, tributary of rio Uruguai, Rosário do Sul, 30 ° 15 ’ S 54 ° 55 ’ 14 ” W. MCP 23662, 7 (1 c & s), 42.3 - 91.4 mm SL, Sanchuri reservoir, Uruguaiana. MZUSP 47689, 4, 128.6 —

Review of the Odontesthes perugiae species group from Río de La Plata drainage, with the description of a new species (Atherinomorpha: Atherinopsidae)