Pseudotocinclus juquiae, Takako & Oliveira & Oyakawa, 2005

Takako, Adriana Kazue, Oliveira, Claudio & Oyakawa, Osvaldo Takeshi, 2005, Revision of the genus Pseudotocinclus (Siluriformes: Loricariidae: Hypoptopomatinae), with descriptions of two new species, Neotropical Ichthyology 3 (4), pp. 499-508 : 504-506

Pseudotocinclus juquiae , new species

Fig. 4

Pseudotocinclus tietensis (not of Ihering, 1907). - Bizerril & Lima, 2000:109 (reference, distribution).

Holotype. MZUSP 49333 , male, 57.0 mm SL, Brazil, São Paulo, first tributary of the rio Juquiá, near ribeirão das Antas on the road from São Lourenço da Serra to Juquitiba , 23°59’49.1’’S, 46°56’01.0’’W, Juquitiba, O. T. Oyakawa & A. Akama, 20 Jan 1996.

Paratypes. Brazil, São Paulo: MZUSP 42040 (1), 31.7 mm SL, ribeirão Poço Grande, a tributary of the rio Juquiá , 25º15’14.8 “S, 47º37’12.6" W, Juquiá, A. A. Andreata & C. Oliveira, 5 May 1989 . MZUSP 49339 (1), 28.5 mm SL, ribeirão das Antas, a tributary of the rio Juquiá, at Fazenda Estio, on the road from São Lourenço da Serra to Juquitiba , 23°55’S, 46°55’W, Juquitiba, O . T. Oyakawa & A. Akama, 20 Jan 1996 . MZUSP 79047 (2), 48.5-55.9 mm SL; collected with the holotype . MZUSP 58805 (3), 33.7-56.3 mm SL; same locality as the holotype; O . T. Oyakawa, A. Akama & F. C. Lima , 25 Oct 1999 . MZUSP 79048 (2), 57.1-60.2 mm SL; same locality as the holotype; Projeto Biota / Fapesp Ribeira, 26 Jun 2002 . MZUSP 58816 (2) (2 c&s), 53.7-57.5 mm SL; same locality as the holotype; O . T. Oyakawa, A. Akama & F. C. Lima , 8 Nov 1999 .

Non-type material. Brasil, São Paulo: LBP 616 (13), 28.9-58.7 mm SL, same locality as the holotype, 8 Nov 1999 . LBP 1160 (6), 32.1-62.2 mm SL; same locality as the holotype, 30 Apr 2001 .

Diagnosis. Distinguished from its congeners by having the orbital ring very prominent and conspicuous (vs. orbital ring not prominent or conspicuous in P. tietensis and P. parahybae ); the parieto-supraoccipital and paired compound pterotic bones with a very high crest (vs. parieto-supraoccipital and paired compound pterotic bones with a low crest); the parieto-supraoccipital bordered posteriorly by ten or more small plates (vs. parieto-supraoccipital bordered by three to four large plates in P. parahybae , and three to six large plates in P. tietensis ); and the exposed portion of the cleithrum and coracoid comparatively smaller than in P. parahybae and P. tietensis .

Description. Morphometric and meristic data given in Table 1; examined specimens 28.5-62.2 mm SL; dorsal profile of head convex from snout tip to orbital ring; relatively straight from this point to end of parieto-supraoccipital; dorsal profile of trunk straight and gently descending from parieto-supraoccipital to end of caudal peduncle; ventral profile of body gently straight from snout tip to end of caudal peduncle. All plates of head with small odontodes and comparatively rugged; median region of snout with low crest that finishes between nares, which are surrounded posteriorly by low crest, more noticeable in adults males; another low crest on either side of snout, that continues in very high crest on dorsal region of orbit; orbital ring very prominent and conspicuous; parieto-supraoccipital and paired compound pterotic bones with very high crest. Compound pterotic crest continuing in one keel up to plates located near midway of dorsal-fin base. Posteriorly, parieto-supraoccipital is bordered by ten or more small plates; interorbital region slightly concave.Anterior orbit margin positioned approximately midway between snout tip and pterotic posterior process; distance between ventral orbit margin and ventral surface of head greater than twice orbit length. Snout tip entirely covered with small platelets with odontodes; sometimes leaving small naked area. Narrow area of upper lip, near tip of snout, with platelets with odontodes. Length of maxillary barbel proportionally greater than in P. parahybae . Sphenotic ventral margin contributing to orbit and contacting frontal anteriorly and compound pterotic posteriorly; as consequence, infraorbital canals of cephalic laterosensory system enter infraorbital series via sphenotic. Infraorbital 4 not expanded ventrally and not contacting preopercle; space between these two bones filled with several small plates. Mid-dorsal series of plates interrupted, only five plates counting from dorsal-fin origin. Dorsal series of plates ventrally expanded, and touching median series of plates. Plates in median (lateral) series with lateral line system pore; third lateral line plate reduced in size, as other two anterior plates, and positioned posterior to rib of sixth centrum, and not covering distal tip of rib. First five plates of midventral series comparatively small; inferior tip of first plate contacting tip of coracoid ventrolateral process, fifth plate only touching lateropterygium tip; unplated area above pelvic fin comparatively large. First three plates of ventral series comparatively small; their tips touching external side of basipterygium posterior process. Coracoid with only small ventrolateral portion exposed and covered with odontodes implanted directly on bone; exposed portion of cleithrum and coracoid comparatively smaller than in P. parahybae and P. tietensis . Abdomen covered with comparatively small and roughly rounded platelets not in contact with each other, leaving naked area of skin exposed; region between pelvic-fin and urogenital pore scarcely covered with platelets; dorsal-fin origin situated slightly posterior to vertical line through pelvic-fin origin; posterior margin of dorsal fin straight. When depressed, tip of second unbranched dorsal-fin ray reaching vertical line through second or third anal-fin ray. First unbranched dorsal-fin ray width equals width of second dorsal-fin ray; unbranched pectoral-fin ray covered with small odontodes; its tip extending slightly beyond pelvic-fin origin; length of first branched pectoral-fin ray equal to pectoral-fin unbranched ray length. Posterior margin of pelvic fin slightly rounded; its tip surpassing anus. In adult males, tip of unbranched pelvicfin ray reaches origin of anal fin; internal and external anterior processes of pelvic-fin basypterigyum growing independently forward, and connected anteriorly delimiting one large foramen; basal lamina of first proximal radial of anal fin greatly expanded, covered with skin and sometimes with small rounded plates covered with odontodes; and not visible externally; hemal spines of vertebrae 16 and 17 with small bifurcated process that becomes progressively larger in vertebrae 18-20; caudal fin with five dorsal procurrent rays and four ventral procurrent rays.

Color in alcohol. Light-brown ground coloration on dorsal, lateral and ventral regions of body; these regions spotted by numerous dark brown melanophores distributed randomly, and more concentrated just below lower lips; one dark brown midlateral stripe extending from snout to end of caudal peduncle; stripe larger anteriorly, becoming progressively narrower on caudal peduncle. Three transverse dark brown bands on dorsal region of body coalesced with midlateral stripe, first just behind dorsal-fin base, second in middle of caudal peduncle, and last in end of caudal peduncle; second band broader than first and third. Unbranched caudal-fin rays with four to five dark brown blotches; branched rays with bands of melanophores irregularly arranged forming reticulated pattern, or sometimes arranged in two near-vertical bands; interradial membranes hyaline; unbranched rays of other fins with four to five dark brown bands; branched rays with bands of melanophores irregularly arranged; interradial membranes hyaline.

Distribution and habitat. This species is known from a few localities of the rio Juquiá basin ( Fig. 1 ). The type-locality, Juquitiba, is a small creek 0.5 m to 1.0 m deep, 1.0 m wide at approximately 670 meters above sea level. It is clear, with a slow current, mud, and in some places, sand on the bottom. Marginal vegetation includes a small area of pastures, small trees and shrubs. The following species occur with Pseudotocinclus juquiae at the type-locality: Hyphessobrycon bifasciatus , Hyphessobrycon reticulatus , Characidium schubarti , Characidium pterostictum , Hoplias malabaricus , Gymnotus pantherinus , Geophagus brasiliensis , and Phalloceros caudimaculatus . The other locality is the ribeirão Poço Grande, a tributary on the right margin of the rio Juquiá, Juquiá. This locality, an old swamp area near the city of Juquiá, was a site where a team from MZUSP has been collecting since 1897. Nowadays, the area is heavily impacted by human activities, and is also used for garbage and sewage disposal. The following species occur syntopically with Pseudotocinclus juquiae at ribeirão Poço Grande: Astyanax ribeirae , Mimagoniates microlepis , Rineloricaria sp. , Parotocinclus maculicauda , Pseudotothyris obtusa , Rhamdia quelen , Gymnotus pantherinus , Rivulus santensis , and Microcambeva ribeirae .

Etymology. The specific epithet, juquiae , from Tupi Language “yeke´a”, “juquia” or “jequiá” in Portuguese, means a small fishing device used in shallow water, and refers to the name of the river basin where this species had been collected. Treated as a noun in apposition.

Figures

Fig. 4. Pseudotocinclus juquiae, holotype, MZUSP 49333, 57.04 mm SL; first tributary of the rio Juquiá, near ribeirão das Antas on the road from São Lourenço da Serra to Juquitiba, Juquitiba, São Paulo, Brazil.

Fig. 1. Southern part of São Paulo, Brazil, showing the geographic distribution of P. tietensis (squares), P. juquiae (triangles), and P. parahybae (circle). Some symbols represent more than one lot or locality. Open symbols = type locality. The precise type locality of P. tietensis is not known. 1- rio Paraíba do Sul basin; 2 - rio Tietê basin; 3 - rio Ribeira de Iguape basin.