Bijdragen tot de Dierkunde, 52 (2): 155-168 — 1982 New data on Metaloricaria paucidens from French Guiana and Surinam (Pisces, Siluriformes, Loricariidae) by I.J. H. Isbrücker & H. Nijssen Institute of Taxonomie Zoology, University of Amsterdam, P.O. Box 20125, 1000 HC Amsterdam, The Netherlands Abstract minae Regan, 1904, and Lithogeneinae Gosline, 1947. A large number of previously unrecorded specimens of mailed catfishes of the Metaloricaria 1975 Harttiinae genus Isbrücker, (Lori- The former subfamilies Boeseman, cariinae, tribe Harttiini, subtribe Metaloricariina) is com- 1971, and Acestridiinae Isbriicker & Nijssen, pared with the known specimens from French Guiana and 1974, are considered as tribes of the Loricariinae. Surinam. This results in the recognition of two subspecies, viz., M. paucidens paucidens Isbrücker, 1975, from the rivers The Astroblepidae Bleeker, 1862 (■= Argeini Oyapock and Maroni (French Guiana, Surinam), and M. p. Bleeker, 1862, and Cyclopidae Eigenmann, 1910) nijsseni (Boeseman, 1976) from the rivers Suriname, Sara- and & — both Nickerie and These Scoloplacidae Bailey Baskin, 1976 macca, Corantijn (Surinam). subspecies ranked — were originally described as two different species, even previously as subfamilies are excluded within two different Metaloricaria paucidens Isbrü- genera: from the family Loricariidae (Isbriicker, 1980: cker, 1975, and Harttia nijsseni Boeseman, 1976. Morpho- 5 and 130). metric and meristic data, together with illustrations are given into of the two subspecies. Diagnostic characters of Metaloricaria The subfamily Loricariinae is subdivided and within the Harttiini is in- are provided, its position four tribes: dicated. Loricariini Bonaparte, 1831, Farlowellini 1958, Résumé Fowler, Harttiini Boeseman, 1971, Une comparaison a été réalisée entre les exemplaires de pois- Acestridiini Isbriicker & Nijssen, 1974. sons-chats cuirassés du genre Metaloricaria Isbrücker, 1975 (Loricariinae, tribu Harttiini, subtribu Metaloricariina) déjà Harttiini usually have 12 branched caudal fin connus française et du et de nom- (de Guyane Surinam), whereas the of rays (rarely 11), eighteen genera breux étude exemplaires pas signalés auparavant. Cette the Loricariini have 10 branched caudal conduit à distinguer deux sous-espèces, à savoir: M. pauci- always dens des paucidens Isbrücker, 1975, rivières Oyapock et fin rays. Maroni française, Surinam) et M. nijsseni (Guyane p. The tribe Harttiini is subdivided into two sub- (Boeseman, 1976), des rivières Suriname, Saramacca, Nickerie tribes with the following genera: et Corantijn (Surinam). Ces sous-espèces avaient été précé- demment décrites comme espèces distinctes, et même comme (1) H a r 11 i i n a Boeseman, 1971. appartenant à des genres distincts: Metaloricaria paucidens Isbrücker, et Harttia Boeseman, The Harttia 1975 nijsseni 1976. On (a) genus-group (a depressed des données présente morphométriques et méristiques pour body; snout tip naked) comprises: les deux illustration. sous-espèces, en même temps qu’une Des Harttia Steindachner, 1876, caractères diagnostiques du genre Metaloricaria sont fournis, Harttiella et on indique sa position dans le cadre des Harttiini. Boeseman, 1971, Cteniloricaria Isbriicker & Nijssen, in Isbriicker, 1979. INTRODUCTION The Sturi (b) s oma genus-group (a com- The family Loricariidae Bonaparte, 1831, is pressed body; snout tip not naked ) presently subdivided into the subfamilies Lorica- comprises: riinae Bonaparte, 1831, Hypostominae Kner, Sturisoma Swainson, 1838, 1853, Ancistrinae Kner, 1853, Hypoptopomatinae Lamontichthys P. de Miranda Ribeiro, Eigenmann & Eigenmann, 1890, Neoplecosto- 1939, - METALORICARIA PAUCIDENS 156 I. J. H. ISBRUCKER & H. NIJSSEN Advancement of Tropical Research and the Pterosturisoma Isbrücker & Nijssen, (WOTRO) University of Amsterdam. 1978b, wish for the information, We to express our gratitude Isbrücker Sturisomatichthys & Nijssen, loan and/or gift of specimens, and for the hospitality received during the of this to the following in Isbrücker, 1979. preparation study Bauchot and persons: Mrs. Dr. M. L. Mr. F. dAubenton i i Boeseman (2) M e t a 1 o r i c a r n a Isbrücker, 1979- (MNHN), Drs. M. J. P. van Oijen and Dr. M. and Mr. L. Wal- (RMNH), Mr. G. J. Howes (BMNH), Metaloricaria Isbrücker, 1975. 2-4 by Mr. schaerts (IRScNB). Figs. were photographed drawn Mr. L. A. van der Laan (ZMA) and fig. 5 was by Metaloricaria was described from 14 specimens J. Zaagman (ZMA). of M. paucidens (type-species) by Isbrücker (1975). This species is recently recorded from Metaloricaria Isbrücker, 1975 French Guiana by Boeseman (1982, pertaining Metaloricaria Isbriicker, 1975: 2 (original diagnosis; type- to 2 described as Metalori- specimens). Thirty specimens species, by original designation and monotypy, Isbriicker, 1975). Harttia nijsseni by Boeseman (1976) were sub- caria paucidens sequently assigned to Metaloricaria (Isbrücker & This is the of the sub- genus only representative Nijssen, 1978a). tribe Metaloricariina. Sixty-six previously unrecorded specimens from the of the subtribe Hart- Compared to genera 16 localities in French Guiana and Surinam were tiina (cf. Introduction), Metaloricaria has much available for this study. All the 112 specimens of shorter and more solid teeth, whereas the teeth Metaloricaria now known have been reviewed or Meta- are less bent near the crown. Moreover, examined. The of this is to purpose paper present with loricaria has bilobate crowns a small outer further descriptive and distributional data. As the inner the lobe and a large lobe, outer lobe originat- result of our comparison we recognize a single ing much lower along the tooth than in the Hart- with in the Meta- species two subspecies genus: tiina which possess a strongly bifurcate crown on loricaria p. paucidens from the river Oyapock each tooth, both crown lobes being about equally (= Oiapoque), bordering French Guiana and large (Isbriicker, 1975: 8, fig. 4). Brazil, Território do Amapâ, and from the river maximum teeth Metaloricaria has a of 26 (Boe- Maroni ( =Marowijne), bordering French Guiana table no. seman, 1976: 172, 5, specimen 28, and Surinam; the second subspecies is M. p. nijs- records 27 mandibular teeth in the holotype of seni which occurs in the rivers Suriname, Sara- the Harttia nijsseni, which we re-examined); macca, Nickerie and Corantijn in Surinam (the number of teeth increases with size, from 4 (in latter river is the boundary between Surinam and specimens of about 57 mm in SL) to 26 (in Guyana ). about in The specimens of 270-295 mm SL). Notes the and and illustra- on genus species, of the subtribe Harttiina have at least genera tions of both subspecies are included for direct 40 teeth in each jaw. The comparison. present publication is part of a the of the Compared to genera Harttiina, intended series to provide information for a revi- Metaloricaria is characterized by its premaxillae sion of the subfamily Loricariinae. The methods which do not meet at the symphysis, showing a and of taking measurements meristic data were furthermore it is distinct its large gap; by pre- defined by Isbriicker & Nijssen (1978a: 180-182). maxilla and dentary, which are much shorter in transverse view. The material reported upon herein is deposited in the fol- In Metaloricaria is distinct its lowing institutions: British Museum (Natural History), Lon- addition, by don (BMNH), Institut Royal des Sciences Naturelles de papillose anterior and lateroventral side of the Brussels Belgique, (IRScNB), Instituut voor Taxonomische upper lip (fig. 1), which is conspicuous and Zoölogie (Zoölogisch Museum), Amsterdam (ZMA), Mu- broad in with the of the Hart- séum National d'Histoire Naturelle, Paris (MNHN), and comparison genera Rijksmuseum van Natuurlijke Historie, Leyden (RMNH). tiina; its lower lip is longer and broader, whereas collected by The specimens Nijssen were assembled during the maxillary ( = rictal) barbel is distinctly longer the Biological Brokopondo Research Project (1966/1967), an in head in Metaloricaria expedition sponsored by the Netherlands Foundation for the (2.0-4.0 length against BIjDRAGEN TOT DE DIERKUNDE, 52 (2) - 1982 157 1. Metaloricaria anteroventral view of in ZMA Fig. paucidens nijsseni (Boeseman, 1976), a specimen 106.334, SL 255 mm, and of from showing the mouth lips which are characteristic the genus (reproduced Nijssen, 1970: 13). in of sides and 5.0-10.7 Harttiina). The posterior margin outer of the premaxilla dentary ) a promi- the lower is convex concave at either is The lip medially, nently fleshy, papillose flap present. upper side towards the maxillary barbel. Upper and oral valve membrane is provided medially with lower lips, together with the maxillary barbels, an elongate membranaceous extension, which is form a horseshoe-like outline 1 in con- several times than that in ( fig. ), larger genera of the trast to the oval to roundish outline of the lips Harttiina. in the Harttiina; the lip shape of Metaloricaria is Apart from the differences mentioned above, the Loricariidae. On the surface neither unique among morphometric characters, expressed as of the lip inside the buccal cavity (between the ratios, nor most of the counts distinguish Meta- 158 I. J. H. ISBRUCKER & H. NIJSSEN - METALORICARIA PAUCIDENS of the Harttiina. The branches of the all loricaria clearly from genera subsidiary fin rays stem main However, Metaloricaria comprises a larger species from one side of the (anterior) branch, in than found in of the for the branch the dorsal fin (up to 295 mm SL)