Neotropical Ichthyology, 11(3):507-512, 2013 Copyright © 2013 Sociedade Brasileira de Ictiologia Description of a new species of Microglanis (Siluriformes: Pseudopimelodidae) from the Amazon basin, Amazonas State, Brazil Lucas Ribeiro Jarduli1 and Oscar Akio Shibatta1,2 The first species of Microglanis from the rio Amazonas, Amazonas State, Brazil is described. This species differs from all congeners by the forked caudal fin, and color pattern of the supraoccipital region consisting of two elliptical and juxtaposed pale spots, besides a combination of morphometrics characters. A primeira espécie de Microglanis da calha do rio Amazonas, estado do Amazonas, Brasil é descrita. Essa espécie difere de todas as congêneres pela nadadeira caudal bifurcada e padrão de colorido da região supraoccipital constituído por duas manchas elípticas claras e justapostas, além de uma combinação de caracteres morfométricos. Key words: Bumble-bee catfish, Multivariate morphometrics, Systematics. Introduction During the field expeditions for fish collection in rio Amazonas during the Calhamazon project between 1994 and Microglanis Eigenmann, 1912 is the most species-rich genus 1996, first specimens of a new species of Microglanis were of Pseudopimelodidae, with 21 described species (Ottoni et caught near the mouth of some major tributaries. Subsequent al., 2010; Ruiz & Shibatta, 2010), besides other possible new effort provided additional material and this species is herein species (Shibatta, 2003). The genus was considered described. monophyletic by Shibatta (1998) and differs from other pseudopimelodids especially by the sharing of three characters: Material and Methods small size, rarely reaching 80 mm standard length; incomplete lateral line; and premaxillary tooth patch with rounded margin, Body measurements were taken point-to-point with a without posterior projection (Schultz, 1944; Gomes, 1946; Mees, digital caliper with accuracy of 0.1 mm. Twenty morphometric 1974, 1978). The species have a body color pattern consisting characters and counts were taken preferably on the left side of orange-brown with large dark-brown spots, which justify of the fish, under stereomicroscope, according to Mori & their vernacular name: bumble-bee catfish. Shibatta (2006). Meristic data included counts of dorsal, Species of Microglanis are widely distributed in South pectoral, pelvic, anal and caudal-fin rays; gill rakers; serrations America, from northern Venezuela to Uruguay, and also west of pectoral-fin spine; and pores of lateral line of trunk. Counts of Andes (Shibatta, 2003). However, a more scrutinous of vertebrae, ribs, branchiostegal rays, proximal evaluation on the distribution of these species reveals a large pterygiophores and procurrent caudal-fin rays, along with gap in the brazilian Amazon region, where no new species osteological observations, were made on one cleared and had been registered to date. Species of Microglanis described stained specimen prepared according to Dingerkus & Uhler from the Amazon basin were so far restricted to the upper (1977). Vertebral counts included only free centra (anterior region, in Peru and Ecuador: Microglanis zonatus Eigenmann elements of complex centrum were not counted), and the & Allen, 1942, from río Morona, Peru and M. pellopterigius compound caudal centra (preural 1 + ural 1) counted as a Mees, 1978, from río Araguarico, Ecuador. Microglanis single element. poecilus Eigenmann, 1912 and M. secundus Mess, 1974 are Specimens of all other described species of Microglanis also recorded to the Amazon basin (Mees, 1974; Shibatta, were examined for comparison with the new species, except 2007), however they were originally described from coastal M. ater Ahl, 1936, M. zonatus Eigenmann & Allen, 1942 and areas of the Guiana shield. M. minutus Ottoni, Mattos & Barbosa, 2010. For those species 1Universidade Estadual de Londrina, Programa de Pós-Graduação em Ciências Biológicas, Departamento de Biologia Animal e Vegetal, Centro de Ciências Biológicas, 86057-970 Londrina, PR, Brazil. [email protected] (OAS) 507 508 Description of a new species of Microglanis comparisons were through characters obtained from pictures It also differs from other species on the following morphometric and data available in the literature. The new species and characters: length of the head 27.4-30.0% of SL (vs. 24.7-26.4% congeners were compared by size-free canonical variate in M. carlae; 23.9-25.1% in M. iheringi; 23.0-26.1% in M. analysis with the program PAST (Hammer et al., 2001). parahybae; 23.0-25.4% in M. pataxo; 23.5-26.3% in M. The examined material belongs to the following robustus); eye diameter 8.0-9.9% of HL (vs. 12.4-17.6% in M. institutions: Academy of Natural Sciences of Drexel University, variegatus); interorbital distance 40.4-44.2% of HL (vs. 45.9- Philadelphia (ANSP); California Academy of Sciences, San 51.5% in M. cottoides; 46.5-49.8% in M. leptostriatus; 46.6- Francisco (CAS); Instituto Nacional de Pesquisas da 48.6% in M. malabarbai; 38.1-39.1% in M. pellopterygius; Amazônia, Manaus (INPA); Museu de Ciências e Tecnologia 50.9-53.1% in M. poecilus); mouth width 38.0-47.3% of HL da Pontifícia Universidade Católica do Rio Grande do Sul, (vs. 19.0-25.8% in M. cibelae; 17.5-21.9% in M. garavelloi; Porto Alegre (MCP); Museo de la Escuela Politécnica Nacional 20.1-22.6% in M. nigripinnis); predorsal length 35.5-38.6% of de Quito, Ecuador (MEPN); Museu Nacional de Historia SL (vs. 38.9-46.2% in M. eurystoma); lateral line pores 6-8 (vs. Natural del Paraguay, San Lorenzo (MNHNP); Museu 9 in M. ater and M. secundus); principal caudal rays 15 (vs. 14 Nacional, Rio de Janeiro (MNRJ); Museu de Zoologia da in M. zonatus). Universidade Estadual de Londrina, Paraná (MZUEL); Museu de Zoologia da Universidade de São Paulo, São Paulo Description. Morphometric data are summarized in Table 1. (MZUSP); Muséum d’histoire naturelle de la Ville de Genève, Small size (up to 27.7 mm SL), head and anterior part of trunk Geneva (MHNG); National Museum of Natural History, depressed, laterally compressed from dorsal fin to caudal Smithsonian Institution,Washington, D.C. (USNM); and peduncle. Greatest body depth at dorsal-fin origin, greatest Royal Ontario Museum, Toronto (ROM). body width at pectoral-fin base. Results Head slightly depressed, anteriorly rounded in dorsal view. Eye small, closer to mouth than to distal margin of operculum, Microglanis lundbergi new species more dorsal than lateral, inserted after first third of head length, Figs. 1-2 completely covered by skin without free orbital margin. Snout short. Anterior nostril tubular, closer to upper lip than to eye; Holotype. INPA 28577, 27.7 mm SL, Brazil, Amazonas, Tefé posterior nostril near anterior margin of eye, with anterior municipality, Alvarães, Costas das Capivaras, rio Solimões, membrane. Gill membrane free from isthmus; nine 03º14.11’S 64º41.15’W, 13 Jan 2001, W. Crampton. branchiostegal rays. Gill rakers spiniform, usually small; first branchial arch with 1, 1, 4 gill rakers. Paratypes. Brazil, Amazonas: INPA 18774, 3 (1 c&s, 24.7 mm Mouth wide, terminal. Premaxillary tooth patch with SL), 22.3-24.7 mm SL, collected with the holotype. MZUSP 112217, rounded margin, no posterior projection. Dentary tooth patch 1, 23.3 mm SL, between Santa Maria and Itacoatiara, rio Amazonas, semicircular, larger and wider than premaxillary patch. Tooth close to rio Madeira (7.6 km upstream), stretch between 3º21’26.0”S villiform, curved backwards. 58º40’29.3”W and 3º21’24.1”S 58º39’36.2”W, 18 Oct 1994, Westneat et al. MZUSP 112218, 1, 23.1 mm SL, rio Amazonas, All barbels thin, flattened in cross section. One maxillary nearby tributary, rio Madeira (19.3 km downstream), Itacoatiara, pair, two mental pairs. Outer mental barbel surpassing stretch between 3º16’33.8”S 58º57’03.9”W and 3º16’46.7”S pectoral-fin spine base; inner mental barbel shorter, reaching 58º56’34.0”W, 5 Aug 1996, A. Zanata et al. MZUSP 112219, 2, almost half length of outer mental barbel. Maxillary barbel 21.2-25.7 mm SL, rio Amazonas, nearby tributary, rio Madeira short, not reaching pectoral-fin base. Dorsal fin I,6, located (17.6 km downstream), Nova Oriente, stretch between 3º16’35.6”S anteriorly to half of body length, posterior margin rounded; 58º56’52.1”W and 3º16’49.1”S 58º56’36.5”W, 4 Aug 1996, Cox- spinelet present. Dorsal-fin spine straight, shorter than Fernandes et al. MZUSP 112220, 1, 24.5 mm SL, rio Amazonas, branched rays. nearby tributary, rio Madeira (22.2 km downstream), Nova Oriente, Adipose fin relatively small. Caudal fin forked with deep stretch between 3º16’40.8”S 58º56’52.8”W and 3º16’50.6”S 58º56’30.4”W, 4 Aug 1996, C. Cox-Fernandes et al. MZUSP 112221, notch, lower lobe slightly longer than upper lobe. Principal 1, 20.8 mm SL, rio Amazonas, nearby tributary, rio Madeira, stretch caudal rays 15, dorsal procurrent rays 15, ventral procurrent between 3º16’34.3”S 58º57’02.2”W and 3º16’45.2”S 58º56’39.8”W, rays 10. Anal fin short and rounded, iv,7. Pectoral fin I,5. 5 Aug 1996, M. Toledo-Piza et al. Pectoral spine strong, slightly flattened, with developed serrations on both margins, completely covered by thin skin. Diagnosis. Microglanis lundbergi is distinguished from all Anterior margin of pectoral spine with 10-14 hooks; hooks on congeners by the presence of a forked caudal fin with a deep distal portion antrorse or straight. Posterior margin of pectoral notch between upper and lower lobes (vs. rounded, spine with 7-9 retrorse serrations greater than anterior margin, emarginated, or slightly forked), two pale juxtaposed and increasing in size from proximal to distal portion (Fig. 2). Tip elliptical spots in the supraoccipital region (vs. wide, or narrow, of pectoral spine ossified, very strong and sharp.