— PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 116(3):557-600. 2003. A systematic review of Planaltina (Teleostei: Characiformes: Characidae: Glandulocaudinae: Diapomini) with a description of two new species from the upper rio Parana, Brazil* Naercio A. Menezes, Stanley H. Weitzman, and John R. Burns (NAM) Museu de Zoologia, Universidade de Sao Paulo, Caixa Postal 42694; CEP 04299-970, Sao Paulo, S.P, Brazil, e-mail: [email protected]; (SHW) Department of Systematic Biology, National Museum of Natural History, Division of Fishes, MRC 0159, Smithsonian Institution, PO Box 37012, Washington, D.C. 20013-7012, U.S.A., e-mail: [email protected]; (JRB) Department of Biological Sciences, The George Washington University, Washington, D.C. 20052, U.S.A., e-mail: [email protected] — Abstract. Two new species, Planaltina glandipedis and Planaltina britskii, glandulocaudine fishes of the family Characidae, tribe Diapomini, are described herein. They were collected from tributaries of the rio Grande and or the rio Tiete, both tributaries of the upper rio Parana in the State of Sao Paulo, Brazil. The previously described species, Planaltina myersi, until now known almost exclusively from the holotype, is here redescribed from 47 specimens taken from tributaries of the rio Corumba, a tributary of the upper rio Parana. The two new species differ most prominently from the previously known species by possession of three somewhat elongate scales along the dorsal border of the male's caudal pouch opening. There is only one elongate scale in P. myersi. Planaltina glandipedis differs from P. britskii in having six or seven horizontal scale rows between the dorsal-fin origin and the lateral line versus five in the later species. The possible phylogenetic relationships among the three insem- inating species within the tribe Diapomini, subfamily Glandulocaudinae, are discussed along with the putative phylogenetic relationships of the Diapomini to the newly recognized glandulocaudine outgroup containing the characid gen- era Knodus and a new genus related to Attonitus. Brief comments are presented concerning the geographical distribution and ecology of the species of Plan- altina. — Resumo. Duas novas especies, Planaltina glandipedis e Planaltina britskii, peixes glandulocaudineos da familia Characidae, tribo Diapomini, sao aqui des- critas. Elas foram coletadas em afluentes do rio Grande e/ou do rio Tiete, ambos A tributarios do rio Parana no Estado de Sao Paulo, Brasil. especie apenas descrita, Planaltina myersi, conhecida ate o presente apenas a partir do holo- tipo, e aqui redescrita com base em 47 exemplares originarios do rio Corumba, tambem tributario do rio Parana. As duas especies novas diferem marcadamente da especie previamente conhecida pela presen9a de tres escamas algo alongadas ao longo da margem dorsal da abertura da bolsa glandular dos machos. Ha apenas uma escama alongada em P. myersi. Planaltina glandipedis difere de P. britskii pela presen^a de seis ou sete series horizontals de escamas entre a * This paper is part of the project, Diversidade de Peixes de Riachos e Cabeceiras da Bacia do Aho Rio Parana no Estado de Sao Paulo/Brasil, supported by the State of Sao Paulo Research Foundation (FAPESP) The Biodiversity Virtual Institute Program (www.biotasp.org.br); coordinated by Dr. Ricardo Macedo Correa e Castro; see Anonymous (2000). 558 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON origem da nadadeira dorsal e a linha lateral ao inves de cinco na ultima especie. As possiveis rela^oes filogeneticas entre as tres especies, todas inseminadoras dentro da tribo Diapomini, subfamilia Glandulocaudinae, sao discutidas jun- tamente com as rela^oes filogeneticas tentativas de Diapomini com o grupo externo recentemente reconhecido de Glandulocaudinae constituido pelos ge- neros Knodus, Attonitus e um novo genero relacionado a Attonitus da familia Characidae. Breves comentarios sao feitos sobre a distribui^ao geografica e ecologia das especies de Planaltina. Relatively little is known about Planal- anatomical, histological, and sperm ultra- tina Bohlke (1954:265) except from its structural evidence, concluded that the original description based on Planaltina Glandulocaudinae are probably monophy- & myersi described from a single damaged letic. Weitzman Menezes (1998) also il- specimen collected through the use of dy- lustrated the osteology of the caudal region namite. This specimen, the holotype, was and associated caudal organ of P. myersi. collected from "Sarandi brook, Planaltina, We provide a new definition of Planal- Goyaz, Brazil," 21 September 1923 by Dr. tina, redescribe P. myersi based on 47 spec- Carl Ternetz. Bohlke (1954:265-267) was imens and discuss its putative relationships uncertain of the relationships of Planaltina, with the two new species described herein. but considered it to possibly be among the We also briefly discuss the possible phylo- " 'borderline' genera (between the Tetra- genetic relationships of the Diapomini to gonopterinae and Glandulocaudinae of Ei- the Glandulocaudinae and to some of the genmann) ..." Bohlke referred to these characid species currently in the genera At- genera as Landonia, Argopleura, Acrobry- tonitus Vari & Ortega, Knodus Eigenmann con, and Phenacobrycon. Bohlke (1954) and a species of a new genus Weitzman et doubted the monophyly of the Glandulo- al. (2004). Species oiAttonitus, the new ge- caudinae and considered that these genera nus and Knodus lack caudal organs as de- and the divergent members of the Glandu- scribed for adult glandulocaudine males, locaudinae may have arisen "at different but some species of Knodus and the three times from different members of such gen- species of Attonitus, and the species of the eralized tetragonopterines as Bryconameri- new genus were recently found to be insem- cus.'' No additional specimens were ex- inating, Weitzman et al. (2004), and at least & amined until Weitzman Fink (1985:106) some of these have one or more of the syn- listed additional specimens with locality apomorphies of the primary and/or second- & data. Weitzman et al. in Weitzman Fink ary sexual systems of glandulocaudines that & (1985:113) published a critique of the con- were used by Weitzman Menezes (1998) cept of the monophyly of the Glandulocau- to diagnose that subfamily. Furthermore, dinae and concluded that there was insuf- sexually active males of one of the new ficient evidence to confirm or reject the species described here, P. glandipedis, has monophyly of the subfamily. Burns et al. numerous club cells at or near the surface (1995:135-143) provided information that of the skin of the pelvic fins and the anterior P. myersi is an inseminating species with part of the anal fin whereas the species of aquasperm. Weitzman & Menezes (1998: Attonitus and the new genus possibly relat- 184) assigned this species to the Diapomini, ed to Attonitus are found to have club cells which also included species of the characid at or near the surface of the skin in the an- genera Acrobrycon Eigenmann and Diapo- terior part of the anal fin. These cells have ma Cope, and, based on additional gross been shown to secrete in a holocrine man- VOLUME 116. NUMBER 3 559 ner in the species of the new genus. See all pairwise comparisons of counts were Weitzman et al. (2004) for a more detailed made using Mann-Whitney rank sum tests, discussion of the taxonomic distribution of but also in all cases the results of simple t- these apparent glandulocaudine and glan- tests were compared and although not test- dulocaudine outgroup synapomorphies. ing the same statistical parameters, both Those authors also discuss the possible were used to evaluate differences among phylogenetic relationships of species of the the species. In most cases both kinds of glandulocaudine tribes with the outgroup tests were found to indicate the same over- characid species currently in Knodiis, the all statistical results regarding a statistical new genus, and Attonitus as well as their test of null hypotheses of character similar- apparent relatives not belonging to the ities. However, in a few cases the r-test and Glandulocaudinae. The putative monophy- the Mann-Whitney rank sum test provided letic relationships among the glandulocau- opposing results. In these cases the statis- dine tribes recognized by Weitzman & Me- tical results were of marginal significance nezes (1998) must again come into question for both kinds of tests, and we opted to dis- and be reinvestigated in light of the newly regard the resulting hypotheses of differ- recognized outgroup species for the puta- ences, especially considering the population tive glandulocaudine genera and tribes. sample size limitations. We utilized Tukey box plots for visual Methods and Materials comparison of count distributions of the three species. In these plots the mean is rep- Counts and measurements and methods resented by a thick vertical bar, the median of taking and presenting data follow Me- by a thin vertical line that is often the same & nezes Weitzman (1990:382-383) unless as one of the vertical lateral borders of the otherwise stated. For the most part, statis- boxes. Therefore, the numerical value of tical comparisons were calculated using the median is given in the legend. The 25th SigmaStat 2.0 for Windows 95. Meristic and 75th percentiles are represented by the and morphometric data of males and fe- lateral borders of the boxes and indicate the males were treated separately in order to respective values at which 25% of the sam- probe possible differences between the sex- ples fall below and 25% fall above the lat- es, but secondary sexual differences were eral borders of the boxes. En'or bars rep- detected only in morphometric data. Mor- resent the 10th and 90th percentile points, phometric data were transformed into ratios and the circles represent the 5th and 95th of standard length, or head length when percentiles. Extremes, not shown in the they were subunits of that length, and are plots, are given in the text. presented separately for males and females Regarding analyses for differences in in the tables and regression graphs. sexual dimorphism in body ratios we exe- Although we summarize the statistical cuted a series of tests and present a few procedures used herein, see Weitzman & graphs using regression analyses. We used & Malabarba (1999:2-4) and Weitzman linear regression analysis, even though the Palmer (1997:213-214) for more complete statistics derived from it may rarely be a comments about their use. In making pair- fully accurate representation of the more or wise statistical comparisons of counts, all less curvilinear mean growth lines ex- population samples except those few with pressed by the data. Nevertheless linear re- non-variable counts were found to be at gression graphs provide useful comparative least somewhat skewed about the mean. In visual presentations of the relative morpho- running simple r-tests, all paired samples logical parameters of the population sam- failed to pass the normality test and some ples being compared as well as reasonable failed to pass an equal variance test. Thus population growth patterns. In using the lin- 560 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON ear regression model for comparing body et al. 1991:170). Measurements of testis ar- ratios of population samples, statistical tests eas were taken from mid sagittal sections as of a null hypothesis of character similarities described by Burns et al. (1995:132). for ratios of body measurements follow For counts recorded in the descriptions, & Weitzman Palmer (1997:213-214) and those of the holotype are provided first fol- employed linear multiple regression analy- lowed in parentheses by the mean of the ses using dummy (indicator) variables. See population sample, (or median when the & Glantz Slinker (1990:69-72) for an ex- data are nonparametric), range, and the total planation. Also, analyses of covariance number of specimens counted. (ANCOVA) using BIOM-PC, version 2, The terminations of the dorsal and anal Exeter Publishing Ltd. were performed. fins are morphologically different and are Such tests were done using base 10 log treated as follows. The posterior branched transformed data. However, it was found ray of the dorsal fin has a single pterygiop- that in the cases discussed here the results hore at its base, i.e., the ray is not split to of such tests did not need publication be- its base and is counted as 1, but when it is cause in those cases used to search for pop- rarely split to its base, then its last two rays ulation sample differences, the regression are counted as 1 because there is only 1 graphs, the mean regression lines, and 95% pterygiophore at the base of these rays. In confidence intervals demonstrated clear sta- the anal fin the most posterior pterygiop- tistical differences in ratios of body mea- hore has its ray almost invariably split to surements. Even though statistical tests its base and these two rays are counted as were done using base 10 log transformed one. data, neither the regression graphs, their ac- The word pouch is used for that sac-like companying regression equations, nor the r- area internal to the modified caudal-fin values presented here are derived from base scale or scales, called pouch scales, of the 10 log transformed data because presenta- usually adult, sexually active males of glan- tion of non-transformed data in graphs is dulocaudine characids. The pouch opening more visually accessible to the reader. In to the surrounding water occurs along the regression analyses a series of diagnostic posteroventral border of the scale or scales. tests using SigmaStat Version 2.0 were run In almost all case in males the pouch open- to determine the suitability of the data for ing is provided with modified secretory the linear regression model. In all cases the cells presumably producing a pheromone. normality tests and the constant variance In diapomins both sexes have pouch scales. & tests were passed. See Weitzman Fink (1985) and Weitz- For histological analyses, tissues were re- man & Menezes (1998) for further expla- moved from specimens initially fixed in nation. 10% formalin and subsequently transferred Specimens examined for this research are to 70% ethanol. Tissues containing bony el- deposited in the Museu de Zoologia, Univ- ements were first decalcified. Some tissues ersidade de Sao Paulo (MZUSP); Museu were then dehydrated in an ethanol series, Nacional, Universidade Federal do Rio de embedded in paraffin, sectioned at 5-10 Janeiro (MNRJ); Laboratorio de Ictiologia |jLm, and stained with modified Masson's de Ribeirao Preto, Faculdade de Filosofia trichrome (Schreibman 1964:219). Other Ciencias e Letras de Ribeirao Preto, Univ- tissues were dehydrated in an ethanol series ersidade de Sao Paulo (LIRP); Departamen- to 95% ethanol and infiltrated with and em- to de Zoologia, Universidade Estadual Pau- bedded in glycol methacrylate. Sections lista, Campus de Sao Jose do Rio Preto, Sao were cut at 2.0-3.5 juim and stained with Paulo (DZSJRP); and the Smithsonian In- toluidine blue and periodic acid-Schiff re- stitution, National Museum of Natural His- agent (PAS)/hematoxylin (Quintero-Hunter tory (USNM). Comparative glandulocaudi- VOLUME NUMBER 116, 3 561 ne and other characid specimens used in mediately ventral to lateral-line series this report are hsted in Weitzman & Fink extend posteriorly to form dorsal border (1985: Appendix 1), Weitzman et al. of pouch opening Diapomini (2) (1994), Burns et al. (1995, 1997), Weitz- lb. Female caudal organs as expressed by man & Menezes (1998:176), and Weitzman caudal squamation never as hypertro- phied as that of males; arrangement of et al. (2004). scales bordering pouch opening not as above other Glandulocaudinae Planaltina Bohlke 2a. Dorsal border of pouch opening formed by one or two enlarged and elongate Planaltina Bohlke, 1954:265 (type species: dorsal scales; sperm cell nuclei spheri- P. myersi Bohlke, 1954:267 by monotypy cal to slightly elliptical (aquasperm) and original designation). . . Planaltina (3) — Definition. 1) There are fewer scales 2b. Dorsal border of pouch opening with- out especially enlarged scales or one forming the dorsal border of the caudal somewhat enlarged scale present, but pouch in Planaltina (1-2) than in Acrob- its perimeter entering pouch border not rycon (4-7 or 8) and Diapoma (3—6). 2) In especially large; sperm-cell nucleus Planaltina one of the scales forming the somewhat elongate dorsal border of the pouch opening is elon- Acrobrycon and Diapoma gate and forms most of that border, whereas 3a. One much enlarged and elongate scale in Acrobrycon and Diapoma, even when along dorsal border of pouch opening; one of the dorsal border scales of the pouch adipose fin present .... Planaltina myersi opening is somewhat elongate or larger, its 3b. Three enlarged and somewhat elongate actual contribution to the length of the dor- scales along dorsal border of pouch sal pouch border is little more than that of opening; adipose fin present or absent (4) the other dorsal border scales of the pouch 4a. Six or seven scale rows between dorsal- opening. 3) The three species of Planaltina fin origin and lateral line; 5 scale rows between anal-fin origin and lateral line; produce aquasperm, the nuclei of which 16-17 scale rows around caudal pedun- vary in shape from spherical to slightly el- cle (X = 16.2); 17-20 predorsal scales liptical, whereas both Acrobrycon and Dia- {X — 18.0); adipose fin absent .... poma have elongate sperm cell nuclei. Planaltina glandipedis 4b. Five scale rows between dorsal-fin or- Key to the species of Planaltina igin and lateral line; 4 scale rows be- tween anal-fin origin and lateral line; The characters used in this key, except 12-14 scale rows around caudal pedun- those in couplet la, are not necessarily syn- cle {X = 13.1); 14-16 predorsal scales apomorphies and the key is not intended to (X = 15.2); adipose fin present reflect phylogenetic relationships, only in- Planaltina britskii formation for species identification. The key assumes that at least adult male speci- Planaltina myersi Bohlke mens are available and have a caudal organ Figs. 1-3, Table 1 consisting of hypertrophied scales enclos- ing a pouch that is in part open to the sur- Planaltina myersi Bohlke, 1954:267, orig- rounding water and that the specimens do inal description, Brazil, "Goyaz, Sarandi not fit the diagnosis of the Cheirodontinae brook, Planaltina," now in Distrito Fed- proposed by Malabarba (1998:199-205). eral.—Weitzman & Fink, 1985:106-107, la. Male and female caudal organs as in- listed specimens from several locali- dicated by caudal squamation nearly ties.—Burns et al. (1995:135-143) pre- equivalent in size and morphological sented evidence that spe—cies is insemi- & development; three or more scales im- nating with aquasperm. Weitzman 562 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON Fig. L Planaltina myersi, USNM 221202, adult male above, SL 35.9 mm and adult female, below, SL 32.0 mm; corrego Pipiripau near Planaltina, Distrito Federal, Brazil, about 15°40'S, 47°39'W. — Table 1. Morphometries of Planaltina myersi. Standard length is expressed in mm; measurements through head length are percentages of standard length; the last four entries are percentages of head length. Minimum, maximum, n, X, and SD are based on the holotype, SU 18636 (now at CAS) and the following specimen lots: MNRJ 10634, MNRJ 10635, USNM 363088, USNM 2210202, USNM 236416, USNM 258458, USNM 278966, USNM 278986, USNM 278987, USNM 278989, and MUSP 63588. Males Females Holo- type . ;; Range X SD n Range X SD Standard length (mm) 36.8 14 22.3-38.0 33.7 33 19.0-43.0 30.7 Body depth at dorsal fin origin 24.7 14 22.2-26.2 24.0 1.0 33 21.1-28.3 24.9 1.8 Snout to dorsal-fin origin 54.3 14 54.3-61.6 59.2 1.8 33 53.7-61.1 59.1 1.5 Snout to pectoral-fin origin 25.5 14 24.5-26.2 25.3 0.6 33 22.2-28.6 25.0 1.4 Snout to pelvic-fin origin 46.2 14 45.1-47.1 45.8 0.6 33 46.7-50.0 46.4 1.4 Snout to anal-fin origin 58.4 14 57.3-61.0 59.2 1.0 33 57.1-64.9 60.9 2.0 Caudal peduncle depth 10.9 14 09.3-11.1 10.0 0.5 33 0.84-10.6 09.8 0.5 Caudal peduncle length 12.8 14 10.8-14.2 12.7 1.0 33 11.1-17.1 13.1 1.0 Pectoral-fin length 20.9 14 20.1-24.2 22.1 1.0 33 18.8-25.3 21.7 1.2 Pelvic-fin length 14.4 14 12.5-16.1 15.1 1.1 33 12.0-15.6 14.1 0.7 Dorsal-fin base length 10.9 14 08.9-12.5 10.5 0.8 33 0.93-12.9 10.4 0.8 Dorsal-fin height 19.8 14 18.7-21.4 20.2 0.8 33 18.2-21.3 19.8 0.8 Anal-fin base length 29.9 14 27.6-33.3 30.6 1.4 33 26.0-32.0 28.6 1.5 Anal-fin lobe length 17.7 14 16.8-18.8 17.9 0.7 33 16.1-19.6 18.1 1.0 Eye to dorsal-fin origin 46.5 14 44.6^7.9 46.1 1.0 33 41.7^8.6 45.7 1.5 Dorsal-fin origin to caudal-fin base 43.5 14 40.1-43.9 42.2 1.1 33 38.7-47.7 42.2 1.6 Bony head length 23.4 14 22.6-25.4 23.7 0.8 33 20.5-26.4 24.1 1.1 Horizontal eye diameter 35.4 14 35.0-37.7 36.2 0.7 33 33.7-42.6 36.7 1.8 Snout length 22.1 14 18.8-23.7 21.2 1.6 33 17.8-23.4 21.2 1.2 Least interorbital width 31.4 14 31.4-36.1 33.8 1.4 33 31.1-38.3 33.5 1.5 Upper jaw length 43.0 14 40.0-^5.9 43.1 1.4 33 40.3-47.7 43.8 1.5 1 VOLUME NUMBER 116, 3 563 Fig. 2. Planaltina myersi, USNM 221202, adult male, SL 35.9 mm; corrego Pipiripau near Planaltina, Distrito Federal, Brazil, about 15°40'S, 47°39'W. Displays pigment pattern of head and anterior part of body. mm Menezes (1998:184) discussed relation- ture male, 46.0 SL), rio Pipiripau near ships and assigned it to Diapomini. Planaltina, about 15°40'S, 47°39'W, 30 — Sept. 1977, N. Menezes & party. USNM Specimens examined. All specimens 221202, 6(1 mature male, 35.9 mm; 5 ma- are from Brazil, Distrito Federal, drainage mm ture females, 32.0-43.1 SL), rio Pipi- basin of rio Corumba, tributary of upper rio ripau near Planaltina, about 15°40'S, Parana. & 47°39'W, 30 Sept. 1977. N. Menezes par- Holotype.—SU 18636 (now at CAS), 1 USNM male, 36.8 mm SL. Type locality: Brazil: ty. 236416, 3 (immmamtures to 1 ma- ture female, 19.0—39.7 SL), corrego "Goyaz, Sarandi brook, Planaltina" (ap- proximately 15°40'S, 47°45'W). Now in Vargem de Tras, rio Pipiripau, near Plan- Distrito Federal, see discussion below re- altina, about 15°40'S, 47°39'W, 1 Jun. 1979, & USNM N. Menezes E. Bastos. 258458, garding type locality. — mm Additional specimens. Brazil: Distrito 1 (mature female, c&s, 41.0 SL), rio Federal. MNRJ 10634, 24 (2 mature males, Pipiripau near Planaltina, about 15°40'S, USNM from 30.5 to 31.5 mm SL; 22 immatures of 47°39'W, 19 Jan. 1976, E.C. Calaf. either sex to mature females, from 22.3 to 278966, 8 (7 mature sexually active males, mm 36.6 mm SL), corrego Fumal, where cross- 35.5-38.3 SL; 1 mature female, 37.8 mm es road between Brasilia and Planaltina, SL), corrego Papuda, tributary of rio near Planaltina, about 15°20'S, 47°50'W, 1 Sao Bartolomeu, about 40 km south east of Apr. 1982, L.E. de Macedo Cordoso. MNRJ Brasilia, 1 Feb. 1985, M. Ribeiro & party. mm USNM mm 10635, 13 (including 1 c&s male, 33.3 278985, 1 (mature male, 36.4 mm SL; c&s female, 36.4 SL), corrego SL), rio Pipiripau near PlanaUina, about 1 Fumal, where it crosses road between Bra- 15°40'S, 47°39'W, 1985, M. Ribeiro. USNM mm silia and Planaltina, near Planaltina, about 278986, 1 (mature female, 39.6 15°20'S, 47°50'W, 5 Aug. 1981, L. E. de SL), corrego Papuda, tributary to rio Sao Macedo Cordoso. USNM 363088, 1 (ma- Bartolomeu, 28 Aug. 1985, M. Ribeiro & 564 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON USNM R.C. Mendonga. 278987, 1 (mature rio Paranaiba]." Bohlke continued: "Thus mm male, 37.1 SL), corrego Forquilha, trib- the particular brook which Ternetz collected utary to rio Sao Bartolomeu, Sept. 1985, M. may drain into the Amazon system to the USNM Ribeiro. 278989, 3 (mature females, north or into the Parana to the south, but mm 28.7-37.4 SL), rio Taboca, tributary to more likely the latter ..." Subsequent to rio Sao Bartolomeu, Sept. 1985, M. Ribeiro the original description, several collections & J. Dalmaco. MZUSP 63588, 3 (mature were made in this region as listed above mm & females, 34.3-41.3 SL), corrego Var- and in Weitzman Fink (1985:106). Plan- gem de Tras, rio Pipiripau, near Planaltina, altina myersi so far has been found only in & 1 Jun. 1979, N. Menezes E. Bastos. the upper rio—Parana system. Note.—Bohlke (1954:267) with the aid Definition. Following features distin- of other Dr. Carl Ternetz localities of about guish Planaltina myersi from P. glandipe- the same date discussed the type locality dis and P. britskii: One much enlarged and "as a small brook somewhere along the elongate scale along dorsal border of pouch Chapadao do Sarandy, lying between the opening; adipose fin present. In addition, headwaters of the Rio Maranhao (which anterior teeth of inner tooth row of premax- empties into the Tocantins) and those of the illa of P. myersi pentacuspid, and dentary Rio Sao Bartholomeo [= rio Sao Bartolo- with its anterior large teeth pentacuspid or meu] (which empties into the [rio] Cor- quadricuspid. Lower jaw not extending be- umba and then into the [rio] Paranahyba [= yond upper. Planaltina glandipedis with tri- l?i:::« .«H. «., • Fig. 3. Planaltina myersi, MNRJ 10635, c&s, sexually active male, SL 33.3 mm. Premaxilla, maxilla and mandible, left side, external view. Note relative positions of maxilla and premaxilla with dentary not normal so that all jaw teeth can be illustrated. VOLUME NUMBER 116, 3 565 Fig. 4. Planahina glandipedis, new species, paratype, USNM 362135, sexually active male, c&s, SL 24.3 mm. Premaxilla, maxilla and mandible, left side, external view. Note relative positions and premaxilla with dentary not normal so that all jaw teeth can be illustrated. cuspid teeth in inner row of premaxilla; sum tests regarding differences and similar- dentary with tricuspid anterior large teeth, ities among P. myersi, P. britskii, and P. lower jaw protrudes somewhat beyond up- glandipedis in number of lateral-series per jaw. Planahina britskii with teeth of in- scales. Fig. 6; number of predorsal scales. ner row of premaxilla and large anterior Fig. 7; number of branched anal-fin rays. teeth of dentary pentacuspid and lowerjaw Fig. 8; total number of vertebrae including included by upper (Figs. 3-5, but note: in those of Weberian apparatus. Fig. 9; least drawings upper and lower jaws reproduced number of scale rows around caudal pedun- from independent drawings and not in a cle. Fig. 10; number of lower-limb gill rak- natural position in relation to one another, ers. Fig. 1 1; number of scale rows between thus some dentary teeth not hidden by up- dorsal-fin origin and lateral line. Fig. 12; per jaw teeth). and number of scale rows between anal-fin Figures 6-13 illustrate Tukey Box Plot origin and lateral line. Fig. 13. — distributions of population sample data for Description. Morphometries of the ho- species of Planahina. Captions of these fig- lotype and additional specimens presented ures provide results of Mann-Whitney rank in Table Tables, graphs, and descriptions 1 . 566 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON Fig. 5. Planaltina britskii, new species, paratype, MZUSP 62758, c&s, sexually active male, SL 35.6 mm. Premaxilla, maxilla and mandible, left side, external view. Note relative positions of maxilla and premaxilla with dentary not normal so that all jaw teeth can be illustrated. provided below based on combined lots of cle. Dorsal-fin origin nearer to caudal-fin this species because no statistical differenc- base than snout tip. Ventral body profile es were found among examined same-sex convex from tip of lower jaw to anal-fin population samples. All collection localities origin, nearly straight along anal-fin base geographically close and in one drainage and slightly concave from end of anal fin system, rio Corumba, upper rio Parana. to origin of procurrent caudal-fin rays. Body large, compressed and moderately Lower jaw terminal or only slightly pro- elongate; greatest body depth between truding anterior to upper jaw. Mouth gape snout tip and dorsal-fin origin, near origin somewhat inclined posteroventrally towards of pelvic fin. Dorsal body profile somewhat mandibular joint. Maxilla extending poste- convex between nape and just anterior to riorly beyond vertical line passing through dorsal-fin origin, only slightly elevated at anterior border of orbit, but falling short of dorsal-fin origin. Head profile to snout tip reaching a vertical line passing through an- slightly convex. Snout rounded. Body pro- terior border of pupil of eye (see Fig. 2). file nearly straight along dorsal-fin base and Dorsal-fin rays ii, 8 in 44 of 45 speci- slightly concave in region of caudal pedun- mens including holotype, I, 7 in one spec-