ABSTRACT Crenicichla dandara, new species, is endemic to the rio Xingu above the Belo Monte narrows, and its major left bank tributary the rio Iriri. The new species is distinguished from all congeners by the following combination of characters: body uniformly black (live fishes) or dark brown (preserved specimens) in adults and 74–86 scales in the E1 row. Crenicichla dandara is considered herein to be the tenth species of the C. lugubris group, but its allies within the group are not clear. Among members of this group, C. dandara is most similar in general body shape, snout characteristics and squamation to C. lugubris and C. adspersa, but lacks a caudal-fin blotch as does C. johanna and C. monicae, a condition rare within the Crenicichla-Teleocichla clade. The overall black coloration in Crenicichla dandara is shared with the syntopic, but not closely related, Teleocichla preta. Both species inhabit clear water rapids where they hide among the shadows of large rocks, suggesting that the dark coloration is for camouflage and ambush predation. Based on a preliminary assessment of its conservation status following the criteria and categories of IUCN classification, Crenicichla dandara is considered as a species of least concern (LC).
{"title":"Crenicichla dandara, new species: the black jacundá from the Rio Xingu (Teleostei: Cichlidae)","authors":"H. R. Varella, P. M. M. Ito","doi":"10.1635/053.166.0109","DOIUrl":"https://doi.org/10.1635/053.166.0109","url":null,"abstract":"ABSTRACT \u0000 Crenicichla dandara, new species, is endemic to the rio Xingu above the Belo Monte narrows, and its major left bank tributary the rio Iriri. The new species is distinguished from all congeners by the following combination of characters: body uniformly black (live fishes) or dark brown (preserved specimens) in adults and 74–86 scales in the E1 row. Crenicichla dandara is considered herein to be the tenth species of the C. lugubris group, but its allies within the group are not clear. Among members of this group, C. dandara is most similar in general body shape, snout characteristics and squamation to C. lugubris and C. adspersa, but lacks a caudal-fin blotch as does C. johanna and C. monicae, a condition rare within the Crenicichla-Teleocichla clade. The overall black coloration in Crenicichla dandara is shared with the syntopic, but not closely related, Teleocichla preta. Both species inhabit clear water rapids where they hide among the shadows of large rocks, suggesting that the dark coloration is for camouflage and ambush predation. Based on a preliminary assessment of its conservation status following the criteria and categories of IUCN classification, Crenicichla dandara is considered as a species of least concern (LC).","PeriodicalId":54579,"journal":{"name":"Proceedings of the Academy of Natural Sciences of Philadelphia","volume":"166 1","pages":"1 - 13"},"PeriodicalIF":0.7,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42718411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT A new species of Hyphessobrycon is described from the middle and lower rio Xingu Basin, Pará state, Brazil. The new species can be distinguished from all congeners by the combination of a large caudal peduncle blotch (largest in mature males), absence of humeral blotch, and largest teeth on dentary, inner premaxillary and maxillary relatively compressed with 6-9 cusps. The new species is compared to three other congeners with similar color pattern: Hyphessobrycon diastatos Dagosta, Marinho & Camelier 2014, Hy. negodagua Lima & Gerhard 2001, and Hy. parvellus Ellis 1911, and one species of Hemigrammus, He. rodwayi Durbin 1909.
{"title":"A new Hyphessobrycon (Characiformes: Characidae) from the rio Xingu Basin, Brazil","authors":"T. C. Faria, F. Lima, D. Bastos","doi":"10.1635/053.166.0108","DOIUrl":"https://doi.org/10.1635/053.166.0108","url":null,"abstract":"ABSTRACT A new species of Hyphessobrycon is described from the middle and lower rio Xingu Basin, Pará state, Brazil. The new species can be distinguished from all congeners by the combination of a large caudal peduncle blotch (largest in mature males), absence of humeral blotch, and largest teeth on dentary, inner premaxillary and maxillary relatively compressed with 6-9 cusps. The new species is compared to three other congeners with similar color pattern: Hyphessobrycon diastatos Dagosta, Marinho & Camelier 2014, Hy. negodagua Lima & Gerhard 2001, and Hy. parvellus Ellis 1911, and one species of Hemigrammus, He. rodwayi Durbin 1909.","PeriodicalId":54579,"journal":{"name":"Proceedings of the Academy of Natural Sciences of Philadelphia","volume":"166 1","pages":"1 - 9"},"PeriodicalIF":0.7,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45472101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT. A new species of Hyphessobrycon is described from the middle and lower rio Xingu Basin, Pará state, Brazil. The new species can be distinguished from all congeners by the combination of a large caudal peduncle blotch (largest in mature males), absence of humeral blotch, and largest teeth on dentary, inner premaxillary and maxillary relatively compressed with 6–9 cusps. The new species is compared to three other congeners with similar color pattern: Hyphessobrycon diastatos Dagosta, Marinho & Camelier 2014, Hy. negodagua Lima & Gerhard 2001, and Hy. parvellus Ellis 1911, and one species of Hemigrammus, He. rodwayi Durbin 1909.
{"title":"A new Hyphessobrycon (Characiformes: Characidae) from the rio Xingu Basin, Brazil","authors":"T. C. Faria, F. Lima, D. Bastos","doi":"10.1635/053.166.0103","DOIUrl":"https://doi.org/10.1635/053.166.0103","url":null,"abstract":"ABSTRACT. A new species of Hyphessobrycon is described from the middle and lower rio Xingu Basin, Pará state, Brazil. The new species can be distinguished from all congeners by the combination of a large caudal peduncle blotch (largest in mature males), absence of humeral blotch, and largest teeth on dentary, inner premaxillary and maxillary relatively compressed with 6–9 cusps. The new species is compared to three other congeners with similar color pattern: Hyphessobrycon diastatos Dagosta, Marinho & Camelier 2014, Hy. negodagua Lima & Gerhard 2001, and Hy. parvellus Ellis 1911, and one species of Hemigrammus, He. rodwayi Durbin 1909.","PeriodicalId":54579,"journal":{"name":"Proceedings of the Academy of Natural Sciences of Philadelphia","volume":"166 1","pages":"1 - 10"},"PeriodicalIF":0.7,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1635/053.166.0103","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42077227","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Mansur, D. Pereira, P. E. A. Bergonci, Daniel M PimpÃo, J. R. Barradas, M. Sabaj
ABSTRACT. Rheodreissena Geda et al. 2018, a recently described genus of Dreissenidae, is represented by living species that inhabit inland freshwaters of Brazil and Venezuela. The type species of Rheodreissena is R. hoeblichi (Schütt 1991a) described from the lower Orinoco basin, Venezuela. Three species are added in this study: R. lopesi (Alvarenga & Ricci, 1989) from the Tocantins and Xingu basins; R. cordilineata n. sp. from the Madeira, Trombetas and Xingu basins, and R. xinguana n. sp. from the Tapajós and Xingu basins. Those three species are recorded from Volta Grande, the stretch of the Xingu River impacted by the Belo Monte dam complex. All Rheodreissena typically attach in shallow clusters to clean, rocky substrates associated with rapids in the main channels of large clear water rivers. Species of Rheodreissena are distinguished by aspects of shell morphology and soft anatomy that presumably reflect adaptations to a rheophilic lifestyle. In Xingu and Tocantins populations of Rheodreissena, larval broods were observed in the ctenidial (R. lopesi and R. xinguana) and pallial cavities of females (all three species). Examples of pallial broods included a few prodissoconch-1 (D-shaped) larvae in R. xinguana n. sp., 24 larvae/juveniles representing three different stages (prodissoconch 1 and 2, dissoconch) in R. cordilineata and up to 65 larvae/juveniles representing the same three stages in R. lopesi. In R. cordilineata and R. lopesi, the prodissoconch is attached to the parental mantle via a modified velum (adhesivelum), and dissoconchs attain lengths of 800 µm and 987 µm, respectively. For larvae brooded in the pallial cavity, a biphasic growth pattern was demonstrated statistically in R. lopesi and determined by observation in R. cordilineata. Juveniles are presumably released gradually into the environment at the crawl-away dissoconch stage. Biphasic brooding (ctenidial and pallial) was previously described for the European cave-dwelling dreissenid species Congeria kusceri; differences between brooding in Congeria and Rheodreissena are noted. Various morphological and lifehistory traits of species of Rheodreissena are summarized and compared to the other living species of Dreissenidae: Mytilopsis leucophaeata, M. sallei, Dreissena polymorpha, D. rostriformis (ex. bugensis), and the three nominal species of Congeria.
{"title":"Morphological assessment of Rheodreissena (Bivalvia: Veneroida: Dreissenidae) with an updated diagnosis of the genus, descriptions of two new species, redescription of R. lopesi, and the first account of larval brooding in New World dreissenids","authors":"M. Mansur, D. Pereira, P. E. A. Bergonci, Daniel M PimpÃo, J. R. Barradas, M. Sabaj","doi":"10.1635/053.166.0112","DOIUrl":"https://doi.org/10.1635/053.166.0112","url":null,"abstract":"ABSTRACT. \u0000 Rheodreissena Geda et al. 2018, a recently described genus of Dreissenidae, is represented by living species that inhabit inland freshwaters of Brazil and Venezuela. The type species of Rheodreissena is R. hoeblichi (Schütt 1991a) described from the lower Orinoco basin, Venezuela. Three species are added in this study: R. lopesi (Alvarenga & Ricci, 1989) from the Tocantins and Xingu basins; R. cordilineata n. sp. from the Madeira, Trombetas and Xingu basins, and R. xinguana n. sp. from the Tapajós and Xingu basins. Those three species are recorded from Volta Grande, the stretch of the Xingu River impacted by the Belo Monte dam complex. All Rheodreissena typically attach in shallow clusters to clean, rocky substrates associated with rapids in the main channels of large clear water rivers. Species of Rheodreissena are distinguished by aspects of shell morphology and soft anatomy that presumably reflect adaptations to a rheophilic lifestyle. In Xingu and Tocantins populations of Rheodreissena, larval broods were observed in the ctenidial (R. lopesi and R. xinguana) and pallial cavities of females (all three species). Examples of pallial broods included a few prodissoconch-1 (D-shaped) larvae in R. xinguana n. sp., 24 larvae/juveniles representing three different stages (prodissoconch 1 and 2, dissoconch) in R. cordilineata and up to 65 larvae/juveniles representing the same three stages in R. lopesi. In R. cordilineata and R. lopesi, the prodissoconch is attached to the parental mantle via a modified velum (adhesivelum), and dissoconchs attain lengths of 800 µm and 987 µm, respectively. For larvae brooded in the pallial cavity, a biphasic growth pattern was demonstrated statistically in R. lopesi and determined by observation in R. cordilineata. Juveniles are presumably released gradually into the environment at the crawl-away dissoconch stage. Biphasic brooding (ctenidial and pallial) was previously described for the European cave-dwelling dreissenid species Congeria kusceri; differences between brooding in Congeria and Rheodreissena are noted. Various morphological and lifehistory traits of species of Rheodreissena are summarized and compared to the other living species of Dreissenidae: Mytilopsis leucophaeata, M. sallei, Dreissena polymorpha, D. rostriformis (ex. bugensis), and the three nominal species of Congeria.","PeriodicalId":54579,"journal":{"name":"Proceedings of the Academy of Natural Sciences of Philadelphia","volume":"166 1","pages":"1 - 45"},"PeriodicalIF":0.7,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42368063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Sousa, Mateus S. Chaves, A. Akama, J. Zuanon, M. Sabaj
Abstract. A new species of Platydoras is described from the rio Xingu Basin, Brazil. Platydoras birindellii is distinguished from congeners by having gas bladder simple (vs. with posterior secondary chamber) and dorsal and caudal fins uniformly dusky (vs. with distinct marks composed of dark broad band or blotch on central portion of dorsal fin and pair of dark broad stripes on caudal fin, one central to each lobe). Platydoras birindellii shares a simple gas bladder with the sister taxon to Platydoras, Centrochir crocodili, a monotypic genus endemic to the Magdalena Basin. With respect to the caudal skeleton, the parhypural is incompletely fused to hypurals 1+2 in P. birindellii, a condition that is intermediate between those of Centrochir (parhypural typically separated from hypurals 1+2 by distinct suture) and Platydoras (parhypural typically fully fused to hypurals 1+2). Platydoras birindellii is commonly found in rocky clearwater rapids and apparently endemic to the middle and upper portions of the Xingu draining the Brazilian Shield. New taxa: Platydoras birindellii Sousa, Chaves, Akama, Zuanon & Sabaj
{"title":"Platydoras birindellii, new species of striped raphael catfish (Siluriformes: Doradidae) from the Xingu Basin, Brazil","authors":"L. Sousa, Mateus S. Chaves, A. Akama, J. Zuanon, M. Sabaj","doi":"10.1635/053.166.0106","DOIUrl":"https://doi.org/10.1635/053.166.0106","url":null,"abstract":"Abstract. A new species of Platydoras is described from the rio Xingu Basin, Brazil. Platydoras birindellii is distinguished from congeners by having gas bladder simple (vs. with posterior secondary chamber) and dorsal and caudal fins uniformly dusky (vs. with distinct marks composed of dark broad band or blotch on central portion of dorsal fin and pair of dark broad stripes on caudal fin, one central to each lobe). Platydoras birindellii shares a simple gas bladder with the sister taxon to Platydoras, Centrochir crocodili, a monotypic genus endemic to the Magdalena Basin. With respect to the caudal skeleton, the parhypural is incompletely fused to hypurals 1+2 in P. birindellii, a condition that is intermediate between those of Centrochir (parhypural typically separated from hypurals 1+2 by distinct suture) and Platydoras (parhypural typically fully fused to hypurals 1+2). Platydoras birindellii is commonly found in rocky clearwater rapids and apparently endemic to the middle and upper portions of the Xingu draining the Brazilian Shield. New taxa: Platydoras birindellii Sousa, Chaves, Akama, Zuanon & Sabaj","PeriodicalId":54579,"journal":{"name":"Proceedings of the Academy of Natural Sciences of Philadelphia","volume":" ","pages":"1 - 13"},"PeriodicalIF":0.7,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1635/053.166.0106","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49009832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Sousa, Mateus S. Chaves, A. Akama, J. Zuanon, M. Sabaj
Abstract A new species of Platydoras is described from the rio Xingu Basin, Brazil. Platydoras birindellii is distinguished from congeners by having gas bladder simple (vs. with posterior secondary chamber) and dorsal and caudal fins uniformly dusky (vs. with distinct marks composed of dark broad band or blotch on central portion of dorsal fin and pair of dark broad stripes on caudal fin, one central to each lobe). Platydoras birindellii shares a simple gas bladder with the sister taxon to Platydoras, Centrochir crocodili, a monotypic genus endemic to the Magdalena Basin. With respect to the caudal skeleton, the parhypural is incompletely fused to hypurals 1+2 in P. birindellii, a condition that is intermediate between those of Centrochir (parhypural typically separated from hypurals 1+2 by distinct suture) and Platydoras (parhypural typically fully fused to hypurals 1+2). Platydoras birindellii is commonly found in rocky clearwater rapids and apparently endemic to the middle and upper portions of the Xingu draining the Brazilian Shield.
{"title":"Platydoras birindellii, new species of striped raphael catfish (Siluriformes: Doradidae) from the Xingu Basin, Brazil","authors":"L. Sousa, Mateus S. Chaves, A. Akama, J. Zuanon, M. Sabaj","doi":"10.1635/053.166.0111","DOIUrl":"https://doi.org/10.1635/053.166.0111","url":null,"abstract":"Abstract \u0000 A new species of Platydoras is described from the rio Xingu Basin, Brazil. Platydoras birindellii is distinguished from congeners by having gas bladder simple (vs. with posterior secondary chamber) and dorsal and caudal fins uniformly dusky (vs. with distinct marks composed of dark broad band or blotch on central portion of dorsal fin and pair of dark broad stripes on caudal fin, one central to each lobe). Platydoras birindellii shares a simple gas bladder with the sister taxon to Platydoras, Centrochir crocodili, a monotypic genus endemic to the Magdalena Basin. With respect to the caudal skeleton, the parhypural is incompletely fused to hypurals 1+2 in P. birindellii, a condition that is intermediate between those of Centrochir (parhypural typically separated from hypurals 1+2 by distinct suture) and Platydoras (parhypural typically fully fused to hypurals 1+2). Platydoras birindellii is commonly found in rocky clearwater rapids and apparently endemic to the middle and upper portions of the Xingu draining the Brazilian Shield.","PeriodicalId":54579,"journal":{"name":"Proceedings of the Academy of Natural Sciences of Philadelphia","volume":" ","pages":"1 - 13"},"PeriodicalIF":0.7,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45013070","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT. Crenicichla dandara, new species, is endemic to the rio Xingu above the Belo Monte narrows, and its major left bank tributary the rio Iriri. The new species is distinguished from all congeners by the following combination of characters: body uniformly black (live fishes) or dark brown (preserved specimens) in adults and 74–86 scales in the E1 row. Crenicichla dandara is considered herein to be the tenth species of the C. lugubris group, but its allies within the group are not clear. Among members of this group, C. dandara is most similar in general body shape, snout characteristics and squamation to C. lugubris and C. adspersa, but lacks a caudal-fin blotch as does C. johanna and C. monicae, a condition rare within the Crenicichla-Teleocichla clade. The overall black coloration in Crenicichla dandara is shared with the syntopic, but not closely related, Teleocichla preta. Both species inhabit clear water rapids where they hide among the shadows of large rocks, suggesting that the dark coloration is for camouflage and ambush predation. Based on a preliminary assessment of its conservation status following the criteria and categories of IUCN classification, Crenicichla dandara is considered as a species of least concern (LC).
{"title":"Crenicichla dandara, new species: the black jacundá from the Rio Xingu (Teleostei: Cichlidae)","authors":"H. R. Varella, P. M. M. Ito","doi":"10.1635/053.166.0104","DOIUrl":"https://doi.org/10.1635/053.166.0104","url":null,"abstract":"ABSTRACT. \u0000 Crenicichla dandara, new species, is endemic to the rio Xingu above the Belo Monte narrows, and its major left bank tributary the rio Iriri. The new species is distinguished from all congeners by the following combination of characters: body uniformly black (live fishes) or dark brown (preserved specimens) in adults and 74–86 scales in the E1 row. Crenicichla dandara is considered herein to be the tenth species of the C. lugubris group, but its allies within the group are not clear. Among members of this group, C. dandara is most similar in general body shape, snout characteristics and squamation to C. lugubris and C. adspersa, but lacks a caudal-fin blotch as does C. johanna and C. monicae, a condition rare within the Crenicichla-Teleocichla clade. The overall black coloration in Crenicichla dandara is shared with the syntopic, but not closely related, Teleocichla preta. Both species inhabit clear water rapids where they hide among the shadows of large rocks, suggesting that the dark coloration is for camouflage and ambush predation. Based on a preliminary assessment of its conservation status following the criteria and categories of IUCN classification, Crenicichla dandara is considered as a species of least concern (LC).","PeriodicalId":54579,"journal":{"name":"Proceedings of the Academy of Natural Sciences of Philadelphia","volume":"166 1","pages":"1 - 12"},"PeriodicalIF":0.7,"publicationDate":"2017-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1635/053.166.0104","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47182527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"环境科学与生态学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
ABSTRACT. Trachydoras is a genus of Doradidae (thorny catfishes) with five nominal valid species distributed in lowland areas of the Amazon, Orinoco, Paraná-Paraguay and Essequibo river basins of South America. A sixth species is described here as Trachydoras gepharti and diagnosed by five characteristics unique among congeners: mental barbels thick, tapered and profusely ornamented with many elongate fleshy papillae loosely arranged in 2–3 rows (vs. mental barbels thinner, papillae lacking or fewer, arranged in 1–2 rows); distinct columns of small, soft papillae along medial and lateral margins of gill filaments on all gill arches (vs. gill filaments lacking conspicuous papillae in congeners); gas bladder acorn-shaped (vs. cordiform) with smooth anterolateral shoulder (vs. shoulder with accessory diverticulum) and terminal diverticula medially united into singular, finger-like projection formed mostly by elongation of only one of the two posterior chambers (vs. both chambers elongated, contributing more or less equally to terminal diverticula in congeners or terminal diverticula absent or reduced in some specimens of T. nattereri and T. paraguayensis). Trachydoras gepharti is known from the Amazon and Orinoco basins where it often occurs syntopically with T. microstomus, T. nattereri and a separate undescribed species of Trachydoras. Like other species of Trachydoras, T. gepharti is specialized for vacuuming chironomid larvae from sandy substrates in medium to large river channels. Redescriptions and diagnoses are provided for the five nominal valid species of Trachydoras along with a key to identification and comments on characteristics used to diagnose the genus and delimit species. Designations include a lectotype (NMW 46375, 91.7 mm SL) for Trachydoras brevis (Kner 1853) and neotype (ANSP 178443, 100 mm SL) for T. nattereri (Steindachner 1881). The true holotype of T. microstomus (Eigenmann 1912) is identified as FMNH 118302 [ex. FMNH 53207, ex. CM 1650] and the specimen previously cataloged as the holotype (FMNH 53206) is identified as T. brevis.
摘要。Trachydoras是多刺鲶鱼科的一个属，有五种名义有效物种，分布在南美洲亚马逊、奥里诺科、巴拉那-巴拉圭和埃塞奎博河流域的低地地区。第六个物种在这里被描述为Trachydoras gepharti，并通过同类中特有的五个特征进行诊断：精神杠铃厚、锥形，装饰丰富，有许多细长的肉质乳头，松散地排列在2-3排（而精神杠铃更薄，乳头缺失或更少，排列在1-2排）；在所有鳃弓上，沿着鳃丝的内侧和外侧边缘有明显的小而软的乳头列（与同类中缺乏明显乳头的鳃丝相比）；具有光滑的前外侧肩（相对于具有副憩室的肩）和末端憩室的气囊橡子形（相对于心形）向内合并为单一的，指状突起主要由两个后腔中的一个的伸长形成（与两个腔伸长相比，两个腔都伸长，对同类中的终末期憩室的贡献或多或少相等，或对纳特勒氏锥虫和巴拉圭锥虫的一些标本中缺失或减少的终末憩室的贡献）。在亚马逊和奥里诺科河流域，人们都知道gepharti Trachydoras，在那里它经常与微小T.tomus、纳特勒T.nattereri和一个单独的未描述的Trachydora物种同生。与其他Trachydoras物种一样，T.gepharti专门用于从中大型河道的沙质基质中抽真空处理摇蚊幼虫。对Trachydoras的五个名义有效物种进行了重新描述和诊断，并提供了识别关键和对用于诊断属和界定物种的特征的评论。名称包括Trachydoras brevis（Kner 1853）的选择型（NMW 46375，91.7 mm SL）和T.nattereri（Steindachner 1881）的新型（ANSP 178443，100 mm SL）。微小T.microtomus的真正正模标本（Eigenmann 1912）被鉴定为FMNH 118302[例如，FMNH 53207，例如，CM 1650]，并且之前被编目为正模标本的标本（FMNH 53/206）被鉴定为由短T.brevis。
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C. Volkmer-Ribeiro, I. E. D. Drago, V. S. Machado, M. Sabaj
ABSTRACT. A recent survey of the aquatic fauna in the rio Xingu, Pará State, Brazil, revealed a new species of Drulia Gray 1867, an extraordinary genus of freshwater sponge endemic to South America. Drulia cristinae n. sp. is distinguished in part by having gemmoscleres typically with elliptical outline and outer face with small, central crest or irregular bulge (exceptionally nude), oscules set atop conical projections of skeleton, and microscleres minute, wholly nanospined amphioxea. A taxonomic key is presented for the six species now composing the restored and redefined genus Drulia: D. brownii, D. cristata, D. uruguayensis, D. conifera, D. ctenosclera and D. cristinae n. sp. Furthermore, the monotypic South American genus Houssayella is retained as valid in Spongillidae on the basis of sharing gemmoscleres with true birotulate pattern (i.e., symmetrical disks separated by short or long, spiny or smooth shaft).
摘要最近对巴西帕尔州里约热内卢Xingu水生动物群的调查发现了一种新的Drulia Gray 1867，这是南美洲特有的一种非凡的淡水海绵属。朱丽鱼的特点之一是具有典型的椭圆形轮廓和外表面有小的中央嵴或不规则凸起(异常裸露)的双孔，位于骨骼的圆锥形突起上的双孔，以及微小的、完全纳米棘的文文类微孔。本文提出了由恢复和重新定义的海绵属组成的6个物种的分类关键:D. brownii, D. cristata, D. uruguayensis, D. conifera, D. ctenosclera和D. cristinae n. sp。此外，单型的南美属Houssayella在海绵科中被保留为有效的，因为它们具有真正的双轮状模式(即由短或长，带刺或光滑的轴分开的对称盘)。
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T. P. Carvalho, J. Lundberg, J. Baskin, J. Friel, R. Reis
ABSTRACT A new species of the aspredinid catfish tribe Hoplomyzontini Micromyzon is described from two specimens collected with trawl nets in two localities, at 10 and 18 m depth, in the main channel of the lower Orinoco River in Venezuela almost 40 years ago. The new species is distinguished from its only congener, Micromyzon akamai, by the: straight anterior margin of the mesethmoid; open posterior cranial fontanel; ossified first pectoral-fin radial; single tubular infraorbital bone; infraorbital sensory canal entering neurocranium via the frontal; enclosed foramen for the abductor superficialis muscle in the coracoid; higher vertebral count (33 vs. 28–32); higher anal-fin ray count (10 or 11 vs. 7–9); and some morphometric features. The holotype of the new species was scanned using High-Resolution X-ray Computed Tomography to illustrate, describe, and compare its bony skeleton to other hoplomyzontins.
摘要:近40年前，在委内瑞拉奥里诺科河下游主河道10米和18米深度的两个地方，用拖网采集了两个标本，描述了一种新的卷尾纲鲶鱼部落Hoplomyzontini Micromyzon。这个新种与它唯一的同系物akamai小种的区别在于:中筛直的前缘;打开颅后囟门;骨化的第一胸鳍放射状;单管眶下骨;眶下感觉管经额部进入神经颅骨;喙状肌外展浅肌的封闭孔;较高的椎体计数(33 vs 28-32);肛门鳍数更高(10或11比7-9);还有一些形态特征。使用高分辨率x射线计算机断层扫描对新物种的全型进行了扫描，以说明，描述并将其骨骼与其他全型区进行比较。
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