Description of Neblinichthys brevibracchium and N. echinasus from the upper Mazaruni River, Guyana (Siluriformes: Loricariidae), and recognition of N. roraima and N. yaravi as distinct species
Neblinichthys brevibracchium and N. echinasus are new sympatric species from upland tributaries of the Mazaruni River (Essequibo River basin) of Guyana. These two new species are the first Neblinichthys reported from Guyana. Adult males of both new species have short pectoral-fin spines and several...
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Ictiologia
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| Series: | Neotropical Ichthyology |
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| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252010000300006&lng=en&tlng=en |
| _version_ | 1818969211329839104 |
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| author | Donald C. Taphorn Jonathan W. Armbruster Hernán López-Fernández Calvin R. Bernard |
| author_facet | Donald C. Taphorn Jonathan W. Armbruster Hernán López-Fernández Calvin R. Bernard |
| author_sort | Donald C. Taphorn |
| collection | DOAJ |
| description | Neblinichthys brevibracchium and N. echinasus are new sympatric species from upland tributaries of the Mazaruni River (Essequibo River basin) of Guyana. These two new species are the first Neblinichthys reported from Guyana. Adult males of both new species have short pectoral-fin spines and several series of hypertrophied odontodes covering the entire dorsal surface and along the entire edge of the snout. They are distinguished from each other by dorsal-fin base length/standard length (18.1-22.8% in N. brevibracchium vs. 24.3-27.0% in N. echinasus), dorsal-anal distance/SL (13.7-18.3% in N. brevibracchium vs. 11.9-12.5% in N. echinasus), by having the snout decreasing in steep arc just anterior to eyes and then flattening in area anterior of nares in N. brevibracchium vs. the snout tapering shallowly and continuously from eyes to snout tip in N. echinasus); and by having the adpressed dorsal fin reaching the anterior preadipose plate in N. brevibracchium (vs. not reaching anterior preadipose plate in N. echinasus). They are distinguished from all congeners by lacking odontodes on the opercle (vs. odontodes present); and by completely lacking an iris operculum (vs. congeners with small iris operculum present or at least dorsal portion of iris flat instead of rounded). Neblinichthys echinasus and N. brevibracchium differ from all congeners by having a spotted or vermiculated pigment pattern on the abdomen (vs. abdomen plain); in N. echinasus the abdomen is darkly pigmented with bold white spots and in Neblinichthys brevibracchium the abdomen is light-colored with gray spots and vermiculations. Neblinichthys brevibracchium and N. echinasus differ from N. roraima by having one to two preadipose plates (vs. four or more). New observations revealed Neblinichthys roraima and N. yaravi to be distinct, with N. roraima having four or more preadipose plates and N. yaravi having one or two. Both are present in the upper río Caroní, an Orinoco tributary that drains the slopes of Mount Roraima and other mountains of the Pacaraima Range in Venezuela and interdigitates with headwaters of the Mazaruni River. |
| first_indexed | 2024-12-20T14:16:59Z |
| format | Article |
| id | doaj.art-e7852c4b5e8b46ec938e4a3099b511f7 |
| institution | Directory Open Access Journal |
| issn | 1982-0224 |
| language | English |
| last_indexed | 2024-12-20T14:16:59Z |
| publisher | Sociedade Brasileira de Ictiologia |
| record_format | Article |
| series | Neotropical Ichthyology |
| spelling | doaj.art-e7852c4b5e8b46ec938e4a3099b511f72022-12-21T19:38:01ZengSociedade Brasileira de IctiologiaNeotropical Ichthyology1982-02248361562410.1590/S1679-62252010000300006S1679-62252010000300006Description of Neblinichthys brevibracchium and N. echinasus from the upper Mazaruni River, Guyana (Siluriformes: Loricariidae), and recognition of N. roraima and N. yaravi as distinct speciesDonald C. TaphornJonathan W. Armbruster0Hernán López-Fernández1Calvin R. Bernard2Auburn UniversityUniversity of TorontoUniversity of GuyanaNeblinichthys brevibracchium and N. echinasus are new sympatric species from upland tributaries of the Mazaruni River (Essequibo River basin) of Guyana. These two new species are the first Neblinichthys reported from Guyana. Adult males of both new species have short pectoral-fin spines and several series of hypertrophied odontodes covering the entire dorsal surface and along the entire edge of the snout. They are distinguished from each other by dorsal-fin base length/standard length (18.1-22.8% in N. brevibracchium vs. 24.3-27.0% in N. echinasus), dorsal-anal distance/SL (13.7-18.3% in N. brevibracchium vs. 11.9-12.5% in N. echinasus), by having the snout decreasing in steep arc just anterior to eyes and then flattening in area anterior of nares in N. brevibracchium vs. the snout tapering shallowly and continuously from eyes to snout tip in N. echinasus); and by having the adpressed dorsal fin reaching the anterior preadipose plate in N. brevibracchium (vs. not reaching anterior preadipose plate in N. echinasus). They are distinguished from all congeners by lacking odontodes on the opercle (vs. odontodes present); and by completely lacking an iris operculum (vs. congeners with small iris operculum present or at least dorsal portion of iris flat instead of rounded). Neblinichthys echinasus and N. brevibracchium differ from all congeners by having a spotted or vermiculated pigment pattern on the abdomen (vs. abdomen plain); in N. echinasus the abdomen is darkly pigmented with bold white spots and in Neblinichthys brevibracchium the abdomen is light-colored with gray spots and vermiculations. Neblinichthys brevibracchium and N. echinasus differ from N. roraima by having one to two preadipose plates (vs. four or more). New observations revealed Neblinichthys roraima and N. yaravi to be distinct, with N. roraima having four or more preadipose plates and N. yaravi having one or two. Both are present in the upper río Caroní, an Orinoco tributary that drains the slopes of Mount Roraima and other mountains of the Pacaraima Range in Venezuela and interdigitates with headwaters of the Mazaruni River.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252010000300006&lng=en&tlng=enEssequiboGuiana ShieldIsolationEndemismPunk Catfish |
| spellingShingle | Donald C. Taphorn Jonathan W. Armbruster Hernán López-Fernández Calvin R. Bernard Description of Neblinichthys brevibracchium and N. echinasus from the upper Mazaruni River, Guyana (Siluriformes: Loricariidae), and recognition of N. roraima and N. yaravi as distinct species Neotropical Ichthyology Essequibo Guiana Shield Isolation Endemism Punk Catfish |
| title | Description of Neblinichthys brevibracchium and N. echinasus from the upper Mazaruni River, Guyana (Siluriformes: Loricariidae), and recognition of N. roraima and N. yaravi as distinct species |
| title_full | Description of Neblinichthys brevibracchium and N. echinasus from the upper Mazaruni River, Guyana (Siluriformes: Loricariidae), and recognition of N. roraima and N. yaravi as distinct species |
| title_fullStr | Description of Neblinichthys brevibracchium and N. echinasus from the upper Mazaruni River, Guyana (Siluriformes: Loricariidae), and recognition of N. roraima and N. yaravi as distinct species |
| title_full_unstemmed | Description of Neblinichthys brevibracchium and N. echinasus from the upper Mazaruni River, Guyana (Siluriformes: Loricariidae), and recognition of N. roraima and N. yaravi as distinct species |
| title_short | Description of Neblinichthys brevibracchium and N. echinasus from the upper Mazaruni River, Guyana (Siluriformes: Loricariidae), and recognition of N. roraima and N. yaravi as distinct species |
| title_sort | description of neblinichthys brevibracchium and n echinasus from the upper mazaruni river guyana siluriformes loricariidae and recognition of n roraima and n yaravi as distinct species |
| topic | Essequibo Guiana Shield Isolation Endemism Punk Catfish |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252010000300006&lng=en&tlng=en |
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