Difference between revisions of "Pseudancistrus sidereus"

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(Pseudancistrus sidereus)
(Pseudancistrus sidereus)
 
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{{Publication to wiki notice
 
{{Publication to wiki notice
  | author = Jonathan W. Armbruster
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  | author = Armbruster, Jonathan W.
  | author_abbreviated = Jonathan W. Armbruster
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  | author_abbreviated = Armbruster, Jonathan W.
 
  | year = 2004
 
  | year = 2004
  | title = Pseudancistrus sidereus, a new species from southern Venezuela (Siluriformes: Loricariidae) with a redescription of Pseudancistrus.
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  | title = Pseudancistrus sidereus, a new species from southern Venezuela (Siluriformes: Loricariidae) with a redescription of Pseudancistrus
 
  | journal = Zootaxa
 
  | journal = Zootaxa
 
  | volume = 628
 
  | volume = 628
  | pages = 8 -- 13
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  | pages = 8 -- 11
 
  | doi = TODO
 
  | doi = TODO
  | citationurl = http://www.zoobank.org/urn:lsid:zoobank.org:pub:C8D199F9-0677-41B1-ACD1-8A685EE26AE2
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  | citationurl =  
  | url = http://www.zoobank.org/urn:lsid:zoobank.org:pub:C8D199F9-0677-41B1-ACD1-8A685EE26AE2
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  | url =  
 
  | publisher =  
 
  | publisher =  
 
  | publisherurl =  
 
  | publisherurl =  
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{{Treatment start
 
{{Treatment start
  | Ordo =  
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  | Ordo = Siluriformes
 
  | Familia = Loricariidae
 
  | Familia = Loricariidae
 
  | Genus = Pseudancistrus
 
  | Genus = Pseudancistrus
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  | Infraspecific name =  
 
  | Infraspecific name =  
 
  | Taxon rank = species
 
  | Taxon rank = species
  | Taxon authority = Jonathan W. Armbruster, 2004
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  | Taxon authority = Armbruster, Jonathan W., 2004
 
  | Taxon status =  
 
  | Taxon status =  
  | Nomenclature citation = {{Nomenclature citation| ''{{Taxon name|Pseudancistrus sidereus}}'' Jonathan W. Armbruster, 2004, Zootaxa 628: 8-13.}}  
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  | Nomenclature citation = {{Nomenclature citation| ''{{Taxon name|Pseudancistrus sidereus}}'' Armbruster, Jonathan W., 2004, Zootaxa 628: 8-11.}}  
 
  | Wikispecies page name = Pseudancistrus_sidereus
 
  | Wikispecies page name = Pseudancistrus_sidereus
  | ZooBank ID = urn:lsid:zoobank.org:act:CB650BA4-2944-44D4-8690-7FCEBD43DE58
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  | ZooBank ID =  
 
  | Pensoft Profile = Pseudancistrus_sidereus
 
  | Pensoft Profile = Pseudancistrus_sidereus
 
}}
 
}}
  
{{Section|class=description|heading = Description|content=Fig. 3}}
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{{Section|class=materials_examined|heading = Materials Examined|content=[[Holotype]]:[[VENEZUELA]], Amazonas, Ro {{Taxon name|Lithoxancistrus orinoco|''Orinoco''}} dr.: MCNG26125, 175.6, Río Siapa from 10 to 15 km downstream, Río Casiquiare – Río Negro dr., 01.50000°, ­065.71667°, ABD and F. Morillo, 20 April 1991.
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[[Paratype|Paratypes]].[[VENEZUELA]], Amazonas, Río {{Taxon name|Lithoxancistrus orinoco|''Orinoco''}} dr.: MCNG 48261, 1, 1 CS, 149.8, AUM 37562, 1, 148.7, same data as [[holotype]]. FMNH 105294, 4, 149.5 ­ 176.7, Río {{Taxon name|Lithoxancistrus orinoco|''Orinoco''}} ca. 5 h above Atabapo by falca; at rocks and beach, B. Chernoff, A. and D. Machado, and J. Wheeler, 23 January 1991.}}
  
{{Section|id=type_material|heading = Type Material|content={{Collection Event
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{{Section|class=diagnosis|heading = Diagnosis|content=Diagnosis: {{Taxon name|Pseudancistrus sidereus|''Pseudancistrus sidereus''}} is diagnosed by a unique modification of the ventral plates on the caudal peduncle. In loricariids, the plates of the ventral row on the caudal peduncle are typically bent at an approximately 90 ° angle to follow the contour of the body. The bend is often the site of a slight keel formed from one or more rows of slightly longer odontodes. In {{Taxon name|Pseudancistrus sidereus|''P. sidereus''}}, the keel is accentuated by having the dorsal laminae of the plates strongly concave. Although some loricariids may have the dorsal laminae slightly concave, it is much more pronounced in P. s i d e re u s.
| Country = Venezuela
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{{Taxon name|Pseudancistrus sidereus|''Pseudancistrus sidereus''}} can be separated from all other species of the Ancistrini by the presence of the keel mentioned above and by the presence of a single large white to yellow spot located at the center of the posterior lateral plates. The only species with a similar coloration are some {{Taxon name|Hypancistrus|''Hypancistrus''}} and some {{Taxon name|Panaque|''Panaque''}}, both of which have far fewer than 25 teeth per jaw ramus (vs. much more than 25 teeth), some other species of {{Taxon name|Pseudancistrus|''Pseudancistrus''}} which have hypertrophied odontodes along the snout in males and females (vs. no hypertrophied snout odontodes), and have the dorsal fin reaching at least the preadipose plate when depressed (vs. about two plates anterior to preadipose plate); and some {{Taxon name|Hemiancistrus|''Hemiancistrus''}} and {{Taxon name|Peckoltia|''Peckoltia''}} which generally have the spots much more diffuse (vs. borders of spots distinct) and have the dorsal fin reaching at least the preadipose plate when depressed (vs. about two plates anterior to preadipose plate).}}
}}
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{{Collection Event
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| Country = Venezuela
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}}
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{{Collection Event
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| Country = Venezuela
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}}
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{{Collection Event
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| Country = Venezuela
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}}
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}}
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{{Section|class=diagnosis|heading = Diagnosis|content=Diagnosis: {{Taxon name|Pseudancistrus sidereus|''Pseudancistrus sidereus''|ZooBank LSID = urn:lsid:zoobank.org:act:CB650BA4-2944-44D4-8690-7FCEBD43DE58}} is diagnosed by a unique modification of the ventral plates on the caudal peduncle. In loricariids, the plates of the ventral row on the caudal peduncle are typically bent at an approximately 90° angle to follow the contour of the body. The bend is often the site of a slight keel formed from one or more rows of slightly longer odontodes. In {{Taxon name|Pseudancistrus sidereus|''P. sidereus''|ZooBank LSID = urn:lsid:zoobank.org:act:CB650BA4-2944-44D4-8690-7FCEBD43DE58}}, the keel is accentuated by having the dorsal laminae of the plates strongly concave. Although some loricariids may have the dorsal laminae slightly concave, it is much more pronounced in {{Taxon name|Pseudancistrus sidereus|''P. sidereus''|ZooBank LSID = urn:lsid:zoobank.org:act:CB650BA4-2944-44D4-8690-7FCEBD43DE58}}.
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{{Section|class=description|heading = Description|content=Description. Fairly large loricariids, largest specimen 176.7 mm SL. Body elongate, fairly narrow, and dorsoventrally flattened. Head and anterior part of trunk gently sloped from snout tip to dorsal­fin origin, dorsal profile of body straight to adipose fin with slight decrease in depth, dorsal profile of caudal peduncle very concave, shallowest at posterior insertion of adipose fin. Ventral surface flat.
{{Taxon name|Pseudancistrus sidereus|''Pseudancistrus sidereus''|ZooBank LSID = urn:lsid:zoobank.org:act:CB650BA4-2944-44D4-8690-7FCEBD43DE58}} can be separated from all other species of the Ancistrini by the presence of the keel mentioned above and by the presence of a single large white to yellow spot located at the center of the posterior lateral plates. The only species with a similar coloration are some {{Taxon name|Hypancistrus|''Hypancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:3F46C42E-67EB-4801-B2FE-F132B8D9E370}} and some {{Taxon name|Panaque|''Panaque''|ZooBank LSID = urn:lsid:zoobank.org:act:07C2F0C3-785D-4516-ACF2-A239A9197587}}, both of which have far fewer than 25 teeth per jaw ramus (vs. much more than 25 teeth), some other species of {{Taxon name|Pseudancistrus|''Pseudancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:65E9F392-A294-426E-9C9E-1695549A3390}} which have hypertrophied odontodes along the snout in males and females (vs. no hypertrophied snout odontodes), and have the dorsal fin reaching at least the preadipose plate when depressed (vs. about two plates anterior to preadipose plate); and some {{Taxon name|Hemiancistrus|''Hemiancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:2AC0D766-F761-4436-B6F4-395BBA997694}} and {{Taxon name|Peckoltia|''Peckoltia''|ZooBank LSID = urn:lsid:zoobank.org:act:CAAEE496-AF6C-4F5B-AFDD-F2E8E6519E80}} which generally have the spots much more diffuse (vs. borders of spots distinct) and have the dorsal fin reaching at least the preadipose plate when depressed (vs. about two plates anterior to preadipose plate).}}
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Head contours smooth. Slight, rounded ridge from anterolateral corner of nares, above orbit to posterior edge of pterotic­supracleithrum, dorsal margin of orbit higher than mesial portion of head. Mesethmoid slightly higher than lateral surface of head forming rounded ridge on snout, continued posterior to mesethmoid and terminating at level of posterior margin of orbits. Supraoccipital with slight posterior point medially. Following head bones supporting odontodes: frontal, infraorbitals, opercle, nasal, pterotic­supracleithrum, sphenotic, supraoccipital, and suprapreopercle.
 
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{{Section|class=description|heading = Description|content=Description. Fairly large loricariids, largest specimen 176.7 mm SL. Body elongate, fairly narrow, and dorsoventrally flattened. Head and anterior part of trunk gently sloped from snout tip to dorsal-fin origin, dorsal profile of body straight to adipose fin with slight decrease in depth, dorsal profile of caudal peduncle very concave, shallowest at posterior insertion of adipose fin. Ventral surface flat.
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Head contours smooth. Slight, rounded ridge from anterolateral corner of nares, above orbit to posterior edge of pterotic-supracleithrum, dorsal margin of orbit higher than mesial portion of head. Mesethmoid slightly higher than lateral surface of head forming rounded ridge on snout, continued posterior to mesethmoid and terminating at level of posterior margin of orbits. Supraoccipital with slight posterior point medially. Following head bones supporting odontodes: frontal, infraorbitals, opercle, nasal, pterotic-supracleithrum, sphenotic, supraoccipital, and suprapreopercle.
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Lips wide, fairly thin. Upper lip with wide, thin papillae. Lower lip with small papillae anteriorly, a band of larger papillae, and then smaller papillae posteriorly, papillae fading towards posterior edge. Maxillary barbel only barbel present, not reaching base of evertible cheek plates. Mouth with small, narrow buccal papilla. Iris with small dorsal flap, not reaching ventral to center of pupil.
 
Lips wide, fairly thin. Upper lip with wide, thin papillae. Lower lip with small papillae anteriorly, a band of larger papillae, and then smaller papillae posteriorly, papillae fading towards posterior edge. Maxillary barbel only barbel present, not reaching base of evertible cheek plates. Mouth with small, narrow buccal papilla. Iris with small dorsal flap, not reaching ventral to center of pupil.
25 plates in median series. Ventral plates forming a right angle on caudal peduncle with dorsal margin of plates concave forming a strong keel along lower portion of caudal peduncle. Dorsal plate series bent between dorsal and adipose fins to form slight ridge, ridges on two sides converging just posterior to insertion of adipose-fin spine. Inframedian plate series bent in middle from cleithrum to insertion of pelvic-fin forming slight keel. Abdomen naked except for some small, embedded plates laterally between pectoral and pelvic fins. Five rows of plates on caudal peduncle.
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25 plates in median series. Ventral plates forming a right angle on caudal peduncle with dorsal margin of plates concave forming a strong keel along lower portion of caudal peduncle. Dorsal plate series bent between dorsal and adipose fins to form slight ridge, ridges on two sides converging just posterior to insertion of adipose­fin spine. Inframedian plate series bent in middle from cleithrum to insertion of pelvic­fin forming slight keel. Abdomen naked except for some small, embedded plates laterally between pectoral and pelvic fins. Five rows of plates on caudal peduncle.
18-39 (average = 28, N=7) evertible cheek odontodes. Evertible cheek odontodes fairly short, longest reaches posterodorsal corner of opercular opening. Evertible cheek odontodes supported by plates than can be everted up to approximately 90° from the head. Hypertrophied cheek odontodes relatively weak. Single adult male with modestly hypertrophied odontodes on tip of pectoral-fin spine, females with odontodes on tip of pectoralfin spine slightly longer than those at base (Fig. 3).
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18–39 (average = 28, N= 7) evertible cheek odontodes. Evertible cheek odontodes fairly short, longest reaches posterodorsal corner of opercular opening. Evertible cheek odontodes supported by plates than can be everted up to approximately 90 ° from the head. Hypertrophied cheek odontodes relatively weak. Single adult male with modestly hypertrophied odontodes on tip of pectoral­fin spine, females with odontodes on tip of pectoralfin spine slightly longer than those at base (Fig. 3).
All fin spines and rays supporting odontodes. Dorsal fin II7; dorsal-fin spinelet V- shaped, dorsal-fin lock functional; dorsal-fin spine elongated relative to other fin rays in some specimens making edge of fin emarginate; dorsal fin not reaching adipose fin when adpressed. Adipose fin with single median preadipose plate and fairly long curved spine. Caudal fin I14I; caudal fin forked, lower lobe longer than upper; usually six dorsal and five ventral procurrent caudal-fin spines. Pectoral fin I6; pectoral-fin spine reaching posterior insertion of pelvic fin to slightly beyond base of pelvic fin when adpressed ventral to pelvic fin. Pelvic fin I5; pelvic-fin spine reaching end of base of anal fin when adpressed. Anal fin I4; unbranched anal-fin spine ray two thirds the length of the first branched ray. First anal-fin pterygiophore not exposed to form a platelike structure.
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All fin spines and rays supporting odontodes. Dorsal fin II 7; dorsal­fin spinelet Vshaped, dorsal­fin lock functional; dorsal­fin spine elongated relative to other fin rays in some specimens making edge of fin emarginate; dorsal fin not reaching adipose fin when adpressed. Adipose fin with single median preadipose plate and fairly long curved spine. Caudal fin I 14 I; caudal fin forked, lower lobe longer than upper; usually six dorsal and five ventral procurrent caudal­fin spines. Pectoral fin I 6; pectoral­fin spine reaching posterior insertion of pelvic fin to slightly beyond base of pelvic fin when adpressed ventral to pelvic fin. Pelvic fin I 5; pelvic­fin spine reaching end of base of anal fin when adpressed. Anal fin I 4; unbranched anal­fin spine ray two thirds the length of the first branched ray. First anal­fin pterygiophore not exposed to form a platelike structure.
Teeth very long and bicuspid with a longer, median lobe. 73-85 dentary teeth (median = 77, N=7). 78-93 premaxillary teeth (median = 84, N=7). Jaws very wide, dentaries forming a very oblique angle, premaxillaries forming a gentle arc.
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Teeth very long and bicuspid with a longer, median lobe. 73–85 dentary teeth (median = 77, N= 7). 78–93 premaxillary teeth (median = 84, N= 7). Jaws very wide, dentaries forming a very oblique angle, premaxillaries forming a gentle arc.
Color. Ground color dark brown dorsally and laterally, fading to tan on ventral half of inframedian plate series, tan ventrally. Head with small white spots (possibly yellow in life), spots getting larger posteriorly. Usually 2-3 spots per plate anteriorly and one posteriorly. Ventral spots lengthening dorsoventrally on inframedian and ventral plates series until fading into ventral coloration. Ventral surface of upper lip brown. Dorsal-fin membranes hyaline or with slight spotting; dorsal-fin spine and rays with oval spots. Adipose fin with weak spots or mottled. Caudal fin distinctly lighter ventrally; spots on ventral lobe fairly large and round and spots on dorsal lobe smaller and oval. Leading edge of pectoralfin spine light; pectoral-fin spine with or without spots; small round spots centered on pectoral-fin rays; color slightly fading posteriorly on pectoral fin. Pelvic fin with larger spots fading distally, spots on both rays and membrane. Anal fin tan or mottled.
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Color. Ground color dark brown dorsally and laterally, fading to tan on ventral half of inframedian plate series, tan ventrally. Head with small white spots (possibly yellow in life), spots getting larger posteriorly. Usually 2–3 spots per plate anteriorly and one posteriorly. Ventral spots lengthening dorsoventrally on inframedian and ventral plates series until fading into ventral coloration. Ventral surface of upper lip brown. Dorsal­fin membranes hyaline or with slight spotting; dorsal­fin spine and rays with oval spots. Adipose fin with weak spots or mottled. Caudal fin distinctly lighter ventrally; spots on ventral lobe fairly large and round and spots on dorsal lobe smaller and oval. Leading edge of pectoralfin spine light; pectoral­fin spine with or without spots; small round spots centered on pectoral­fin rays; color slightly fading posteriorly on pectoral fin. Pelvic fin with larger spots fading distally, spots on both rays and membrane. Anal fin tan or mottled.
Sexual dimorphism. One potentially nuptial male examined with hypertrophied odontodes on the sides similar to {{Taxon name|Peckoltia|''Peckoltia''|ZooBank LSID = urn:lsid:zoobank.org:act:CAAEE496-AF6C-4F5B-AFDD-F2E8E6519E80}} and {{Taxon name|Panaque|''Panaque''}} (Panaqolus), but shorter and sharper. Hypertrophied odontodes on pectoral-fin spine larger in the potentially nuptial male.}}
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Sexual dimorphism. One potentially nuptial male examined with hypertrophied odontodes on the sides similar to {{Taxon name|Peckoltia|''Peckoltia''}} and {{Taxon name|Panaque|''Panaque''}} ({{Taxon name|Panaqolus|''Panaqolus''}}), but shorter and sharper. Hypertrophied odontodes on pectoral­fin spine larger in the potentially nuptial male.
 
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Range: Known from the Río Casiquiare drainage and the upper Río {{Taxon name|Lithoxancistrus orinoco|''Orinoco''}} drainage of Amazonas, [[Venezuela]] (Fig. 4).}}
{{Section|class=distribution|heading = Distribution|content=Range: Known from the Rio Casiquiare drainage and the upper Rio Orinoco drainage of Amazonas, Venezuela (Fig. 4).}}
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{{Section|class=etymology|heading = Etymology|content=Etymology: From the Latin sidereus for starry. Named because the dark background makes the white to gold spots look like stars.}}
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{{Section|class=discussion|heading = Discussion|content=Discussion
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Even with the phylogeny of Armbruster (2004), it is difficult to assign basal members of the Ancistrini to genus. Many of the basal groups are without strong synapomorphies supporting the genera; however, {{Taxon name|Pseudancistrus|''Pseudancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:65E9F392-A294-426E-9C9E-1695549A3390}} is strongly supported by several characteristics. Although none of these characteristics are unique to {{Taxon name|Pseudancistrus|''Pseudancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:65E9F392-A294-426E-9C9E-1695549A3390}}, the genus is very well supported in the phylogenetic analysis with a decay value of five (Armbruster 2004).}}
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{{Section|class=discussion|heading = Discussion|content=The previous use of the lack of evertibility of cheek plates as a diagnostic characteristic in {{Taxon name|Pseudancistrus|''Pseudancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:65E9F392-A294-426E-9C9E-1695549A3390}} is weak. Some advanced species such as {{Taxon name|Pseudancistrus nigrescens|''P. nigrescens''|ZooBank LSID = urn:lsid:zoobank.org:act:E05A51CE-C823-48BC-B0A1-A7ECF620BAE3}} appear to have little ability to evert the cheek plates while some specimens of {{Taxon name|Pseudancistrus barbatus|''P. barbatus''}} appear to be able to evert the plates almost to the same degree as most other members of the Ancistrini (pers. obs.). All species of {{Taxon name|Pseudancistrus|''Pseudancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:65E9F392-A294-426E-9C9E-1695549A3390}} retain the modified opercle of the Ancistrini that is used as an aid to evert the cheek plates in most of the Ancistrini, and all retain hypertrophied odontodes on the cheek.
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{{Section|class=etymology|heading = Etymology|content=Etymology: From the Latin {{Taxon name|Pseudancistrus sidereus|''sidereus''}} for starry. Named because the dark background makes the white to gold spots look like stars.}}
{{Taxon name|Guyanancistrus|''Guyanancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:9D74B17A-8881-4E4E-A6DE-D0C62E4DEE65}} is not likely to be a monophyletic entity. Although only {{Taxon name|Pseudancistrus brevispinis|''Pseudancistrus brevispinis''}} has been examined osteologically, the species attributed to {{Taxon name|Guyanancistrus|''Guyanancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:9D74B17A-8881-4E4E-A6DE-D0C62E4DEE65}} vary from {{Taxon name|Pseudancistrus brevispinis|''P. brevispinis''}} that lacks hypertrophied odontodes along the snout and that has fully evertible cheek plates to {{Taxon name|Pseudancistrus niger|''P. niger''}} that develops at least small hypertrophied odontodes on the snout and that has the cheek plates very weakly evertible. No characteristics were given to diagnose the genus or separate it from any genus other than {{Taxon name|Lasiancistrus|''Lasiancistrus''}} in the original description (Isbruecker et al. 2001). {{Taxon name|Lasiancistrus|''Lasiancistrus''}} is a very well diagnosed genus that is not particularly closely related to {{Taxon name|Pseudancistrus|''Pseudancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:65E9F392-A294-426E-9C9E-1695549A3390}} (Armbruster 2004). {{Taxon name|Lasiancistrus|''Lasiancistrus''}} is readily identifiable from {{Taxon name|Pseudancistrus|''Pseudancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:65E9F392-A294-426E-9C9E-1695549A3390}} by having whiskerlike odontodes among the hypertrophied cheek odontodes and three rows of plates on the caudal peduncle (vs. 4-5 in {{Taxon name|Pseudancistrus|''Pseudancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:65E9F392-A294-426E-9C9E-1695549A3390}}; Armbruster 2004).
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{{Taxon name|Hemiancistrus megacephalus|''Hemiancistrus megacephalus''}} was transferred to {{Taxon name|Pseudancistrus|''Pseudancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:65E9F392-A294-426E-9C9E-1695549A3390}} by Armbruster (2004). The genus {{Taxon name|Hemiancistrus|''Hemiancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:2AC0D766-F761-4436-B6F4-395BBA997694}} is a mix of unrelated forms, and it remains one of the largest taxonomic problems in the Ancistrini (Armbruster 2004). The type species of {{Taxon name|Hemiancistrus|''Hemiancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:2AC0D766-F761-4436-B6F4-395BBA997694}} is {{Taxon name|Hemiancistrus medians|''H. medians''}}, and it differs from {{Taxon name|Pseudancistrus megacephalus|''P. megacephalus''}} mainly in color (it is almost the inverse of the color of {{Taxon name|Pseudancistrus megacephalus|''P. megacephalus''}}) and by slight differences in jaw morphology. I have not examined a skeleton of {{Taxon name|Hemiancistrus medians|''H. medians''}}, but it may also be related to {{Taxon name|Pseudancistrus|''Pseudancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:65E9F392-A294-426E-9C9E-1695549A3390}} because it is so similar to {{Taxon name|Pseudancistrus megacephalus|''P. megacephalus''}}. Because {{Taxon name|Hemiancistrus|''Hemiancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:2AC0D766-F761-4436-B6F4-395BBA997694}} is so confused taxonomically, decisions on where {{Taxon name|Hemiancistrus medians|''H. medians''}} fits, and any final decision on the fate of {{Taxon name|Hemiancistrus|''Hemiancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:2AC0D766-F761-4436-B6F4-395BBA997694}} await skeletal examination of {{Taxon name|Hemiancistrus medians|''H. medians''}}.
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The type of {{Taxon name|Pseudancistrus coquenani|''Pseudancistrus coquenani''|ZooBank LSID = urn:lsid:zoobank.org:act:1B3D4A9E-0C91-40B9-96D7-A0A6D23A978D}} has the enlarged papilla behind the dentary teeth that was used to diagnose {{Taxon name|Lithoxancistrus orinoco|''Lithoxancistrus orinoco''|ZooBank LSID = urn:lsid:zoobank.org:act:41A9FC79-E8EA-4D64-AF08-CA553689AD07}} (Isbruecker et al. 1988). It is likely that {{Taxon name|Pseudancistrus orinoco|''P. orinoco''}} and {{Taxon name|Pseudancistrus guentheri|''P. guentheri''}} are sisters based on this characteristic. Several other loricariids have a sister group relationship between species in the upper Rio Orinoco and the upper Rio Caroni including the two described species of {{Taxon name|Neblinichthys|''Neblinichthys''|ZooBank LSID = urn:lsid:zoobank.org:act:1A8841E9-92B3-489A-842F-9FA899B71F16}} and the two known species (one is undescribed) of {{Taxon name|Exastilithoxus|''Exastilithoxus''|ZooBank LSID = urn:lsid:zoobank.org:act:A8FD08FD-8A1E-4892-8287-3B1E60F436D3}} (Provenzano et al. 1995; pers. obs.). Although this range is currently disjunct, further collecting in the rivers between the upper Rio Orinoco and the upper Rio Caura may yield specimens similar to {{Taxon name|Pseudancistrus orinoco|''P. orinoco''}} and {{Taxon name|Pseudancistrus coquenani|''P. coquenani''|ZooBank LSID = urn:lsid:zoobank.org:act:1B3D4A9E-0C91-40B9-96D7-A0A6D23A978D}}.
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Isbruecker (2001) placed {{Taxon name|Pseudancistrus genisetiger|''Pseudancistrus genisetiger''|ZooBank LSID = urn:lsid:zoobank.org:act:1EE72C35-9169-4DE6-B101-D70CDC906C13}} and {{Taxon name|Pseudancistrus papariae|''P. papariae''|ZooBank LSID = urn:lsid:zoobank.org:act:1C23F531-5A44-4C2C-8BD2-6E0C83CFF88A}} in {{Taxon name|Lithoxancistrus|''Lithoxancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:377A602F-7922-4A09-B062-4D9BBD4C45FA}} without comment. These two species lack the dentary papillae used by Isbruecker et al. (1988) to diagnose {{Taxon name|Lithoxancistrus|''Lithoxancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:377A602F-7922-4A09-B062-4D9BBD4C45FA}} and appear to be advanced members of {{Taxon name|Pseudancistrus|''Pseudancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:65E9F392-A294-426E-9C9E-1695549A3390}} as the cheek plates are only weakly evertible.
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Isbruecker et al. (2001) place {{Taxon name|Hypostomus guacharote|''Hypostomus guacharote''|ZooBank LSID = urn:lsid:zoobank.org:act:0D61D19A-3684-498F-8C64-8CBA4999AB7B}} Valenciennes 1840 and {{Taxon name|Chaetostomus trinitatis|''Chaetostomus trinitatis''|ZooBank LSID = urn:lsid:zoobank.org:act:67252623-7C1B-4F6E-9015-2C6CBC8CA0BA}} Guenther 1864 into {{Taxon name|Guyanancistrus|''Guyanancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:9D74B17A-8881-4E4E-A6DE-D0C62E4DEE65}}. The type of {{Taxon name|Hypostomus guacharote|''H. guacharote''|ZooBank LSID = urn:lsid:zoobank.org:act:0D61D19A-3684-498F-8C64-8CBA4999AB7B}} (MNHN A-9567) is clearly a {{Taxon name|Lasiancistrus|''Lasiancistrus''}} (pers. obs.) as it has the whiskerlike odontodes on the cheek (Armbruster 2004). The type locality for {{Taxon name|Lasiancistrus guacharote|''L. guacharote''}}, new combination, is Puerto Rico; however, this species shares characteristics with specimens of {{Taxon name|Lasiancistrus|''Lasiancistrus''}} from the Lago Maracaibo basin of Venezuela (pers. obs.). No loricariids are known to naturally occur on Puerto Rico, and the island is located far to the north of the range of the Loricariidae suggesting that the locality is incorrect. {{Taxon name|Chaetostomus trinitatis|''Chaetostomus trinitatis''|ZooBank LSID = urn:lsid:zoobank.org:act:67252623-7C1B-4F6E-9015-2C6CBC8CA0BA}} was described by Guenther (1864) based on specimens reported by Gill (1858) from Trinidad. No type specimens are available for the species, the description of the species is inadequate to place the species within a genus of the Ancistrini, and the only loricariids I have examined from Trinidad are {{Taxon name|Ancistrus|''Ancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:35063369-E231-4E03-A49C-EE29CD36526F}} and {{Taxon name|Hypostomus|''Hypostomus''|ZooBank LSID = urn:lsid:zoobank.org:act:E0BC8DAD-9CD9-4E32-920A-063D33AD0E80}}. In all likelihood, {{Taxon name|Chaetostomus trinitatis|''C. trinitatis''|ZooBank LSID = urn:lsid:zoobank.org:act:67252623-7C1B-4F6E-9015-2C6CBC8CA0BA}} is a species of {{Taxon name|Ancistrus|''Ancistrus''|ZooBank LSID = urn:lsid:zoobank.org:act:35063369-E231-4E03-A49C-EE29CD36526F}}, and the species should be referred to as {{Taxon name|Ancistrus trinitatis|''Ancistrus trinitatis''}} new combination.}}
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==Taxon Treatment==
 
==Taxon Treatment==
*{{aut|Jonathan W. Armbruster}}; 2004: Pseudancistrus sidereus, a new species from southern Venezuela (Siluriformes: Loricariidae) with a redescription of Pseudancistrus., Zootaxa '''628''': 8-13. {{doi|TODO}}
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*{{aut|Armbruster, Jonathan W.}}; 2004: Pseudancistrus sidereus, a new species from southern Venezuela (Siluriformes: Loricariidae) with a redescription of Pseudancistrus, Zootaxa '''628''': 8-11. {{doi|TODO}}
  
 
[[Category:Work Pending at Plazi]]
 
[[Category:Work Pending at Plazi]]
  
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This page should be cited as follows (rationale):
Armbruster, Jonathan W. (2004) Pseudancistrus sidereus, a new species from southern Venezuela (Siluriformes: Loricariidae) with a redescription of Pseudancistrus. Zootaxa 628 : 8 – 11, doi. Versioned wiki page: 2016-04-19, version 92379, https://species-id.net/w/index.php?title=Pseudancistrus_sidereus&oldid=92379 , contributors (alphabetical order): PlaziBot.

Citation formats to copy and paste

BibTeX:

@article{Armbruster2004Zootaxa628,
author = {Armbruster, Jonathan W.},
journal = {Zootaxa},
title = {Pseudancistrus sidereus, a new species from southern Venezuela (Siluriformes: Loricariidae) with a redescription of Pseudancistrus},
year = {2004},
volume = {628},
issue = {},
pages = {8 -- 11},
doi = {TODO},
url = {},
note = {Versioned wiki page: 2016-04-19, version 92379, https://species-id.net/w/index.php?title=Pseudancistrus_sidereus&oldid=92379 , contributors (alphabetical order): PlaziBot.}

}

RIS/ Endnote:

TY - JOUR
T1 - Pseudancistrus sidereus, a new species from southern Venezuela (Siluriformes: Loricariidae) with a redescription of Pseudancistrus
A1 - Armbruster, Jonathan W.
Y1 - 2004
JF - Zootaxa
JA -
VL - 628
IS -
UR - http://dx.doi.org/TODO
SP - 8
EP - 11
PB -
M1 - Versioned wiki page: 2016-04-19, version 92379, https://species-id.net/w/index.php?title=Pseudancistrus_sidereus&oldid=92379 , contributors (alphabetical order): PlaziBot.

M3 - doi:TODO

Wikipedia/ Citizendium:

<ref name="Armbruster2004Zootaxa628">{{Citation
| author = Armbruster, Jonathan W.
| title = Pseudancistrus sidereus, a new species from southern Venezuela (Siluriformes: Loricariidae) with a redescription of Pseudancistrus
| journal = Zootaxa
| year = 2004
| volume = 628
| issue =
| pages = 8 -- 11
| pmid =
| publisher =
| doi = TODO
| url =
| pmc =
| accessdate = 2024-12-23

}} Versioned wiki page: 2016-04-19, version 92379, https://species-id.net/w/index.php?title=Pseudancistrus_sidereus&oldid=92379 , contributors (alphabetical order): PlaziBot.</ref>


Taxonavigation

Ordo: Siluriformes
Familia: Loricariidae
Genus: Pseudancistrus

Name

Pseudancistrus sidereus Armbruster, Jonathan W., 2004Wikispecies linkPensoft Profile

  • Pseudancistrus sidereus Armbruster, Jonathan W., 2004, Zootaxa 628: 8-11.

Materials Examined

Holotype:VENEZUELA, Amazonas, Ro Orinoco dr.: MCNG26125, 175.6, Río Siapa from 10 to 15 km downstream, Río Casiquiare – Río Negro dr., 01.50000°, ­065.71667°, ABD and F. Morillo, 20 April 1991. Paratypes.VENEZUELA, Amazonas, Río Orinoco dr.: MCNG 48261, 1, 1 CS, 149.8, AUM 37562, 1, 148.7, same data as holotype. FMNH 105294, 4, 149.5 ­ 176.7, Río Orinoco ca. 5 h above Atabapo by falca; at rocks and beach, B. Chernoff, A. and D. Machado, and J. Wheeler, 23 January 1991.

Diagnosis

Diagnosis: Pseudancistrus sidereus is diagnosed by a unique modification of the ventral plates on the caudal peduncle. In loricariids, the plates of the ventral row on the caudal peduncle are typically bent at an approximately 90 ° angle to follow the contour of the body. The bend is often the site of a slight keel formed from one or more rows of slightly longer odontodes. In P. sidereus, the keel is accentuated by having the dorsal laminae of the plates strongly concave. Although some loricariids may have the dorsal laminae slightly concave, it is much more pronounced in P. s i d e re u s. Pseudancistrus sidereus can be separated from all other species of the Ancistrini by the presence of the keel mentioned above and by the presence of a single large white to yellow spot located at the center of the posterior lateral plates. The only species with a similar coloration are some Hypancistrus and some Panaque, both of which have far fewer than 25 teeth per jaw ramus (vs. much more than 25 teeth), some other species of Pseudancistrus which have hypertrophied odontodes along the snout in males and females (vs. no hypertrophied snout odontodes), and have the dorsal fin reaching at least the preadipose plate when depressed (vs. about two plates anterior to preadipose plate); and some Hemiancistrus and Peckoltia which generally have the spots much more diffuse (vs. borders of spots distinct) and have the dorsal fin reaching at least the preadipose plate when depressed (vs. about two plates anterior to preadipose plate).

Description

Description. Fairly large loricariids, largest specimen 176.7 mm SL. Body elongate, fairly narrow, and dorsoventrally flattened. Head and anterior part of trunk gently sloped from snout tip to dorsal­fin origin, dorsal profile of body straight to adipose fin with slight decrease in depth, dorsal profile of caudal peduncle very concave, shallowest at posterior insertion of adipose fin. Ventral surface flat. Head contours smooth. Slight, rounded ridge from anterolateral corner of nares, above orbit to posterior edge of pterotic­supracleithrum, dorsal margin of orbit higher than mesial portion of head. Mesethmoid slightly higher than lateral surface of head forming rounded ridge on snout, continued posterior to mesethmoid and terminating at level of posterior margin of orbits. Supraoccipital with slight posterior point medially. Following head bones supporting odontodes: frontal, infraorbitals, opercle, nasal, pterotic­supracleithrum, sphenotic, supraoccipital, and suprapreopercle. Lips wide, fairly thin. Upper lip with wide, thin papillae. Lower lip with small papillae anteriorly, a band of larger papillae, and then smaller papillae posteriorly, papillae fading towards posterior edge. Maxillary barbel only barbel present, not reaching base of evertible cheek plates. Mouth with small, narrow buccal papilla. Iris with small dorsal flap, not reaching ventral to center of pupil. 25 plates in median series. Ventral plates forming a right angle on caudal peduncle with dorsal margin of plates concave forming a strong keel along lower portion of caudal peduncle. Dorsal plate series bent between dorsal and adipose fins to form slight ridge, ridges on two sides converging just posterior to insertion of adipose­fin spine. Inframedian plate series bent in middle from cleithrum to insertion of pelvic­fin forming slight keel. Abdomen naked except for some small, embedded plates laterally between pectoral and pelvic fins. Five rows of plates on caudal peduncle. 18–39 (average = 28, N= 7) evertible cheek odontodes. Evertible cheek odontodes fairly short, longest reaches posterodorsal corner of opercular opening. Evertible cheek odontodes supported by plates than can be everted up to approximately 90 ° from the head. Hypertrophied cheek odontodes relatively weak. Single adult male with modestly hypertrophied odontodes on tip of pectoral­fin spine, females with odontodes on tip of pectoralfin spine slightly longer than those at base (Fig. 3). All fin spines and rays supporting odontodes. Dorsal fin II 7; dorsal­fin spinelet Vshaped, dorsal­fin lock functional; dorsal­fin spine elongated relative to other fin rays in some specimens making edge of fin emarginate; dorsal fin not reaching adipose fin when adpressed. Adipose fin with single median preadipose plate and fairly long curved spine. Caudal fin I 14 I; caudal fin forked, lower lobe longer than upper; usually six dorsal and five ventral procurrent caudal­fin spines. Pectoral fin I 6; pectoral­fin spine reaching posterior insertion of pelvic fin to slightly beyond base of pelvic fin when adpressed ventral to pelvic fin. Pelvic fin I 5; pelvic­fin spine reaching end of base of anal fin when adpressed. Anal fin I 4; unbranched anal­fin spine ray two thirds the length of the first branched ray. First anal­fin pterygiophore not exposed to form a platelike structure. Teeth very long and bicuspid with a longer, median lobe. 73–85 dentary teeth (median = 77, N= 7). 78–93 premaxillary teeth (median = 84, N= 7). Jaws very wide, dentaries forming a very oblique angle, premaxillaries forming a gentle arc. Color. Ground color dark brown dorsally and laterally, fading to tan on ventral half of inframedian plate series, tan ventrally. Head with small white spots (possibly yellow in life), spots getting larger posteriorly. Usually 2–3 spots per plate anteriorly and one posteriorly. Ventral spots lengthening dorsoventrally on inframedian and ventral plates series until fading into ventral coloration. Ventral surface of upper lip brown. Dorsal­fin membranes hyaline or with slight spotting; dorsal­fin spine and rays with oval spots. Adipose fin with weak spots or mottled. Caudal fin distinctly lighter ventrally; spots on ventral lobe fairly large and round and spots on dorsal lobe smaller and oval. Leading edge of pectoralfin spine light; pectoral­fin spine with or without spots; small round spots centered on pectoral­fin rays; color slightly fading posteriorly on pectoral fin. Pelvic fin with larger spots fading distally, spots on both rays and membrane. Anal fin tan or mottled. Sexual dimorphism. One potentially nuptial male examined with hypertrophied odontodes on the sides similar to Peckoltia and Panaque (Panaqolus), but shorter and sharper. Hypertrophied odontodes on pectoral­fin spine larger in the potentially nuptial male. Range: Known from the Río Casiquiare drainage and the upper Río Orinoco drainage of Amazonas, Venezuela (Fig. 4).

Etymology

Etymology: From the Latin sidereus for starry. Named because the dark background makes the white to gold spots look like stars.

Taxon Treatment

  • Armbruster, Jonathan W.; 2004: Pseudancistrus sidereus, a new species from southern Venezuela (Siluriformes: Loricariidae) with a redescription of Pseudancistrus, Zootaxa 628: 8-11. doi
Link to Plazi.org

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