scholarly journals Description of a new Lithoxus (Siluriformes: Loricariidae) from the Guayana Highlands with a discussion of Guiana Shield biogeography

2008 ◽  
Vol 6 (3) ◽  
pp. 413-418 ◽  
Author(s):  
Nathan K. Lujan
Keyword(s):  
Posterior Margin ◽  
French Guiana ◽  
Guiana Shield ◽  
Unique Combination ◽  
Modern Distribution ◽  
Fin Rays ◽  
Adipose Fin ◽  
Clearwater River ◽  
Guayana Highlands ◽  
Oral Disk

Lithoxus jantjae, new species, is described from above Tencua Falls in headwaters of the Ventuari River, a white- to clearwater river flowing west from the Maigualida and Parima mountains in the Guayana Highlands of southern Venezuela. Lithoxus jantjae represents a nearly 600 km westward range expansion for a genus historically known only from Guyana, Suriname, French Guiana, and Brazil. Lithoxus jantjae shares with other species of Lithoxus a dorsoventrally depressed body and a large, papilose oral disk with small toothcups and few teeth. It can be distinguished from congeners by a unique combination of characters including 12 branched caudal-fin rays, medial premaxillary tooth cusps enlarged, and a convex posterior margin of the adipose-fin membrane. With the discovery of L. jantjae, Lithoxus becomes the most recent example of a growing list of rheophilic loricariid genera with disjunct distributions on east and west sides of the Guayana Highlands. A biogeographic hypothesis relying on the existence of a proto-Berbice River uniting the southern Guayana Highlands with rivers of the central Guiana Shield is advanced to partially explain the modern distribution of these species.

Acrochordonichthys gyrinus, a new species of akysid catfish (Teleostei: Siluriformes) from Thailand

Zootaxa ◽  
2003 ◽  
Vol 183 (1) ◽  
pp. 1 ◽  
Author(s):  
CHAVALIT VIDTHAYANON ◽  
HEOK HEE NG
Keyword(s):  
New Species ◽  
Posterior Margin ◽  
Anterior Margin ◽  
Species Group ◽  
Unique Combination ◽  
Maximum Width ◽  
Body Depth ◽  
Adipose Fin ◽  
Chao Phraya River ◽  
A New Species

Acrochordonichthys gyrinus, a new species of akysid catfish belonging to the A. ischnosoma species group, is described from the Chao Phraya River drainage in Thailand. It can be distinguished from congeners by a concave posterior margin of the pectoral fin and the unique combination of the following characteristics: head depth 9.8–11.4% SL; dorsal to adipose distance 7.4–8.6% SL; body depth at anus 8.3–10.5% SL; maximum width of humeral process 16.3% its length; and anterior margin of anal fin and posterior margin of adipose fin straight. This species represents the northernmost distribution of the genus.

Hyphessobrycon petricolus, a new species of tetra (Characiformes: Characidae) from the rio Madeira basin, Mato Grosso, Brazil

Zootaxa ◽  
2017 ◽  
Vol 4221 (2) ◽  
pp. 242 ◽  
Author(s):  
WILLIAN M. OHARA ◽  
FLÁVIO C. T. LIMA ◽  
BRUNO S. BARROS
Keyword(s):  
New Species ◽  
Posterior Margin ◽  
Unique Combination ◽  
Caudal Fin ◽  
Mato Grosso ◽  
Fin Rays ◽  
A New Species ◽  
Rio Madeira

A new species of Hyphessobrycon is described from the rio Roosevelt, rio Madeira basin, Mato Grosso State, Brazil. Hyphessobrycon petricolus sp. n. can be distinguished from its congeners by the unique combination of the following features: a well-defined, relatively narrow dark midlateral stripe on body extending from immediately behind posterior margin of opercle to the middle caudal-fin rays, relatively conspicuous humeral blotch, and 16–20 branched anal-fin rays. Comments on the remaining Hyphessobrycon species presenting a conspicuous dark midlateral stripe are presented. 

scholarly journals Chrysobrycon yoliae, a new species of stevardiin (Characiformes: Characidae) from the Ucayali basin, Peru

2014 ◽  
Vol 12 (2) ◽  
pp. 291-300 ◽  
Author(s):  
James Anyelo Vanegas-Ríos ◽  
María de las Mercedes Azpelicueta ◽  
Hernán Ortega
Keyword(s):  
New Species ◽  
Posterior Margin ◽  
The Body ◽  
Pelvic Bone ◽  
Body Depth ◽  
Dorsal Fin ◽  
Fin Rays ◽  
Adipose Fin ◽  
Fin Length ◽  
A New Species

Chrysobrycon yoliae, new species, is described from a drainage flowing into the río Yucamia basin, río Ucayali basin, Peru. Chrysobrycon yoliaeis readily distinguished from its congeners by the anterior tip of pelvic bone situated anterior to the fifth rib (vs. situated posterior to the fifth rib), the presence of 20-26 dentary teeth (vs. 11-19), and the possession of a terminal lateral-line tube between caudal-fin rays 10 and 11 (vs. the absence of this tube, except in C. eliasi). The new species differs from C. eliasiand C. myersiby the presence of teeth on third pharyngobranchial (vs. the absence of teeth on this bone) and also differs from C. eliasiby the dorsal-fin origin situated at vertical through anal-fin rays 5 to 7 (vs. located at vertical through anal-fin rays 8 to 10), the posterior extent of the ventral process of quadrate reaching the vertical through posterior margin of symplectic (vs. not reaching the vertical through posterior margin of symplectic), the dorsal-fin to adipose-fin length 26.8-28.8% SL (vs. 23.9-26.8% SL), and the body depth at dorsal-fin origin 34.4-42.2% SL (vs. 24.1-34.5% SL). A key for the identification of Chrysobryconspecies is provided.

Leiocassis rudicula (Teleostei: Siluriformes: Bagridae), a new catfish from eastern Borneo

Zootaxa ◽  
2019 ◽  
Vol 4651 (1) ◽  
pp. 191-200
Author(s):  
HEOK HEE NG ◽  
RENNY K. HADIATY
Keyword(s):  
New Species ◽  
Posterior Margin ◽  
Unique Combination ◽  
Caudal Peduncle ◽  
Body Depth ◽  
Dorsal Fin ◽  
Brown Band ◽  
Eye Diameter ◽  
Adipose Fin ◽  
A New Species

A new species of bagrid catfish in the genus Leiocassis is described from the Mahakam River drainage in eastern Borneo. Leiocassis rudicula, new species, can be distinguished from congeners in having a unique combination of: distinct concavity at level of orbit in dorsolateral profile of head; tip of supraoccipital spine not reaching anterior nuchal plate element; smooth posterior margin of dorsal spine; presence of an irregular pale band on sides of body between dorsal and adipose fins; anal fin with narrow brown band across middle third of fin; narrow caudal-fin lobes with nearly straight posterior margins; snout length 36–40% HL; eye diameter 14–20% HL; head depth 17.6–20.0% SL; length of dorsal-fin spine 14.1–18.5% SL; length of pectoral-fin spine 15.1–17.7 %SL; dorsal-to-adipose distance 10.9–14.3% SL; body depth at anus 16.4–19.5% SL; length of adipose-fin base 18.9–24.1% SL; length of anal-fin base 18.8–22.6% SL; and caudal peduncle depth 9.1–10.9% SL. A revised key to the genus is also provided. 

Description of two new species of Lithoxus (Hypostominae: Loricariidae) from rio Jari and rio Amapá basins, Brazilian Guiana Shield

Zootaxa ◽  
2017 ◽  
Vol 4347 (1) ◽  
pp. 151 ◽  
Author(s):  
GABRIEL S. C. SILVA ◽  
RAPHAEL COVAIN ◽  
CLAUDIO OLIVEIRA ◽  
FÁBIO F. ROXO
Keyword(s):  
New Species ◽  
Color Pattern ◽  
The Body ◽  
Guiana Shield ◽  
Caudal Peduncle ◽  
Number Of Teeth ◽  
Two New Species ◽  
Fin Rays ◽  
Adipose Fin ◽  
Fin Length

Two new species of Lithoxus, a genus diagnosed by possessing a dorsoventrally depressed body, a large round oral disk, and small tooth cusps with few teeth, are described from two drainages of the Guiana Shield: Lithoxus jariensis from the rio Jari basin and L. raso from the rio Raso, rio Amapá basin. The new species, L. jariensis, is distinguished from congeners by having an adipose fin, by the number of branched anal-fin and caudal-fin rays, by color pattern of the body, number of teeth, adipose-fin length, dorsal adipose-caudal distance, caudal peduncle depth, cleithral width, and dorsal-anal distance. Lithoxus raso can be diagnosed from congeners by coloration pattern, by having an adipose fin, by the number of branched anal-fin rays, number of teeth, adipose-fin length, dorsal adipose–caudal distance, caudal peduncle depth, and cleithral width. Greater genetic divergence in mitochondrial cytochrome oxidase subunit I (COI) confirms L. jariensis and L. raso as two new species. 

scholarly journals Human Q Fever on the Guiana Shield and Brazil: Recent Findings and Remaining Questions

2021 ◽  
Author(s):  
Loïc Epelboin ◽  
Carole Eldin ◽  
Pauline Thill ◽  
Vincent Pommier de Santi ◽  
Philippe Abboud ◽  
...  
Keyword(s):  
South America ◽  
Geographical Distribution ◽  
Coxiella Burnetii ◽  
French Guiana ◽  
Q Fever ◽  
Guiana Shield ◽  
Animal Reservoir ◽  
The World ◽  
Unique Strain ◽  
Amazonian Region

Abstract Purpose of Review In this review, we report on the state of knowledge about human Q fever in Brazil and on the Guiana Shield, an Amazonian region located in northeastern South America. There is a contrast between French Guiana, where the incidence of this disease is the highest in the world, and other countries where this disease is practically non-existent. Recent Findings Recent findings are essentially in French Guiana where a unique strain MST17 has been identified; it is probably more virulent than those usually found with a particularly marked pulmonary tropism, a mysterious animal reservoir, a geographical distribution that raises questions. Summary Q fever is a bacterial zoonosis due to Coxiella burnetii that has been reported worldwide. On the Guiana Shield, a region mostly covered by Amazonian forest, which encompasses the Venezuelan State of Bolivar, Guyana, Suriname, French Guiana, and the Brazilian State of Amapá, the situation is very heterogeneous. While French Guiana is the region reporting the highest incidence of this disease in the world, with a single infecting clone (MST 117) and a unique epidemiological cycle, it has hardly ever been reported in other countries in the region. This absence of cases raises many questions and is probably due to massive under-diagnosis. Studies should estimate comprehensively the true burden of this disease in the region.

New species and records of Chasmogenus Sharp, 1882 from the southwestern margin of the Guiana Shield (Coleoptera: Hydrophilidae: Acidocerinae)

Zootaxa ◽  
2021 ◽  
Vol 5048 (3) ◽  
pp. 435-443
Author(s):  
RACHEL D. GLYNN ◽  
ANDREW EDWARD Z. SHORT
Keyword(s):  
New Species ◽  
Male Genitalia ◽  
French Guiana ◽  
Molecular Data ◽  
Integrative Approach ◽  
Guiana Shield ◽  
Adult Morphology ◽  
Northern Brazil ◽  
Southwestern Margin ◽  
Three New Species

The Neotropical water scavenger beetle genus Chasmogenus Sharp, 1882 is a diverse lineage with 34 described species. Here, three new species from the southwestern margin of the Guiana Shield are described using an integrative approach combining adult morphology and molecular data: Chasmogenus clinatus sp. n. (Brazil: Amazonas, Venezuela: Amazonas), C. gironae sp. n. (Venezuela: Amazonas), and C. inpa sp. n. (Brazil: Amazonas). Examination of the male genitalia is essential for confident identifications and thus unassociated females may prove extremely difficult to identify. New distributional records in Brazil for C. acuminatus Smith & Short, 2020 are provided as well as habitus images of newly described species and an updated key to the species from Venezuela, Suriname, Guyana, French Guiana and northern Brazil.  

scholarly journals New species of Cyphocharax (Characiformes: Curimatidae) from the upper rio Negro, Amazon basin

2014 ◽  
Vol 12 (2) ◽  
pp. 327-332 ◽  
Author(s):  
Bruno F. Melo ◽  
Richard P. Vari
Keyword(s):  
New Species ◽  
Amazon Basin ◽  
Caudal Peduncle ◽  
Caudal Fin ◽  
Rio Negro ◽  
Fin Rays ◽  
Dark Pigmentation ◽  
Northern Brazil ◽  
Adipose Fin ◽  
A New Species

A new species of Cyphocharax, Curimatidae, apparently endemic to the blackwater upper rio Negro of the Amazon basin in northern Brazil, is described.The new species is readily distinguished from its congeners by the presence of a distinctly longitudinally elongate, posteriorly vertically expanding patch of dark pigmentation along the midlateral surface of the caudal peduncle, with the patch extending from the base of the middle caudal-fin rays anteriorly past the vertical through the posterior terminus of the adipose fin. The new species additionally differs from all congeners in details of body and fin pigmentation and meristic and morphometric ratios. Evidence for the assignment of the species to Cyphocharax and the occurrence of other species of the Curimatidae apparently endemic to the upper rio Negro catchment is discussed.

scholarly journals Two new species of Hyphessobrycon (Teleostei: Characidae) from upper rio Tapajós basin on Chapada dos Parecis, central Brazil

2006 ◽  
Vol 4 (3) ◽  
pp. 301-308 ◽  
Author(s):  
Tiago Pinto Carvalho ◽  
Vinicius Araújo Bertaco
Keyword(s):  
New Species ◽  
Posterior Margin ◽  
Caudal Fin ◽  
Mato Grosso ◽  
Central Brazil ◽  
Dorsal Fin ◽  
Two New Species ◽  
Fin Rays ◽  
Black Band

Two new species of Hyphessobrycon are described from the upper rio Tapajós basin, Mato Grosso, Brazil. Hyphessobrycon melanostichos is distinguished from its congeners by the combination of a conspicuous longitudinal broad black band beginning on the posterior margin of orbit and reaching the tip of middle caudal fin rays, a distinct vertically elongate humeral spot, and 16 to 18 branched anal-fin rays. Hyphessobrycon notidanos is distinguished from its congeners by the combination of an elongate dorsal fin in mature males, a vertically elongate humeral spot, 2-4 maxillary teeth, iii,8 dorsal-fin rays, and 16 to 21 branched anal-fin rays.

scholarly journals Gobiesox lanceolatus, a new species of clingfish (Teleostei:  Gobiesocidae) from Los Frailes submarine canyon, Gulf of California, Mexico

Zootaxa ◽  
2017 ◽  
Vol 4221 (3) ◽  
pp. 393 ◽  
Author(s):  
PHILIP A. HASTINGS ◽  
KEVIN W. CONWAY
Keyword(s):  
New Species ◽  
Posterior Margin ◽  
Gulf Of California ◽  
Baja California ◽  
Submarine Canyon ◽  
Single Specimen ◽  
Dorsal Fin ◽  
Fin Rays ◽  
A New Species ◽  
Pectoral Fin Rays

Gobiesox lanceolatus is described from a single specimen collected from 300 meters depth in the Los Frailes submarine canyon in the southwestern Gulf of California. The "Canyon Clingfish" is unique within Gobiesox in having a lanceolate caudal fin, with the central rays longer than those above and below them. It is also distinguished by 14 dorsal-fin rays (first tiny and unsegmented), 11 anal-fin rays, 28 pectoral-fin rays, anus slightly closer to anal-fin origin than to posterior margin of pelvic disc, and dorsal-fin origin in front of vertical from anus. It is most similar to Gobiesox eugrammus, known from Isla Guadelupe, the coast of outer Baja California and southern California. This is the deepest record for a species of Gobiesox and only four other species of clingfishes are known from greater depths. 

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