Caudal Peduncle Spot Research Articles

Analysis of a new species of the Astyanax orthodus group (Characiformes: Characidae) from the upper Madre de Dios River, Amazon River Basin, Peru

Based on ten specimens, using morphometric, meristic and osteological characters, Astyanax leoni n. sp. is described from the upper Madre de Dios River drainage, Amazon River Basin of Peru. A. leoni n. sp. is a member of the Astyanax orthodus species group and is distinguished (except from A. multidens, A. villwocki, and A. gandhiae) in having an inconspicuous rod-shaped stripe on the caudal peduncle that extends anteriorly on top of a silver lateral stripe. It differs from the species mentioned above as follows: from A. multidens by having shorter chevron marks that cover up to only two series of scales above and below the apex of the chevron (vs. chevrons taller, with extensions that cover three series of scales); from A. villwocki by having chevron markings along the entire body (vs. no chevrons on the caudal peduncle); It differs from Astyanax gandhiae in having the caudal peduncle spot extending anteriorly to beyond the tip of the dorsal fin (vs. caudal peduncle spot not reaching anteriorly to tip of dorsal fin), and not of a uniform width as in A. villwocki. A dichotomous key to the species of Astyanax orthodus group is included.

Pethia chakpiensis (Cyprinidae), a New Species of Cyprinid Fish from the Chindwin-Irrawaddy Drainage of Manipur, India

Pethia chakpiensis sp. nov. is described from the Chakpi River of the Chindwin-Irrawaddy drainage in Manipur, India. This new species is characterized in having an incomplete lateral line with 4–7 pored scales, 21–24 scales in lateral series; 15 preanal scales; intercalated scale row originates above and after the 5th scale of lateral line scale row; absence of humeral spot; caudal peduncle spot on the 17th and 18th lateral series scales and a longitudinal stripe along the flank.

Redescription of Astyanax brevoortii (Gill, 1858) (Characiformes, Characidae) and description of three new species of Astyanax subgenus Poecilurichthys, from Caribbean Sea basins, Venezuela

In Astyanax (Poecilurichthys), we recognize six species-groups defined by the distribution of melanophores on the body: 1. bimaculatus; 2. rupununi; 3. abramis: 4. orthodus; 5. asuncionensis; and 6. anterior, which are named for a representative species. Astyanax brevoortii1 is redescribed using specimens from Trinidad (including types). This species, as a member of the bimaculatus species-group, is distinguished by lacking a concentration of melanophores outlining the scale margins on the sides of body. Three new species of the bimaculatus species-group are described: A. caroni n. sp. from the Caroni River drainage, which differs in having all of the teeth of the internal premaxillary series pentacuspid (vs. heptacuspid), and the length of the caudal-peduncle spot which is less than two times the eye diameter (vs. at least twice eye diameter). A. garuttii n. sp. from the San Juan River and Gulf of Cariaco drainages is distinguished by osteological characters and by morphological characters identified by principal component analysis. A. cuyuni n. sp. from the Cuyuni River (Essequibo River Basin), is distinguished by having a foramen in the pterotic and sphenotic bones (vs. absent), and the shape of the last two neural spines that form a posteriorly directed arc, that covers the epineurals.

Redescription of Astyanax brevoortii (Gill, 1858) (Characiformes, Characidae) and description of three new species of Astyanax subgenus Poecilurichthys, Caribbean Sea, Venezuela

In Astyanax (Poecilurichthys), we recognize six species-groups defined by the distribution of melanophores on the body: 1. bimaculatus; 2. rupununi; 3. abramis: 4. orthodus; 5. asuncionensis; and 6. anterior, which are named for a representative species. Astyanax brevoortii1 is redescribed using specimens from Trinidad (including types). This species, as a member of the bimaculatus species-group, is distinguished by lacking a concentration of melanophores outlining the scale margins on the sides of body. Three new species of the bimaculatus species-group are described: A. caroni n. sp. from the Caroni River drainage, which differs in having all of the teeth of the internal premaxillary series pentacuspid (vs. heptacuspid), and the length of the caudal-peduncle spot which is less than two times the eye diameter (vs. at least twice eye diameter). A. garuttii n. sp. from the San Juan River and Gulf of Cariaco drainages is distinguished by osteological characters and by morphological characters identified by principal component analysis. A. cuyuni n. sp. from the Cuyuni River (Essequibo River Basin), is distinguished by having a foramen in the pterotic and sphenotic bones (vs. absent), and the shape of the last two neural spines that form a posteriorly directed arc, that covers the epineurals.

A new glass tetra species of Phenacogaster from the rio Salitre, rio São Francisco drainage, Brazil (Characiformes: Characidae)

ABSTRACT A new species of Phenacogaster is described from the rio Salitre, a tributary of the lower middle rio São Francisco drainage. The new species can be clearly distinguished from all its congeners in having a conspicuous, broad caudal peduncle spot reaching the upper and lower margins of the peduncle with a short extension onto the middle caudal fin rays and another weaker extension over the lower lobe of the caudal fin.

Review of species of the Astyanax bimaculatus "caudal peduncle spot" subgroup sensu Garutti & Langeani (Characiformes, Characidae) from the rio La Plata and rio São Francisco drainages and coastal systems of southern Brazil and Uruguay.

The species of the Astyanax bimaculatus 'caudal peduncle spot' subgroup of the drainages of the rios La Plata and São Francisco, as well as southeastern coastal systems of Brazil and Uruguay, are revised. Two nominal species are considered valid and are redescribed: Astyanax lacustris and A. abramis. Astyanax jacuhiensis, A. asuncionensis and A. altiparanae are recognized as new junior synonyms of A. lacustris. Bertoniolus paraguayensisis recognized as a new junior synonym of A. abramis. The names Astyanax orbignyanus, A. vittatus, and A. borealis are considered species inquirendae. Notes on A. maculisquamis, included in the 'caudal peduncle spot' subgroup from rio Guaporé (rio Madeira drainage), and Astyanax bahiensis from Bahia, mistakenly considered of the same subgroup, are presented.

A new species of Moenkhausia Eigenmann (Characiformes: Characidae) from the upper rio Machado at Chapada dos Parecis, rio Madeira basin, Brazil

ABSTRACT A new species of Moenkhausia is described from the upper rio Machado at Chapada dos Parecis, rio Madeira basin, Rondônia State, Brazil. Among congeners, the new species is similar to Moenkhausia chlorophthalma, M. cotinho , M. lineomaculata , M. plumbea, and M. petymbuaba by having dark blotches on the anterior portion of the body scales, which are absent in the remaining species of the genus. The new speciesdiffers from aforementioned species by possessing blue eyes in life, 15-18 branched anal-fin rays, and a well-defined, round caudal-peduncle spot that does not reach the upper and lower margins of the caudal peduncle and does not extend to the tip of the middle caudal-fin rays.

Description of two new species of Laubuka (Teleostei: Cyprinidae) from River Cauvery, southern Iandia.

Fishes currently identified as Laubuka laubuca from the Cauvery River and its tributaries in the Western Ghats of India are shown to represent two different species: Laubuka trevori, sp. nov., and L. latens, sp. nov., distinguished from all species of Chela and Laubuka by possessing 7½ branched dorsal-fin rays; 14 precaudal vertebrae; 17-18 predorsal scales; 5 branched pelvic-fin rays and 5+4+2 teeth on the fifth ceratobranchial. Laubuka trevori is further distinguished from its congeners by possessing 14½-15½ branched anal-fin rays; ½6/1/1½ scales in transverse line on body; a short pelvic fin (10.1-16.3% SL) and two longitudinal stripes: a golden and a bluish-green stripe on the body, running from behind the opercle to the base of the caudal fin, the latter broken and less distinct in the anterior half of the body. Laubuka latens is further distinguished by its long pelvic fin (23.2-26.9% SL) and the absence of any markings on the side of the body other than a humeral spot and a caudal-peduncle spot.

Hyphessobrycon natagaima (Characiformes: Characidae) a new species from Colombia, with a key to the Magdalena Basin Hyphessobrycon species

<p>A new species, Hyphessobrycon natagaima, is described from the upper Magdalena River Basin in Colombia. It differs from all other species of Hyphessobrycon with a dark lateral stripe inhabiting the Magdalena River Basin: H. poecilioides, H. proteus and H. ocasoensis, by having eight to twelve pored lateral-line scales (vs. 14-26); four scales between the lateral line and the pelvic-fin insertions (vs. five or six); one tooth on the maxilla (vs. zero in H. poecilioides, and two to five in H. proteus; except H. ocasoensis, with one), a dark, interrupted, lateral stripe that is not in contact with the caudal peduncle spot (vs. absence of caudal spot in H. poecilioides, lateral stripe continued that is in contact with the caudal peduncle spot in H. ocasoensis). It has a rhomboid shaped caudal-peduncle spot that continues on to middle caudal-fin rays (vs. absence of caudal peduncle spot in H. poecilioides and caudal peduncle spot round and not continued on to middle caudal-fin rays in H. ocasoensis); and presence of hooks on all fins in mature males (vs. males with hooks on anal, pelvic and pectoral fins). Hyphessobrycon natagaima differs from H. ocasoensis, in addition to the above characters, by having four scale rows between the lateral line and the anal-fin origin (vs. six); three or four scale rows between the lateral line and the pelvic-fin insertions (vs. six); ten or eleven predorsal scales (vs. nine); i,9,i dorsal-fin rays (vs. ii,8,i); 18-20 branched anal-fin rays (vs. 21-22) and eleven branched pectoral-fin rays (vs. twelve). A key for the identification of Hyphessobrycon species present in the Magdalena River Basin is provided.</p>

A new species of Bryconamericus (Characiformes, Stevardiinae, Characidae) from the Pacific coast of northwestern Ecuador, South America

A new species of Bryconamericus (Characiformes, Characidae, Stevardiinae) is described from the Pacific coast of northwestern Ecuador, South America. The new species is distinguished from all congeners by the presence in males of bony hooks on the caudal fin rays (vs. absence). The different layers of pigment that constitute the humeral spots have differing degrees of development and structure that are independent of each other. Brown melanophores are distributed in a thin, vertical, superficial layer of the epithelium (layer 1) and in another deeper (layer 2) that overlaps the first and is centered over the lateral–line. B. ecuadorensis has a horizontally oval or elliptical shape layer 2 pigment in the anterior humeral spot (vs. a rectangular or circular layer 2). The new species further differs in having an anterior extension of the caudal peduncle spot (vs. no anterior extension of the caudal peduncle spot) and by having a dark lateral stripe overlaid by the peduncular spot and by the regularly distributed pigmentation on scales on the sides of the body (vs. peduncular spot and other body pigments not superimposed over a dark lateral stripe). Hooks present on all fins of males (vs. hooks present only on anal and pelvic fins of males) distinguishes the new species from B. dahli, the only sympatric congener. Seven other diagnostic characters separating the new taxon from B. dahli are reported. We also include physical, chemical and biological habitat parameters and analyse the impacts from mining on this new species and other organisms present at the type locality.

A new species of Astyanax Baird & Girard (Ostariophysi: Characidae) from the rio Taquari-Antas basin, southern Brazil

A new Astyanax is described from the rio Taquari-Antas basin, rio Jacuí drainage, laguna dos Patos system, Rio Grande do Sul State, Brazil. The new species is distinguished from its congeners inhabiting the rio Uruguay, laguna dos Patos and rio Tramandaí basins by the presence of two vertically elongated humeral spots, the anterior humeral spot with the upper portion wider than the lower portion and slightly directed forward, 37-39 perforated scales along the lateral line, 14 scale rows around caudal peduncle, 2-4 maxillary tricuspid teeth, 24-28 branched anal-fin rays, bony hooks on all fins of mature males, and conspicuous caudal peduncle spot. Furthermore, the new species differs from its congeners by body depth (37.9-45.9% of standard length), preanal distance (62.4-69.1% of SL), anal-fin base length (29.7-35.6% of SL), and orbital diameter (29.5-38.2% of head length).

New species of Bryconamericus Eigenmann (Characiformes: Characidae)from the rio Teles Pires, rio Tapajós basin, central Brazil.

A new species of Bryconamericus is described from the rio Teles Pires, a tributary of the rio Tapajós. The new taxon can be distinguished from its congeners by having a short anal fin with 11-13 branched rays, two maxillary teeth, four outer premaxillary teeth, and 34-38 perforated lateral-line scales. Other diagnostic characters of the species are the absence of a caudal-peduncle spot and the presence of a pigmented vertical band at the caudal-fin rays base. The phylogenetic position of the new species is inferred based in two available phylogenetic hypotheses, and a discussion on its generic placement is provided.

A new species of Hyphessobrycon Durbin (Characiformes: Characidae) from the middle rio São Francisco and upper and middle rio Tocantins basins, Brazil, with comments on its biogeographic history

A new species of Hyphessobrycon Durbin is described from tributaries of the rio Grande (rio São Francisco basin) draining east to the Serra Geral de Goiás, of the rio São Domingos (upper rio Tocantins basin) and rio do Sono basins (middle rio Tocantins basin). Hyphessobrycondiastatos can be diagnosed from its congeners by the absence of humeral spot, 15-18 branched anal-fin rays, 1-3 maxillary conical to tricuspid teeth, a relatively well-defined dark caudal-peduncle spot, and elongation of dorsal- and anal-fin rays in mature males. The biogeographical significance of the distribution of the new species is evaluated and discussed.

Description of Apistogramma allpahuayo sp. n., a new dwarf cichlid species (Teleostei: Perciformes: Geophaginae) from in and around the Reserva Nacional Allpahuayo Mishana, Loreto, Peru

A new species of Apistogramma is described from Peru, based on a total of 51 specimens collected in small forest brooks in and around the Reserva Nacional Allpahuayo Mishana in the drainage of the Nanay river basin about 30 kilometres southwest of Iquitos, Departamento Loreto (approximately 73° 25’ W/03° 59’ S). Apistogramma allpahuayo sp. n. is distinguished from all other Apistogramma species by the combination of black w-shape marking on lower jaw, (in adult males) lyrate caudal fin, massive jaws and hypertrophied orange lips, distinct roundish caudal-peduncle spot clearly separated from lateral band ending at vertical bar 7, serrated dorsal fin with conspicuous extensions of first membranes, and proportions of dorsal-fin spines differing from those otherwise typical within genus. Apistogramma allpahuayo sp. n. is thought to be a representative of the Apistogramma cacatuoides complex within the Apistogramma cacatuoides lineage.

Apistogramma barlowi sp. n. - description of a new facultative mouth-brooding cichlid species (Teleostei: Perciformes: Geophaginae) from Northern Peru

Apistogramma barlowi sp. n. is described based on a total of 32 specimens from small tributaries of the Rio Ampiyacu near the village of El Pozo, District Santa Maria, Province Mariscal Ramon Castilla, Departamento Loreto, Peru (near 71°55 ́W and 03°10 ́S). Apistogramma barlowi sp. n. is separated from all other Apistogramma species by the combination of over-proportionally large head and jaws, in males lyrate caudal-fin horizontally divided in two colour zones, extended first membranes of the dorsal fin, a distinct breast band in basal part of vertical bar 2 and posterior lateral spot in females, missing caudal peduncle spot, and, unique in Apistogramma, facultative biparental mouth-breeding. Apistogramma barlowi sp. n. is a representative of the Apistogramma-cacatuoides-complex living in small brooks.

New Astyanax from the upper rio Tapajós drainage, Central Brazil (Characiformes: Characidae)

Astyanax utiariti, new species, is described from the upper rio Tapajós drainage, Mato Grosso, Brazil. Astyanax utiariti has a horizontally oval black humeral spot, a lozenge-shaped caudal-peduncle spot, continuing to the tip of the middle caudal-fin rays, and two brown bars in the humeral region that allows its inclusion in the A. bimaculatus species group. It also possesses a black stripe extending along midlateral body. The new species is distinguished from its congeners by a reticulate scale pattern, a black longitudinal stripe, toothless maxilla, larger dentary teeth and teeth of the inner row of the premaxilla with five to seven cusps, body depth 33.3-39.9% of standard length (SL), head length (HL) 23.9-26.4% of SL, caudal-peduncle depth 12.0-13.4% of SL, orbital diameter 28.5-34.3% of HL, interorbital width 32.7-38.4% of HL, 36-38 perforated scales along the lateral line, and 22-26 branched anal-fin rays.

Moenkhausia pankilopteryx, new species from rio Tocantins drainage, Brazil (Ostariophysi: Characiformes, Characidae)

A new characid species, Moenkhausia pankilopteryx, is described from the rio Tocantins drainage. The new species is distinguished from its congeners by the combination of 37–41 pored scales in the lateral line; a deep body, 43.3–51.0 % SL; the presence of bony hooks on all fins of mature males; a caudal-peduncle spot; two humeral spots, the first of which is black, larger and vertically elongate, with the second dark and very diffuse (not visible in some specimens); two or three tricuspid or pentacuspid maxillary teeth; and anal-fin rays: ii–iv, 24–27.

Astyanaxelachylepis, a new characid fish from the rio Tocantins drainage, Brazil (Teleostei: Characidae)

A new characid species, Astyanax elachylepis, is described from the rio Tocantins drainage. The new species is distinguished from its congeners by possessing 48-53 perforated scales along the lateral line, a large caudal-peduncle spot, the presence of bony hooks on dorsal, anal, pelvic, and pectoral fins of males, one or two vertically-elongated humeral spots, one maxillary tooth, and 22-27 branched anal-fin rays.

New Species of Wrasse, Pseudocoris ocellatus (Pisces: Labridae), from Taiwan

Pseudocoris ocellatus is described from 11 specimens from southern and northern Taiwan. It is distinctive in having a more elongate body (depth 4.1-5.3 in standard length), long caudal peduncle (7.9-8.5 in standard length), 66-69 lateral-line scales, and distinctive color pattern (young and females with two longitudinal stripes and caudal peduncle spot; male, the stripes becoming faint, peduncle spot absent, a dumbbell-shaped ocellus appears on the midbody). Underwater and specimen photos of different stages of this new species are presented.