A new species of Glyptothorax (Teleostei: Sisoridae) from the Brahmaputra River basin, Arunachal Pradesh, India

Glyptothorax rupiri, a new sisorid catfish, is described from the Brahmaputra River basin in Arunachal Pradesh, northeast India. It differs from its congeners in the Indian subcontinent by the following combination of characters: the presence of plicae on the ventral surface of the pectoral spine and first pelvic-fin ray; a posteriorly serrated dorsal-fin spine, its length 11.3–12.2% SL; body depth at anus 11.2–13.4% SL; a thoracic adhesive apparatus longer than broad, with a V-shaped median depression which opens posteriorly; an arrow-shaped anterior nuchal plate element; adipose-fin base length 10.9–12.6% SL; nasal barbel not reaching anterior orbital margin; 14–18 serrae on posterior margin of the pectoral-fin spine; body with two longitudinal pale-cream stripes; densely tuberculated skin; and the presence of numerous tubercles on the dorsal surface of pectoral and pelvic-fin rays.

Pseudobagarius eustictus, a new species of catfish from northern Laos (Siluriformes: Akysidae)

Pseudobagarius eustictus, new species, is described from the Nam Heung drainage (a tributary of the Mekong River) in northern Laos. It is distinguished from congeners in having a unique combination of the following characters: a weakly-produced snout in which the upper jaw extends only slightly beyond the margin of the lower jaw when viewed ventrally, 3 tubercles on the posterior margin of the pectoral spine, eye diameter 8% HL, head width 24.1% SL, dark yellow dorsal and lateral surfaces of the head, pectoral spine lacking elongate extensions, pectoral fin reaching the pelvic-fin base when adpressed against the body, dorsolateral surfaces of body without longitudinal series of prominent tubercles, body depth at anus 13.7% SL, length of adipose-fin base 17.7% SL, caudal-peduncle depth 7.0% SL, and 33 vertebrae.

Two new catfish species of typically Amazonian lineages in the Upper Rio Paraguay (Aspredinidae: Hoplomyzontinae and Trichomycteridae: Vandelliinae), with a biogeographic discussion

Two new species of particular biogeographic significance are described from the upper rio Paraguay basin, one of the genus Paracanthopoma (Trichomycteridae, Vandelliinae) and the other of the genus Ernstichthys (Aspredinidae, Hoplomyzontinae). The two species occur sympatrically in the Rio Taquarizinho, tributary of the Rio Taquari, in the upper Paraguay system. Paracanthopoma saci is distinguished from its only congener, P. parva, by a spatulate caudal peduncle; a minuscule premaxillary dentition (reduced to three delicate teeth); the supraorbital latero-sensory canals opening as two separate s6 pores; the caudal fin slightly convex or truncate with round edges; the skull roof entirely open, unossified; the origins of dorsal and anal fins approximately at same vertical; and the pelvic fin with three rays. Ernstichthys taquari is diagnosed among congeners by the narrow bony shields on dorsal and ventral series, not overlapping or contacting each other; by the presence of seven or eight serrations on the posterior margin of the pectoral spine; and by the pectoral-fin spine only slightly larger than subsequent soft rays. Both Paracanthopoma and Ernstichthys were previously unknown outside of the Greater Amazonian river systems (Amazon, Orinoco, Essequibo and smaller surrounding drainages). Their presence restricted to the Rio Taquari is unexpected and suggests a peculiar biogeographical history. Ancestral geographic distributions were reconstructed using S-DIVA and BBM methods in RASP. A majority of resulting hypotheses support that the two species reached the Paraguay from the Amazon. The alternative explanation accounts for their presence in the Paraguay by vicariant events. In no case, their presence in the Paraguay is an ancestral distribution with subsequent Amazonian dispersal. Though unusual, this pattern is also seen in a few other fish taxa, showing that the Rio Taquari is biogeographically hybrid, combining elements from both the Paraguay and Amazon drainages.

A new Corydoras (Ostariophysi: Siluriformes: Callichthyidae) with an unusual sexual dimorphism from the rio Juruena basin, Brazil

A new Corydoras is described from the rio Juruena system, upper rio Tapajós drainage, Amazon basin, Brazil. The new Corydoras is distinguished from all congeners by presenting a combination of a conspicuous broad vertical dark bar on head, at the level of the eye (mask), an overall light background color without large blotches or stripes on body or fins, the presence of two to four small dark blotches along the midline, and pectoral spine with antrorse serrations on its posterior margin. Males of the new species possess numerous, well-developed odontodes over the lateral portions of head, pectoral girdle, and pectoral spines, an uncommon feature for the genus. The new species is hypothesized to belong, within the genus Corydoras, either to Lineage 6 or Lineage 9.

Morphometric and meristic characteristics of silver catfish Chrysichthys nigrodigitatus (Lacepède, 1803) (Siluriformes: Claroteidae) from Epe Lagoon, Lagos, Southwest Nigeria

The morphometric and meristic characteristics of 300 fish samples of silver catfish Chrysichthys nigrodigitatus (Lacepède, 1803) (Siluriformes: Claroteidae) inhabiting the Epe Lagoon, Lagos, was conducted between October 2012 and January 2013 in order to investigate the growth and health status of this species. The meristic characteristics deduced in this study were counted and ranged as follows; dorsal spine had constant value of one all through, and the pectoral spine had a constant value of two, dorsal rays were counted 6-7 (6.03 +/- 0.25), pectoral rays were counted 6-7 (6.04 +/- 0.27), gill rakers were counted 15-18 (17.86 +/- 0.96), opercula bones were counted 2-4 (3.22 +/- 1.11) and vertebrae count was 8-10 (8.43 +/- 1.95). All the morphometric characteristics except body weight were measured with measuring board of precision of 0.1 cm. Body weight was measured with a metler electronic chemical balance of precision of 0.1 g. Morphometric data includes total length 15.5-38.5 cm (25.43 +/- 3.87 cm), fork length 2.0-11.6 cm (8.61 +/- 1.53 cm), standard length 10.0-28.3 cm (17.85 +/- 3.90 cm), head length 2.0-3.5 cm (2.91 +/- 0.79 cm), head depth 1.0-3.3 cm (2.41 +/- 1.05 cm), eye diameter 0.5 1.0 cm (1.28 +/- 0.77 cm), body depth 1.6-6.5 cm (3.57 +/- 0.90 cm) and body weight 24.5-451.6 g (157.48 +/- 5.60 g). The length and the weight of this species were not directly proportional. Growth parameter has a negative allometric range (b = 0.256) and the condition factor (k) ranged from 0.103-2.97 (1.08 +/- 0.64) which indicated a good condition of the fish species in the Lagoon. This study provided baselines of the population structure of this species in Epe Lagoon, Lagos State and also shown that their present growth pattern calls for further monitoring.

Description of a new species of Gymnotocinclus from the rio Tocantins basin with phylogenetic analysis of the subfamily Hypoptopomatinae (Siluriformes: Loricariidae)

Gymnotocinclus canoeiro n. sp. of the Hypoptopomatinae is described from small tributaries of the upper rio Tocantins basin. It is distinguished from G. anosteos by having five characters: (1) the presence of body dermal plates, (2) the pectoral girdle not exposed in ventral view, (3) the pelvic spine longer than pectoral spine in males, (4) the pectoral fin with seven to eight branched rays, and (5) the presence of an adipose fin. Furthermore, maximum likelihood (ML) analysis was used to estimate a molecular phylogeny from previously published data of one nuclear (F-Reticulon 4) and three mitochondrial (16S RNA, COI and CytB) genes. The phylogenetic results revealed the new species as a sister taxon of Gymnotocinclus anosteos within the Otothyrini. We also included samples of Nannoplecostomus eleonorae that appeared sister group to all other Neoplecostomini species, and Plesioptopoma curvidens that appeared within the Neoplecostomini forming a sister clade to all species of Neoplecostomus, except N. ribeirensis and the species of Pareiorhina, except P. rudolphi.

Pangasiid Catfishes of Indonesia

<p>Pangasiidae are economically important riverine catfishes generally occurring in freshwater from the Indian subcontinent to the Indonesian Archipelago. Morphologically, they are recognized by a laterally compressed body, two pairs of barbels, a short dorsal fin with two spines, a well developed adipose fin, a long anal fin, and a strong pectoral spine. The systematics of this family are still poorly known. Consequently, the lack of this basic information is a great barrier in understanding the biology and hence the study of the aquaculture potential of species, the improvement of their seed production and growth performance. Objectives of the study are to present all species and genera of pangasiid catfishes of Indonesia including their distribution and detailed identification.</p><p> </p><p><strong>Abstrak</strong></p><p>Kelompok ikan pangasius atau pangasiidae merupakan jenis penting ikan &amp;ldquo;catfish&amp;rdquo; (bersungut) yang hidup di air tawar dan tersebar dari daratan India hingga kepulauan Indonesia. Secara umum ikan ini memiliki bentuk tubuh memanjang dan ramping, dua pasang sungut, sirip punggung yang relatif pendek dengan dua duri keras, sirip lunak tambahan yang berkembang sempurna sebagai pengontrol renang, dan tulang sirip dada yang kuat. Secara sistematik, kelompok ikan pangasius masih belum dikenal secara baik. Oleh karena itu, kurangnya informasi dasar yang dimiliki pada kelompok ikan ini merupakan hambatan utama untuk memahami sifat-sifat biologinya, pengembangan budidayanya, produksi benih, dan perbaikan keragaannya. Tujuan dari studi yang dilakukan adalah untuk menyajikan semua spesies dan genus ikan pangasius yang ada di Indonesia mencakup distribusi, sebaran, dan kunci identifikasinya secara detail.</p>

Reappraisal of Rhamdia branneri Haseman, 1911 and R. voulezi Haseman, 1911 (Siluriformes: Heptapteridae) from the rio Iguaçu with notes on their morphometry and karyotype

ABSTRACT The species Rhamdia branneri Haseman, 1911 and the subspecies Rhamdia branneri voulezi Haseman, 1911 from rio Iguaçu are currently recognized as synonyms of Rhamdia quelen (Quoy & Gaimard, 1824). However, recent karyotype and ecomorphology studies distinguish R. branneri and R. voulezi as different species. Examination of Rhamdia populations from rio Iguaçu, including type specimens, together with other congeners from rio Tibagi, allowed to properly reexamine the situation of these Haseman's taxa and references given to Rhamdia in the Iguaçu. The species R. branneri and R. voulezi have strong serrae with large basis on both margins of the pectoral-fin spine, uncommon in the remaining species of Rhamdia and different from the fine serrate margins of the pectoral spine of R. quelen ; a regular dorsal profile, slightly curved between supraoccipital and dorsal fin; with dorsal dark-brown or light-gray coloration along body, abdomen pale, without profuse small black spots, common in populations of the upper Paraná species and the type-material of R. quelen . Also the following morphometric characters discriminate these species: Rhamdia voulezi , adipose fin elongate; smaller distance between dorsal and adipose fin; smaller length between adipose fin to base of caudal fin and smaller distance from posterior margin of eye to opercular border. Rhamdia branneri , larger distance from dorsal and adipose fins; deeper caudal peduncle; higher trunk depth in the vertical distance through adipose, between pelvic and anal fins; larger scapular bridge; shorter maxillary barbel; shorter external mental barbel; shorter interorbital distance; shorter length of dorsal fin basis and shorter adipose-fin base length. A PCA between the populations of Rhamdia from Iguaçu and a population from rio Tibagi, upper Paraná basin, discriminates the population from Tibagi on basis of dorsal to adipose fin distance, dorsal-fin spine length, maxillary barbel length, eye diameter, and pectoral-fin spine length. This morphometric study allied to the karyotype known differences suggest R. branneri and R. voulezi as valid species. The complex state of R. quelen with the neotype recently designated from rio Samiria recommend new studies on basis of molecular genetics and provision of the names R. branneri and R. voulezi in the Iguaçu basin.

A new species of Corydoras Lacépède, 1803 (Siluriformes: Callichthyidae) from the río Madre de Dios basin, Peru

ABSTRACT A new species of Corydoras is described from the río Madre de Dios basin, Peru. The new species can be distinguished from its congeners by presenting the following features: a longitudinal black stripe along midline of flank; mesethmoid short, with anterior portion poorly developed; serrations on posterior margin of pectoral spine directed towards the tip of the spine; dorsal fin with the region of the first branched ray, including membrane, with concentration of black pigmentation, the remaining areas with irregular black blotches; absence of a vertically elongated black blotch across the eyes; conspicuously rounded moderately-developed black spots on the snout; and ventral expansion of infraorbital 1 moderately developed.

Revisionary study of the armored catfish Corydoras paleatus (Jenyns, 1842) (Siluriformes: Callichthyidae) over 180 years after its discovery by Darwin, with description of a new species

ABSTRACT The taxon known as Corydoras paleatus carries one of the most complex taxonomic histories among Corydoradinae catfishes. A comprehensive review of specimens attributed to that species from several localities was carried out, allowing the clear recognition of C. paleatus and also of a new species previously misidentified as C. paleatus , described herein. Corydoras paleatus can be distinguished from its congeners by presenting the following unique combination of features: perpendicularly directed serrations along entire posterior margin of the pectoral spine; three large black blotches along midline of flank; hyaline or black pectoral fin; and transversal black bars on caudal-fin lobes. Corydoras paleatus is known from the lower rio Paraná basin, coastal rivers from Southern Brazil and Uruguay and rio Uruguai basin. The new species can be distinguished from its congeners by having the following unique combination of features: three large black blotches along midline of flank; three nasal pores; mesethmoid short; infraorbital 2 not in contact with compound pterotic; striated black spots from the snout tip to nuchal plate region; markedly rounded snout; and anterior portion of dorsal fin spotted. The new species is known from the upper rio Uruguai basin, from the rivers Canoas, do Peixe and Pelotas.