Una nueva especie de Xyliphius de la Argentina (Siluriformes, Bunocephalidae).

Reconocimiento de una nuevo género de la familia Bunocephalidae existente en las colecciones del Museo de La Plata.

Redescription of Hypoptopoma inexspectata (Holmberg, 1883), with notes on its anatomy (Siluriformes: Loricariidae).

Hypoptopoma inexspectata is diagnosed and redescribed based on the examination of additional material and comparison with its congeners. This poorly known hypoptopomine species is distributed in the Paraguay and Paraná river draínages. Hypoptopoma inexspectata is diagnosable based on the autapomorphy biserial arrangement of anterior snout rostral margin odontodes, laterally extended to limit between second and third infraorbital plates, with dorsally directed dorsad series separated from ventrally directed ventrad series by a narrow odontode-free area, which at the level of first and second infraorbital plates is reduced to a dividing line of the series. The species can be further distinguished by the combination (1) low number of canal-bearing lateral plates (20-22, typically 21), (2) presence of a shield of prepectoral dermal plates, (3) arrangement of abdominal plates in one paired series of 3-5 plates, (4) shorter least interorbital distance 4856% head lengh, (5) larger horizontal eye diameter 17-20% head lengh, and (6) least orbit-nare distance 812% head lengh. Intraspecific variation skull dermal bones, neuracranium and suspensorium bones, dermal plates, adipose fin is reported. (PDF has 20 pages.)

Length-weight relationship and the diets of Clarias lazera (Cuvier and Valenciennes), family Clariidae (Osteichthyes: Siluriformes) in Zaria, Nigeria

The length-weight relationship and the diets of Clarias lazera were investigated between July 1981 and June 1982. About 450 specimens were examined. The standard lengths of the fish ranged from 8.5 cm to 42.2 cm. Significant differences were found between the standard lengths of the males and females with the latter slightly shorter. Somatic weights varied between 10 g to 502 g. Length-weight regression analysis gave a "b" value of 3.02 for both males and females combined; thus indicating an isometric growth. Analysis of the food in the stomachs showed that the fish is an omnivore although, it fed more on insects and fish than other food items

A new species of catfish of the genus Clupisoma (Siluriformes : Schilbidae) from the Salween River, Yunnan, China

A new species of the schilbid catfish genus Clupisoma Swainson, 1838, was discovered in the Salween River [= Nujiang] of western Yunnan Province, China. There are no previous records of schilbid catfish from the middle reaches of the Salween River before this discovery. Clupisoma nujiangense, new species, is the ninth species of the genus Clupisoma and only the third schilbid catfish species recorded from China.

Threatened fishes of the world: Silurus mento Regon, 1904 (Siluriformes: Siluridae)

Conservation status, identification, distribution, abundance, habitat and ecology, threats, conservation actions and recommendations of an endemic catfish, King's bullhead, Silurus mento were introduced.

PRELIMINARY STUDY ON MITOCHONDRIAL CYTOCHROME b DNA SEQUENCES AND PHYLOGENY OF FORMALIN FIXED SISORID FISHES(Teleostei: Siluriformes)

从９种科鱼类的福尔马林标本中获得了３３３ｂｐ的细胞色素ｂ基因片段的序列。这９个种分别代表科鱼类的８个属。３３３ｂｐ的ＤＮＡ序列经ＭＵＳＴ软件排序后，有１０１个变异位点，其中有３９个信息位点。序列在成对物种间的距离为８～４８。平均遗传距离为２４％～１４４％。简约分析产生了最大简约系统树，其步长是１６２（ＣＩ＝０７３５，ＲＩ＝０４９４）。在该系统树上，Ｂａｇａｒｉｕｓ是最原始的属，并与所有其他的物种形成姊妹群。其余８个属形成一个单系类群并分为二个姊妹群。尽管在形态上具有１３个离征，但在分子系统树上

Analysis of genetic diversity in Glyptosternum maculatum (Sisoridae, Siluriformes) populations with AFLP markers

We determined the genetic diversity of geographic populations from three spawning grounds (Nyang River, Lhasa River, Shetongmon Reach of Yarlung Zangbo River) of Glyptosternum maculatum with amplified fragment length polymorphism (AFLP) markers. Five primer combinations detected 332 products, 51 of them (15.4%) were polymorphic in at least one population. The Shetongmon population was found to be the richest in genetic diversity as was indicated by the percentage of polymorphic loci and heterozygosity, followed by the Nyang population and the Lhasa population. The pair-wise genetic distance between populations were all very close, ranging from 0.0015 to 0.0042 with an average of 0.0024. The genetic distance was not proportional to the geographic distance. The analysis of molecular variance demonstrated that all variation occurred within populations. The average estimated fixation index (F (st)) of three populations across all polymorphic loci was -0.0184, indicating the absence of genetic differences among the three sampled populations. The differentiation among populations was not significant, and population structure was weak. Our observations will help identify the genetic relationship among populations as the first approach to understand the genetic diversity of Glyptosternum maculatum.

Population genetic structure and geographical differentiation of the Chinese catfish Hemibagrus macropterus (Siluriformes, Bagridae): Evidence for altered drainage patterns

National Natural Science Foundation of China (NSFC) [2007CB411600, 30530120]

Molecular evidence for diphyly of the Asian catfish family Amblycipitidae (Teleostei: Siluriformes) and exclusion of the South American Aspredinidae from Sisoroidea

Amblycipitidae Day, 1873 is an Asian family of catfishes (Siluriformes) usually considered to contain 28 species placed in three genera: Amblyceps (14 spp.), Liobagrus (12 spp.) and Xiurenbagrus (2 spp.). Morphology-based systematics has supported the monophyly of this family, with some authors placing Amblycipitidae within a larger group including Akysidae, Sisoridae and Aspredinidae, termed the Sisoroidea. Here we investigate the phylogenetic relationships among four species of Amblyceps, six species of Liobagrus and the two species of Xiurenbagrus with respect to other sisoroid taxa as well as other catfish groups using 6100 aligned base pairs of DNA sequence data from the rag1 and rag2 genes of the nuclear genome and from three regions (cyt b, COL ND4 plus tRNA-His and tRNA-Ser) of the mitochondrial genome. Parsimony and Bayesian analyses of the data indicate strong support for a diphyletic Amblycipitidae in which the genus Amblyceps is the sister group to the Sisoridae and a clade formed by genera Liobagrus and Xiurenbagrus is the sister group to Akysidae. These taxa together form a well supported monophyletic group that assembles all Asian sisoroid taxa, but excludes the South American Aspredinidae. Results for aspredinids are consistent with previous molecular studies that indicate these catfishes are not sisoroids, but the sister group to the South American doradoid catfishes (Auchenipteridae + Doradidae). The redefined sisoroid clade plus Bagridae, Horabagridae and (Ailia + Laides) make up a larger monophyletic group informally termed "Big Asia." Likelihood-based SH tests and Bayes Factor comparisons of the rag and the mitochondrial data partitions considered separately and combined reject both the hypothesis of amblycipitid monophyly and the hypothesis of aspredinid inclusion within Sisoroidea. This result for amblycipitids conflicts with a number of well documented morphological synapomorphies that we briefly review. Possible nomenclatural changes for amblycipitid taxa are noted.

Phylogeography of the freshwater catfish Hemibagrus guttatus (Siluriformes, Bagridae): Implications for South China biogeography and influence of sea-level changes

National Natural Science Foundation of China (NSFC) ; [2007CB411600]; [30530120]

Phylogenetic relationships of glyptosternoid fishes (Siluriformes : Sisoridae) inferred from mitochondrial cytochrome b gene sequences

To explore phylogenetic relationships among glyptosternoid fishes, we determined nucleotide sequences of the complete mitochondrial cytochrome b gene region (1138 base pair). Thirteen species of glyptosternoid fishes and six species of non-glyptosternoids represent 10 sisorid genera were examined. Molecular phylogenetic trees were constructed using the maximum parsimony, minimum evolution, maximum likelihood, and Bayesian methods. Bayesian and maximum likelihood analyses support the monophyly of glyptosternoids, but our hypothesis of internal relationships differs from previous hypothesis. Results indicated that glyptosternoid is a monophyletic group and genera Glyptosternum and Exostoma are two basal species having a primitive position among it. Genera Euchiloglanis and Pareuchiloglanis form a sister-group. Then they form a sister-group with Pseudexostoma plus Oreoglanis. Our result also found that Pareuchiloglanis anteanalis might be considered as the synonyms of Parechiloglanis sinensis, and genus Euchiloglanis might have only one valid species, Euchiloglanis davidi. (C) 2003 Elsevier Inc. All rights reserved.

The uplift of Qinghai-Xizang (Tibet) Plateau and the vicariance speciation of glyptosternoid fishes (Siluriformes : Sisoridae)

Based on the phylogenetic and biogeographical studies of the glyptosternoid fishes in Qinghai-Tibet area, the following hypothesis is proposed: the speciation of this group has a direct relationship with the three uplift intervals of the Qinghai-Tibet Plateau. This process was explained by the theory of vicariance of biogeography. The ancestor of this group was similar to Bagarus and/or Glyptothorax, which still have a wide distribution. At the moment when the Tethys sea closed, the Indian tectonic plate collided with the Eurasian tectonic plate, so the Glyptothorax-like and Bagarus-like ancestors entered Eurasia and gradually became widely distributed. After the Pleistocene, with the enforced colliding, the gradual uplift of the Qinghai-Tibet Plateau brought about the current water environment, and the Glyptosternoids were generated from Glyptothorax-like fish under this environment. The present Glyptosternum, distributed across the Himalayas is the ancestor of Glyptosternoids. In the three uplift intervals of the plateau, the water system of this region was separated gradually and Glyptosternum-like ancestor was isolated in different rivers and evolved into various species. All this resulted in the speciation and formation of the biogeographical pattern of glyptosternoids.

Phylogeny of the Amphiliidae (Teleostei : Siluriformes)

The freshwater African catfish family Amphiliidae had been reviewed based on the 73 osteological characters with Diplomystidae, dagger Hypsidoridae, Amblycipitidae, Sisoridae, and Bagridae as out-groups. Because the family position of Leptoglanis (Bagridae/Amphiliidae) is under debate, this genus has been taken as an out-group too. Results of the study indicate that: 1) the Amphiliidae is not a monophyletic group and must now be restricted to the genera Amphilius and Paramphilius; the two subfamilies Amphiliinae and Doumeinae are separated by the sisorids Euchiloglanis (with most of the glyptosternid fishes) and Glyptothorax (with most of the non-glyptosternid fishes); 2) no synapomorphies were found for the subfamily Amphiliinae. 3) The five genera of subfamily Doumeinae constitute a monophyletic group, Andersonia being the sister-group of the four other genera; subfamily Doumeinae + Leptoglanis form the family Doumeidae. The glyptosternids no longer belong to the Sisoridae (family restricted to the non-glyptosternids) and represent the new family Glyptosternidae. (C) 1999 Editions scientifiques et medicales Elsevier SAS.