Isozyme variation among four species of the catfish genus Clarias

Native Thai species of Clarias catfishes and one species introduced from Africa can be easily distinguished by horizontal starch gel electrophoresis of allozymes. An undescribed species of Clarias was collected from Thailand and found to possess several fixed allelic differences from the Clarias previously studied.     

Hypostomus sertanejo (Siluriformes: Loricariidae), new armoured catfish species from north‐eastern Brazil

A re‐evaluation of the armoured catfish species of Hypostomus in the Rio Jaguaribe, north‐eastern Brazil, was prompted by the discovery of specimens with pale spots on a dark background collected from that basin c. 1936 and deposited at the Academy of Natural Sciences of Philadelphia. Recent field collections in the Rio Jarguaribe basin confirmed the presence of the pale‐spotted specimens and its distinctiveness as a new species. Hypostomus sertanejo n. sp. is diagnosed from other species of Hypostomus by having fins and dermal‐plated regions of head and body with pale spots or vermiculations on darker background, teeth slender, asymmetrically bicuspid and numerous (34–75) on dentary and premaxilla, depressed dorsal‐fin spine not reaching adipose spine, unbranched pectoral‐fin spine longer than unbranched pelvic‐fin ray, seven branched dorsal‐fin rays and one (rarely two) predorsal plate(s) bordering supraoccipital. Ancistrus salgadae Fowler 1941 is hypothesized to be a junior synonym of Hypostomus carvalhoi (Miranda‐Ribeiro, 1937), a dark‐spotted Hypostomus described from the Rio Granjeiro, a tributary to the upper Rio Salgado.     

A phylogenetic study of the neotropical catfish family Cetopsidae (Osteichthyes, Ostariophysi, Siluriformes), with a new classification

A hypothesis on the phylogenetic relationships of the neotropical catfish family Cetopsidae is proposed on the basis of the parsimony analysis of 127 morphological characters and most of the species currently recognized. The family and its two recognized subfamilies, the Cetopsinae and Helogeninae, are corroborated as monophyletic, in agreement with recent studies. Previously proposed classifications of the Cetopsinae, however, were found to be poorly representative of the phylogenetic relationships within the subfamily. Major generic rearrangements are implemented in order that the classification of the Cetopsinae reflects the phylogenetic hypothesis. Pseudocetopsis Bleeker (1862) was found to be polyphyletic and to include several disjunct lineages. One of these lineages, recently named as the genus Cetopsidium Vari, Ferraris, and de Pinna (2005), is the sister group to the rest of the Cetopsinae. Denticetopsis Ferraris (1996) is the next sister group to the remainder of the Cetopsinae. The remaining species of the Cetopsinae belong to one of two sister genera, Paracetopsis Bleeker (1862) and Cetopsis Spix and Agassiz (1829). The latter genus includes species formerly assigned to Hemicetopsis Bleeker (1862), Bathycetopsis Lundberg and Rapp Py‐Daniel (1994) and Pseudocetopsis Bleeker (1862). Continued recognition of Hemicetopsis and Bathycetopsis would have required the creation of several additional new genera for various species previously in Pseudocetopsis that form a series of sister groups to a clade composed of Cetopsis oliveirai (Lundberg and Rapp Py‐Daniel, 1994), C. coecutiens (Lichtenstein, 1819) and C. candiru (Spix and Agassiz, 1829). Cetopsis oliveirai is a highly paedomorphic species that displays surprising similarities with conditions in juvenile specimens of C. coecutiens, a species that attains a large body size. Such similarities are not evident in adult specimens of the latter species. A new classification is proposed, within which the subfamily Cetopsinae consists of three tribes, the Cetopsidiini, the Cetopsini and the Denticetopsini. The results of the study form the basis for a discussion of the phylogenetic position of the family within the Siluriformes, the phylogenetic biogeography of the Cetopsidae, paedomorphosis and gigantism in the family, and the effect of different semaphoronts on the intrafamilial phylogeny. Journal compilation © 2007 The Linnean Society of London, Zoological Journal of the Linnean Society, 2007, 150 , 755–813. No claim to original US government works.     

A catfish of the genus Trichomycterus from a thermal stream in southern South America (Teleostei, Siluriformes, Trichomycteridae), with comments on relationships within the genus

The first record of two trichomycterid species from the thermal waters of a small stream in Miraflores, north of Potosí, Bolivia is given. The reported species are Trichomycterus therma n. sp. and Trichomycterus tiraquae . The new species differ from all congeners in the possession of thickened transverse skin on the ventral surface of the head. They are further distinguished from all congeners by the following combination of characteristics: presence of spatulate incisiform premaxillary teeth; presence of large and rounded papilla-like structures on trunk of body; continuous segment of the laterosensory canal within the frontal with the presence of a segment between pores 2 and 6; long laterosensory canal with four to six pores; maxilla with a short anterior process that is smaller than the main axis of the bone, and has an anterior orientation; mesethmoid shaft narrower than the width of the lateral cornua; prepelvic length 58·7–61·0% of standard length ( L _S); head width 19·1–22·8% of L _S; submaxillary barbel length 23·9–37·5% of head length ( L _H). Two derived characters, namely the presence of spatulate incisiform premaxillary teeth and large and rounded papilla-like structures, define a monophyletic group within Trichomycterus , comprising T. therma , T. corduvensis and T. tiraquae .     

Contribution to the study of african rotifers: rotifers from Mali

In samples collected from different parts of the Republic of Mali (W-Africa), ninety-two taxa of rotifers were identified. Some were present in different forms; 56% were cosmopolitan, 19% thermophilous with a wide distribution, 20% tropicopolitan and 5% cold-stenothermous. These latter species seem to be relicts of palaeoclimatic conditions in Africa.     

Molluscs,isotopes and ecological fractionation: Examples from the upper Palaeogene of the Hampshire Basin

Carbon and oxygen isotopic analyses from upper Palaeogene molluscs collected in the Hampshire Basin (S. England) show that, in addition to long‐term trends in the data caused by climatic change, there is variation within samples collected from any one horizon. This variation is not attributable to diagenesis or other “noise”;. Linear trends in data from the meso‐ and oligohaline organisms are salinity‐dependent, as is a differentiation into clusters of the marine and brackish water animals. Within the marine organisms there is further distinction between taxa, controlled by micro‐environment. This is quite distinct from disequilibrium precipitation, as shell growth occurs in equilibrium with local isotopic ratios, though this may not necessarily be the same as contemporary mean ocean values. This “ecological fractionation”; can seriously affect the isotopic signal from a suite of fossils. Its existence should therefore be borne in mind when interpreting any biogenic isotope data from diverse taxa, localities, or micro‐habitats.     

Tracing the patterns of non-marine turtle richness from the Triassic to the Palaeogene: from origin to global spread

Turtles are key components of modern vertebrate faunas and their diversity and distributions are likely to be affected by anthropogenic climate change. However, there is limited baseline data on turtle taxonomic richness through time or assessment of their past responses to global environmental change. We used the extensive Triassic–Palaeogene (252–223 Ma) fossil record of terrestrial and freshwater turtles to investigate diversity patterns, finding substantial variation in richness through time and between continents. Globally, turtle richness was low from their Triassic origin until the Late Jurassic. There is strong evidence for high richness in the earliest Cretaceous of Europe, becoming especially high following the Cretaceous Thermal Maximum and declining in all continents by the end-Cretaceous. At the K–Pg boundary, South American richness levels changed little while North American richness increased, becoming very high during the earliest Palaeogene (Danian). Informative data are lacking elsewhere for this time period. However, the Selandian–Thanetian interval, approximately 5 myr after the K–Pg mass extinction, shows low turtle richness in Asia, Europe and South America, suggesting that the occurrence of exceptional turtle richness in the post-extinction Paleocene fauna of North America is not globally representative. Richness decreased over the Eocene–Oligocene boundary in North America but increased to its greatest known level for Europe, implying very different responses to dramatic climatic shifts. Time series regressions suggest number of formations sampled and palaeotemperature are the primary influencers of face-value richness counts, but additional factors not tested here may also be involved.     

New chondrichthyan fauna from the Palaeogene deposits of Barmer district,Rajasthan, western India: Age,palaeoenvironment and intercontinental affinities

Field investigations of the Palaeogene sections exposed in Barmer district, Rajasthan (India) led to the discovery of a new fossiliferous horizon in the Padma Rao Open Cast Bentonitic Clay Quarry. The bentonitic clay sequence of this quarry is considered as representing the upper part of the shale, carbonaceous shale, lignite and bentonitic clay succession of the Akli Formation exposed in the Giral Lignite Mine, 2.5 km to its north. Screen-washing of the sediments from a fossiliferous level within the bentonitic clay of the new site has yielded nine taxa of sharks and batoids: Squatiscyllium nigeriensis White, 1934, Ginglymostoma sokotoense White, 1934, Ginglymostomatidae gen. et sp. indet., Brachycarcharias sp., Abdounia recticona Winkler, 1873, Premontreia (Oxyscyllium) peypouqueti Noubhani et Cappetta, 1997, Eotorpedo hilgendorfi Jaekel, 1904, Coupatezia sp. cf. C. danica, and Myliobatidae gen. et sp. indet. The fauna recovered is mainly represented by nearshore shallow marine forms. This fauna is quite different from that of Palaeocene Fatehgarh Formation, the Lower Eocene Kapurdi Formation (Barmer Basin), the Khuiala Formation (Jaisalmer Basin) and the Cambay Shale (Cambay Basin), and favours a late Palaeocene (Thanetian) age for the upper part of the Akli Formation. A nearshore shallow marine palaeoenvironment is favored for the investigated stratigraphic horizon on the basis of the selachian fauna. Majority of the fossil shark species described from the Padma Rao quarry section are known from a number of sites in Africa, western Europe, Asia and southeastern USA, suggesting that free faunal interchanges were possible between the western Tethys and Indo-Madagascan faunal provinces during the late Palaeocene.     

A new species of sisorid catfish of the genus Exostoma from the Salween drainage,Yunnan, China

A new species of the sisorid catfish genus Exostoma Blyth,1860 was collected from two hill-stream tributaries of the Nujiang (Salween River) drainage in Gaoligong Mountain,south-western Yunnan Province,China from 2003 to 2006 and from two tributaries of the Salween River in Cangyuan County,Lingcang Prefecture,Yunnan Province,China (in 2007) and in Yongde County,Lingcang Prefecture,Yunnan Province,China (in 2015).Exostoma gaoligongense sp.nov.is the 10th species of the genus and is most similar to E.vinciguerrae in morphology but can be distinguished by pelvic fin reaching anus vs.not reaching;maxillary barbels just reaching or slightly surpassing pectoral-fin origin vs.surpassing pectoral-fin origin or even reaching posterior end of gill membrane;abdominal vertebrae 23-25 vs.25-27;length of dorsal fin/dorsal to adipose distance 90.3％-287.0％ vs.59.2-85.7.A key to Exostoma spp.is provided.     

A new species ofPsilochilus(Orchidaceae) from the Dominican Republic

Psilochilus crenatifolius, a new species from the Dominican Republic, is described and illustrated. It is only known from the type collection. The taxonomic affinity of the new entity is briefly discussed.     

Natural Resource Management, Paradigm Shifts, and the Decentralization Reform in Mali

The mainstream view in natural resource management in African drylands has been that local people are responsible for natural resource degradation. Today, alternative views or new paradigms are emerging in several fields. These new paradigms, which support decentralization of natural resource management, are discussed in relation to the ongoing decentralization process in Mali. During the colonial period, heavily centralized governments were installed in all the French colonies. This structure was maintained by Malian governments after independence. However, following the recent transition to democracy, a decentralizing reform is being implemented. It is presently not clear whether these reforms will lead to mere deconcentration, involving the redistribution of administrative responsibilities within the central government, or whether Mali is heading toward real decentralization, devolving decision making powers to local communities. The gestion de terroir approach, which may be a useful tool in achieving decentralization in farming communities, would, in pastoral areas, cause more damage than benefit.     

Development of the chondrocranium in the suckermouth armored catfish Ancistrus cf. triradiatus (Loricariidae, Siluriformes)

The chondrocranium of the suckermouth armored catfish Ancistrus cf. triradiatus was studied. Its development is described based on specimens ranging from small prehatching stages with no cartilage visible, to larger posthatching stages where the chondrocranium is reducing. Cleared and stained specimens, as well as serial sections, revealed a cartilaginous skeleton with many features common for Siluriformes, yet several aspects of A. cf. triradiatus are not seen as such in other catfishes, or to a lesser extent. The skull is platybasic, but the acrochordal cartilage is very small and variably present, leaving the notochord protruding into the hypophyseal fenestra in the earlier stages. The ethmoid region is slender, with a rudimentary solum nasi. A lateral commissure and myodomes are present. The larger posterior myodome is roofed by a prootic bridge. The maxillary barbel is supported by a conspicuous cartilaginous rod from early prehatching stages. The ceratohyal has four prominent lateral processes. Infrapharyngobranchials I-II do not develop. During ontogeny, the skull lengthens, with an elongated ethmoid, pointing ventrally, and a long and bar-shaped hyosymplectic-pterygoquadrate plate. Meckel's cartilages point medially instead of rostrally.     

Development of the osteocranium in the suckermouth armored catfish Ancistrus cf. triradiatus (Loricariidae, siluriformes)

The development of the osteocranium of the suckermouth armored catfish Ancistrus cf. triradiatus is described based on specimens ranging from prehatching stages to juvenile stages where the osteocranium is more or less fully formed. The first bony elements that arise are the opercle, jaws, and lateralmost branchiostegal rays, as well as the basioccipital and parasphenoid in the skull floor. The supracleithrum and the membranous and perichondral pterotic components form one large, double-layered skull bone during ontogeny, without clear evidence of the involvement of a supratemporal. The Baudelot's ligament ossifies from two sides, i.e., from the basioccipital medially and the supracleithrum laterally. The lower jaw consists of a dentary, mentomeckelian, and angulo-articular, which all soon fuse. The parurohyal, formed by the fusion of a ventral sesamoid bone and a dorsal cartilage element associated with the first basibranchial, is pierced by a vein, unlike in some other siluriforms. The interhyal cartilage disappears during ontogeny; medially of it, a small sesamoid bone appears in a ligament. The largest, canal-bearing cheek plate is not homologous to the interopercle. The results of the present research, with emphasis on bone formations and homologies, are compared with studies on related catfishes.     

A new sawshark,Pristiophorus laevis,from the Eocene of Antarctica with comments on Pristiophorus lanceolatus

The highly fossiliferous Eocene deposits of the Antarctic Peninsula are among the most productive sites for fossil remains in the Southern Hemisphere and offer rare insights into high-latitude faunas during the Palaeogene. Chondrichthyans, which are represented by abundant isolated remains, seemingly dominate the marine assemblages. Eocene Antarctic sawsharks have only been known from few isolated rostral spines up to now, that were assigned to Pristiophorus lanceolatus. Here, we present the first oral teeth of a sawshark from the Eocene of Seymour Island and a re-evaluation of previously described Pristiophorus remains from Gondwana consisting exclusively of rostral spines. The holotype of Pristiophorus lanceolatus represents a single, abraded and insufficiently illustrated spine from the Oligocene of New Zealand. All other Cenozoic rostral spines assigned to this species are morphologically very indistinct and closely resemble those of living taxa. Consequently, we regard this species as dubious and introduce a new species, Pristiophorus laevis, based on oral teeth. The combination of dental characteristics of the new species makes it unique compared to all other described species based on oral teeth. Rostral spines from the Eocene of Seymour Island are assigned to this new species whereas those from other Cenozoic Gondwana localities remain ambiguous.

LSID urn:lsid:zoobank.org:pub:7177A373-527B-4315-85F6-25180DB5E087     

A new species of Henriettea (Melastomataceae) from the Sierra de Baoruco, the Dominican Republic

Henriettea uniflora, which is known only from a diverse moist montane forest in the vicinity of Loma Trocha de Pey (or “Monteada Nueva”), Loma Pie de Palo, and Loma Remigio, the easternmost peaks of the Sierra de Baoruco, is described and illustrated. It is compared to species of the Henriettea squamulosa complex, especially H. squamulosa and H. ciliata. The species of this complex are characterized by an indumentum of ferruginous, stellate-lepidote hairs.     

Neoplecostomus doceensis: a new loricariid species (Teleostei,Siluriformes) from the rio Doce basin and comments about its putative origin

A new species of Neoplecostomus is described from the rio Doce basin representing the first species of this genus in the basin. The new species is distinguished from its congeners by having enlarged, fleshy folds between dentaries, two or three series of developed papillae anterior to premaxillary teeth and a adipose-fin membrane present, and by lacking enlarged odontodes along snout lateral margins in mature males, a well-developed dorsal-fin spinelet wider than dorsal-fin spine base, lower number of lateral-line figs and developed membrane on the dorsal portion of the first, second and third pelvic-fin branched rays. Additionally, we present a brief discussion of biogeographic scenarios that may explain the distribution of the new species in the rio Doce basin. We suggested that the ancestral lineage of the new species reached the rio Doce from the upper portions of rio Paraná drainages about 3.5 Mya (95% HPD: 1.6–5.5) indicating a colonization route of the N. doceensis ancestral lineage from the south end of Serra do Espinhaço, probably as a result of headwater capture processes between the upper rio Paraná and rio Doce basins.     

Monophyly of the catfish family Siluridae (Teleostei: Siluriformes), with a critique of previous hypotheses of the family's relationships

Monophyly of the Eurasian catfish family Siluridae is established according to five synapomorphies unique to the family: (1) palatine reduced to a small nodule; (2) lateral ethmoid and sphenotic contact by narrow extensions lateral to the frontal; (3) ossified transscapular ligament anteroposteriorly compressed; (4) distal radials of dorsal-fin pterygiophores absent; (5) articulations of anal-fin rays with pterygiophores posterodorsally shifted. Previous hypotheses of silurid non-monophyly or a close relationship of the Siluridae to the Malapteruridae, Plotosidae or Amblycipitidae are shown to be poorly supported by available evidence. Silurids share with other subgroups of the Siluroidea character states that are derived within the Siluroidea; these are described in an appendix. Additional character state evidence is needed before a hypothesis of sister-group relationshipi between the Siluridae and another siluroid subgroup can be proposed.