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1.
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 .  相似文献   

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3.
Silvinichthys huachi new species, is described from a stream along the lower slope of the Andean Cordillera in the Provincia de San Juan, Argentina. It shares the distinctive modifications characteristic of Silvinichthys, but is distinguished from the four previously described congeners by the combination of a lack of the pelvic fin and the pelvic girdle, details of pigmentation and various meristic and morphometric features. Silvinichthys huachi is apparently endemic to the type locality situated within an arid region of western central Argentina in the Andino Cuyana Province. Major gaps in the range of species of Silvinichthys may indicate that the origin of the genus predates the uplift events that subdivided drainages along the eastern slopes of the Andean Cordillera in west central Argentina. Silvinichthys huachi is hypothesized to be the sister species of Silvinichthys bortayro.  相似文献   

4.
This paper reports on a new species of Trichomycterus from the Rio Doce basin. Unusually for new taxa in the genus during the past few decades, the new species is not narrowly endemic but instead widely distributed in its major drainage, the Rio Doce. The species has been collected and deposited in scientific collections for some years, but has been systematically misidentified as the more abundant Trichomycterus immaculatus or, to a lesser degree, as other morphologically similar species from south-eastern Brazil such as T. nigricans and T. pradensis. A combination of several morphological characteristics, such as vertebral number, pectoral-fin ray counts, pigmentation pattern and barcoding distance, were iteratively used and unambiguously distinguish the new species from all congeners. The present case reveals a pattern of diversity-discovery in which rare and narrowly endemic morphologically conspicuous species are discovered and described before visually inconspicuous taxa, even when the latter are more abundant and widespread. The morphological similarities among south-eastern Brazilian species with a uniform dark-grey color serve as basis for a brief discussion about the concepts of cryptic and pseudo-cryptic species in Trichomycterus and their consequences for potentially hidden diversity in the genus.  相似文献   

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6.
The population ecology of the trichomycterid catfish, Trichomycterus itacarambiensis, from the Olhos d'Àgua Cave, Itacarambi Co., Minas Gerais, eastern Brazil, was investigated by the mark-recapture method during the dry season of 1994 (April to October). The cave is subject to a pronounced seasonality, and is flooded during part of the rainy period. All individuals captured along the 5000 m long stream gallery (divided in 50 sections) were marked by tattooing, measured and examined for the degree of pigmentation reduction. About one third of the population is truly albinic; the remainder may exhibit partial depigmentation. After five bimestrial collections, 583 specimens have been marked, of which 150 were recaptured at least once. Estimated population size was 1500–2000 individuals longer than 20 mm SL. The total population size of T. itacarambiensis is considered small when compared to those of epigean trichomycterids and of other studied cavefishes as well. Mean population density was 0.15–0.20 individuals m-2 throughout the dry season; it increased with the distance to the stream resurgence, probably due to the higher food availability upstream. This population density may be considered intermediate to those of other troglobitic fishes. Most recaptures (66%) were done in the same section as the previous capture. Active movements, both upstream and downstream, were recorded up to distances of 600 m; a few possibly passive, downstream movements covered distances from 900 to 1500 m. T. itacarambiensis catfishes move more frequently and for longer distances than the Brazilian blind pimelodids, Pimelodella kronei. Individual growth in T. itacarambiensis probably occurs in pulses, during the rainy seasons; interruption of growth in the dry season is attributed to the pronounced food shortage. The mean longevity was estimated as seven years. Differences between pigmented and albino individuals include a higher frequency of downstream movements and slightly higher growth rates in the latter.  相似文献   

7.
A new species of the candiru genus Paracanthopoma is described from the floodplains of the Bananal Island, a transition area between the Cerrado and Amazon, in the Araguaia River basin, central Brazil. Paracanthopoma cangussu sp. nov. is distinguished from its congeners, Paracanthopoma parva and Paracanthopoma saci, by the presence of seven opercular odontodes, five dentary teeth, five median premaxillary teeth, and first dorsal-fin pterygiophore in a vertical through the centrum of the 23th or 24th vertebra. It is further distinguished from each congener by an exclusive combination of character states, comprising the number of vertebrae, number of precaudal vertebrae, number of dorsal procurrent caudal-fin rays, number of ventral procurrent caudal-fin rays, number of dorsal-fin rays, disposition of pores on the cephalic portion of the latero-sensory system, absence of an anterior process on the anterior margin of parieto-supraoccipital, number of dorsal-fin pteryigiophores and number of interopercular odontodes. Although vandelliines are known for being exclusively hematophagous, with guts gorged with blood, two cleared and stained specimens of P. cangussu sp. nov. had Chironomidae larvae (Insecta) on their guts. Because most specimens of P. cangussu sp. nov. were collected with stomachs filled with blood, it was hypothesized that the species feeds accidentally or occasionally on insects.  相似文献   

8.
The configuration of the pectoral girdle bones and muscles of numerous catfishes was studied in detail and compared with that of other siluriforms, as well as of other teleosts, described in the literature. The pectoral girdle of catfishes is composed of only three bones, which probably correspond to the posttemporo-supracleithrum (posttemporal + supracleithrum), scapulo-coracoid (scapula + coracoid), and cleithrum of other teleosts. These latter two bones constitute the place of origin of the pectoral girdle muscles. Two of these muscles are related to the movements of the pectoral fin. These two muscles correspond, very likely, to the abductor superficialis and to the adductor superficialis of other teleostean fishes. In relation to the pectoral spine (thickened first pectoral fin ray), it is usually moved by three well-developed muscles, which are probably homologous with the arrector ventralis, arrector dorsalis, and abductor profundus of nonsiluriform teleosts. The morphological diversity and the plesiomorphic configuration of these muscles, as well as of the other catfish pectoral girdle structures, are discussed.  相似文献   

9.
We examined the role of several earth history events on the phylogeographic distribution of the catfish Trichomycterus areolatus in Chile using the cytochrome b gene. We explored three biogeographic hypotheses: that sea level changes have resulted in the isolation of populations by drainages; that glaciation has impacted genetic diversity; and that ichthyological subprovince boundaries correspond to phylogeographic breaks in our focal species. We found seven well-supported clades within T. areolatus with high levels of genetic divergence. The strongest signal in our data was for an important role of sea level changes structuring populations. Five of the seven clades mapped cleanly to the geographic landscape and breaks corresponded closely to areas of narrowest continental shelf. In addition, few haplotypes were shared between rivers within clades, suggesting that only limited local movement of individuals has occurred. There was no relationship between the levels of genetic diversity and the proportion of individual drainages covered by glaciers during the last glacial maximum. Two phylogeographic breaks within T. areolatus did match the two previously identified faunal boundaries, but we found three additional breaks, which suggests that faunal breaks have only limited utility in explaining phylogeographic patterns. These results imply that the narrow continental shelf coupled with sea level changes had a strong influence on the obligate freshwater fishes in Chile.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 876–892.  相似文献   

10.
The Copionodontinae is described as a new subfamily of the neotropical catfish family Trichomycteridae. It comprises two new genera and three new species from north-eastern Brazil: Copionodon gen. nov. (including C. pecten sp. nov. and C. orthiocarinatus sp. nov. ) and Glaphyropoma gen nov. (including G. rodriguesi sp. nov. ) The Copionodontinae can be diagnosed externally by the anterior position of the dorsal fin, the presence of a well-developed adipose fin, and the strongly spatulate shape of the jaw teeth. The subfamily is hypothesized as monophyletic on the basis of several synapomorphies in internal and external anatomy. Copionodontines have the plesiomorphic condition of several characters, relative to all other trichomycterids, including the presence of ductus pneumaticus; the possession of separate pterosphenoids, sphenotics and prootics; the presence of the intercalarium; the complete infraorbital latero-sensory canal; the presence of the interhyal; and the wide lateral opening of the swimbladder capsule. Elsewhere within trichomycterids, these primitive traits are found only in Trichogenes. These and other characters support the hypothesis that copionodontines are the plesiomorphic sister group of all other trichomycterids, and that Trichogenes is their next successive sister group. Contrary to the currently accepted hypothesis, the monotypic Nematogenyidae is proposed as the sister group of the Trichomycteridae, and not of all remaining loricarioids. This change is to a major extent induced by the inclusion of copionodontines and Trichogenes in the analysis of lower loricarioid relationships. The present case is given as an example of the impact that undiscovered taxa, fossil or Recent, may have upon hypotheses of phylogenetic relationships.  相似文献   

11.
A new miniature species of geophilomorph centipede, Ityphilus grismadoi sp. nov. (Chilopoda: Geophilomorpha: Ballophilidae) is fully described and illustrated on the basis of specimens collected in Yasuní Scientific Station and Jatun Sacha Biological Station, both located in the Ecuadorian Amazon. The new species is characterized by having the internal edge of the forcipular tarsungulum completely smooth, this trait being shared by six other Neotropical members of the genus Ityphilus Cook, 1899; and another species (I. cifuentesi Cupul Magaña, 2014) from the transition area between the Neotropical and Nearctic regions. Ityphilus grismadoi sp. nov. is distinguished from these seven species by the low number of leg-bearing segments (37, 39), and the very small body size (7–9 mm in length) and for a confident identification it is compared in detail with those having a roughly similar range of leg-bearing segments. This is the first record of the genus Ityphilus from Ecuador and the second report of a ballophilid centipede from the country (the other represented by Zygethmus pantenus Chamberlin, 1957). A key to the Neotropical members of Ityphilus with forcipular tarsungulum smooth (including I. cifuentesi) is also given.

http://zoobank.org/urn:lsid:zoobank.org:pub:32F77890-9DC5-47AC-A794-29C4437C3B93http://zoobank.org/urn:lsid:zoobank.org:act:3EB64970-F159-4C6E-B9FF-AF9D09128553  相似文献   


12.
Ituglanis australis new species, is described from tributaries of the Laguna dos Patos and Río Uruguay, in Brazil and Uruguay. This represents the southernmost record of the genus and the first occurrence of a species of Ituglanis in those systems. It is distinguished from all its congeners, except Ituglanis parahybae and Ituglanis cahyensis, by its body pigmentation with three well‐defined dark brown stripes running along each flank. Ituglanis australis differs from I. parahybae and I. cahyensis in the pectoral‐ and pelvic‐fin ray counts, the pattern of the cephalic laterosensory system and the number of dorsal‐fin basal radials. The new species, as well as several other examined congeners, has the levator internus IV muscle attached to the dorsal face of the posttemporo‐supracleithrum; a condition that corroborates the inclusion of Ituglanis into a large trichomycterine clade that also includes Bullockia, Hatcheria, Scleronema and several species of Trichomycterus. Previous proposals of the affinities within Ituglanis are reviewed and, despite some advances, the phylogenetic relationships among species of the genus remain largely unknown.  相似文献   

13.
From comparisons of the cephalic and pectoral girdle structures of Plotosus lineatus with those of other plotosid as well as non-plotosid siluriforms, plotosid catfishes can be defined by at least six autapomorphies. These are: (1) the absence of the ventral division of the muscle arrector dorsalis; (2) the double articulation between the neurocranium and the anterior part of the suspensorium; (3) the greatly enlarged utricular otolith, which profoundly inflates the ventral surfaces of both the prootic and the pterotic; (4) the attachment of the muscle extensor tentaculi on the neurocranium lies further anteriorly than its insertion on the autopalatine; (5) the coronoid process of the mandible is linked to the maxillary by means of two thick, long ligaments; (6) the enlarged base of the maxillary barbel.  相似文献   

14.
记述采自云南省绿春县牛孔乡的直翅目蚱总科枝背蚱科1新属:盾蚱属Aspiditettix gen.nov.及1新种--云南盾蚱Aspiditettix yunnanensis,sp.nov..模式标本保存于中山大学生物博物馆昆虫标本室.  相似文献   

15.
记述采自滇西地区螳螂1新种,即小屏顶螳Kishinouyeum parvula,sp.nov.。模式标本保存于大理学院生命科学与化学系。  相似文献   

16.
As the first taxonomic and faunistic report of Nanomis Lugo-Ortiz and McCafferty, 1999 for Venezuela, we describe a new species, N. rasmusseni sp. n., based on material from Andean streams. Comparisons of the nymphal and imaginal stages of N. rasmusseni with those of N. galera Lugo-Ortiz and McCafferty, 1999 – the only species currently known for this genus – are done in detail. Further, additional morphological characters are discussed to delineate the genus from the other baetid genera. Likewise, ecological data and distribution of N. rasmusseni in the Andean highlands of Venezuela are provided, which improves knowledge of the richness and distribution of the genus in South America.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:C9DF3936-101F-4240-B067-AC5DF394C805  相似文献   

17.
中国云南省奇春蜓属一新种(蜻蜓目:春蜓科)   总被引:1,自引:0,他引:1  
记述中国新记录属——奇春蜓属Perissogomphus Laidlaw,1922和1新种——朝氏奇春蜓P.asahinai,sp.nov.,模式标本保存在大理学院。  相似文献   

18.
王文采 《植物研究》2018,38(6):809-819
描述了自西藏发现的毛茛科翠雀花属七新种,隆子翠雀花,黄花翠雀花,绿房翠雀花,二距翠雀花,扎囊翠雀花,宽片翠雀花和狭裂翠雀花,并给出其等与近缘种的区别特征。  相似文献   

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20.
We compare the cranial morphology of four fish species with an increasing anguilliformism in the following order: Clarias gariepinus, Clariallabes melas, Gymnallabes typus, and Channallabes apus. The main anatomical‐morphological disparities are the stepwise reduction of the skull roof along with the relative enlargement of the external jaw muscles, which occurred in each of them. Gymnallabes typus and C. apus lack a bony protection to cover the jaw muscles. The neurocranial bones of C. gariepinus, however, form a closed, broad roof, whereas the width of the neurocranium in C. melas is intermediate. Several features of the clariid heads, such as the size of the mouth and the bands of small teeth, may be regarded as adaptations for manipulating large food particles, which are even more pronounced in anguilliform clariids. The jaw musculature of G. typus is hypertrophied and attached on a higher coronoid process of the lower jaw, causing a larger adductive force. The hyomandibula interdigitates more strongly with the neurocranium and its dentition with longer teeth is posteriorly extended, closer to the lower jaw articulation. The anguilliform clariids also have their cranial muscles modified to enable a wider gape. The adductor mandibulae and the levator operculi extend more posteriorly, and the anterior attachment site of the protractor hyoidei dorsalis shifts toward the sagittal plane of the head. A phylogenetic analysis of the Clariidae, which is in progress, could check the validity of Boulenger's hypothesis that predecessors of the primitive fishes, such as Heterobranchus and most Clarias, would have evolved into progressively anguilliform clariids. J. Morphol. 240:169–194, 1999. © 1999 Wiley‐Liss, Inc.  相似文献   

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