1,720,976 research outputs found
Palaeoplex gen. nov. and Lufubuchromis gen. non, two new monotypic cichlid genera (Teleostei: Cichlidae) from northern Zambia
No full textSchedel, Frederic D.B., Kupriyanov, Viviane M.S., Katongo, Cyprian, Schliewen, Ulrich K. (2020): Palaeoplex gen. nov. and Lufubuchromis gen. non, two new monotypic cichlid genera (Teleostei: Cichlidae) from northern Zambia. Zootaxa 4718 (2): 191-229, DOI: 10.11646/zootaxa.4718.2.
FIGURE 2 in A new species of Pseudocrenilabrus (Perciformes: Cichlidae) from Lake Mweru in the Upper Congo River System
No full textFIGURE 2. Pseudocrenilabrus pyrrhocaudalis sp.nov, female, paratype (SAIAB 191530, 66.7 mm SL) from Kalobwa Beach, Lake Mweru in live (a) and in preserved colour pattern (b).Published as part of Katongo, Cyprian, Seehausen, Ole & Snoeks, Jos, 2017, A new species of Pseudocrenilabrus (Perciformes: Cichlidae) from Lake Mweru in the Upper Congo River System, pp. 181-190 in Zootaxa 4237 (1) on page 184, DOI: 10.11646/zootaxa.4237.1.10, http://zenodo.org/record/32276
FIGURE 1 in Palaeoplex gen. nov. and Lufubuchromis gen. non, two new monotypic cichlid genera (Teleostei: Cichlidae) from northern Zambia
No full textFIGURE 1. Map of northern Zambia, with colour indications of the type localities of Lufubuchromis relictus sp. nov. (purple) and Palaeoplex palimpsest sp. nov. (dark green) and sample locations of additional material of Palaeoplex palimpsest "Kalungwishi" (red). Star = type locality, circle = either paratype locality or sample locality of comparative specimens. Kasama (a major city) is depicted in black. Map is based on shape files obtained from DIVA-GIS (http://www.diva-gis.org/Data).Published as part of Schedel, Frederic D.B., Kupriyanov, Viviane M.S., Katongo, Cyprian & Schliewen, Ulrich K., 2020, Palaeoplex gen. nov. and Lufubuchromis gen. non, two new monotypic cichlid genera (Teleostei: Cichlidae) from northern Zambia, pp. 191-229 in Zootaxa 4718 (2) on page 195, DOI: 10.11646/zootaxa.4718.2.3, http://zenodo.org/record/360233
The Evolutionary biology and taxonomic review of Zambian riverine haplochromine cichlids
No full textThis study aimed at reconstructing the phylogenetic relationships among Zambian riverine haplochromine cichlids and at reviewing their taxonomic status. The riverine haplochromines used were from the Zambezi River and the Luapula-Congo River systems. The target taxa were from two major groups: the Serranochromine species and the Pseudocrenilabrus species complex. Phylogenetic studies were based on mitochondrial DNA sequence analysis while the taxonomic studies were based on principal component analysis (PCA) of morphological characters. The results indicate that the Zambian riverine haplochromines share a common ancestor, which is likely to have originated from the Congo drainage and later colonized the Zambezi drainage. The results also indicate a need to revise the genera Serranochromis, Sargochromis, Pseudocrenilabrus and Pharyngochromis from all the rivers of Zambia. There are likely to be a number of undescribed species and/or misidentifications within these genera. There might be at least 3 species of Pseudocrenilabrus in Zambia. The Pseudocrenilabrus 'sp haplochromis-orange' population from the Lake Mweru / Mwatishi River confluence is morphologically the most distant from the other populations. Some of the Pseudocrenilabrus species from Luc de Vos' collection from the Lufubu River drainage, held in the Royal Museum of Central Africa at Tervuren, Belgium (MRAC 96-031-P and MRAC 96-083-P) may be members of a new species. The Sargochromis specimens from the Luapula, collected by Van Zwieten (MRAC 9-035-P) and those collected during this study (MRAC A4-25), both held at the Royal Museum of Central Africa, appear to consist of two morpho-types with one of them likely to be Sargochromis mellandi while the second is likely to be different. There seem to be two or more undescribed species of Sargochromis- collected from the Kafue River. One of them, a slender type with a long snout (Sargochromis 'sp longsnout-kafue'), was quite abundant during the field fcrjp of the summer of 2002, while another one with longitudinal stripes Hvas less abundant (Sargochromis 'sp striped'). Van der Waal's collection (RUSI 062863) has one Sargochromis species collected from below the Itezhi tezhi Dam, on the Kafue River. This taxon (Sargochromis 'sp Zambia') is very likely to be a new record in the Kafue system or even an undescribed species. The Pharyngochromis group seems to consist of at least more than one species. The Pharyngochromis acuticeps from Lake Kariba fits very well into the description of Skelton (1993) and Greenwood (1992). The other Pharyngochromis individuals are generally bigger in size with a different coloration on the head. There seem to be some individuals, which are intermediate between Sargochromis and Pharyngochromis from the Upper Zambezi. There was one Serranochromis 'sp elongate', collected from Lake Mweru, which is morphologically similar to (but does not fit into the description of) either S. macrocephalus or S. stappersi, which have both been documented in that lake. It has a close mitochondrial phylogenetic relationship with Serranochromis angusticeps
Pseudocrenilabrus pyrrhocaudalis Katongo, Seehausen & Snoeks, 2017, sp. nov.
No full text<i>Pseudocrenilabrus pyrrhocaudalis</i> sp. nov. <p>Fire-tailed Pseudocrenilabrus</p> <p>Figs. 1, 2. Tables 2, 3.</p> <p> <b>Holotype</b>. SAIAB-191528, male 62.8 mm SL; Zambia; Kalobwa Beach (1,134 meters above sea level with coordinates 8°57'0" S and 29°6'0" E), Lake Mweru, Luapula-Congo River system, seine net, C. Katongo and O. Seehausen, 15 September 2005 (Fig. 1 a).</p> <p> <b>Paratypes</b>. MRAC A9-034-P-0238-247, 57.3–73.1 mm SL, Luapula-Congo River system, Mukwakwa, Lake Mweru, Zambia, P. van Zwieten, 1994; MRAC A4-025-P0103-07 and MRAC A4-025-0137-38, 46.5–54 mm SL, Luapula-Congo River system, Mwatishi River / Lake Mweru confluence, gillnet, C. Katongo, 2002; SAIAB 191530 (1-13), 45.3–68.3 mm SL, Luapula-Congo River system, Kalobwa beach, Lake Mweru, C. Katongo and O. Seehausen, September, 2005.</p> <p> <b>Diagnosis.</b> <i>Pseudocrenilabrus pyrrhocaudalis</i> can be differentiated from the other species of the genus <i>Pseudocrenilabrus</i> on the basis of its colour pattern and its subtruncate caudal fin. Male <i>P. pyrrhocaudalis</i> have a unique colour pattern characterized by some orange colour on their anal and caudal fins that can become bright orange-red in breeding males, extending over the proximal parts of the anal and caudal fins and the distal part of the caudal and the upper and lower parts of the caudal peduncle (Fig. 1 a). In addition, <i>P. pyrrhocaudalis</i> can be distinguished from its sympatric congener <i>P. philander</i> (Fig. 3), by a combination of the following characters (Figs.1, 2, 4; Tables 2, 3): pelvic fin white (vs. black), posterior part of dorsal fin orange (vs. olive green in the other species), comparatively thinner lips (vs. comparatively thicker lips), larger eye diameter 27.0–39.3% HL (vs 22.9–33.1% HL), narrower head width 37.0–47.3% HL (vs. 38.5–53.7% HL), narrower interorbital distance 14.6– 22.3% HL (vs. 20.5–29.4% HL) and a more slender caudal peduncle 8.8–11.8% SL (vs. 11.3–13.9% SL), and 50.0–64.7% CPL (vs 64.3–93.5% CPL).</p> <p> <b>Description.</b> In both sexes: body relatively deep, head profile somewhat convex, mouth inclined upwards with relatively thin lips, interorbital distance narrow, caudal fin sub-truncate. Lower pharyngeal bone relatively slender and slightly longer than wide. Pharyngeal teeth all fine; those of the posterior row clearly larger than the others. Teeth of the two median rows somewhat enlarged. There is a small gradient in the orientation of the major cusp of the pharyngeal teeth from slightly backwards on the anterior parts of the pharyngeal jaw towards more erect posteriorly and slightly forward in the posteriormost rows. Breeding males with a bright orange coloration on caudal and anal fins; an orange spot on the anal fin, distal parts of caudal and anal fins white. Base of the caudal fin bright orange more than 2/3 of fin. Head and upper lateral part of body grey, while the lower part yellowish orange. Dorsal fin with white lateral dots arranged as stripes radiating from base to tips of dorsal-fin rays. Pelvic fins bright white (Fig. 1 a). Females generally grey, with no anal-fin spot; pelvic fins bright white; bright orange lower half of caudal; some orange flashes at base of caudal and anal fins; some spots and streaks on dorsal and caudal fins (Fig. 2 a).</p> <p> A scatter plot of mainly male specimens of <i>P. pyrrhocaudalis</i> <b>sp. nov.</b> and Lake Mweru <i>P. philander</i> on the first and second axes of a PCA on log transformed measurements (Figure 4) shows that there are clear morphological differences between the two species. The characters with the highest loadings on the second axis (responsible for the observed morphological differences) are caudal peduncle length (CPL), interorbital width (IOW), eye diameter (ED), anal fin base (AFB), head width (HW) and caudal peduncle depth (CPD), (Table 1). Comparisons of morphometric ratios between <i>P. pyrrhocaudalis</i> <b>sp. nov.</b> and <i>P. philander</i> (Table 2) indicate that the characters responsible for the observed morphological differences are eye diameter as a proportion of head length (ED_HL), interorbital width as a proportion of head length (IOW_HL) and as a proportion of head width (IOW_HW), head width as a proportion of head length (HW_HL), caudal peduncle depth as a proportion of standard length (CPD_ SL) and as a proportion of caudal peduncle length (CPD_ CPL). Comparisons of meristic counts between <i>P. pyrrhocaudalis</i> <b>sp. nov.</b> and <i>P. philander</i> (Table 3) indicate that the characters responsible for the differences are number of upper jaw teeth (UJT), number of upper jaw inner rows (UJIR), dorsal spiny rays (Dspiny), anal soft rays (Asoft) and number of scales around the caudal peduncle (CP). The columns with Mann Whitney U test results (probabilities) in both Tables 2 and 3 were generated using <i>P. pyrrhocaudalis</i> <b>sp. nov.</b> and <i>P. philander</i> specimens of similar size class (44–73mm SL). These results (in the last column of each of Tables 2 and 3) indicate the relative contribution of the highlighted characters to the differences between the two species.</p> <p> <b>Etymology.</b> Named <i>Pseudocrenilabrus pyrrhocaudalis</i> because this species has a bright orange tail which resembles a flame of fire. The common name fire-tailed Pseudocrenilabrus is proposed for this species. <b>Distribution</b>. Probably endemic to Lake Mweru where it has been found near the beaches at Kalobwa, Kabuta, Ntoto and Kashikishi and at the Mwatishi River estuary (Fig. 5).</p> <p> <b>Variable PC1 PC2 PC3</b></p> <p>Lachrymal depth 0.851 0.142 -0.207</p> <p>Snout length 0.893 0.241 -0.044</p> <p>Lower jaw length 0.872 -0.250 0.249</p> <p>Premaxillary pedicel length 0.958 0.025 0.056</p> <p>Cheek depth 0.934 -0.034 0.061</p> <p> <b>Eye diameter</b> 0.613 <b>-0.465 -0.596</b></p> <p> <b>Interorbital width</b> 0.810 <b>0.485</b> 0.043</p> <p> <b>Head width</b> 0.905 <b>0.310</b> -0.007</p> <p>Head length 0.983 0.023 -0.030</p> <p>Standard length 0.978 -0.124 0.062</p> <p>Body depth 0.952 0.006 0.106</p> <p>Dorsal fin base length 0.964 -0.081 0.118</p> <p> <b>Anal fin base length</b> 0.824 <b>-0.316 0.323</b></p> <p>Predorsal distance 0.972 0.040 -0.064</p> <p>Prepelvic distance 0.933 0.024 0.012</p> <p>Preventral distance 0.976 -0.023 -0.064</p> <p>Pre-anal distance 0.972 0.044 -0.057</p> <p> <b>Caudal peduncle length</b> 0.685 <b>-0.579</b> 0.041</p> <p> <b>Caudal peduncle depth</b> 0.888 <b>0.280</b> -0.166</p> <p>Explained variance 15.333 1.231 0.646</p> <p>Proportion of total variance 0.807 0.065 0.034</p>Published as part of <i>Katongo, Cyprian, Seehausen, Ole & Snoeks, Jos, 2017, A new species of Pseudocrenilabrus (Perciformes: Cichlidae) from Lake Mweru in the Upper Congo River System, pp. 181-190 in Zootaxa 4237 (1)</i> on pages 182-186, DOI: 10.11646/zootaxa.4237.1.10, <a href="http://zenodo.org/record/322765">http://zenodo.org/record/322765</a>
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
