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Comparison of anatomical characters in allopatric Petrocephalus species focussing on the Lower Zambezi sample; multivariate analysis of variance (MANOVA) followed by univariate ANOVAs. PDL/SL PAL/SL LD/SL LA/SL pD/SL CPL/SL CPD/CPL LSc/HL HL/SL BD/SL nD nA SPc MANOVA <10 −4 ANOVA <10 −4 <10 −4 <10 −4 <10 −4 <10 −4 <10 −4 <10 −4 <10 −4 <10 −4 <10 −4 <10 −4 <10 −4 <10 −4
Source publication
We morphologically and genetically studied the southern African electric fish Petrocephalus catostoma, or churchill, and its six nominal species, five of which by synonymization (three valid subspecies). We reinstate the synonymized species, and recognize Petrocephalus tanensis (Whitehead and Greenwood, 195982.
Whitehead , PJ and
Greenwood , PH....
Contexts in source publication
Context 1
... Zambezi samples differed from the standard, Rovuma samples, in seven characters, from Kafue samples also in seven, from Upper Zambezi samples in six (among them the three meristic characters), and from Sabie samples (P. wesselsi) in seven characters (Table 3). ...
Context 2
... degeni (type, n = 1) of Lake Victoria, also in East Africa, is the next closest nominal species. However, the measurements for its anatomical characters were below the lowest of the Tana samples for LD, LA, pD, CPL, LSc, Na, nD and Table 3), lower panels, analyses on 17 characters (see Table 1, with HL/Na and LSc/HL excluded). Prin1-Prin3, for Principal Components 1-3. ...
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Citations
... 2022). However, recent studies have shown that this species is native to the Zambezi ichthyofaunal province (Kramer et al., 2012). Being a riverine species, this new evidence suggests that presence of this species in Uganda is unlikely. ...
Freshwater fishes are the second most threatened group of vertebrates after amphibians. In most developing countries, the conservation of freshwater fishes is largely hampered by limited information and data. The Red List assessments by the International Union for Conservation of Nature (IUCN) provide a benchmark for monitoring and mitigating species extinction risk, but these assessments require, inter alia, quantitative information on the species range in the wild. This information is largely missing for many species that face extinction threats. Here, we combine species occurrence data, expert knowledge, and literature to (i) review and update the distribution of non-Haplochromis fish species native to Uganda and (ii) determine the national geographical range of these fish species relative to their global range. For the latter, we use the IUCN’s standard protocol for mapping distribution of freshwater species from which we derive both the national and global extent of occurrence (EOO) and area of occupancy (AOO). We show that at least 110 non-Haplochromis species occur in Uganda, with the majority species having a wide distribution outside the national boundaries. However, substantial gaps exist in data on presence of the species in their native range, where more than 60% of the species are designated as “possibly extant.” We elaborate on fish species previously believed to occur in Uganda, e.g., Amphilius kivuensis Pellegrin, 1933; Bagrus degeni Boulenger, 1906; Marcusenius macrolepidotus (Peters, 1852); Petrocephalus catostoma (Günther, 1866); and Lacustricola pumilus (Boulenger, 1906), but where recent studies suggest they lack a native distribution within the country. In addition, we highlight fishes with occurrence records that site them in areas beyond their previously known range, requiring further investigations to ascertain their present status. This work has potential to (i) trigger evidence-driven policies aimed at site-based conservation and rethinking of extent of protected areas, (ii) stimulate data collection, especially in areas where fishes are designated as “possibly extant” and “presence uncertain,” and (iii) aid the IUCN Red List assessments, for which conservation status of the majority non-Haplochromis species is outdated and many others remain unevaluated due to lack of quantitative information on their range.
... Marcusenius victoriae and P. degeni occupy habitats with greatly differing environmental conditions within the Lake Victoria basin of East Africa, including Lake Victoria, Katonga River, and Lake Nabugabo (Chapman et al., 1996b ;Chapman and Chapman, 1998 ;Chapman and Hulen, 2001 ;Chapman et al., 2002 ;Clarke et al., 2020 ;Kramer et al., 2012 ;Moulton et al., 2020 ;Ogutu-Ohwayo, 1993). They belong to different subfamilies of the Mormyridae, Mormyrinae and Petrocephalinae, respectively, and differ in their electrosensory anatomy, overall morphology, and social behavior (Figure 2; Carlson, 2016). ...
In dieser Arbeit wurden die Morpho-Physiologie und das Verhalten zweier Arten Afrikanischer schwach elektrischer Fische, Marcusenius victoriae und Petrocephalus degeni, im Labor und in einem ihrer natürlichen Habitate im Lwamunda Sumpf in Uganda untersucht. Die zwei Hauptziele dieser Arbeit waren (i) tageszeitabhängige Verhaltensrhythmen (Aktivität, Habitatnutzung) im Labor und im Freiland zu untersuchen und (ii) die Ausprägung und Plastizität der morpho-physiologischen Merkmale von P. degeni zu untersuchen, die ihnen erlauben bei natürlich vorkommender, geringer Sauerstoffverfügbarkeit (Hypoxie) zu überleben. Tageszeitabhängige Verhaltensrhythmen beider Arten wurden im Labor über 42 Stunden und im natürlichen Habitat dieser Fische für sechs Tage erfasst. In den Laborversuchen verbrachten beide Arten tagsüber annähernd 100% der Zeit in einem bereitgestellten Versteck und schwammen nachts heraus um aktiv ihre Umwelt zu erkunden. Im Habitat wurden die meisten Fische in strukturell komplexen Habitaten unter schwimmenden Pflanzen detektiert. Nachts schwammen die Fische aktiv in die offenen und ungeschützten Bereiche der Lagune, vermutlich um nach Futter zu suchen und zu interagieren. Die Begleitende in-situ Messung der Sauerstoffverfügbarkeit zeigte, dass beide Arten präsent und vermutlich sogar am aktivsten waren während Phasen extremer nächtlicher Hypoxie. Zur Untersuchung der respiratorischen Merkmale von P. degeni wurden Respirometrieversuche mit hypoxie-akklimatisierten Tieren durchgeführt, Hämoglobin- und Laktatkonzentration im Blut gemessen, und morphologische Parameter an den ersten beiden Kiemenbögen erfasst. Die Fische zeigten niedrige Sauerstoffverbrauchsraten, welche sie bis zu einem sehr niedrigem äußeren Sauerstoffpartialdruck aufrechterhielten. Zusätzlich zeigten sie hohe Hämoglobin- und Laktatkonzentrationen im Blut. Bis zu 75 Tage Normoxie-Akklimatisierung führte zu reduzierter Hämoglobinkonzentration und kürzeren Kiemenfilamenten.
... It is listed by Greenwood (1966) to occur in Lake Victoria and Nabugabo and the Victoria Nile (East Coast Ichthyofaunal province), while other occurrence records from GBIF extend the distribution to Lakes Albert, Kyoga, George, Nabugabo, Kagera, and Nyaguo, which span two Ichthyofaunal provinces (Fig. 1). Such a distribution is not likely for lacustrine species, and therefore, the records in Uganda can be considered Petrocephalus degeni (Kramer et al., 2012). ...
Freshwater fishes are the second most threatened group of vertebrates after amphibians. In most developing countries, the conservation of freshwater fishes is largely hampered by limited information and data. The Red List assessments by the International Union for Conservation of Nature (IUCN) provide a benchmark for conservation and planning, but these assessments require, inter alia , quantitative information on the species range in the wild. This information is largely missing for many species that face extinction threats. In this paper, we combined species occurrence data, expert knowledge, and literature to review and update the distribution of non- Haplochromis fish species native to Uganda and determine their geographical extent relative to the global range. Results showed that (i) at least 110 non- Haplochromis species occur in Uganda, (ii) the current status in the entire native range for more than 60% of these species is unknown; (iii) five species previously known to occur in Uganda: Amphilius kivuensis, Bagrus degeni, Marcusenius macrolepidotus, Petrocephalus catostoma , and Lacustricola pumilus lack a native locus and hence not Ugandan fishes, (iv) 17 species occur in areas beyond their previously known range, and therefore, their presence needs further investigations, preferably by examining specimen collections, and (v) majority of the non- Haplochromis species native to Uganda have a wide distribution outside the national boundaries. We anticipate this information to be relevant both for the national and global IUCN Red List assessments for the non- Haplochromis fishes in Uganda. Furthermore, the identified data gaps will be relevant in prioritizing limited resources during surveys and collections.
... studies in the region have shown that most mormyrid genera contain a number of species that were previously unknown to science (Kramer, 2013;Kramer et al., 2003;Kramer et al., 2004;Kramer et al., 2007;Kramer et al., 2012;Kramer et al., 2016;Kramer & Swartz, 2010;Kramer & van der Bank, 2000;Kramer & van der Bank, 2011;Kramer & Wink, 2013;Maake et al., 2014). These studies have led to the description of 17 new species and the resurrection of 1 species, indicating that mormyrid diversity in southern Africa remains underestimated. ...
... Findings from the present study support a growing body of literature which shows that many of the species that were previously considered to have broad geographic ranges across multiple isolated river systems in southern Africa are complexes comprising several historically isolated lineages, with some of them representing novel species (Chakona et al., 2018;Eccles et al., 2011;Kramer et al., 2012;Maake et al., 2014;Riddin et al., 2016). There are at least seven lineages within the H. ansorgii complex that need to be formally described following generation of additional data and detailed examination of a comprehensive number of voucher specimens. ...
The present study used molecular and morphological approaches to investigate hidden diversity within the Hippopotamyrus ansorgii species complex in southern Africa. Phylogenetic reconstructions and three species delimitation methods based on two mitochondrial markers (cytochrome b and cytochrome oxidase I) and one nuclear marker (S7) revealed 12 Molecular Operational Taxonomic Units (MOTUs), with two of them representing two recently described species, H. longilateralis and H. szaboi. The highest diversity occurred in the Kwanza River system, which contained five MOTUs, and the upper Zambezi River system that had two MOTUs. Five other river systems contained a single MOTU each. A major impediment to the review of this complex has been the uncertainty surrounding the type locality of the specimens that were used for the description of H. ansorgii. The present study has, through careful examination of published literature and synthesis of information on the travel activities of Dr William Ansorge who collected the specimens, identified the Kwanza River system as the most plausible source of the syntypes. The resolution of the type locality of H. ansorgii facilitates future work on the review of this complex which is critical for providing reliable biodiversity estimates, identifying effective conservation management strategies and understanding the evolutionary history and biogeographic patterns of the fishes of this region.
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... OVA using data from 168 individuals pooled from 13 species. Given the morphological, physiological and behavioural differences between weakly electric fishes and other teleosts (Albert et al., 1997;Chapman et al., 2002;Chapman & Chapman, 1998;Chapman & Hulen, 2001;Sukhum et al., 2016), a common curve may not be appropriate (Lapointe et al., 2018). B. Kramer et al., 2012). Although consistent with previous studies of M. victoriae and other mormyrids, this extremely low critical oxygen tension in mormyrids is, nonetheless, remarkable given the previously estimated high metabolic cost of the EOD and T A B L E 2 Routine metabolic rates (RMR; adjusted to a common body mass of 17.10 g), routine electric organ ...
In this study, the hypoxia tolerance of a mormyrid weakly electric fish, Marcusenius victoriae, was assessed by examining both its metabolic rate and electric‐organ discharge (EOD) production using a critical threshold (pcrit) paradigm. Routine metabolic rate was 1.42 mg O2 hr–1 and the associated critical oxygen tension was 14.34 mm Hg. Routine EOD rate was 5.68 Hz with an associated critical tension of 15.14 mm Hg. These metabolic indicators of hypoxia tolerance measured in this study were consistent with prior studies on M. victoriae and other weakly electric fishes. Furthermore, our results suggest that some aerobic processes may be reduced in favour of maintaining the EOD rate under extreme hypoxia. These findings underscore the importance of the active electrosensory modality to these hypoxia‐tolerant fish. This article is protected by copyright. All rights reserved.
... (Arnegard et al., , 2006(Arnegard et al., , 2010aArnegard & Hopkins, 2003;Gallant et al., 2011;Rich et al., 2017;Sullivan et al., 2002), Petrocephalus(Kramer et al., 2012;Lavoué et al., 2008Lavoué et al., , 2010Lavoué & Sullivan, 2014;Moritz et al., 2009), PollimyrusMarkowski et al., 2008) and Stomatorhinus Boulenger 1898.Carlson et al. (2011) and Carlson (2016) made a distinction between general patterns of EOD diversity in clade A mormyrids (this clade comprises most genera in the subfamily Mormyrinae, e.g. Paramormyrops, Marcusenius and Stomatorhinus) v. non-clade A taxa outside this clade (the subfamily Petrocephalinae, which comprises only Petrocephalus and the mormyrin genus Myomyrus). ...
Electroreception, the capacity to detect external underwater electric fields with specialised receptors, is a phylogenetically widespread sensory modality in fishes and amphibians. In passive electroreception, a capacity possessed by c. 16% of fish species, an animal uses low‐frequency‐tuned ampullary electroreceptors to detect microvolt‐range bioelectric fields from prey, without the need to generate its own electric field. In active electroreception (electrolocation), which occurs only in the teleost lineages Mormyroidea and Gymnotiformes, an animal senses its surroundings by generating a weak (< 1 V) electric‐organ discharge (EOD) and detecting distortions in the EOD‐associated field using high‐frequency‐tuned tuberous electroreceptors. Tuberous electroreceptors also detect the EODs of neighbouring fishes, facilitating electrocommunication. Several other groups of elasmobranchs and teleosts generate weak (< 10 V) or strong (> 50 V) EODs that facilitate communication or predation, but not electrolocation. Approximately 1.5% of fish species possess electric organs. This review has two aims. First, to synthesise our knowledge of the functional biology and phylogenetic distribution of electroreception and electrogenesis in fishes, with a focus on freshwater taxa and with emphasis on the proximate (morphological, physiological and genetic) bases of EOD and electroreceptor diversity. Second, to describe the diversity, biogeography, ecology and electric signal diversity of the mormyroids and gymnotiforms and to explore the ultimate (evolutionary) bases of signal and receptor diversity in their convergent electrogenic–electrosensory systems. Four sets of potential drivers or moderators of signal diversity are discussed. First, selective forces of an abiotic (environmental) nature for optimal electrolocation and communication performance of the EOD. Second, selective forces of a biotic nature targeting the communication function of the EOD, including sexual selection, reproductive interference from syntopic heterospecifics and selection from eavesdropping predators. Third, non‐adaptive drift and, finally, phylogenetic inertia, which may arise from stabilising selection for optimal signal‐receptor matching.
... Growing evidence from previous and ongoing DNA-based studies shows that many species of freshwater fishes that were previously considered to have wide geographic ranges are instead complexes comprising several genetically divergent lineages (e.g., Goodier et al. 2011;Kramer et al. 2004;Kramer and Wink 2013;Linder et al. 2010;Swartz et al. 2007Swartz et al. , 2009). These studies have stimulated renewed interest in the systematics of freshwater fishes in the region as evidenced by the recent revalidation of some junior synonyms as well as the identification and description of several new species (e.g., Chakona et al. 2014;Chakona and Skelton 2017;Kramer et al. 2003Kramer et al. , 2007Kramer et al. , 2012Kramer et al. , 2013Kramer et al. , 2014Kramer and Swartz 2010;Kramer and van der Bank 2011;Maake et al. 2014). There is thus need for expanding the application of molecular approaches as these may lead to the identification of presently unrecognised diversity and provide insights on the patterns of endemism of stream fishes from other understudied regions in southern Africa such as the EZH freshwater ecoregion. ...
Stream fishes of the Eastern Afromontane region are among the least studied vertebrates in this region, despite the potential for harbouring cryptic diversity. The present study examined mitochondrial cytochrome oxidase subunit I (COI) sequence divergence in 153 specimens of stream fishes belonging to four genera and three families, [( Amphilius and Zaireichthys (Amphiliidae); Chiloglanis (Mochokidae); and Hippopotamyrus (Mormyridae)], in the Eastern Zimbabwe Highlands (EZH) freshwater ecoregion to explore the extent to which the current taxonomy conceals the ichthyofaunal diversity in the region. The General Mixed Yule Coalescent (GMYC) species delineation method identified 14 clusters within five currently recognised ‘species’ from the EZH ecoregion. Only one of these clusters represents a named species, while 13 of them represent candidate or undescribed species. Our results revealed that effective conservation of this region’s unique biota is limited by the incomplete knowledge of taxonomic diversity and inaccurate mapping of species distribution ranges.
... with additions and modifications byKramer, Bills, Skelton, and Wink (2012) for measurements of the caudal peduncle depth, pectoral-pelvic distance, and snout length; caudal peduncle length was measuredfrom the ends of both dorsal and anal fins. Eleven meristic counts were taken in each specimen including numbers of rays in the dorsal, anal, pectoral and pelvic fins, numbers of scales in the lateral line and around the caudal peduncle, number of scale rows between the lateral line and origins of the dorsal and pelvic fins, numbers of teeth in upper and lower jaws, and total number of vertebrae. ...
Based on morphological data and analysis of mitochondrial cytochrome b gene and nuclear (S7 intron 1) DNA sequences, the phylogenetic relationships of all Pollimyrus species known from the Omo-Turkana enclosed basin and Nile system below the Murchison Falls were solved. A mormyrid “Pollimyrus” petherici is distantly related to all other studied Pollimyrus species and clusters together with Cyphomyrus species forming with the later a monophyletic group. Moreover, the West African (but not the Congo River) populations of Cyphomyrus psittacus, the type species of the genus, seem to be conspecific to C. petherici. That is, the range of the genus Cyphomyrus is extended toward the Nile and Omo-Turkana basins. This genus belongs to the large clade widely distributed in sub-Saharian Africa and characterized by the presence of a chin appendage. Significance of this character for mormyrid phylogeny is discussed. Two distinct lineages of Pollimyrus occurring sympatrically in the White Nile tributaries and previously reported as the light and dark forms of Pollimyrus isidori together with five other congeneric species studied form a monophyletic group. The light form apparently represents P. isidori distributed in the Nile system downstream of the Murchison Falls and West Africa; the dark-colored form (designated as Pollimyrus “D”) represents a distinct phylogenetic lineage inhabiting both the Omo-Turkana and the White Nile basin. Morphological and ecological data suggest that this form may be conspecific to East African Pollimyrus nigricans or most probably represents a new species.
... In certain mormyrid genera, such as Hippopotamyrus, Mormyrops and Pollimyrus, closely-related species-as far as they have been studied-are more easily recognized by the marked and characteristic differences in their EOD pulse waveforms than by their morphology. In other mormyrid genera, such as Petrocephalus, the EOD waveforms of all species which have been studied are basically similar, and rather cryptic, species-characteristic differences are often revealed only by quantitative comparisons at high resolution (for example, Kramer et al. 2012;Lavoué et al. 2010). Yet another case is a single East-African species, Mormyrus tenuirostris, which differs radically in waveform type from all other known Mormyrus species throughout Africa, all of which display basically similar waveforms (Kramer 2013). ...
Recent morphological and genetic studies have revealed two new species of snoutfish in South Africa, Marcusenius caudisquamatus and M. krameri, which had been confused with M. pongolensis, the South African bulldog fish. All known mormyriform fish are nocturnal and emit electric organ discharges (EODs) for communication that are characteristic for their species. This paper examines whether or not the EODs of these three closely-related South African species can be differentiated from each other. An EOD pulse of a bulldog fish consists of a head-positive phase P, followed by a head-negative phase N of short duration. We measured and compared six variables of the EOD pulse waveform for South African samples for the three species from different locations using MANOVA, ANOVA and Discriminant Analysis, with M. devosi from Kenya as an outgroup. The EOD waveforms, normalized to the same P-phase amplitude, varied significantly from each other in four variables, most strongly in the amplitude of the N phase and the duration of the P phase. In two species, M. devosi and M. krameri, there was no evidence of difference between sexes, in contrast to M. pongolensis and M. caudisquamatus whose male pulses were of longer duration. M. devosi and M. krameri were statistically significantly independent of each other and of any other group studied. By contrast, the M. pongolensis specimens from different locations showed a high degree of variability amongst each other, including significant separation, and overlap with M. caudisquamatus.
... It currently includes 45 valid species (46 with the new species described herein) . About one-third of the species of Petrocephalus were described during the last decade, making use of diverse morphological, electrophysiological and genomic characters (Kramer et al. 2012;Lavoué 2011;2012;Lavoué et al. 2004;Lavoué et al. 2010;Lavoué & Sullivan 2014). ...
A new species of the African weakly electric fish genus Petrocephalus (Osteoglossomorpha: Mormyridae: Petrocephalinae) is described from the Oubangui (Ubangi) River basin, the principal right-bank tributary of the Congo River. Petrocephalus leo sp. nov. is one of the most distinctive species of Petrocephalus as it combines (among other characteristics) the absence of electroreceptive rosettes on the head with a unique melanin pattern. Only four other species of Petrocephalus lack all electroreceptive rosettes: Petrocephalus microphthalmus, Petrocephalus haullevillii, Petrocephalus schoutedeni, and Petrocephalus zakoni. Petrocephalus leo sp. nov. can be distinguished from these four species in having a distinctive black mark at the base of the pectoral fins (versus absent in P. microphthalmus, P. haullevillii and P. schoutedeni) and no subdorsal black mark (versus present in P. zakoni). A phylogenetic analysis using mitochondrial cytochrome b gene sequences shows haplotypes of P. leo sp. nov. are distinct, but are unexpectedly nested within P. zakoni haplotypes, making this latter species paraphyletic. To investigate this conflict between morphology and mitochondrial cytochrome b, a nuclear marker, the first intron of the gene coding for the S7 ribosomal protein, was sequenced. The presence of four diagnostic indels between P. zakoni and P. leo sp. nov. sequences supports the reciprocal monophyly of these two species. This is the first reported case of conflict between morphology and mitochondrial phylogeny within the genus Petrocephalus. Finally, three species of Petrocephalus are reported for the first time from the Oubangui region bringing the total of Petrocephalus species in this region to 12.
