@article {628, title = {Impact of environmental features on the distribution of Marcusenius species (Pisces, Mormyridae) in Malebo Pool of Kinshasa in the Congo River}, volume = {16}, year = {2022}, month = {May-31-2022}, pages = {164-172}, abstract = {

The current anarchic exploitation of Marcusenius fish in the Malebo Pool located in the Congo River stands as a threat of extinction to certain species, while the ecology of most of them are hardly known. This study aims at evaluating the impact of environmental factors on the distribution of Marcusenius fish caught in six fishing stations in the Malebo Pool. Canonical correspondence analysis of environmental factors classified the stations into two groups, which differ in vegetation formation, bottom substrates, water current velocity, pH, suspended particles and in dissolved oxygen. Thus, the five stations located upstream and in the middle of the pool are characterized by low water current velocity, slightly acidic pH, bottom substrates composed of silt, plant debris, clay, silt and sand. The predominant Echinocloa and Eichhornia plant formations found in these sites provide shelter, food sources and impact on the distribution and abundance of seven Marcusenius species in Malebo pool. The rocky substrate of Kinsuka station associated with the plant formation dominated by Ledermanniella and Pennisetum, and a high-water current constitute a habitat that is not favourable for Marcusenius species.

}, issn = {1996-0786}, doi = {10.5897/ajest2022.3102}, url = {http://dx.doi.org/10.5897/ajest2022.3102}, author = {Jean M{\'e}tis Ntu Mabedi and Victorine Mbadu Zebe and Victor Pwema Kiafu and Lise-Marie PIGNEUR and Johan R. Michaux and Jean-Claude Micha} } @article {620, title = {The Complete Genome Sequences of 38 Species of Elephantfishes (Mormyridae, Osteoglossiformes)}, year = {2022}, month = {Nov-21-2022}, abstract = {

We present the complete genome sequences of 38 species of elephantfishes from 20 genera. Illumina sequencing was performed on genetic material from single wild-caught individuals. The reads were assembled using a de novo method followed by a finishing step. The raw and assembled data is publicly available via Genbank.

}, issn = {2687-7945}, doi = {10.56179/001c.56077}, url = {http://dx.doi.org/10.56179/001c.56077}, author = {Rose Peterson and John P Sullivan and Stacy Pirro} } @article {10.3897/zookeys.1129.90287, title = {Mitogenome recovered from a 19th Century holotype by shotgun sequencing supplies a generic name for an orphaned clade of African weakly electric fishes (Osteoglossomorpha, Mormyridae)}, journal = {ZooKeys}, volume = {1129}, year = {2022}, pages = {163-196}, publisher = {Pensoft Publishers}, abstract = {

Heteromormyrus Steindachner, 1866, a genus of Mormyridae (Teleostei: Osteoglossomorpha), has been monotypic since the description of Heteromormyrus pauciradiatus (Steindacher, 1866) from a single specimen. No type locality other than \“Angola\” was given and almost no specimens have been subsequently identified to this species. In order to investigate the relationship of this taxon to fresh specimens collected in Angola and elsewhere, whole genome paired-end sequencing of DNA extracted from the holotype specimen of Heteromormyrus pauciradiatus was performed and a nearly complete mitogenome assembled from the sequences obtained. Comparison of cytochrome oxidase I and cytochrome b sequences from this mitogenome to sequences from recently collected material reveal that Heteromormyrus pauciradiatus is closely related to specimens identified as Hippopotamyrus ansorgii (Boulenger, 1905), Hippopotamyrus szaboi Kramer, van der Bank \& Wink, 2004, Hippopotamyrus longilateralis Kramer \& Swartz, 2010, as well as to several undescribed forms from subequatorial Africa collectively referred to in the literature as the \“Hippopotamyrus ansorgii species complex\” and colloquially known as \“slender stonebashers.\” Previous molecular phylogenetic work has shown that these species are not close relatives of Hippopotamyrus castor Pappenheim, 1906, the type species of genus Hippopotamyrus Pappenheim, 1906 from Cameroon, and are thus misclassified. Hippopotamyrus ansorgii species complex taxa and another species shown to have been misclassified, Paramormyrops tavernei (Poll, 1972), are placed in genus Heteromormyrus and one genetic lineage from the Kwanza and Lucala rivers of Angola are identified as conspecific Heteromormyrus pauciradiatus. Three additional new combinations and a synonymy in Mormyridae are introduced. The morphological characteristics and geographical distribution of the genus Heteromormyrus are reviewed. The electric organ discharges (EODs) of Heteromormyrus species are to be treated in a separate study.

}, keywords = {Angolan freshwater fishes, Heteromormyrus, Hippopotamyrus, historical DNA, mitogenomics, mormyrid, museomics, slender stonebasher}, issn = {1313-2989}, doi = {10.3897/zookeys.1129.90287}, url = {https://doi.org/10.3897/zookeys.1129.90287}, author = {John P Sullivan and Carl D Hopkins and Stacy Pirro and Rose Peterson and Albert Chakona and Tadiwa I. Mutizwa and Christian Mukweze Mulelenu and Fahad H. Alqahtani and Emmanuel Vreven and Casey B. Dillman} } @article {618, title = {Sustainable exploitation and participative conservation of Mormyridae fishes in the Malebo Pool, Congo River, Kinshasa}, volume = {4}, year = {2022}, month = {Oct-05-2022}, pages = {77-91}, abstract = {

Mormyridae fish, which make up 20 to 25\% of the catches in the Malebo Pool, are subject to pressure from local fishermen. This pressure on the resource is the basis of the decrease in catches, which has an impact on the social situation of the people involved in the sector. The objective of this study is to evaluate the exploitation of Mormyridae fish in the Malebo Pool and to propose conservation measures for sustainable management. The data was collected using the survey method with the interview technique. The results obtained confirm overfishing with a decrease in catches, which has consequences on the social situation of fishermen, fishmongers, processors and consumers. Thus, in order to reduce overfishing to a sustainable exploitation, co-management between the manager and the stakeholders, compliance with regulations, awareness raising and training in conservation and sustainable exploitation based on a series of biological and socioeconomic indicators accepted by all stakeholders are necessary.

}, keywords = {Malebo Pool}, issn = {2663-2187}, doi = {10.33472/afjbs.4.4.2022.77-91}, url = {http://dx.doi.org/10.33472/afjbs.4.4.2022.77-91}, author = {M{\'e}tis, Ntumba Mabedi Jean and ZebeVictorine, Mbadu and Michaux Johan, R. and Jean-Claude, Micha} } @article {617, title = {Karyotype of a Nigerian population of Hyperopisus bebe (Osteoglossiformes: Mormyridae) revealed another evolutionary lineage in the monospecific genus: Hyperopisus}, journal = {Ife Journal of Science }, volume = {24}, year = {2022}, month = {20 October 2022}, pages = {361-370}, chapter = {361}, abstract = {

This study provides data on the gross chromosome morphology, including centromeric and silver nitrate banding of a Nigerian population of Hyperopisus bebe, sampled from Asejire Reservoir, Osun River basin. The chromosomes of the fish samples were extracted using the Giemsa staining technique, and the centromeric and silver nitrate bandings were analyzed based on standard cytogenetic methods. The H. bebe population had a chromosome number of 2n = 40 and a karyotype formula of 2n = 40 (24m+6sm+10st/a), FN = 70. C-bands were restricted to the centromeric regions, suggesting that Robertsonian events are the major mechanism in the karyotype evolution in the population. Currently, H. bebe represents the only species in the genus Hyperopisus. The karyomorph data from this study suggest that the fish sample belongs to another species. However, other systematic approaches are needed to establish its taxonomic status.

}, keywords = {Chromosome rearrangements, Cytogenetics, karyomorphs, mormyrids, Robertsonian events}, doi = {10.4314/ijs.v24i2.15}, url = {https://www.ajol.info/index.php/ijs/article/view/233919}, author = {Jegede, OI} } @article {615, title = {Marcusenius elegans: a replacement name for Marcusenius gracilis Kramer 2013 (Osteoglossiformes: Mormyridae), a secondary junior homonym of Marcusenius senegalensis gracilis (Pellegrin 1922)}, volume = {5175}, year = {2022}, month = {Aug-18-2022}, pages = {499-500}, abstract = {

The West African mormyrid Marcusenius gracilis Kramer 2013 is a secondary homonym of Gnathonemus gracilis Pellegrin 1922 when both species are placed in the same genus Marcusenius (International Code of Zoological Nomenclature, article 57.3). Marcusenius gracilis was first described by Kramer (2013: 123), based on a holotype and 16 paratypes from Ivory Coast, West Africa. The taxon was subsequently treated as a valid species of Marcusenius by Kramer \& Wink (2013: 2334), and by Fricke et al. (2022). Kramer (2013) was not aware of Gnathonemus gracilis Pellegrin 1922, which was originally described by Pellegrin (1922: 221), based on a specimen from the Gribingui River, Lake Chad basin, in today\’s Central African Republic. The holotype is extant (MNHN 1922-0023). The taxon was treated as a synonym of the West African species Marcusenius senegalensis (Steindachner 1870), but as a valid subspecies (Gosse 1984: 89, L\év\êque et al. 1991: 138). Marcusenius senegalensis gracilis (Pellegrin 1922) has precedence over Marcusenius gracilis Kramer 2013, and the latter must be renamed when both taxa are classified in genus Marcusenius. Marcusenius elegans nom. nov. is herein proposed as the replacement name for Marcusenius gracilis Kramer 2013. The new species epithet is based on the Latin word elegans, meaning elegant, referring to its slender body; the name is treated as an adjective.

}, issn = {1175-5334, 1175-5326}, doi = {10.11646/zootaxa.5175.4.8}, url = {http://dx.doi.org/10.11646/zootaxa.5175.4.8}, author = {Fricke, R. and Bernd Kramer} } @article {611, title = {Convergence is Only Skin Deep: Craniofacial Evolution in Electric Fishes from South America and Africa (Apteronotidae and Mormyridae)}, year = {2022}, month = {Jun-14-2022}, abstract = {

Apteronotidae and Mormyridae are species-rich clades of weakly electric fishes from Neotropical and Afrotropical freshwaters, respectively, known for their high morphological disparity and often regarded as a classic example of convergent evolution. Here we use CT-imaging and 3D geometric morphometrics to quantify disparity in craniofacial morphologies, and to test the hypothesis of convergent skull-shape evolution in a phylogenetic context. For this study we examined 391 specimens representing 78 species of Apteronotidae and Mormyridae including 30 of 37 (81\%) of all valid genera with the goal to sample most of the craniofacial disparity known in these clades. We found no overlap between Apteronotidae and Mormyridae in the skull-shape morphospace using PCA and a common landmark scheme, and therefore no instances of complete phenotypic convergence. Instead, we found multiple potential instances of incomplete convergence, and at least one parallel shift among electric fish clades. The greatest components of shape variance in both families are the same as observed for most vertebrate clades: heterocephaly (i.e., opposite changes in relative sizes of the snout and braincase regions of the skull), and heterorhynchy (i.e., dorsoventral changes in relative snout flexion and mouth position). Mormyrid species examined here exhibit less craniofacial disparity than do apteronotids, potentially due to constraints associated with a larger brain size, ecological constraints related to food-type availability. Patterns of craniofacial evolution in these two clades depict a complex story of phenotypic divergence and convergence in which certain superficial similarities of external morphology obscure deeper osteological and presumably developmental differences of skull form and function. Among apteronotid and mormyrid electric fishes, craniofacial convergence is only skin deep.

}, issn = {2517-4843}, doi = {10.1093/iob/obac022}, url = {http://dx.doi.org/10.1093/iob/obac022}, author = {Ford, Kassandra L and Rose Peterson and Bernt, Maxwell and Albert, James S} } @article {609, title = {Is the medium the message? Functional diversity across abiotic gradients in freshwater electric fishes}, year = {2022}, month = {Mar-28-2022}, abstract = {

Abstract Evolutionary transitions across abiotic gradients can occur among habitats at multiple spatial scales, and among taxa and biotas through a range of ecological and evolutionary time frames. Two diverse groups of electric fishes, Neotropical Gymnotiformes and Afrotropical Mormyroidea, offer interesting examples of potentially convergent evolution in aspects of morphological, physiological, and life history traits. We examined biogeographical, morphological, and functional patterns across these two groups to assess the degree of convergence in association with abiotic environmental variables. While there are superficial similarities across the groups and continents, we found substantially more differences in terms of habitat occupancy, electric signal diversity, and morphological disparity. These differences likely correlate to differences in biogeographical histories across the Neotropics and Afrotropics, biotic factors associated with aquatic life and electric signals, and sampling issues plaguing both groups. Additional research and sampling are required to make further inferences about how electric fishes transition throughout diverse freshwater habitats across both microevolutionary and macroevolutionary scales. We find little evidence that abiotic gradients in the freshwater habitat medium have driven convergent evolution of functional traits in these two continental radiations of electric fishes.

}, issn = {1540-7063, 1557-7023}, doi = {10.1093/icb/icac010}, url = {http://dx.doi.org/10.1093/icb/icac010}, author = {Ford, Kassandra L and Albert, James S} } @article {608, title = {Intergenus F1-hybrids of African weakly electric fish (Mormyridae: Gnathonemus petersii ♂ {\texttimes} Campylomormyrus compressirostris ♀) are fertile.}, journal = {J Comp Physiol A Neuroethol Sens Neural Behav Physiol}, year = {2022}, month = {2022 Feb 04}, abstract = {

Hybridisation is an important element of adaptive radiation in fish but data are limited in weakly electric mormyrid fish in this respect. Recently, it has been shown that intragenus hybrids (Campylomormyrus) are fertile and are able to produce F2-fish. In this paper, we demonstrate that even intergenus hybrids (Gnathonemus petersii ♂ \× Campylomormyrus compressirostris ♀) are fertile. Three artificial reproduction (AR) trials, with an average fertilisation rate of ca. 23\%, yielded different numbers of survivals (maximally about 50\%) of the F1-hybrids. The complete ontogenetic development of these hybrids is described concerning their morphology and electric organ discharge (EOD). Two EOD types emerged at the juvenile stage, which did not change up to adulthood. Type I consisted of four phases and Type II was triphasic. The minimum body length at sexual maturity was between 10 and 11\ cm. Malformations, growth and mortality rates are also described.

}, issn = {1432-1351}, doi = {10.1007/s00359-022-01542-5}, author = {Korniienko, Yevheniia and Nzimora, Kingsley C and Vater, Marianne and Ralph Tiedemann and Kirschbaum, Frank} } @article {607, title = {Phylogenomics of bonytongue fishes (Osteoglossomorpha) shed light on the craniofacial evolution and biogeography of the weakly electric clade Mormyridae}, journal = {Systematic Biology}, volume = {71}, year = {2022}, month = {Jan-18-2022}, pages = {1032{\textendash}1044}, chapter = {1032}, abstract = {

Abstract Bonytongues (Osteoglossomorpha) constitute an ancient clade of teleost fishes distributed in freshwater habitats throughout the world. The group includes well-known species such as arowanas, featherbacks, pirarucus, and the weakly electric fishes in the family Mormyridae. Their disjunct distribution, extreme morphologies, and electrolocating capabilities (Gymnarchidae and Mormyridae) have attracted much scientific interest, but a comprehensive phylogenetic framework for comparative analysis is missing, especially for the species-rich family Mormyridae. Of particular interest are disparate craniofacial morphologies among mormyrids which might constitute an exceptional model system to study convergent evolution. We present a phylogenomic analysis based on 546 exons of 179 species (out of 260), 28 out of 29 genera, and all six families of extant bonytongues. Based on a recent reassessment of the fossil record of osteoglossomorphs, we inferred dates of divergence among trans-continental clades and the major groups. The estimated ages of divergence among extant taxa (e.g., Osteoglossomorpha, Osteoglossiformes, Mormyroidea) are older than previous reports, but most of the divergence dates obtained for clades on separate continents are too young to be explained by simple vicariance hypotheses. Biogeographic analysis of mormyrids indicates that their high species diversity in the Congo Basin is a consequence of range reductions of previously widespread ancestors and that the highest diversity of craniofacial morphologies among mormyrids originated in this basin. Special emphasis on a taxon-rich representation for mormyrids revealed pervasive misalignment between our phylogenomic results and mormyrid taxonomy due to repeated instances of convergence for extreme craniofacial morphologies. Estimation of ancestral phenotypes revealed contingent evolution of snout elongation and unique projections from the lower jaw to form the distinctive Schnauzenorgan. Synthesis of comparative analyses suggests that the remarkable craniofacial morphologies of mormyrids evolved convergently due to niche partitioning, likely enabled by interactions between their exclusive morphological and electrosensory adaptations.

}, keywords = {Africa, Ancestral State Estimation, Diversity, Exon Capture, Freshwater fishes, Phylogenomics}, issn = {1063-5157, 1076-836X}, doi = {10.1093/sysbio/syac001}, url = {http://dx.doi.org/10.1093/sysbio/syac001}, author = {Rose Peterson and John P Sullivan and Carl D Hopkins and Santaquiteria, Aintzane and Casey B. Dillman and Stacy Pirro and Betancur-R, Ricardo and Arcila, Dahiana and Hughes, Lily C and Ort{\'\i}, Guillermo} }