03384nas a2200349 4500008004100000022001400041245018800055210006900243260002300312300001200335490000900347520225000356653003002606653001902636653001902655653001902674653001702693653001302710653001402723653002402737100002302761700002202784700001702806700001902823700002002842700002402862700003202886700002502918700002102943700002302964856004702987 2022 eng d a1313-298900aMitogenome recovered from a 19th Century holotype by shotgun sequencing supplies a generic name for an orphaned clade of African weakly electric fishes (Osteoglossomorpha, Mormyridae)0 aMitogenome recovered from a 19th Century holotype by shotgun seq bPensoft Publishers a163-1960 v11293 a

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.

10aAngolan freshwater fishes10aHeteromormyrus10aHippopotamyrus10ahistorical DNA10amitogenomics10amormyrid10amuseomics10aslender stonebasher1 aSullivan, John, P.1 aHopkins, Carl, D.1 aPirro, Stacy1 aPeterson, Rose1 aChakona, Albert1 aMutizwa, Tadiwa, I.1 aMukweze Mulelenu, Christian1 aAlqahtani, Fahad, H.1 aVreven, Emmanuel1 aDillman, Casey, B. uhttps://doi.org/10.3897/zookeys.1129.9028702342nas a2200145 4500008004100000022001400041245022900055210006900284260001600353520167800369100001902047700002302066700002202089856008502111 2017 eng d a0024-408200aRediscovery and description of Paramormyrops sphekodes (Sauvage, 1879) and a new cryptic Paramormyrops (Mormyridae: Osteoglossiformes) from the Ogooué River of Gabon using morphometrics, DNA sequencing and electrophysiology0 aRediscovery and description of Paramormyrops sphekodes Sauvage 1 cMay-05-20173 a

Species of the African electric fish in the genus Paramormyrops Taverne, Thys van den Audenaerde & Heymer, 1977 constitute a recently recognized species flock with an impressive diversity of electric signals, but only modest morphological differentiation. For more than a century, confusion has surrounded the identity of Paramormyrops sphekodes (Sauvage, 1879), the earliest described species in this genus. Here we compare the morphometrics of type material to new specimens collected at the type locality on the Ogooué River of Gabon from which we additionally study DNA sequences and electric organ discharges (EODs). Based on our findings, we revise the diagnosis and description of P. sphekodes and also identify and describe a new species of Paramormyrops that is large, common and widespread in the Ogooué River basin, but cryptic and easily confounded with P. sphekodes. We designate as lectotype of P. sphekodes a specimen formerly regarded, in error, as the holotype and a second specimen originally collected with the lectotype as paralectotype. We conclude that only nine additional specimens can be identified with confidence as P. sphekodes: four from the type locality and five from a second site 45 km away. Instead of being widespread as previously thought, P. sphekodes may be restricted to a small region of the upper Ogooué River basin. Additionally, we present a revised diagnosis for the genus Paramormyrops Taverne et al., 1977, and key to species from Lower Guinea. This study illustrates the value of vouchered EOD recordings and of revisiting type localities, and lays a foundation for additional systematic work on this group.

1 aRich, Madeline1 aSullivan, John, P.1 aHopkins, Carl, D. uhttps://academic.oup.com/zoolinnean/article-lookup/doi/10.1093/zoolinnean/zlw00403858nas a2200277 4500008004100000022001400041245013400055210006900189260001600258300001400274490000800288520299800296653003003294653000803324653002903332653000803361653002503369653001503394653001403409653001103423653002503434100002303459700002403482700002203506856005203528 2016 eng d a1313-298900aCryptomyrus: a new genus of Mormyridae (Teleostei, Osteoglossomorpha) with two new species from Gabon, West-Central Africa0 aiCryptomyrusi a new genus of Mormyridae Teleostei Osteoglossomor cAug-02-2016 a117 - 1500 v5613 a

Abstract
We use mitochondrial and nuclear sequence data to show that three weakly electric mormyrid fish specimens collected at three widely separated localities in Gabon, Africa over a 13-year period represent an unrecognized lineage within the subfamily Mormyrinae and determine its phylogenetic position with respect to other taxa. We describe these three specimens as a new genus containing two new species. Cryptomyrus, new genus, is readily distinguished from all other mormyrid genera by a combination of features of squamation, morphometrics, and dental attributes. Cryptomyrus ogoouensis, new species, is differentiated from its single congener, Cryptomyrus ona, new species, by the possession of an anal-fin origin located well in advance of the dorsal fin, a narrow caudal peduncle and caudal-fin lobes nearly as long as the peduncle. In C. ona, the anal-fin origin is located only slightly in advance of the dorsal fin, the caudal peduncle is deep and the caudal-fin lobes considerably shorter than the peduncle. Continued discovery of new taxa within the “Lower Guinea Clade” of Mormyridae highlights the incompleteness of our knowledge of fish diversity in West-Central Africa. We present a revised key to the mormyrid genera of Lower Guinea.

Résumé
Nous avons démontré avec des marqueurs mitochondriaux et nucléaires que trois spécimens de poissons mormyridés faiblement électriques, collectés à trois localités au Gabon sur une période de 13 ans, forment une lignée inconnue au sein de la sous famille des Mormyrinae dont nous avons déterminé la position phylogénétique. Nous décrivons un nouveau genre et deux nouvelles espèces pour ces trois spécimens. Cryptomyrus, nouveau genre, se distingue des autres genres de mormyridés par une combinaison de caractères de l’écaillure, morphométriques, et dentaires. Cryptomyrus ogoouensis, nouvelle espèce, se distingue de sa seule espèce congénérique par sa nageoire anale qui commence nettement en avant de sa nageoire dorsale, son pédoncule caudal gracile et les lobes de sa nageoire caudale pratiquement aussi longs que son pédoncule caudal. Chez Cryptomyrus ona, nouvelle espèce, la nageoire anale commence légèrement en avant de l’origine de la nageoire dorsale, le pédoncule caudal est large, et les lobes de la nageoire caudale sont plus courts que le pédoncule caudal. La découverte ininterrompue de nouveaux taxa dans le «clade de basse Guinée» des Mormyridae illustre notre connaissance incomplète de la diversité des poissons de l’ouest de l’Afrique centrale. Nous présentons une clé révisée des genres de Mormyridae de basse Guinée.

10aAfrican freshwater fishes10aDNA10aelectric organ discharge10aEOD10aintegrative taxonomy10aMormyrinae10aphylogeny10ararity10aweakly electric fish1 aSullivan, John, P.1 aLavoué, Sébastien1 aHopkins, Carl, D. uhttp://zookeys.pensoft.net/articles.php?id=713700456nas a2200121 4500008004100000245011400041210006900155300001200224490000700236100002100243700002200264856004800286 1989 eng d00aDetection of a previously unrecognized mormyrid fish (Mormyrus subungulatus) by electric discharge characters0 aDetection of a previously unrecognized mormyrid fish Mormyrus su a319-3260 v131 aCrawford, J., D.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/7600370nas a2200133 4500008004100000245002700041210002700068260002000095300001200115100002200127700001800149700002100167856004800188 1986 eng d00aBehavior of Mormyridae0 aBehavior of Mormyridae aNew YorkbWiley a527-5761 aHopkins, Carl, D.1 aBullock, T.H.1 aHeiligenberg, W. uhttps://mormyrids.myspecies.info/en/node/8100514nas a2200133 4500008004100000245014900041210006900190300001200259490000700271100001800278700001400296700002200310856004800332 2001 eng d00aMorphological and electrophysiological evidence for synonomy of two Marcusenius species (Osteoglossomorpha, Mormyridae) from west Central Africa0 aMorphological and electrophysiological evidence for synonomy of  a239-2490 v251 aTeugels, G.G.1 aBoden, G.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/5800616nas a2200145 4500008004100000245017900041210006900220300001200289490000700301653001500308100002400323700002300347700002200370856007800392 2003 eng d00aPhylogenetic utility of the first two introns of the S7 ribosomal protein gene in African electric fishes (Mormyroidea: Teleostei) and congruence with other molecular markers0 aPhylogenetic utility of the first two introns of the S7 ribosoma a273-2920 v7810aMormyridae1 aLavoué, Sébastien1 aSullivan, John, P.1 aHopkins, Carl, D. uhttp://www.blackwell-synergy.com/doi/abs/10.1046/j.1095-8312.2003.00170.x00546nas a2200145 4500008004100000245013800041210006900179300001200248490000800260653001500268100002300283700002400306700002200330856004800352 2000 eng d00aMolecular systematics of the African electric fishes (Mormyroidea: Teleostei) and a model for the evolution of their electric organs.0 aMolecular systematics of the African electric fishes Mormyroidea a665-6830 v20310aMormyridae1 aSullivan, John, P.1 aLavoué, Sébastien1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/5900448nas a2200121 4500008004100000245010700041210006900148300001200217490000700229100002000236700002200256856004800278 1997 eng d00aMolecular insights into the phylogeny of mormyriform fishes and the evolution of their electric organs0 aMolecular insights into the phylogeny of mormyriform fishes and  a324-3510 v491 aAlves-Gomes, J.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/6500502nas a2200121 4500008004100000245015500041210006900196300001200265490000700277100002600284700002200310856004800332 2003 eng d00aElectric signal variation among seven blunt-snouted Brienomyrus species (Teleostei: Mormyridae) from a riverine species flock in Gabon, Central Africa0 aElectric signal variation among seven bluntsnouted Brienomyrus s a321-3390 v671 aArnegard, Matthew, E.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/5400482nas a2200121 4500008004100000245014100041210006900182300001200251490000900263100001800272700002200290856004800312 1998 eng d00aMorphological and osteological evidence for the generic position of Mormyrus kingsleyae in the genus Brienomyrus (Teleostei: Mormyridae)0 aMorphological and osteological evidence for the generic position a199-2040 v19981 aTeugels, G.G.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/6301670nas a2200157 4500008004100000245014900041210006900190260001200259300001400271490000700285520111800292100001401410700001801424700002201442856004801464 1997 eng d00aA systematic revision of the large-scaled Marcusenius with description of a new species from Cameroon (Teleostei; Osteoglossomorpha; Mormyridae)0 asystematic revision of the largescaled Marcusenius with descript c10/1997 a1645-16820 v313 a

Nine out of 37 recognized species in the genus Marcusenius have eight large circumpeduncular scales rather than 12 or 16, which is more typical of the genus. They are: M. dundoensis, M. fuscus, M. ghesquierei, M. intermedius, M. kutuensis, M. lambouri, M. moorii, M. paucisquamatus and M. schilthuisiae. All nine are restricted to West-Central and Central Africa. A detailed morphometric analysis could not distinguish differences between M. moorii, M. paucisquamatus and M. lambouri. Therefore they are considered as synonyms with M. morrii as the senior synonym. The systematic status of M. intermedius is uncertain owing to the existence of only three specimens. Within this species complex a new species, Marcusenius sanagaensis, is described from the Sanaga River basin in Cameroon. It differs from all the others in the number of scales on the lateral line and in the extent of the broad dark band between the anterior base of the dorsal fin and the anterior base of the anal fin. All valid Marcusenius species with eight circumpeduncular scales are redescribed and a key to these species is given.

1 aBoden, G.1 aTeugels, G.G.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/6400473nam a2200133 4500008004100000245007700041210006900118260002300187490001300210100002800223700001800251700002200269856004800291 2007 eng d00aThe Fresh and Brackish Water Fishes of Lower Guinea, West-Central Africa0 aFresh and Brackish Water Fishes of Lower Guinea WestCentral Afri bIRD Editions, MRAC0 vI and II1 aStiassny, Melanie, L.J.1 aTeugels, G.G.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/3700504nas a2200133 4500008004100000245012200041210006900163300001400232490000800246100002600254700002000280700002200300856004800322 2006 eng d00aTime-domain signal divergence and discrimination without receptor modification in sympatric morphs of electric fishes0 aTimedomain signal divergence and discrimination without receptor a2182-21980 v2081 aArnegard, Matthew, E.1 aJackson, B., S.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/4100487nas a2200133 4500008004100000245010800041210006900149300001200218490000700230100002600237700002000263700002200283856004800305 2005 eng d00aMultiple cases of striking genetic similarity between alternate electric fish signal morphs in sympatry0 aMultiple cases of striking genetic similarity between alternate  a324-3430 v591 aArnegard, Matthew, E.1 aBogdanowicz, S.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/4500518nas a2200145 4500008004100000245012200041210006900163260000900232300001200241490000700253100002400260700002200284700001800306856004800324 2004 eng d00aThe Petrocephalus (Pisces, Osteoglossomorpha, Mormyridae) of Gabon, Central Africa, with description of a new species0 aPetrocephalus Pisces Osteoglossomorpha Mormyridae of Gabon Centr c2004 a511-5350 v261 aLavoué, Sébastien1 aHopkins, Carl, D.1 aToham, Kamdem uhttps://mormyrids.myspecies.info/en/node/4700558nas a2200145 4500008004100000245014000041210006900181300001200250490000700262100002300269700002400292700002600316700002200342856004800364 2004 eng d00aAFLPs resolve phylogeny and reveal mitochondrial introgression within a species flock of African electric fish (Mormyroidea: Teleostei)0 aAFLPs resolve phylogeny and reveal mitochondrial introgression w a825-8410 v581 aSullivan, John, P.1 aLavoué, Sébastien1 aArnegard, Matthew, E.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/5000471nas a2200133 4500008004100000245010600041210006900147300000900216490000800225653001100233100002300244700002200267856004800289 2005 eng d00aA new Stomatorhinus (Osteoglossomorpha: Mormyridae) from the Ivindo River, Gabon, West Central Africa0 anew Stomatorhinus Osteoglossomorpha Mormyridae from the Ivindo R a1-230 v84710aIvindo1 aSullivan, John, P.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/4600507nas a2200193 4500008004100000020002200041245001900063210001800082260000800100300001400108490000600122100002200128700002400150700002300174700002800197700001800225700002200243856004800265 2007 eng d a978-2-7099-1621-900a12. Mormyridae0 a12 Mormyridae bIRD a220–3340 v11 aHopkins, Carl, D.1 aLavoué, Sébastien1 aSullivan, John, P.1 aStiassny, Melanie, L.J.1 aTeugels, G.G.1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/3503507nas a2200349 4500008004100000020001400041245015000055210006900205260000800274300001400282490000700296520244700303653002302750653000902773653001802782653002902800653003602829653001802865653001202883653002202895653001602917653001402933653002502947653002702972653001502999653001403014100002403028700002303052700002603075700002203101856003403123 2008 eng d a1010-061X00aDifferentiation of morphology, genetics and electric signals in a region of sympatry between sister species of African electric fish (Mormyridae)0 aDifferentiation of morphology genetics and electric signals in a cJul a1030-10450 v213 a

Mormyrid fishes produce and sense weak electric organ discharges (EODs) for object detection and communication, and they have been increasingly recognized as useful model organisms for studying signal evolution and speciation. EOD waveform variation can provide important clues to sympatric species boundaries between otherwise similar or morphologically cryptic forms. Endemic to the watersheds of Gabon (Central Africa), Ivindomyrus marchei and Ivindomyrus opdenboschi are morphologically similar to one another. Using morphometric, electrophysiological and molecular characters [cytochrome b sequences and amplified fragment length polymorphism (AFLP) genotypes], we investigated to what extent these nominal mormyrid species have diverged into biological species. Our sampling covered the known distribution of each species with a focus on the Ivindo River, where the two taxa co-occur. An overall pattern of congruence among datasets suggests that I. opdenboschi and I. marchei are mostly distinct. Electric signal analysis showed that EODs of I. opdenboschi tend to have a smaller initial head-positive peak than those of I. marchei, and they often possess a small third waveform peak that is typically absent in EODs of I. marchei. Analysis of sympatric I. opdenboschi and I. marchei populations revealed slight, but significant, genetic partitioning between populations based on AFLP data (F-ST approximate to 0.04). Taken separately, however, none of the characters we evaluated allowed us to discriminate two completely distinct or monophyletic groups. Lack of robust separation on the basis of any single character set may be a consequence of incomplete lineage sorting due to recent ancestry and/or introgressive hybridization. Incongruence between genetic datasets in one individual, which exhibited a mitochondrial haplotype characteristic of I. marchei but nevertheless fell within a genetic cluster of I. opdenboschi based on AFLP genotypes, suggests that a low level of recent hybridization may also be contributing to patterns of character variation in sympatry. Nevertheless, despite less than perfect separability based on any one dataset and inconclusive evidence for complete reproductive isolation between them in the Ivindo River, we find sufficient evidence to support the existence of two distinctive species, I. opdenboschi and I. marchei, even if not ’biological species’ in the Mayrian sense.

10aadaptive radiation10aaflp10aelectric fish10aelectric organ discharge10agnathonemus-petersii mormyridae10aintrogression10amarkers10amitochondrial-DNA10amormyroidea10aphylogeny10apopulation-structure10areproductive isolation10aspeciation10ateleostei1 aLavoué, Sébastien1 aSullivan, John, P.1 aArnegard, Matthew, E.1 aHopkins, Carl, D. u://00025668710001003423nas a2200373 4500008004100000020001400041245016600055210006900221260001200290300001200302490000800314520221100322653002302533653002602556653002702582653002902609653002802638653001602666653003602682653002402718653001802742653002302760653002702783653002802810653002202838653001902860653002602879653001502905100002402920700002602944700002302970700002202993856003403015 2008 eng d a0928-425700aPetrocephalus of Odzala offer insights into evolutionary patterns of signal diversification in the Mormyridae, a family of weakly electrogenic fishes from Africa0 aPetrocephalus of Odzala offer insights into evolutionary pattern cJul-Nov a322-3390 v1023 a

Electric signals of mormyrid fishes have recently been described from several regions of Africa. Members of the Mormyridae produce weak electric organ discharges (EODs) as part of a specialized electrosensory Communication and orientation system. Sympatric species often express distinctive EODs, which may contribute to species recognition during mate choice in some lineages. Striking examples of interspecific EOD variation within assemblages have been reported for two monophyletic radiations: the Paramormyrops of Gabon and the Campylomormyrus of Lower Congo. Here, we describe a speciose assemblage of Petrocephalus in the Lekoli River system of Odzala National Park, Republic of Congo. This widespread genus comprises the Subfamily (Petrocephalinae) that is the Sister group to all other mormyrids (Mormyrinae). Eleven Petrocephalus species were collected in Odzala, five of which are not described taxonomically. We quantify EOD variation within this assemblage and show that all eleven species produce EOD waveforms of brief duration (species means range from 144 to 663 mu s) compared to many other mormyrids. We also present reconstructed phylogenetic relationships among species based on cytochrome b sequences. Discovery of the Odzala assemblage greatly increases the number of Petrocephalus species for which EODs and DNA sequence data are available, permitting a first qualitative comparison between mormyrid Subfamilies of the divergence patterns that have been described within lineages. We find that the Petrocephalus assemblage in Odzala is not a monophyletic radiation. Genetic divergence among Petrocephalus species often appears higher than among Paramormyrops or Campylomormyrus species. In contrast, results of this study and others Suggest that Petrocephalus may generally exhibit less interspecific EOD divergence, as well as smaller sex differences in EOD waveforms, compared to Paramormyrops and Campylomormyrus. We discuss possible causes and consequences of EOD diversification patterns observed within mormyrid subfamilies as a framework for future comparative studies of signal evolution using this emerging model system. (c) 2008 Elsevier Ltd. All rights reserved.

10aadaptive radiation10acommunication signals10aelectric organ anatomy10aelectric organ discharge10aelectrosensory modality10afood-habits10agnathonemus-petersii mormyridae10amolecular evolution10apetrocephalus10apollimyrus-isidori10ariverine species flock10asexual signal evolution10asexual-dimorphism10aspecies marker10atype npp electrocytes10awave-forms1 aLavoué, Sébastien1 aArnegard, Matthew, E.1 aSullivan, John, P.1 aHopkins, Carl, D. u://00026362510001900749nas a2200229 4500008004100000022001400041245009800055210006900153260001200222300001400234490000800248100002600256700002400282700002100306700002500327700002800352700002200380700002300402700002400425700002200449856004800471 2010 eng d a1537-532300aSexual Signal Evolution Outpaces Ecological Divergence during Electric Fish Species Radiation0 aSexual Signal Evolution Outpaces Ecological Divergence during El c09/2010 a335 - 3560 v1761 aArnegard, Matthew, E.1 aMcIntyre, Peter, B.1 aHarmon, Luke, J.1 aZelditch, Miriam, L.1 aCrampton, William, G.R.1 aDavis, Justin, K.1 aSullivan, John, P.1 aLavoué, Sébastien1 aHopkins, Carl, D. uhttps://mormyrids.myspecies.info/en/node/2602756nas a2200193 4500008004100000245011900041210006900160260001200229300001100241490000600252520212000258100002402378700001702402700002602419700002302445700002202468700002102490856005102511 2012 eng d00aComparable Ages for the Independent Origins of Electrogenesis in African and South American Weakly Electric Fishes0 aComparable Ages for the Independent Origins of Electrogenesis in c05/2012 ae362870 v73 a

One of the most remarkable examples of convergent evolution among vertebrates is illustrated by the independent origins of an active electric sense in South American and African weakly electric fishes, the Gymnotiformes and Mormyroidea, respectively. These groups independently evolved similar complex systems for object localization and communication via the generation and reception of weak electric fields. While good estimates of divergence times are critical to understanding the temporal context for the evolution and diversification of these two groups, their respective ages have been difficult to estimate due to the absence of an informative fossil record, use of strict molecular clock models in previous studies, and/or incomplete taxonomic sampling. Here, we examine the timing of the origins of the Gymnotiformes and the Mormyroidea using complete mitogenome sequences and a parametric Bayesian method for divergence time reconstruction. Under two different fossil-based calibration methods, we estimated similar ages for the independent origins of the Mormyroidea and Gymnotiformes. Our absolute estimates for the origins of these groups either slightly postdate, or just predate, the final separation of Africa and South America by continental drift. The most recent common ancestor of the Mormyroidea and Gymnotiformes was found to be a non-electrogenic basal teleost living more than 85 millions years earlier. For both electric fish lineages, we also estimated similar intervals (16–19 or 22–26 million years, depending on calibration method) between the appearance of electroreception and the origin of myogenic electric organs, providing rough upper estimates for the time periods during which these complex electric organs evolved de novo from skeletal muscle precursors. The fact that the Gymnotiformes and Mormyroidea are of similar age enhances the comparative value of the weakly electric fish system for investigating pathways to evolutionary novelty, as well as the influences of key innovations in communication on the process of species radiation.

1 aLavoué, Sébastien1 aMiya, Masaki1 aArnegard, Matthew, E.1 aSullivan, John, P.1 aHopkins, Carl, D.1 aNishida, Mutsumi uhttp://dx.doi.org/10.1371/journal.pone.003628702925nas a2200169 4500008004100000022001400041245014800055210006900203260001200272300001600284490000800300520233300308100002302641700002202664700002102686856004802707 2012 eng d a1477-914500aDifferential expression of genes and proteins between electric organ and skeletal muscle in the mormyrid electric fish Brienomyrus brachyistius0 aDifferential expression of genes and proteins between electric o c07/2012 a2479 - 24940 v2153 a

Electric organs (EOs) have evolved independently in vertebrates six times from skeletal muscle (SM). The transcriptional changes accompanying this developmental transformation are not presently well understood. Mormyrids and gymnotiforms are two highly convergent groups of weakly electric fish that have independently evolved EOs: while much is known about development and gene expression in gymnotiforms, very little is known about development and gene expression in mormyrids. This lack of data limits prospects for comparative work. We report here on the characterization of 28 differentially expressed genes between SM and EO tissues in the mormyrid Brienomyrus brachyistius, which were identified using suppressive subtractive hybridization (SSH). Forward and reverse SSH was performed on tissue samples of EO and SM resulting in one cDNA library enriched with mRNAs expressed in EO, and a second library representing mRNAs unique to SM. Nineteen expressed sequence tags (ESTs) were identified in EO and nine were identified in SM using BLAST searching of Danio rerio sequences available in NCBI databases. We confirmed differential expression of all 28 ESTs using RT-PCR. In EO, these ESTs represent four classes of proteins: (1) ion pumps, including the - and -subunits of Na+/K+-ATPase, and a plasma membrane Ca2+-ATPase; (2) Ca2+-binding protein S100, several parvalbumin paralogs, calcyclin-binding protein and neurogranin; (3) sarcomeric proteins troponin I, myosin heavy chain and actin-related protein complex subunit 3 (Arcp3); and (4) the transcription factors enhancer of rudimentary homolog (ERH) and myocyte enhancer factor 2A (MEF2A). Immunohistochemistry and western blotting were used to demonstrate the translation of seven proteins (myosin heavy chain, Na+/K+-ATPase, plasma membrane Ca2+-ATPase, MEF2, troponin and parvalbumin) and their cellular localization in EO and SM. Our findings suggest that mormyrids express several paralogs of muscle-specific genes and the proteins they encode in EOs, unlike gymnotiforms, which may post-transcriptionally repress several sarcomeric proteins. In spite of the similarity in the physiology and function of EOs in mormyrids and gymnotiforms, this study indicates that the mechanisms of development in the two groups may be considerably different.

1 aGallant, Jason, R.1 aHopkins, Carl, D.1 aDeitcher, D., L. uhttps://mormyrids.myspecies.info/en/node/1602946nas a2200169 4500008004100000022001400041245014800055210006900203260001200272300001600284490000800300520235400308100002302662700002202685700002102707856004802728 2012 eng d a1477-914500aDifferential expression of genes and proteins between electric organ and skeletal muscle in the mormyrid electric fish Brienomyrus brachyistius0 aDifferential expression of genes and proteins between electric o c07/2012 a2479 - 24940 v2153 a

Electric organs (EOs) have evolved independently in vertebrates six times from skeletal muscle (SM). The transcriptional changes accompanying this developmental transformation are not presently well understood. Mormyrids and gymnotiforms are two highly convergent groups of weakly electric fish that have independently evolved EOs: while much is known about development and gene expression in gymnotiforms, very little is known about development and gene expression in mormyrids. This lack of data limits prospects for comparative work. We report here on the characterization of 28 differentially expressed genes between SM and EO tissues in the mormyrid Brienomyrus brachyistius, which were identified using suppressive subtractive hybridization (SSH). Forward and reverse SSH was performed on tissue samples of EO and SM resulting in one cDNA library enriched with mRNAs expressed in EO, and a second library representing mRNAs unique to SM. Nineteen expressed sequence tags (ESTs) were identified in EO and nine were identified in SM using BLAST searching of Danio rerio sequences available in NCBI databases. We confirmed differential expression of all 28 ESTs using RT-PCR. In EO, these ESTs represent four classes of proteins: (1) ion pumps, including the α- and β-subunits of Na(+)/K(+)-ATPase, and a plasma membrane Ca(2+)-ATPase; (2) Ca(2+)-binding protein S100, several parvalbumin paralogs, calcyclin-binding protein and neurogranin; (3) sarcomeric proteins troponin I, myosin heavy chain and actin-related protein complex subunit 3 (Arcp3); and (4) the transcription factors enhancer of rudimentary homolog (ERH) and myocyte enhancer factor 2A (MEF2A). Immunohistochemistry and western blotting were used to demonstrate the translation of seven proteins (myosin heavy chain, Na(+)/K(+)-ATPase, plasma membrane Ca(2+)-ATPase, MEF2, troponin and parvalbumin) and their cellular localization in EO and SM. Our findings suggest that mormyrids express several paralogs of muscle-specific genes and the proteins they encode in EOs, unlike gymnotiforms, which may post-transcriptionally repress several sarcomeric proteins. In spite of the similarity in the physiology and function of EOs in mormyrids and gymnotiforms, this study indicates that the mechanisms of development in the two groups may be considerably different.

1 aGallant, Jason, R.1 aHopkins, Carl, D.1 aDeitcher, D., L. uhttps://mormyrids.myspecies.info/en/node/17