03057nas a2200313   4500008004100000022001300041245015100054210006900205260001600274520202800290653002802318653002002346653002802366653001202394653001402406100002202420700001702442700002702459700001502486700001802501700002302519700002102542700002602563700002402589700002302613700002002636700002102656856006602677       2017                        eng d  a0928425700aIntragenus (Campylomormyrus) and intergenus hybrids in mormyrid fish: physiological and histological investigations of the electric organ ontogeny0 aIntragenus Campylomormyrus and intergenus hybrids in mormyrid fi  cJan-01-20173 a<p>African weakly electric mormyrid fish show a high diversity of their electric organ discharge (EOD) both across and within genera. Thanks to a recently developed technique of artificial reproduction in mormyrid fish, we were able to perform hybridizations between different genera and within one genus (Campylomormyrus). The hybrids of intergenus hybridizations exhibited different degrees of reduced survival related to the phylogenetic distance of the parent species: hybrids of the crosses between C. rhynchophorus and its sister genus Gnathonemus survived and developed normally. Hybrids between C. rhynchophorus and a Mormyrus species (a more basal clade compared to Campylomormyrus s) survived up to 42 days and developed many malformations, e.g., at the level of the unpaired fins. Hybrids between C. numenius and Hippopotamyrus pictus (a derived clade, only distantly related to Campylomormyrus) only survived for two days during embryological development. Seven different hybrid combinations among five Campylomormyrus species (C. tamandua, C. compressirostris, C. tshokwe, C. rhynchophorus, C. numenius) were performed. The aim of the hybridizations was to combine species with (1) either caudal or rostral position of the main stalk innervating the electrocytes in the electric organ and (2) short, median or long duration of their EOD. The hybrids, though they are still juveniles, show very interesting features concerning electrocyte geometry as well as EOD form and duration: the caudal position of the stalk is prevailing over the rostral position, and the penetration of the stalk is dominant over the non-penetrating feature (in the Campylomormyrus hybrids); in the hybrid between C. rhynchophorus and Gnathonemus petersii it is the opposite. When crossing species with long and short EODs, it is always the long duration EOD that is expressed in the hybrids. The F1-Hybrids of the cross C. tamandua x C. compressirostris are fertile: viable F2-fish could be obtained with artificial reproduction</p>
10aArtificial reproduction10aCampylomormyrus10aElectric organ ontogeny10aHybrids10amormyrids1 aKirschbaum, Frank1 aNguyen, Linh1 aBaumgartner, Stephanie1 aChi, Linda1 aWolfart, Rene1 aElarbani, Khouloud1 aEppenstein, Hari1 aKorniienko, Yevheniia1 aGuido-Böhm, Lilian1 aMamonekene, Victor1 aVater, Marianne1 aTiedemann, Ralph  uhttp://linkinghub.elsevier.com/retrieve/pii/S092842571730003702081nas a2200217   4500008004100000022001400041245012600055210006900181260001600250300001400266490000800280520136500288100002101653700002301674700002001697700002701717700002101744700002101765700002201786856005501808       2015                        eng d  a0340-759400aComparative histology of the adult electric organ among four species of the genus Campylomormyrus (Teleostei: Mormyridae)0 aComparative histology of the adult electric organ among four spe  cJan-04-2015  a357 - 3740 v2013 a<p>The electric organ (EO) of weakly electric mormyrids consists of flat, disk-shaped electrocytes with distinct anterior and posterior faces. There are multiple species-characteristic patterns in the geometry of the electrocytes and their innervation. To further correlate electric organ discharge (EOD) with EO anatomy, we examined four species of the mormyrid genus Campylomormyrus possessing clearly distinct EODs. In C. compressirostris, C. numenius, and C. tshokwe, all of which display biphasic EODs, the posterior face of the electrocytes forms evaginations merging to a stalk system receiving the innervation. In C. tamandua that emits a triphasic EOD, the small stalks of the electrocyte penetrate the electrocyte anteriorly before merging on the anterior side to receive the innervation. Additional differences in electrocyte anatomy among the former three species with the same EO geometry could be associated with further characteristics of their EODs. Furthermore, in C. numenius, ontogenetic changes in EO anatomy correlate with profound changes in the EOD. In the juvenile the anterior face of the electrocyte is smooth, whereas in the adult it exhibits pronounced surface foldings. This anatomical difference, together with disparities in the degree of stalk furcation, probably contributes to the about 12 times longer EOD in the adult.</p>
1 aPaul, Christiane1 aMamonekene, Victor1 aVater, Marianne1 aFeulner, Philine, G.D.1 aEngelmann, Jacob1 aTiedemann, Ralph1 aKirschbaum, Frank  uhttp://link.springer.com/10.1007/s00359-015-0995-6