First cytogenetic information for five Nilotic elephantfishes and a problem of ancestral karyotype of the family Mormyridae (Osteoglossiformes)

By

Simanovsky, Sergey
Medvedev, Dmitry A.
Tefera, Fekadu
Golubtsov, Alexander

Type

Article

Date of Publication

2020

Original Publication

Comparative cytogenetics : international journal of plant & animal cytogenetics, karyosystematics and molecular systematics

Volume

14

Series / Issue

Issue: 3

Pages

387--397

Subjects

Africa , Brevimyrus , Chromosomes , Cyphomyrus , Hippopotamyrus , karyotype evolution , Marcusenius , Mormyrops

Contributed by

Pensoft Publishers

Language

English

Published by

St. Petersburg, Russia [Published] with technical support of Zoological Institute RAS [2007]-

Identifiers

DOI: https://doi.org/10.3897/CompCytogen.14i3.52727

 

Abstract

The elephantfish family Mormyridae is the most diverse lineage of the primitive teleostean clade Osteoglossomorpha distributed in inland waters of all continents except Antarctica and Europe. The family Mormyridae is endemic to Africa and includes 22 genera and almost 230 species. The evolutionary radiation of mormyrids most probably should be attributed to their capability of both generating and receiving weak electric signals. Up-to-date cytogenetic studies have revealed substantial karyotype differentiation among the nine investigated elephantfish species and genera (a single species studied per each genus). In the present study, karyotypes of five species representing five mormyrid genera (four unexplored ones) collected from the White Nile system in southwestern Ethiopia are described for the first time. The results show substantial variety of the diploid chromosome and fundamental numbers: 2n = 48 and FN = 54 inBrevimyrus niger(Günther, 1866), 2n = 50 and FN = 72 inCyphomyrus petherici(Boulenger, 1898), 2n = 50 and FN = 78 inHippopotamyrus pictus(Marcusen, 1864), 2n = 50 and FN = 76 inMarcusenius cyprinoides(Linnaeus, 1758), 2n = 52 and FN = 52 inMormyrops anguilloides(Linnaeus, 1758). Karyotype structure in the latter species seems to be close to the ancestral condition for the family. This hypothesis is discussed in the light of available data on karyotype diversity and phylogeny of mormyrids.