The evolutionary relationships of two families of cottoid fishes of Lake Baikal (East Siberia) as suggested by analysis of mitochondrial DNA

Abstract

Fragments of mtDNA genes Cyt B, ATPase 6, and ATPase 8 of six cottoid fishes species of Lake Baikal (East Siberia) were amplified and sequenced. In addition mtDNAs of the same fish were subjected to restriction analysis. The data obtained were used to construct phylogenetic trees. The topology of the ATPase tree differs from those of the Res (restriction) and Cyt B trees. Clustering of species within the trees confirms the viewpoint of Taliev (1955, Baicalian Sculpins (Cottoidei)) according to which Baikalian cottoids originate from two ancestral forms. The times of branching obtained do not confirm the existing viewpoint according to which the two golomyankas (Comephorus baicalensis and Comephorus dybowskii) are pre-Baikal (Myocene) relicts: these two species may have originated 1.2-1.8 million years ago in Baikal, and they seem to represent an example of rapid morphological evolution which resulted in the formation of a new family.

Allopatric differentiation in theMarcusenius macrolepidotusspecies complex in southern and eastern Africa: the resurrection ofM. pongolensisandM. angolensis, and the description of two new species (Mormyridae, Teleostei)

“…In cottoid fish of Lake Baikal divergence between related species was between 0.7 and 3.8% (Slobodyanyuk et al 1995), which is also in the same range as in the altisambesi/ devosi/pongolensis species pairs. Distances between well established and unrelated genera, e.g.…”

“…In mammals a crude molecular clock equates 2% nucleotide differences with one million years divergence time (Brown et al 1979;Wilson et al 1987). It has been suggested that the molecular clock shows an even slower rate in fishes than in mammals (Cantatore et al 1994;Slobodyanyuk et al 1995). Even if this calibration is very crude it suggests that the taxa within the Macrolepidotus complex that differ by genetic distances between 1.5 and 8.5% must have separated more than one to four million years ago which would be long enough to develop into separate species.…”

Genetic relationships among six KoreanRanaspecies (Amphibia; Ranidae) based on the mitochondrial cytochromebgene

“…Irwin et al (1991) have analyzed nucleotide sequences of cytochrome b genes of more than 20 mammals. Slobodyanyuk et al (1995) found that the evolution rates determined by Brown et al (1979) and Irwin et al (1991) were very similar (2.1% per million yr). Neighbor Joining is a distance matrix method producing an unrooted tree without the assumption of a clock.…”

Patterns in fish radiation are compatible with Pleistocene desiccation of Lake Victoria and 14 600 year history for its cichlid species flock

“…Species numbers and speciation rates in fishes of other lakes of comparable age and in lineages related to those in Lake Victoria but from older lakes. Note that the negative relationship between age of lake and speciation interval is a general trend (McCune 1997 Strecker et al (1996); Laurentian Great lakes: Smith & Todd (1984); lakes on Texada Island and Vancouver Island: Taylor et al (1997), Taylor & McPhail (1999); single species lakes on the Queen Charlottes: Reimchen et al (1985); lakes in East Canada and Maine: Lu et al (2001); lakes in Alaska: Bernatchez et al (1996); lakes in East Canada and Maine: Taylor & Bentzen (1993); Lake Bunnersjoarna/Sweden: Ryman et al (1979), Schluter (1996); Lake Thingvallavatn/Island: Skulason & Smith (1995), Skulason et al (1999); Norway and Scotland: Hindar et al (1986), Hartley et al (1992); Sweden: Svedaeng (1990); Lake Titicaca: Parker in McCune (1997); Lake Edward: Greenwood (1973Greenwood ( , 1994; Lake Lanao: Kornfield & Carpenter (1984); Lake Malawi: Sodsuk et al (1995); Lake Barombi Mbo: Schliewen et al (1994); Lake Malawi: Lowe-McConnell (1987), Agnese & Teugels (2001); Lake Tana: Nagelkerke et al (1995); Lake Baikal: Slobodyanyuk et al (1995)). …”