Which cichlids grow the biggest?

Did cichlids evolve from a hybrid swarm?

Cichlids of the African rift lake system evolved from an original hybrid swarm. Cichlids provide scientists with a unique perspective of speciation, having become extremely diverse in the more recent geological past.

Is there hybridization among Lake Victoria cichlids?

Notably, each of the two major allele classes of an opsin gene involved in adaptation and speciation among Lake Victoria cichlids 39, 40 is likely derived from one of the two parental lineages. This indicates that a major part of the variation at this gene segregating in the LVRS stems from hybridization between these lineages.

What drives divergence of hybrid inviability genes between two species of Drosophila?

Adaptive evolution drives divergence of a hybrid inviability gene between two species of Drosophila. Nature. 2003;423 (6941):715–9. PubMed pmid:ISI:000183443400034.

What triggers the evolution of egg-spots in cichlids?

A sensory bias has triggered the evolution of egg-spots in cichlid fishes. PLoS ONE 6, e25601 (2011). Theis, A., Salzburger, W. & Egger, B.

What is the best book on cichlid evolution?

BMC Evol. Biol. 5, 17 (2005). Kocher, T. D. Adaptive evolution and explosive speciation: the cichlid fish model. Nat. Rev. Genet. 5, 288–298 (2004). Salzburger, W. The interaction of sexually and naturally selected traits in the adaptive radiations of cichlid fishes. Mol. Ecol. 18, 169–185 (2009). Fryer, G. & Iles, T.

Do haplochromine cichlids have egg-spots?

Figure 1: The egg-spots of haplochromine cichlids. ( a) Phylogeny of the East African cichlid fishes based on a new multimarker data set. The haplochromines are the most species-rich and derived group of cichlids in East Africa. One of the common features of haplochromines is the presence of egg-spots on the anal fin of males.

Where do cichlids Express fhl2a and fhl2b?

An additional series of qPCR experiments in 12 tissues revealed that, in cichlids, fhl2a is primarily expressed in heart, bony structures and muscles, whereas fhl2b is highly expressed in the eye, and further in skin and the egg-spots of haplochromines ( Fig. 3b,c ).

Where did the Lake Victoria cichlids come from?

Seehausen, O. et al. Nuclear markers reveal unexpected genetic variation and a Congolese-Nilotic origin of the Lake Victoria cichlid species flock. Proc. R.

Can genetic distance predict phenotypic novelty in hybrid cichlid fish?

Stelkens, R. B., Schmid, C., Selz, O. & Seehausen, O. Phenotypic novelty in experimental hybrids is predicted by the genetic distance between species of cichlid fish. BMC Evol. Biol. 9, 283–295 (2009).

Do Lake Victoria cichlids segregate between the Congolese and Upper Nile lineages?

We extracted sites for which only one of the two alleles segregating in Lake Victoria cichlids were found in the Congolese and Upper Nile lineage taxa together (category 1).

Do nuptial colors affect opsin sensitivity in Lake Victoria cichlids?

Miyagi, R. et al. Correlation between nuptial colors and visual sensitivities tuned by opsins leads to species richness in sympatric Lake Victoria cichlid fishes. Mol. Biol. Evol. 29, 3281–3296 (2012).

What do we know about the genetics of cichlids?

An array of genomic resources has been developed for cichlids, including genetic and physical maps, and microarrays of expressed sequences. Quantitative trait mapping is identifying the genetic basis for differences in jaw and tooth shape among species.

Are F2 hybrids of African haplochromine cichlid fish viable?

We measured the fitness of F2 hybrids of African haplochromine cichlid fish bred from species pairs spanning several thousand to several million years divergence time. F2 hybrids consistently showed the lowest viability compared to F1 hybrids and non-hybrid crosses (crosses within the grandparental species), in agreement with hybrid breakdown.

When does divergence occur at a candidate speciation gene?

Figure 2. An example of a method to infer that divergence at a candidate speciation gene occurred before the evolution of complete reproductive isolation (following). Depicted are gene trees for different types of loci (e. g. candidate speciation genes versus other loci, such as neutral genes).

Does genetic distance predict phenotypic novelty in hybrid fish?

Stelkens RB, Schmid C, Selz O, Seehausen O. Phenotypic novelty in experimental hybrids is predicted by the genetic distance between species of cichlid fish. BMC Evolutionary Biology. 2009;9 (283) pmid:19961584

Do speciation genes affect hybrid sterility and inviability?

Most of the first specific genes put forth as speciation genes affected intrinsic hybrid sterility or inviability. Our second goal is to broaden coverage of the many forms of reproductive isolation, including extrinsic components, whose genetic basis remains largely unknown.

What happens to the egg-spots of haplochromine females?

Immediately upon spawning, a haplochromine female gathers up her eggs into the mouth; the male then presents his egg-spots to which the female responds by snatching and bringing her mouth close to the male’s genital opening; upon discharging sperm, the eggs become fertilized inside the female’s mouth ( Fig. 1c ).

What is the function of egg spots in haplochromines?

Egg-spots appear to be important in the courtship and spawning behavior of haplochromines, , , (Figure 1C). The exact function of egg-spots is unknown, however, and several hypotheses exist that seek to explain their mode of action and their evolutionary origin.

Why are there no cichlids in Lake Victoria?

Cichlid Extinction in Lake Victoria Due to Specialized Jaw. The rocky reefs of Lake Victoria host many cichlids, but few fish-eating species survive. A UC Davis Evolution and Ecology team has discovered that cichlid fishes in Africa’s Lake Victoria have suffered a unique and unexpected effect of evolutionary adaptation: mass extinction.

What are some interesting facts about Lake Victoria?

The lake includes many species of fish that inhabit nowhere else, especially cichlids. Invasive fish, such as the Nile perch, have driven many endemic species to extinction . Geologically, Lake Victoria is relatively young at about 400,000 years old. It formed when westward-flowing rivers were dammed by an upthrown crustal block.

Where did the superflock of African cichlid fish come from?

Verheyen, E., Salzburger, W., Snoeks, J. & Meyer, A. Origin of the superflock of cichlid fishes from Lake Victoria, East Africa. Science 300, 325–329 (2003). Seehausen, O. African cichlid fish: a model system in adaptive radiation research.

How many species of cichlids are there in Lake Victoria?

a, Multispecies coalescent tree generated by ASTRAL for Lake Victoria cichlids ( n = 100 species).

Is explosive speciation in cichlids concentrated in large lakes?

Here, by reconstructing a large phylogeny of all currently described cichlid species, we show that explosive speciation is solely concentrated in species flocks of several large young lakes. Increases in the speciation rate are associated with the absence of top predators; however, this does not sufficiently explain explosive speciation.