author={C. Darrin Hulsey and Francisco Le{\'o}n and Roc{\'i}o Rodiles‐Hern{\'a}ndez},
Abstract The extent to which elements of functional systems can change independently (modularity) likely influences the diversification of lineages. Major innovations in organismal design, like the pharyngeal jaw in cichlid fishes, may be key to a group's success when they relax constraints on diversification by increasing phenotypic modularity. In cichlid fishes, pharyngeal jaw modifications that enhanced the ability to breakdown prey may have freed their oral jaws from serving their ancestral… 

Tracing evolutionary decoupling of oral and pharyngeal jaws in cichlid fishes

It is shown that the two jaws were evolutionary decoupled at a late stage of the radiation, suggesting that decoupling contributed to micro‐niche partitioning and the associated rapidly increasing trophic diversity during this phase.

Decoupled jaws promote trophic diversity in cichlid fishes

Although decoupling of prey capture and processing functions released constraints on jaw evolution and promoted trophic diversity in cichlids, the natural diversity of consumed prey has also induced a moderate degree of evolutionary integration between the jaw systems, reminiscent of the original mechanical trade‐off between force and mobility.

The cichlid oral and pharyngeal jaws are evolutionarily and genetically coupled

The data show that African cichlid evolutionary success has occurred within the context of a coupled jaw system, an attribute that may be driving adaptive evolution in this iconic group by facilitating rapid shifts between foraging habitats, providing an advantage in a stochastic environment such as the East African Rift-Valley.

Pleiotropic jaw morphology links the evolution of mechanical modularity and functional feeding convergence in Lake Malawi cichlids

A clear case of two cichlid species that have independently evolved to graze algae in less than 2 Myr and have converged on similar jaw protrusion abilities as well as four-bar linkage mechanics, but have evolved these similarities via non-convergent four- bar morphologies is highlighted.

Comparative rates of lower jaw diversification in cichlid adaptive radiations

The lower jaw (LJ) provides an ideal trophic phenotype to compare rates and patterns of macroevolution among cichlid radiations, and the Lake Malawi flock exhibited a much faster rate of evolution in several components of the LJ than the Central America Heroines; this rapid rate of divergence is consistent with natural selection.

Does evolutionary innovation in pharyngeal jaws lead to rapid lineage diversification in labrid fishes?

It is suggested that pharyngeal jaws might have played a more important role in enabling morphological evolution of the feeding apparatus in labrids and scarines rather than in accelerating lineage diversification.

Morphological and Gene Expression Plasticity in Neotropical Cichlid Fishes

The durophagous cichlid Vieja maculicauda is examined for differences in pharyngeal osteology, dentition, and soft tissues when exposed to different diet regimes and plasticity in tooth growth in the lower pharynGEal jaw is examined.

Head Shape Modulates Diversification of a Classic Cichlid Pharyngeal Jaw Innovation

This work explored diversification of lower pharyngeal jaw shape and the extent to which it is influenced by head shape in Neotropical cichlids, and showed that a wide head constrains access to adaptive peaks associated with several trophic roles.

Convergence in a Mechanically Complex Phenotype: Detecting Structural Adaptations for Crushing in Cichlid Fish

Investigation of structural and mechanical similarities of the lower pharyngeal jaw in cichlid fish that have evolved the ability to crush hard-shelled molluscs suggests divergence found in polymorphic species could provide the substrate for trophic differences found in reproductively isolated cichLids.

Co-evolution of the premaxilla and jaw protrusion in cichlid fishes (Heroine: Cichlidae)

Using a combination of morphometrics, kinematics, and new phylogenetic hypotheses for 20 Heroine cichlid species, correlations between the length of the ascending process and maximum jaw protrusion were highly significant when examined as independent contrasts using all three topologies.



Integration and evolution of the cichlid mandible: the molecular basis of alternate feeding strategies.

It is concluded that patterns of morphological integration of the cichlid jaw reflect a balance among conflicting functional demands and has the potential to alter mandibular morphology in a way that mimics adaptive variation among fish species.

Function of a key morphological innovation: fusion of the cichlid pharyngeal jaw

Greater LPJ suturing, pharyngeal jaw splitting under compression and the forces used to crush molluscs in the wild suggest increased LPJ fusion in the trophically polymorphic Herichthys minckleyi operates to strengthen the pharynx, facilitating the ability of cichlids to exploit durable prey.

Cichlid jaw mechanics: linking morphology to feeding specialization

Phylogenetic independent contrasts indicate changes in anterior jaw mechanics may be necessary for diversification of cichlid Jaw protrusion abilities, and the labile evolution of jaw protrusion in Heroine cichLids likely facilitated the repeated specialization on evasive prey during their diversification.

A Functional morphospace for the skull of labrid fishes: patterns of diversity in a complex biomechanical system

It is hypothesized that the functional and ecological diversity of labrids is due in part to a history of decoupled evolution of major components of the feeding system as well as among the muscular and skeletal elements of each component.

Evolutionary Strategies and Morphological Innovations: Cichlid Pharyngeal Jaws

The conversion of the preexisting elements into a new and significantly improved cichlid adaptive complex of high selective value may have evolved by rapid steps under influence of strong selection pressure acting on the minor reconstruction of the -genotype which is involved in evolutionary changes of the pertinent ontogenetic mechanisms.

Pharyngeal biting mechanics in centrarchid and cichlid fishes : insights into a key evolutionary innovation

It is suggested that the key structural innovation in the development of the functionally versatile cichlid (labroid) pharyngeal jaw apparatus was the decoupling of epibranchials 4 from the upper pharynGEal jaws.

Molecular systematics of Middle American cichlid fishes and the evolution of trophic-types in 'Cichlasoma (Amphilophus)' and 'C. (Thorichthys)'.

The phylogenetic hypotheses generated indicate that the substratum-sifting genera Thorichthys and Amphilophus do not share a common ancestor, and both groups should be placed in the resurrected genus Astatheros.


The results of complementary studies of genetics and reproductive biology initiated to resolve the biological status of cichlids of Cuatro Cienegas suggest that both forms belong to a single polymorphic species.

Functional morphology of extreme jaw protrusion in Neotropical cichlids

The feeding behavior of extreme and modest jaw‐protruding Neotropical cichlids is investigated by comparing feeding kinematics, cranial morphology, and feeding performance to represent an adaptation for capturing elusive prey by enhancing the ram velocity of the predator but does not enhance suction feeding performance.

Evolutionary integration and morphological diversification in complex morphological structures: mandible shape divergence in spiny rats (Rodentia, Echimyidae)

Developmental and genetic models were significantly associated with the interspecific integration patterns observed, suggesting a role for neutral evolution during the evolutionary divergence of mandible shape and directional and stabilizing selection were not discarded as processes responsible for the generation of inter specific integration.