Phylogenetic Diversity and Systematics of Decapod Crustaceans

Decapod crustaceans encompass a vast array of familiar forms—crabs, prawns, lobsters and true shrimps—whose evolutionary history spans more than 350 million years. Their systematics has long been shaped by morphological characters such as carapace structure, limb segmentation and gill arrangements, but recent advances in molecular phylogenetics have revealed extensive cryptic diversity and unexpected relationships. Integrative approaches combining mitochondrial and nuclear markers, whole‐mitogenome sequencing and transcriptomic data now underpin robust phylogenies that resolve deep splits among major lineages and clarify the origins of key ecological innovations such as symbiosis, freshwater colonisation and eusociality. Such frameworks illuminate global biogeographic patterns, pinpoint centres of lineage diversification and inform taxonomy by identifying non-monophyletic groups requiring revision. Beyond pure systematics, enhanced understanding of decapod phylogenetic diversity underpins conservation planning, sustainable fisheries management and the use of shrimps and lobsters as bioindicators of environmental change.

Research from Nature Portfolio

Recent multilocus phylogenetic analyses of marine palaemonid shrimps have reconstructed relationships among free-living and symbiotic clades, revealing seven major lineages and demonstrating that symbioses with cnidarians, echinoderms and other invertebrates arose independently on at least eight occasions. Divergence dating places the origin of the focal marine clade in the Late Cretaceous Indo-West Pacific, with subsequent dispersal into the eastern Pacific and Atlantic prior to the closure of the Panama Isthmus. Another study exploring transitions in caridean shrimps used diversification-rate modelling within a time‐calibrated phylogeny to show that shifts into freshwater habitats were associated with more than double the speciation rate of marine relatives, whereas gains of symbiotic ecology corresponded with reduced diversification, highlighting the complex interplay between habitat transition and lineage dynamics.

Phylogenetic Diversity and Systematics of Decapod Crustaceans publication trend

The graph below shows the total number of articles in phylogenetic diversity and systematics of decapod crustaceans across all publications each year (not limited to Nature Index journals).

Technical terms

Phylogenetic diversity: A measure of evolutionary distinctiveness that quantifies the total branch lengths spanned by a set of taxa within a phylogenetic tree.

Systematics: The scientific discipline concerned with the classification, nomenclature and evolutionary relationships of organisms.

Monophyletic: Describing a group of organisms that includes an ancestor and all of its descendants, forming a single complete branch on the tree of life.

Diversification rate: The net rate at which new species form (speciation) minus the rate at which species go extinct, often estimated within a phylogenetic framework.

DNA barcoding: A taxonomic method using a standardized short genetic marker, typically the mitochondrial COI gene, to identify species and uncover cryptic diversity.

Cytochrome c oxidase I (COI): A mitochondrial gene widely employed as the standard barcode region for animals, valued for its variation among species and conserved primer sites.

References

1. Molecular phylogeny and historical biogeography of marine palaemonid shrimps (Palaemonidae: Palaemonella–Cuapetes group). Scientific Reports (2022).
2. Freshwater transitions and symbioses shaped the evolution and extant diversity of caridean shrimps. Communications Biology (2018).
3. New primers for amplification of cytochrome c oxidase subunit I barcode region designed for species of Decapoda (Crustacea). Nauplius (2016).
4. Snapping shrimps of the genus Alpheus Fabricius, 1798 from Brazil (Caridea: Alpheidae): updated checklist and key for identification. Nauplius (2013).