The evolutionary history of Stomatopoda (Crustacea: Malacostraca) inferred from molecular data

• Published in: PeerJ (San Francisco, CA) Vol. 5; p. e3844
• Main Authors: Van Der Wal, Cara, Ahyong, Shane T, Ho, Simon Y W, Lo, Nathan
• Format: Journal Article
• Language: English
• Published: United States PeerJ. Ltd 21.09.2017; PeerJ, Inc; PeerJ Inc
• Subjects: Analysis; Ancestral state reconstruction; Appendages; Bioinformatics; Carnivores; Coastal waters; Computational Biology; Crustacea; Environmental science; Evolution; Evolutionary biology; Evolutionary Studies; Fossil calibration; Gonodactyloidea; Hoplocarida; Identification and classification; Lysiosquilloidea; Malacostraca; Mantis shrimps; Mitochondria; Molecular biology; Molecular clock; Morphology; Museums; Natural history; Ommatidia; Phylogenetic analysis; Phylogenetics; Phylogeny; Prey; Shellfish; Software; Squilloidea; Stomatopoda; Studies; Taxonomy; Unipeltata; Zoology; Phylogenetic analysis; Stomatopoda; Ancestral state reconstruction; Fossil calibration; Molecular clock
• ISSN: 2167-8359; 2167-8359
• DOI: 10.7717/peerj.3844

The crustacean order Stomatopoda comprises seven superfamilies of mantis shrimps, found in coastal waters of the tropics and subtropics. These marine carnivores bear notable raptorial appendages for smashing or spearing prey. We investigated the evolutionary relationships among stomatopods using phylogenetic analyses of three mitochondrial and two nuclear markers. Our analyses recovered the superfamily Gonodactyloidea as polyphyletic, with as the sister group to all other extant stomatopods. A relaxed molecular clock, calibrated by seven fossil-based age constraints, was used to date the origin and major diversification events of stomatopods. Our estimates suggest that crown-group stomatopods (Unipeltata) diverged from their closest crustacean relatives about 340 Ma (95% CRI [401-313 Ma]). We found that the specialized smashing appendage arose after the spearing appendage ∼126 Ma (95% CRI [174-87 Ma]). Ancestral state reconstructions revealed that the most recent common ancestor of extant stomatopods had eyes with six midband rows of hexagonal ommatidia. Hexagonal ommatidia are interpreted as plesiomorphic in stomatopods, and this is consistent with the malacostracan ground-plan. Our study provides insight into the evolutionary timescale and systematics of Stomatopoda, although further work is required to resolve with confidence the phylogenetic relationships among its superfamilies.