Glowing Seashells: Diversity of Fossilized Coloration Patterns on Coral Reef-Associated Cone Snail (Gastropoda: Conidae) Shells from the Neogene of the Dominican Republic

Hendricks, Jonathan R.

doi:10.1371/journal.pone.0120924

Cited by 26 publications

(55 citation statements)

References 33 publications

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“…Shell pigments identified using Raman have usually been determined to be modified carotenoids rather than melanins or tetrapyrroles, which might be explained by the fact that pigments are likely distributed across Mollusca in a phylogenetically relevant manner. [5,6,24,60,61] Most Raman studies have focused on bivalves, caenogastropods, or land snails, where pigments have rarely been identified chemically, but are unlikely to be tetrapyrroles, which tend to occur more frequently in Vetigastropoda (with some exceptions in Bivalvia and Caenogastropoda). Alternatively, signal from carotenoid-based pigments may be masking other shell pigments.…”

Section: Resultsmentioning

confidence: 99%

Colour in bivalve shells: Using resonance Raman spectroscopy to compare pigments at different phylogenetic levels

Wade

Pugh

Nightingale

et al. 2019

J Raman Spectroscopy

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Several studies have suggested that shell colour may be phylogenetically distributed within the phylum Mollusca, but this pattern is confounded by our ignorance of the homology of colour and lack of understanding about the identity of most molluscan pigments. We use resonance Raman spectroscopy to address this problem by examining bivalve pigments producing a range of colours and compare spectra from taxa at different phylogenetic levels. The spectra of most shell pigments exhibited a skeletal signature typical of partially methylated polyenes, possibly modified carotenoids, with the strongest peaks occurring between 1,501–1,540 cm−1 and 1,117–1,144 cm−1 due to the C═C (ν1) and C–C (ν2) stretching modes, respectively. Neither pigment class nor mineral structure differentiated Imparidentia and Pteriomorphia. Spectral acquisitions for purple pigments for two species of Asaphis suggest that identical or nearly identical pigments are shared within this genus, and some red pigments from distantly related species have similar spectra. Conversely, two species with brown shells have distinctly different pigments, highlighting the difficulty in determining the homology of colour even within a single class of pigments. Curiously, we were unable to detect any Raman activity for green‐coloured shell or pigment peaks for the yellow area of Codakia paytenorum, suggesting that these colours are due to structural elements or a pigment that is quite different from those observed in other taxa examined to date. Our results are consistent with the idea that classes of pigments are evolutionarily ancient but heritable modifications may be specific to clades.

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Section: Resultsmentioning

confidence: 99%

Colour in bivalve shells: Using resonance Raman spectroscopy to compare pigments at different phylogenetic levels

Wade

Pugh

Nightingale

et al. 2019

J Raman Spectroscopy

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“…S1 (Duda Jr. et al . 2001; Hendricks 2009, 2015, 2018)) to nodes throughout the phylogeny as minimum age constraints, which MCMCtree treats as soft bounds on the minimum age (Yang 2007). Further information on fossil placement on nodes can be found in the Supplementary.…”

Section: Methodsmentioning

confidence: 99%

Lack of signal for the impact of venom gene diversity on speciation rates in cone snails

Phuong

Alfaro

Mahardika

et al. 2018

Preprint

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25Understanding why some groups of organisms are more diverse than others is a central goal in 26 macroevolution. Evolvability, or lineages' intrinsic capacity for evolutionary change, is thought 27 to influence disparities in species diversity across taxa. Over macroevolutionary time scales, 28 clades that exhibit high evolvability are expected to have higher speciation rates. Cone snails 29 (family: Conidae, >900 spp.) provide a unique opportunity to test this prediction because their 30 venom genes can be used to characterize differences in evolvability between clades. Cone snails 31 are carnivorous, use prey-specific venom (conotoxins) to capture prey, and the genes that encode 32 venom are known and diversify through gene duplication. Theory predicts that higher gene 33 diversity confers a greater potential to generate novel phenotypes for specialization and 34 adaptation. Therefore, if conotoxin gene diversity gives rise to varying levels of evolvability, 35 conotoxin gene diversity should be coupled with macroevolutionary speciation rates. We applied 36 exon capture techniques to recover phylogenetic markers and conotoxin loci across 314 species, 37 the largest venom discovery effort in a single study. We paired a reconstructed timetree using 12 38 fossil calibrations with species-specific estimates of conotoxin gene diversity and used trait-39 dependent diversification methods to test the impact of evolvability on diversification patterns.40 Surprisingly, did not detect any signal for the relationship between conotoxin gene diversity and 41 speciation rates, suggesting that venom evolution may not be the rate-limiting factor controlling 42 diversification dynamics in Conidae. Comparative analyses showed some signal for the impact 43 of diet and larval dispersal strategy on diversification patterns, though whether or not we 44 detected a signal depended on the dataset and the method. If our results remain true with 45 increased sampling in future studies, they suggest that the rapid evolution of Conidae venom 46 may cause other factors to become more critical to diversification, such as ecological opportunity 47 or traits that promote isolation among lineages. 48 49 93 natural way to characterize differences in evolvability between clades. 94 We employ a sequence capture technique previously used in cone snails (Phuong & 95 Mahardika 2017) to recover phylogenetic markers and conotoxin genes from 314 described 96 species. We use the phylogenetic markers to reconstruct a time-calibrated phylogeny and 97 perform trait-dependent diversification analyses to test the impact of evolvability on 98 diversification patterns. We predict that clades with a greater number of conotoxin gene copies 99 should have higher speciation rates. In addition, we test other traits that may have an impact on 100 diversification patterns, including diet and larval dispersal strategy. 101 102 Methods 103 104Bait design 105 We used a targeted sequencing approach to recover markers for phylogenetic inference and 106 ob...

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“…We assigned 12 additional fossils (Table S2, Fig. S1 (Duda Jr. et al 2001;Hendricks 2009Hendricks , 2015Hendricks , 2018) to nodes throughout the phylogeny as minimum age constraints, which MCMCtree treats as soft bounds on the minimum age (Yang 2007). Further information on fossil placement on nodes can be found in the Supplementary.…”

Section: Time Calibrationmentioning

confidence: 99%

Lack of Signal for the Impact of Conotoxin Gene Diversity on Speciation Rates in Cone Snails

Phuong¹,

Alfaro²,

Mahardika

et al. 2019

Systematic Biology

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Understanding why some groups of organisms are more diverse than others is a central goal in macroevolution. Evolvability, or the intrinsic capacity of lineages for evolutionary change, is thought to influence disparities in species diversity across taxa. Over macroevolutionary time scales, clades that exhibit high evolvability are expected to have higher speciation rates. Cone snails (family: Conidae, $>$900 spp.) provide a unique opportunity to test this prediction because their toxin genes can be used to characterize differences in evolvability between clades. Cone snails are carnivorous, use prey-specific venom (conotoxins) to capture prey, and the genes that encode venom are known and diversify through gene duplication. Theory predicts that higher gene diversity confers a greater potential to generate novel phenotypes for specialization and adaptation. Therefore, if conotoxin gene diversity gives rise to varying levels of evolvability, conotoxin gene diversity should be coupled with macroevolutionary speciation rates. We applied exon capture techniques to recover phylogenetic markers and conotoxin loci across 314 species, the largest venom discovery effort in a single study. We paired a reconstructed timetree using 12 fossil calibrations with species-specific estimates of conotoxin gene diversity and used trait-dependent diversification methods to test the impact of evolvability on diversification patterns. Surprisingly, we did not detect any signal for the relationship between conotoxin gene diversity and speciation rates, suggesting that venom evolution may not be the rate-limiting factor controlling diversification dynamics in Conidae. Comparative analyses showed some signal for the impact of diet and larval dispersal strategy on diversification patterns, though detection of a signal depended on the dataset and the method. If our results remain true with increased taxonomic sampling in future studies, they suggest that the rapid evolution of conid venom may cause other factors to become more critical to diversification, such as ecological opportunity or traits that promote isolation among lineages.

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Glowing Seashells: Diversity of Fossilized Coloration Patterns on Coral Reef-Associated Cone Snail (Gastropoda: Conidae) Shells from the Neogene of the Dominican Republic

Cited by 26 publications

References 33 publications

Colour in bivalve shells: Using resonance Raman spectroscopy to compare pigments at different phylogenetic levels

Colour in bivalve shells: Using resonance Raman spectroscopy to compare pigments at different phylogenetic levels

Lack of signal for the impact of venom gene diversity on speciation rates in cone snails

Lack of Signal for the Impact of Conotoxin Gene Diversity on Speciation Rates in Cone Snails

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