Paula Mikkelsen

Paleontological Research Institution, Ithaca, NY

Bivalvia Factoids

• 2nd largest molluscan class, ~ 20,000 extant species

• 100+ extant families• Cambrian origin, excellent fossil record• filter feeders to carnivores; 1 mm to giant clam• often dominant biomass in aquatic habitats• key part of world fisheries & aquaculture• important ecological and economic threat species• endangered freshwater taxa

Zebra mussels

Ship worms

Freshwater mussels

Morphological Diversity

Mikkelsen & Bieler (2008) Princeton University Press

Mikkelsen & Bieler (2008) Princeton University Press

Long research history

• Conflicting single-character classifications– Hinges– Adductor muscles– Siphons– Ctenidia– Ciliation– Stomachs

• Early numerical approaches (Purchon 1978)

Steps toward a synthesis

Taylor (1996) Johnston & Haggart (1998) Harper et al. (2000) Bieler (2006)

Conflicting hypotheses

Alternative hypotheses of higher bivalve relationships based on neontological (A, B, C, D), paleontological (E), molecular (G) and combined morphology + molecular evidence (F)

Chioninae Gouldiinae

Pitarinae

Meretricinae

Gemminae

Dosiniinae

Samaranginae

Venerinae

Sunettinae

Tapetinae

Cyclininae

Clementiniinae

Gafrariinae

Lioconchinae

Meroinae

CallistinaeCallocardiinae

Taxonomic coverage – pre-2006 (ex 825 spp.)

(2)

(3)

(1)

(2)

(1)

(2)

(1)

(2)

(6)

(1)

(1)

(1)

(1)

18 taxa ( 9 morphological) ( 15 molecular )

Mikkelsen, et al. 2006. Phylogeny of Veneroidea (Mollusca: Bivalvia) based on morphology and molecules. Zoological Journal of the Linnean Society, 148: 439-521.

Chioninae Gouldiinae

Pitarinae

Meretricinae

Gemminae

Dosiniinae

Samaranginae

Venerinae

Sunettinae

Tapetinae

Cyclininae

Clementiniinae

Gafrariinae

Lioconchinae

Meroinae

CallistinaeCallocardiinae

Taxonomic coverage – 2006 study

114 taxa ( 103 morphological ) ( 65 molecular )

(8)

(7)

(2)

(1)

(2)

(1)

(6)

(6)

(2)

(2)

(8)

(5)

(2) (27)

(18)

(2)

(1)

(4)

(4)

(2)

(1)

(10)

(6)

(1)(2)

(1)

(2)

(2)

(20)

(11)

Mikkelsen, et al. 2006. Phylogeny of Veneroidea (Mollusca: Bivalvia) based on morphology and molecules. Zoological Journal of the Linnean Society, 148: 439-521.

Arctica islandicaCorbicula flumineaGlauconome rugosaGlauconome chinensisCalyptogena magnificaGafrarium tumidumCirce cf. rivularisCirce plicatinaCirce nummulinaCirce scriptaCirce rivularisCirce rivularisGafrarium disparHyphantosoma caperiLioconcha ornataPetricolaria pholadiformisPetricola lapicidaPitar simpsoniPitarina citrinaPitarina japonicaPitar fulminatusTurtonia minutaGomphina undulosaMacrocallista nimbosaCostacallista imparCostacallista lilacinaCompsomyax subdiaphanaMegapitaria squalidaTivela stultorumParastarte triquetraGemma gemmaNutricola tantillaTivela mactroidesVenerupis galactitesIrus crenatusRuditapes decussatusPaphia duraPaphia vernicosaPaphia euglyptaNeotapes undulataRuditapes philippinarum (male)Tuditapes philippinarum (female)Ruditapes bruguieriKatelysia scalarinaKatelysia sp. 2Katelysia sp. 1Katelysia rhytiphonraMercenaria mercenariaMercenaria mercenaria (GB)Anomalocardia auberianaChamelea gallinaVenus verrucosaPeriglypta listeriAntigona lamellarisEurhomalea lenticularisPectunculus exoletaDosinia sp. 2Dosinia sp. 1Dosinia victoriae

100

99100

98

98

100100

100 96

100

9871

100100100

100

100100

100

100 100100

89100

100100

100100

100100100

78

100100

100 94

100

9997

100100

100100

100

100100

100100

91 100

100 83

100100

100100

91

100 99

100100

100 97

100100

100 93

100100

98100

90

100 96100 99

100 90

Bayesian, 50% MR consensus

90% PP / 70% BP

Molecular analysis

56 taxa, 11 of 17 SFs

16S, COI, 28S, H3Gemminae

Tapetinae

Dosiniinae

Callistinae

Pitarinae s.s.

191 36 227

new GB total

Veneridae +

Veneroidea NOT

Veneridae NOT

Subfamilies 5 of 11

Mikkelsen, et al. 2006. Phylogeny of Veneroidea (Mollusca: Bivalvia) based on morphology and molecules. Zoological Journal of the Linnean Society, 148: 439-521.

• NSF Environmental Biology > Assembling the Tree of Life

• Goal: reconstruct bivalve ToL• 5-year grant, $3 million

DEB-0732854 - 0732903 - 0732860

“BivAToL” research goals

• Reconstruct phylogenetic relationships for 283 representatives of all 100+ families based on a combination of shell, soft-anatomy, and molecular characters.

• Explore new or previously underutilized anatomical and ultra-structural characters (stomach, gills, sperm, mantle), and a suite of new nuclear protein-coding genes never before used for bivalves.

• Estimate the time origin of the major bivalve clades based on molecular sequence and fossil data.

Targeted Markers (ca. 10)

PCR amplified genes (tissues in EtOH or RNAlater)

• Nuclear ribosomal genes (18S rRNA and 28S rRNA)

• Nuclear protein-encoding genes: Histones H3 and H4

• Mitochondrial genes

rt-PCR amplified genes (tissues in RNAlater)

• Nuclear protein-encoding genes: Histones H3 and H4

• Myosin heavy chain type II

• Elongation factors

• RNA polymerases

• Sodium-Potassium ATPase α-subunit gene

• Ribosomal proteins

John Taylor (BMNH) Sarah Chicone (PRI) John Zardus (Citadel) Brian Gollands (PRI)

Dan Graf (ANSP) Gerhard Haszprunar (Munich) Liz Harper (U Cambr.) Tom Waller (NMNH)

Ellen Strong (NMNH) Rob Ross (PRI) John Healy (U Qld) Deidre Gonsalves-Jackson (VWC)

Tim Collins (FIU) Gonzalo Giribet (MCZ) Paula Mikkelsen (PRI) Rüdiger Bieler (FMNH)

Protostome AToL

Treatise on Invertebrate Paleontology

ToLWeb

Morphology

Rüdiger Bieler

Paula Mikkelsen – gills + veneroids

Ellen Strong – stomach

Liz Harper – anomalos

John Taylor – shell + lucinoids

Tom Waller – paleo + pectinoids

Gerhard Haszprunar – mantle

John Healy – sperm

Molecules

Gonzalo Giribet

Tim Collins – heterodonts

John Zardus – protobranchs + development

Dan Graf – unionoids

Outreach

Paula Mikkelsen

Rob Ross – informal education

Sarah Chicone – exhibit

Deirdre Gonsalves-Jackson – undergrad curriculum + reprod

Brian Gollands –webmaster / IT

3 “Hubs”

Character masters

Clade masters

Outreach Component ($500K)

Teaching Evolution using Bivalves

• Teacher development resources (K-12)

• Undergraduate curriculum (undergrad)

• Traveling exhibit (public)

• Website – “one-stop shop” for bivalve info (public +)

http://www.bivatol.org

Current status

• Target taxa (283) & and short-term subset (80)• Preservation protocols• Specimen tracking & collections support in

place• Student/postdoc recruiting underway• Outreach advisory board formed• Project server & webmaster in place• Website http://www.bivatol.org • Specimen acquisition underway