Introduction to annelid biodiversity - Natural History Museum

Dr Adrian GloverZoology Department

The Natural History Museumhttp://www.nhm.ac.uk/research-curation/staff-directory/zoology/a-glover/

Introduction to annelid biodiversity

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I. What are annelids?

II. Where did they come from?

III. What are they doing?

IV. Why do we care?

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1. What are annelids?

Nereis succinea Animation: Hans Hillewaert

a) worms

b) segmented

c) with chaetae

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b) segmentation

1. What are annelids?

Rouse & Pleijel 2001

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Ophryotrocha sp. nov. Photo: Adrian Glover

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c) chaetae

1. What are annelids?

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c) chaetae

1. What are annelids?

Rouse & Pleijel 2001

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c) chaetae

1. What are annelids?

SEM Image: Adrian Glover

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1. What are annelids?

Rouse & Pleijel 2001

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1. What are annelids?

Vigtorniella flokatiPhoto: Adrian Glover Photo: Adrian Glover

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POLYCHAETA OLIGOCHAETA HIRUDINEA

ECHIURA POGONOPHORA(now Siboglinidae)

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1. What are annelids?

Two important questions here:

Do all Annelida share a common annelid ancestor? (i.e not polyphyletic)

Are all descendents of that common ancestor included in the ‘group’ Annelida? (i.e not paraphyletic)

By answering these questions through phylogenetic analysis we can determine if Annelida is monophyletic

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I. What are annelids?

II. Where did they come from?

III. What are they doing?

IV. Why do we care?

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II. Where did annelids come from?

Haeckel, 1866 Ciccarelli et al. 200613

II. Where did annelids come from?

Adapted from Giribet et al. 2007

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II. Where did annelids come from?

HesionidaePhoto: Adrian Glover

‘Errantia’ ‘Sedentaria’

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Study based on morphology and a series of a priori assumptions about the direction of evolution in Annelida

Early DNA study using 1 gene (elongation factor 1 alpha) for a small

number of taxa within Annelida

II. Where did annelids come from?

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II. Where did annelids come from?

Rouse & Pleijel 2001

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“None of our analyses support the major polychaete clades reflected in the current classification scheme of annelids, and hypothesis testing significantly rejects monophyly of Scolecida, Palpata, Canalipalpata, and Aciculata.”

Struck et al. 2007 BMC Evol Biol. 7:57

II. Where did annelids come from?

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II. Where did annelids come from?

Candia spinosa annelid from the Burgess Shale, 515 Mya, and reconstruction with iridescent chaetae

Annelid? from the Chengjiang fauna , China, 520-525 Mya

Photo by Xiaoya Ma

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1. What are annelids?

- segmented worms with chaetae

- and also some unsegmented worms, without chaetae!

- what the ????

Summary of sections 1 and II

II. Where did annelids come from?

- they are part of the Lophotrochozoa radiation, within the protostome group of the Metazoa

- they now include taxa that were formally separated based on morphology (loss of characters)

- they are an ancient lineage dating to at least 525 Mya

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I. What are annelids?

II. Where did they come from?

III. What are they doing?

IV. Why do we care?

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III. What are annelids doing?

a) feeding

b) moving sediment around

c) moving carbon around

d) reproducing

e) dispersing

f) speciating

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a) feeding

III. What are annelids doing?

Video: Craig R. Smith / Adrian Glover 200223

b) moving sediment/soil around

III. What are annelids doing?

Beesley et al. 2000

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b) moving sediment/soil around

III. What are annelids doing?

Video: Craig R. Smith 2008

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c) moving carbon around

III. What are annelids doing?

Video: Thomas G Dahlgren / Adrian Glover 200726

Feeding trochophore larvaeSpirobranchus giganteus (Serpulidae)

Direct-developinglarvae

Exogoninae (Syllidae)

Epigamous epitokeNereididae

Schizogamous epitokesMyrianida (Syllidae)

d) reproducing

III. What are annelids doing?

All from Rouse & Pleijel 2001

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d) dispersing (1)

III. What are annelids doing?

Riftia pachyptila, Hydrothermal Vent, East Pacific RiseImage credit: unknown, on the Total Foundation website

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d) dispersing (2)

III. What are annelids doing?

Shank & Halanych 200729

e) speciating

III. What are annelids doing?

A

BGlover et al. 2005a

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IV. Why do we care?

a) knowing the unknown

b) understanding process

c) predicting impacts

d) making policy decisions

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IV. Why do we care?

a) knowing the unknown (1)

Glover et al. 200232

IV. Why do we care?

a) knowing the unknown (2)

adapted from Giribet et al. 2007

marine & terrestrial (black)marine only (blue)

terrestrial/freshwater only (green)

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IV. Why do we care?

b) understanding process

Welsh 2003

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IV. Why do we care?

c) predicting impacts

Glover & Smith 2003

Image © Ifremer, France

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IV. Why do we care?

d) making policy decisions

from International Seabed Authority, United Nations36

Further reading

Beesley et al (Eds) 2000. Polychaetes & Allies: The Southern Synthesis. CSIRO Publishing.

Rouse & Pleijel 2001. Polychaetes. Oxford University Press

Giribet et al 2007. A modern look at the animal tree of life. Zootaxa 1668: 61-79

Van Dover 2000. The Ecology of Hydrothermal Vents. Princeton University Press

(and google scholar search the authors cited on previous slides for additional references specific to those subjects)

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Questions?

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