Where does the escargot? Tracking marine gastropod larvae using statolith

and protoconch

Danielle ZacherlDepartment of Ecology, Evolution and Marine Biology

University of CaliforniaSanta Barbara, CA 93106

zacherl@lifesci.ucsb.edu

They move fast….really….

Adult Kelletia kelletii lays eggs at ‘natal’ reef

Planktonic veliger larvae hatch out

Oceanic transport?

Larvae ‘settle’ onto benthic habitat, metamorphose intojuveniles

“closed population”

Larvae settle elsewhere…..

“open population”

•Where do incoming larvae originate? •What is the extent of connectivity between spatially separated populations?

Dissolved trace elements

Larval uptake Otolith incorporation

Otoliths as ‘recorders’ of elemental composition

CaCO3 + Ba2+ BaCO3+ Ca2+

10 m200 m

Statolith and protoconch (larval shell) of veliger Kelletia kelletii

Can invertebrate larval hard parts ‘record’ their source of production?

•Point Conception

•Monterey Bay

•Punta Eugenia

Historic range

Extension

Kelletia kelletii

100 Km

• Hopkins Marine Life Refuge (HMLR)McAbee’s Beach

•Diablo Canyon

•Big Creek

JalamaCoho

IV ReefNaples Reef

•Pt. Loma

•La Bufadora

•Punta San Carlos # whelks/m2

0 0.2 0.4 0.6 0.8 1 1.2 1.4

HMLR

Big Creek

Diablo

Jalama

Coho

Naples

Isla Vista

Pt Loma

La Bufadora

Punta San Carlos

0

25

50

0

25

50

% p

opul

atio

n

0

25

50

20 30 40 50 60 70 80 90 100 110 1200

25

50La Bufadora (n=361)

0

25

50

0

25

50

0

25

500

25

50

HMLR (n=129)

Diablo Canyon (n=50)

Jalama (n=72)

Coho (n=515)

Naples Reef (n=337)

IV Reef (n= 225)

Pt. Loma (n=487)

25

50

0

25

50

0

25

50

0

25

50

0

25

50

% p

opul

atio

n

0

25

50

0

25

50

0

25

50

20 30 40 50 60 70 80 90 100 110 1200

25

50

McAbee's Beach (n=87)

HMLR (n=38)

Diablo Canyon (n=52)

Jalama (n=66)

Coho (n=406)

Naples Reef (n= 630)

IV Reef (n=230)

Pt. Loma (n=132)

La Bufadora (n=187)

•Point Conception

•Monterey Bay

•Punta Eugenia

100 Km?

?

Relevant to:•Population ecologists •Biogeographers•Introduced species experts•Resource managers

Sea surface temperature (SST) – June 2001 (monthly composite)

J F M A M J J A S O N D

Monthly mean seawater temperature (30 yr average) at 10 m depth

Baja Ca. N

San Diego

Santa Barbara Channel SSanta Barbara Channel N

Pt. Conception

Diablo Canyon

Big Sur

Monterey

Central Baja Ca. 10

11

12

13

14

15

16

17

How does this affect metal (Me) incorporation?

•Upwelled water is Me rich, Me conc. can affect incorporation

•Upwelled water is cold, temperature can affect Me incorporation

•Do differences in Barium (Ba) concentration in seawater and temperature affect the Ba signal in larval hard parts?

•Are Kelletia kelletii larval hard parts produced north of Point Conception chemically distinguishable from those produced in the Santa Barbara Channel?

•Do differences in Barium (Ba) concentration in seawater and temperature affect the Ba signal in larval hard parts?

Is Ba concentration in protoconch and larval statolith influenced by seawater temperature and Ba concentration?

1x 2x 4x 6x 1x 2x 4x 6x

Cold (11-12° C) Warm (16.5-17.5° C)

Protoconch and statolith samples analyzed separately using ICP-MS

Ba incorporation into protoconch (larval shell)

0

5

10

15

20

25

0 5 10 15 20

Ba/Ca mol/mol seawater

Ba/

Ca

m

ol/m

ol p

roto

con

ch

11-12° C16.5-17.5° C

y = 1.1082x + 0.2218

R2 = 0.9999

y = 0.7585x + 1.3877

R2 = 0.9898

Seawater X Temp

P = 0.0021

Ba incorporation into larval statolith

Seawater X Temp

P = 0.0050

0

5

10

15

20

25

30

0 5 10 15 20

Ba/Ca mol/mol seawater

Ba/

Ca

mol

/mol

sta

toli

th

16.5 - 17.5°C

11 - 12°C

y = 1.4322x + 1.9066

R2 = 0.9966

y = 1.2543x + 0.429

R2 = 0.9964

•Do differences in Ba concentration in seawater and

temperature affect the Ba signal in larval hard parts?

•YES! Ba incorporation increases with increasing Ba SW concentration

•Effect is greater at colder seawater temperatures

•Are Kelletia kelletii larval hard parts produced north of Point

Conception chemically distinguishable from those produced in the

Santa Barbara Channel?

•Do differences in trace metal concentration in seawater and temperature affect the elemental signal in larval hard parts?

•Are Kelletia kelletii larval hard parts produced north of Point Conception chemically distinguishable from those produced in the Santa Barbara Channel?

•Isla Vista (n=21)

Ellwood (n=27)Tajiguas (n=4)

Cojo(n=25)

•Diablo (n=22)

•Monterey (n=37)

•Yellowbanks, SCI (n=7)

Egg mass collection sites

...

Monterey (n=37)

Diablo (n=22)

Tajiguas (n=4)Ellwood (n=27)

Isla Vista (n=21)

Yellowbanks, SCI (n=7)

Elements analyzed: Mg, Li, Sr, Pb, Mn, Cr, Ce, Cd, U, Zn, Ba

Cojo(n=25)

QuickTime™ and aGraphics decompressorare needed to see this picture.

Ba/Ca mol/mol Mg/Ca mmol/mol

Ce/

Ca m

ol/m

ol

Southern samples

Northern samples

Trace elemental composition of K. kelletii protoconchs from two regions

•Using all 11 elements-Canonical Discriminant Analysis shows significant site discrimination (p<.0001)•Serial deletion validation predicts 89% correct, 93% in northern region

•Do differences in trace metal concentration in seawater and

temperature affect the elemental signal in larval hard parts?

•Are Kelletia kelletii larval hard parts produced north of Point

Conception chemically distinguishable from those produced in the

Santa Barbara Channel?

• Yes!

Invertebrate larvae can be ‘naturally’ tagged at their origin

•Finer resolution?

What next?

•Temporal stability?

•Other species, other systems

~ 50 mm

Concholepas concholepas

0

20

40

60

80

100

Antofagasta Las Cruces0

1

2

3

4

5Ba/CaZn/Ca

Ba/

Ca m

ol/m

ol

Zn/

Ca

mm

ol/m

ol

Me/Ca in Concholepas concholepas larval statoliths from two Chilean sites

**Data above generated in collaboration with Juan Carlos Castilla and Patricio Manriquez of Pontificia Universidad Católica de Chile

Acknowledgements

Most especially: Steve Gaines, Steve Swearer, David Lea, Georges Paradis

Financial support: Partnership for Interdisciplinary Studies of Coastal OceansLerner Grey Foundation, Sigma Xi

A league of dive buddies and lab helpers: Steve Lonhart, Chris Faist, Brian Cheng, Alison Haupt, Sarah Kleinshmidt, Jessica Van Leuven, Marina Salonga,

Andrea Hsu, Bryce Wolcott,Alex Pappas, Elsie Tanadjaja, Clara Svedlund, Tiffany Jenkins,Catrina Mangiardi, Alex Wyndham, Ben and Stephanie Best,

Eric Hessel, Mike Hickford, Mauricio Gomez, Mike Behrens

Understanding friends: Rafe Sagarin, P McConnell, Ben Heying, Zorba the cat

Godlike others: Chris Gotshalk, Jenn Caselle, Dotti Pak, Cynthia CudabackShane Anderson, Terry Marciando, Bob Warner

Is Ba concentration in protoconch and larval statolith influenced by seawater temperature and Ba concentration?

1x 2x 4x 6x 1x 2x 4x 6x

Cold (11-12° C) Warm (16.5-17.5° C)

•Egg masses collected, inspected, and randomly assigned to treatment•Three replicates per treatment•Cultures changed every other day•Maintained through maturity•Frozen storage

Egg capsule (~800 larvae each)

50 shells(1 sample)

10 statoliths(10 samples)

Solution ICP-MS

Laser ICP-MS

(peroxide dissolution of organics)

1.4

1.6

1.8

2

2.2

2.4

2.6

2.8

3

3.2

Yellow

banks,

SCI

Isla

Vist

a

Ellwoo

d

Tajig

uas

Cojo

Diablo

Can

yon

Mon

terey

Pro

toco

nch

Ba/

Ca

mol

/mol

Yes, but not entirely…..

10

12

14

16

18

051015

Monterey

Diablo

Cojo

Ellwood

Ylbnks, SCI

Days before collection

° C

Subtidal seawater temperature (14 m) during larval ‘hard part’ formation

Sea surface temperature (SST) – July 2001 (monthly composite)

*