Evidence for widespread hybridization between two closely related lionfishes

Evidence for wide-spread hybridization between

two closely related lionfish

Christie WilcoxHawaii Institute of Marine Biology

Evolution 2011

Hybridization

Indo-Pacific: Intermittent Barrier

Indo-Pacific: Intermittent Barrier

Lionfishes: Subfamily Pteroinae

• Unique lineage of Scorpaenidae

• Phenotypic

• Behavioral

• 18 species in 5 genera

• Native to Indo-Pacific

• Commercially & ecologically important

Pterois miles & Pterois volitans

Photo by Opera User AntoniettaPhoto by jostimages.com

• Very similar morphologically

• Considered synonyms until 1986

(Bennett, 1828) (Linnaeus, 1758)

Meristic Differences

Indian: Pterois miles Pacific: Pterois volitans

Dorsal Fin Rays 10 11

Anal Fin Rays 6 7

Pectoral Fin Size Shorter Longer

Spot Size Smaller Larger

Geographic Range

Africa – Indonesia Indonesia – W Pacific

Schultz, 1986

Sister Species

Kochzius, 2003

Freshwater 2009

Overlapping Native Ranges

Pterois miles Pterois volitans

Dorsal Fin Rays 10 11

Anal Fin Rays 6 7

Pectoral Fin Size Shorter Longer

Spot Size Smaller Larger

Geographic Range

Africa – Indonesia Indonesia – W Pacific

Schultz, 1986

Phylogenetic Investigations

• Kochzius et al. 2003– Cyt b & 16 S: monophyletic clades

• Freshwater et al. 2009– Cyt b: monophyletic clades

ONLY mtDNA

Objective

• Investigate the relationship between P. volitans and P. miles using mitochondrial and nuclear loci

• Compare native & invasive range

Indonesia (n=18)

Philippines (n=22)

Taiwan (n=4)

Africa (n=6)

Methods

• Native: 34 P. miles, 38 P. volitans, 10 mixed meristics• PCR amplification

– 1 mtDNA, 3 nDNA

• Genetic Divergence (Arlequin)• Evolutionary Relationships (Network)

Mitochondrial DNA

mtDNALength

(bp)

Sequence Divergence

Pac-Ind Other Pteroinae

COI 602 3.90% 12.0% - 15.5%

Indian (Pterois miles) lineage

Dendrochirus brachypterusBrachypterois serrulata

Parapterois heterura

Dendrochirus zebraPterois sphex

Pterois radiataPterois antemnata Dendrochirus

biocellatus

99

99

93

49

63

25

8

100

around 2.5 mya separation

PacificPacific (Pterois volitans) (Pterois volitans) lineagelineage

Pterois miles

Mitochondrial DNA

Pterois volitans

20 mutations

Cytochrome Oxidase I

Mixed Meristics

Phenotype:

Indian (Pterois miles) lineage PacificPacific (Pterois volitans) (Pterois volitans) lineagelineage

Mitochondrial DNA

Does this same pattern occur in the nucleus?

mtDNALength

(bp)

Sequence Divergence

Pac-Ind Other Pteroinae

COI 602 3.90% 12.0% - 15.5%

Nuclear DNA4174E20 (2.00% divergence)

8680E3 (0.37% divergence)

S7 RP1 (2.47% divergence)Indian (miles) lineagePacificPacific (volitans) (volitans) lineagelineageIndian (miles) lineagePacificPacific (volitans) (volitans) lineagelineage

Indian (miles) lineagePacificPacific (volitans) (volitans) lineagelineage

Pterois miles

Pterois volitans

Mixed Meristics

Phenotype:

mtDNA nDNA

ID # Phenotype COI S7 8680E3 4147E20

Aq12 P. volitans P. volitans P. volitans P. volitans P. volitans

Aq13 P. volitans P. volitans P. miles P. miles Hybrid

Aq14 P. volitans P. volitans P. miles P. miles P. miles

Aq15 P. volitans P. volitans P. volitans P. volitans P. volitans

Aq16 P. volitans P. volitans P. miles Hybrid Hybrid

Aq17 P. volitans P. volitans P. miles Hybrid Hybrid

Aq19 P. volitans P. volitans P. miles P. volitans Hybrid

Aq20 P. volitans P. volitans P. miles P. miles P. miles

Aq22 P. volitans P. volitans P. miles P. miles P. miles

Aq24 P. miles P. miles P. miles Hybrid P. miles

Aq25 P. miles P. miles P. miles Hybrid P. miles

Aq 26 P. miles P. miles P. miles P. miles P. miles

Dual (Hybrid) LineageDual (Hybrid) Lineage

Indian (P miles) lineage

PacificPacific (P. volitans) (P. volitans) lineagelineage

mtDNA nDNA

ID # Phenotype COI S7 8680E3 4147E20

Aq12 P. volitans P. volitans P. volitans P. volitans P. volitans

Aq13 P. volitans P. volitans P. miles P. miles Hybrid

Aq14 P. volitans P. volitans P. miles P. miles P. miles

Aq15 P. volitans P. volitans P. volitans P. volitans P. volitans

Aq16 P. volitans P. volitans P. miles Hybrid Hybrid

Aq17 P. volitans P. volitans P. miles Hybrid Hybrid

Aq19 P. volitans P. volitans P. miles P. volitans Hybrid

Aq20 P. volitans P. volitans P. miles P. miles P. miles

Aq22 P. volitans P. volitans P. miles P. miles P. miles

Aq24 P. miles P. miles P. miles Hybrid P. volitans

Aq25 P. miles P. miles P. miles Hybrid P. volitans

Aq 26 P. miles P. miles P. miles P. miles P. miles

Dual (Hybrid) LineageDual (Hybrid) Lineage

Indian (P miles) lineage

PacificPacific (P. volitans) (P. volitans) lineagelineage

Hybri

d P

. volita

ns

Genotype:

P.

mile

s

Genotype Spatial Distribution

P. miles P.

volitansHybrid

N = 22

N = 18

N = 3

N = 7

Indonesia

Philippines

Taiwan

N = 4

N = 6

Africa

Genotype:

Morphological Correlation?

Dorsal Fin Rays Anal Fin Rays

Fisher Exact Test, p <0.01 Fisher Exact Test, p <0.01

N = 25

N = 27

N = 17

N = 26

N = 24

N = 18

Genotype Genotype

0% 50% 100%

P volitans

Hybrid

P miles9

10

11

12

0% 50% 100%

P volitans

Hybrid

P miles6

7

Native Range Summary

• Shared haplotypes between species

• Evidence of recombination

• Geographic pattern of genotypes

• Morphological correlation

HYBRIDIZATION

Invasive Species

Photo by Ken Jones.

Invasive Species

Photo by Ken Jones.

One of the top 15 threats to global biodiversity

Sutherland et al., A horizon scan of global conservation issues for 2010, Trends Ecol. Evol. 25 (2010), pp. 1–7.

?mtDNA Data

Says…> 90% P. volitans

< 10% P. milesMethods: 2 P. miles, 38 P. volitans, 17 mixed

Invasive… hybrids?

N = 57

IDed a

s P. vo

lita

ns

Genotype:

P milesHybrid

Hybrid vigor in invasive lionfish?

Future Directions

• Investigate hybridization – Compare native and invasive hybrids

• Thorough geographic sampling

• Population genetics

Thanks to…• Brian Bowen• Laurie Sorensen (UCLA)• D. Wilson Freshwater (UNC Chapel Hill)• Shannon Bennett, Becky Cann• ToBo Labmates

Questions?

Ocean Invasion #9: Lionfish 1, Springbok 0 Daniel DeWitt Brown, Ph.D. © 2010