Vipera aspis meeting- Leysin, Switzerland - 2015
Fernando Martínez-Freiría
CIBIO/InBio, Centro de Investigação em Biodiversidade e Recursos Genéticos. Universidade do Porto. Portugal.
European vipers à genus Vipera
ammodytes
3 clades aspis
pelias
Miocene - Pliocene
Allopatric speciation processes
Reproductive isolation pre-mating barriers post-mating barriers
Parapatric distribution
Contact zones: - sympatry - interspecific competition - gene flow Iberian vipers
3 species
Vipera seoanei Lataste, 1879 Euro-Siberian
Vipera aspis (Linnaeus, 1758)
Mediterranean
Vipera latastei Boscá, 1878 Iberian vipers
Different morphological traits Iberian vipers Similar ecological traits
Feeding Ambush predators
Diet
Activity Hibernation - activity periods
Moulting periods
Reproduction Mating spring autumn
Viviparous Iberian vipers
Parapatric distribution
Different habitat requirements
Different thermoregulatory capacities and abilities contact zones among Iberian vipers
V. seoanei – V. latastei V. seoanei – V. aspis
V. aspis – V. latastei Contact among the 3 species
High course of the Ebro river Local scale latastei-seoanei à allopatry aspis-seoanei à allopatry aspis-latastei à ¿?
Morphological convergence 1. Distribution
2. Potential distribution V. aspis, V. latastei and V. seoanei a) environmental factors b) sympatry areas
3. Morphology a) geographic variation V. aspis and V. latastei b) environmental factors
4. Ecological traits V. aspis, V. latastei and hybrids VA x VL
5. Gene flow and environmental correlates a) genetic structure V. aspis, b) hybridization V. latastei and c) ecological divergence V. seoanei d) environmental transition – species traits
Aim # 1 Distribution
Intermediate forms and syntopy among vipers (V. aspis and V. latastei) in Northern Iberian Peninsula F. Martínez-Freiría, J.C. Brito & M. Lizana (2006). The Herpetological Bulletin 97.
V. aspis V. latastei
intermediate vipers Aim # 2 Potential distribution
GIS-based niche models identify environmental correlates sustaining a contact zone between three species of European vipers F. Martínez-Freiría, N. Sillero, M. Lizana & J.C. Brito (2008). Diversity & Distributions 14. Material and methods
Morphological criterium
Gps locationsà UTM 1x1 km squares:
- 48 V. aspis - 54 V. latastei - 19 V. seoanei
Intermediate forms were not used
7 EGVs
ENMs
Maxent 3.0.4 beta
ArcMap 9.2 (GIS) – “ensemble forecasting” Results
V. aspis V. latastei V. seoanei
Altitude 5.76 (3.0 - 8.5) 2.56 (1.1 - 4.4) 7.67 (4.0 - 14.5)
Precipitation 12.52 (10.0 - 19.7) 54.80 (50.9 - 57.5) 20.28 (13.4 - 27.3)
Precipitation (mm/year) Evapotransp. 44.71 (40.5 - 48.9) 16.53 (14.8 - 18.8) 17.95 (12.5 - 24.7) Subst. cover 14.55 (10.9 - 17.6) 0.89 (0.3 - 1.6) 2.15 (0.4 - 5.4) V. aspis —— V. latastei – · – Slope 9.58 (4.3 - 16.1) 9.65 (5.7 - 16.0) 16.62 (11.2 - 20.0) V. seoanei ------Max. Temp. 4.85 (2.7 - 8.9) 7.97 (1.4 - 14.2) 6.25 (3.4 - 10.0)
Slope (º) Min. Temp. 7.99 (5.0 - 10.5) 7.60 (5.7 - 9.9) 29.10 (21.8 - 41.7)
AUC training 0.915 (0.903 - 0.927) 0.951 (0.943 - 0.960) 0.961 (0.946 - 0.970)
AUC test 0.782 (0.707 - 0.865) 0.873 (0.809 - 0.935) 0.780 (0.708 - 0.923)
EGVs importance
Response curves Results V. latastei
areas of potential distribution
V. aspis V. seoanei
areas of potential VA -VL VL -VS sympatry
V. aspis - V. latastei 76 km2
V. aspis - V. seoanei 23 km2
V. latastei - V. seoanei 2 km2 VA -VS
Aim # 3 Morphology
Geographical patterns of morphological variation and environmental correlates in contact zones: a multi-scale approach using two Mediterranean vipers (Serpentes) F. Martínez-Freiría, X. Santos, J.M. Pleguezuelos, M. Lizana & J.C. Brito (2009). Journal of Zoological Systematics and Evolutionary Research 47. Study areas regional: NE Iberia 64500 km2 2 scales 2 local: High Ebro 300 km
Material and methods 728 vipers à 276 museum collections and 452 field work in the High Ebro
9 meristic traits apical scales à APICA supralabials à SUPRAR infralabials à INFRAR perioculars à PERIR loreals à LORER intercantals+intersupraoculars à INTER ventralsà VENT subcaudalsà SUBCA dorsal marksà DMARK
Morphological criterium and genetic analyses intermediate vipers à mostly hybrids
Intermediate V. aspis V. latastei vipers analyses NE Iberia Models specimens 369 261 98 630 ArcGis 9.2 UTM 10x10 99 41 5 135 High Ebro Idrisi Kilimanjaro 14.01 specimens 183 179 92 362 Results
NE Iberia
Clines, N-S oriented
Results
High Ebro
Clines, N-S oriented
3 areas of morphological variability
Results Environmental correlates
SCALE TRAIT ALT PREC PRECS TEMP TEMPS MINT MAXT
APICA -0.176 -0.722 0.486 0.572 0.555 0.151 0.516 DMARK 0.358 0.734 -0.698 -0.441 -0.528 -0.386 -0.629 Regional: INTER -0.136 -0.655 0.493 0.535 0.718 0.144 0.484 NE Iberia VENTF 0.363 0.708 -0.595 -0.336 -0.225 -0.437 -0.602
VENTM 0.501 0.757* -0.766* -0.368 -0.459 -0.544 -0.716 PC1 0.329 0.789* -0.667 -0.509 -0.568 -0.354 -0.647
APICA 0.195 -0.734 -0.172 0.709 0.762* -0.307 0.487 DMARK -0.219 0.762* 0.187 -0.753* -0.803* 0.337 -0.499 Local: INTER 0.097 -0.676 -0.096 0.573 0.631 -0.196 0.483 High Ebro VENTF -0.145 0.605 0.125 -0.552 -0.649 0.227 -0.400
-0.111 0.795* 0.091 -0.689 -0.700 0.239 -0.576 VENTM PC1 -0.173 0.775* 0.150 -0.720 -0.770* 0.291 -0.529 Aim # 4 Ecological traits
Spatial and temporal segregation allows coexistence in a hybrid zone among two Mediterranean vipers (Vipera aspis and V. latastei) F. Martínez-Freiría, M. Lizana, J.P. do Amaral & J.C. Brito (2010). Amphibia-Reptilia 31. Material and methods Diet V. aspis: 37 (181) V. latastei: 48 (172) Hybrids: 28 (85) 4 categories: invertebrates, reptiles, Soricomorpha and Rodentia. χ2 tests Indexes: Levin, Pianka
Micro-habitat – Activity - radio-tracking of 10 males (4 V. aspis, 3 V. latastei and 3 hybrids)
Micro-habitat: 297 presences/absences area of 9m2 Logistic regression
Activity, 3 indicators: 1) % of active males 2) ratio moved length /days with movement (AMR) 3) home range size, using KERNEL
ArcGis 9.2 χ2 tests
Material and methods Reproduction - captured and road-kills - 13 pregnant females (4 V. aspis, 7 V. latastei and 2 hybrids)
Potential fecundity, effective fecundity and reproductive effort.
New-borns: Biometry (SVL and Weight) ANOVA tests Mortality (NSB) Moulting traits (NMAP and NWFS)
Frequency of reproduction Test de χ2
Demography Relative abundance: standardized transects (18.85km) Mortality on roads (3.62 km around transects) χ2 tests KIA’s
Ad-hoc observations Results – diet
V. aspis V. latastei Hybrids
similar niche breadth Mollusca 0 2.17 3.57 Levin’s index = 0.22 – 0.44 Coleoptera 0 4.35 0 Invertebrates 0 4.17 3.57 Chalcides 5.41 6.52 14.29 high overlap of trophic niche Podarcis 0 2.17 0 Pianka’s index > 0.93 Coronella 0 2.17 0 Vipera 2.7 2.17 0 Reptiles 8.11 14.58 10.71 temporal differences: Sorex 8.11 13.04 10.71 Crocidura 8.11 15.22 14.29 feeding frequency (VA < VL < HY) Soricomorpha 16.22 20.83 17.86 Microtus 43.24 32.61 42.86 feeding period (HY < VL < VA) Apodemus 32.43 17.39 25 Rodentia 75.68 60.42 67.86 Mammals 91.89 81.25 85.71
competition for preys similar preys
Results – micro-habitat selection
V. aspis V. latastei Hybrids Spring competition – segregation for space Bushes (β) 0.06** 0.17* - Rocks (β) 0.07*** 0.27* 0.11* Slope (β) - -2.87 - V. aspis V. latastei Hybrids Trees (β) - 0.14 0.20* Autumn Constant -2.28 -9.87 -5.41 Bushes (β) 0.22* 0.12* 0.18 AUC 0.89 0.99 0.99 Rocks (β) - - 0.13 S.D. 0.04 0.01 0.01 Slope (β) 3.46* 4.81** - CCR Trees (β) 0.08** - - % train. pres. 82.86 95 94.74 Constant -15.65 -14.32 -7.9 % train. abs. 88.57 95 89.47 AUC 0.97 0.97 0.99 % test pres. 100 71.43 100 S.D. 0.02 0.02 0.01 % test abs. 66.67 100 84.62 CCR Total presences 47 27 51 % train. pres. 92 100 92.9 % train. abs. 88 90.9 92.9 Summer % test pres. 62.5 91.67 100 Bushes (β) 0.12* 0.1 0.07* % test abs. 87.5 75 100 Musgo (β) - 0.17 - Total presences 33 45 19 Rocks (β) 0.08* - - Soil (β) - - 0.24* Trees (β) 0.13* - 0.05* Similar elements during most part of the Constant -7.46 -4.93 -4.45 annual cycle: bushes and rocks AUC 0.94 0.98 0.94 S.D. 0.03 0.02 0.04 CCR Different elements in some seasons: summer % train. pres. 86.36 91.7 89.47 % train. abs. 81.82 91.7 84.21 % test pres. 57.14 59 100 Field observations à different locals for % test abs. 71.43 100 66.67 Total presences 29 16 25 hibernation and gestation.
Results – activity patterns segregation in temporal axis
Significant differences
Home range size
Movement rate (AMR) Results – reproductive traits
V. aspis V. latastei Hybrids V. aspis V. latastei Hybrids Detected mating period APRIL APRIL MARCH Fecundity
Minimum size of sexual Avg nº follicles 7.39 (133 foll) 8.80 (88 foll) 8.80 (88 foll) maturation (mm) S.D. 2.56 1.52 1.44 Females Avg nº embryos 5.75 (46 emb) 7.7 (77 emb) 5.6 (28 emb) Embryos or developed S.D. 2.55 2.45 1.67 follicles 341 300 414 Avg reprod effort 0.59 0.74 0.79 S.D. 0.24 0.13 0.28 Mating or with reproductive behaviour 390 470 470 Fecundity: VL > VA >HY
Males Reproductive effort: HY > VL > VA Mating or guarding females 395 400 440 V. aspis V. latastei Hybrids Date of parturition AUG-SEP AUG-SEP AUG Newborns traits Similar traits Avg SVL (mm) 165.86*** 152.42*** 157.58*** Triennial reproductive cycle S.D. 11.09 7.85 19.36 Avg weight (g) 5.28 4.8 4.75 V. aspis V. latastei Hybrids S.D. 0.88 0.87 1.28 Frequency of reproduction (%) Avg NSB 0.75* 0.94* 0.83* 2004* 63.2 65 80 S.D. 0.44 0.23 0.39 2005* 11.1 20 14.3 Avg NMAP 0.61* 0.81* 0.50* 2006* 18.2 35.3 26.7 S.D. 0.5 0.39 0.52 Average 30.8 40.1 40.3 Avg NWFS 0.14** 0.00** 0.00** S.D. 28.23 22.88 34.92 S.D. 0.36 0 0
SVL: VA > HY > VL NSB: VL> HY > VA Hybrids had lower fitness NMAP: VL > VA> HY NWFS: VA > VL= HY
Results – demographic traits
Significant differences
- Hybrids were more abundant
- Males of V. aspis were less abundant
- Hybrids had low mortality
- Females of V. latastei had high mortality
Parental species had disadvantages Hybrids had a good performance Aim # 5 Gene flow and environmental correlates
Hybridization at an ecotone: ecological and genetic barriers between three Iberian vipers P. Tarroso, R. Pereira, F. Martínez-Freiría, R. Godinho & J.C. Brito (2014) Mol Ecol 23 Material and methods
DNA of 218 vipers: 210 nuDNA, 8 microsatellites 211 mitDNA, 2 RFLPs
Structure 2.3.3 cluster membership probabilities (CMPs)
NewHybrids à hybrids and generation?
HybridLab à simulations and thresholds
ENMs: Artificial Neural Networks àSimapse 9 EGVs CMPs of parental taxa Suitability maps were contrasted against nuDNA, mtDNA and SPCA of the EGVs morphological traits
Results – population structure
Cluster membership probabilities (CMPs)
3 populations Pop 1 à V. latastei 68 91 % Pop 2 à V. aspis 87 87 % Pop 3 à V. seoanei 13 100 %
42 ind with admixed ancestry; 41 VAxVL, 1 VLxVS; none F1
mtDNA à mitochondrial introgression
Pop 1 (VL) à 4 ind VA mtDNA
Pop 2 (VA) à 8 ind VL mtDNA
Interpolation of genetic affinity (IDW)
Results – environmental analyses SPCA of the EGVs
strong ecological gradient à ECOTONE
Suitable areas Results – environmental analyses EGVs importance Response curves V. latastei
V. aspis
V. seoanei hybrids mostly occur in sub-optimal areas to parentals
species are ecologically divergent Results – population structure + environmental analyses nuDNA mtDNA morphology
high spatial concordance among traits and ENMs most hybrids occur in unsuitable areas for parentals ADAPTATION Morphological ALLOPATRY convergence HIBRIDIZATION
Vipera seoanei Vipera aspis Vipera aspis
SIMPATRY Intermediate vipers Vipera latastei coexistance Vipera latastei
HYBRIDS Eurosiberian Mediterranean
DIFFERENT HABITAT à pre-mating BARRIER PARENTAL à disadvantages
Vipera aspis BALANCE population dynamics
SIMPATRY limitation to spread
HYBRIDS HYBRIDS à dis- // advantages
ECOTONE endogenous / exogenous suboptimal for selection?? parental taxa
Vipera latastei Ecological segregation Interspecific as barrier to gene flow competition (habitat, micro-habitat and diet) coexistence Niche segregation (spatial and temporal) § Co-authors of the works: J.C. Brito, P. Tarroso, X. Santos, J.M. Pleguezuelos, N. Sillero, J.P. de Amaral, M. Lizana, R. Pereira, R. Godinho.
§ Family and friends.
§ Asociación Socio-cultural Hoces del Alto Ebro y Rudrón (Burgos, Spain).
§ Pre-doctoral grant AP2003-2633 from Ministerio de Educación, Cultura y Deporte (Spain). § Post-doctoral grant SFRH/BPD/109119/2015 from FCT (Portugal)
§ Project POCTI⁄BIA-BDE⁄55596⁄2004 from Fundacâo para a Ciência e Tecnologia (FCT, Portugal). § Project 18.JCY4 463A.C.03 from Junta de Castilla y León (Spain).