Table 7.
Mitochondrial DNA introgression between flat periwinkles in each location
| Location | Ecotype | N | N Littorina fabalis | N Littorina obtusata | Clade I | Clade II | Introgression into L. fabalis (%) | Introgression into L. obtusata (%) |
|---|---|---|---|---|---|---|---|---|
| Burela | ME/FIa | 15 | 14 | 1 | 15 | 0 | 0/14 (0) | 1/1 (100) |
| Morás | — | 9 | 0 | 9 | 6 | 3 | — | 6/9 (66.67) |
| Abelleira | FI | 17 | 17 | 0 | 15 | 2 | 2/17 (11.76) | — |
| Muros North | FI | 35 | 30 | 5 | 30 | 5 | 0/30 (0) | 0/5 (0) |
| Muros Southb | FI | 15 | 15 | 0 | 15 | 0 | 0/15 (0) | — |
| Lanzada North | ZS | 39 | 19 | 20 | 9 | 30 | 10/19 (52.63) | 0/20 (0) |
| Lanzada Southb | ZS | 22 | 22 | 0 | 15 | 7 | 7/22 (31.82) | — |
| Seixiños | ZS | 49 | 25 | 24 | 13 | 36 | 12/25 (48.00) | 0/24 (0) |
| Aldán Northb | — | 19 | 0 | 19 | 0 | 19 | — | 0/19 (0) |
| Aldán South | FI | 18 | 12 | 6 | 1 | 17 | 11/12 (91.67) | 0/6 (0) |
| Borna | FI | 42 | 27 | 15 | 23 | 19 | 9/27 (33.33) | 5/15 (33.33) |
| Tirán | FI | 40 | 39 | 1 | 35 | 5 | 4/39 (10.26) | 0/1 (0) |
| Cangas | FI | 41 | 22 | 19 | 27 | 14 | 4/22 (18.18) | 9/19 (47.37) |
| Redondelab | — | 23 | 0 | 23 | 5 | 18 | — | 5/23 (21.74) |
| La Guia | FI | 36 | 13 | 23 | 20 | 16 | 2/13 (15.38) | 9/23 (39.13) |
| Alcabre | FI | 35 | 14 | 21 | 16 | 19 | 1/14 (7.14) | 3/21 (14.29) |
| Canidob | FI | 21 | 21 | 0 | 21 | 0 | 0/21 (0) | — |
| As Mariñasb | ME | 19 | 19 | 0 | 12 | 7 | 7/19 (36.84) | — |
| Mougásb | ME | 18 | 18 | 0 | 9 | 9 | 9/18 (50.00) | — |
| Viana do Castelob | — | 20 | 0 | 20 | 0 | 20 | — | 0/20 (0) |
| Rio de Moinhosb | — | 30 | 0 | 30 | 0 | 30 | — | 0/30 (0) |
| Póvoa de Varzimb | ME | 21 | 21 | 0 | 21 | 0 | 0/21 (0) | — |
| Mindelo | ME | 66 | 34 | 32 | 34 | 32 | 0/34 (0) | 0/32 (0) |
| Agudelab | ME | 19 | 19 | 0 | 19 | 0 | 0/19 (0) | — |
| Cabo do Mundo | ME/FIa | 54 | 19 | 35 | 23 | 31 | 7/19 (36.84) | 11/35 (31.43) |
| Leça da Palmeirab | ME | 23 | 23 | 0 | 23 | 0 | 0/23 (0) | — |
| Madalenab | ME | 16 | 16 | 0 | 16 | 0 | 0/16 (0) | — |
| Total | 762 | 459 | 303 | 423 | 339 | 85/459 (18.51) | 49/303 (16.17) |
Abbreviations: N, number of samples sequenced for mtDNA; N L. fabalis, number of individuals classified as L. fabalis based on structure global analysis that were sequenced for mtDNA; N L. obtusata, number of individuals classified as L. obtusata based on structure global analysis that were sequenced for mtDNA; Clade I, number of individuals with mtDNA haplotype from clade I (typical of L. fabalis); Clade II, number of individuals with mtDNA haplotype from clade II (typical of L. obtusata); introgression into L. fabalis, number (and percentage) of haplotypes from clade II over the number of individuals classified as L. fabalis based on structure; and introgression into L. obtusata, number (and percentage) of haplotypes from clade I over the number of individuals classified as L. obtusata based on structure.
Individuals were found in Fucus spp. but the co‐occurrence of Mastocarpus spp. does not allow an accurate classification of the ecotype.
Allopatric sites based on field observations during sampling.