Table 3 PNIA—Mean (± sd) δ¹³C and δ¹⁵N values in H. guttulatus and S. acus sampled in spring and summer 2016 in Cíes Archipelago

H. guttulatus

Pooled

− 16.6 ± 0.2

− 16.3

− 16.8

4

11.0 ± 0.4

11.6

10.6

4

Spring

− 16.5 ± 0.2

− 16.3

− 16.6

2

11.2 ± 0.5

11.6

10.9

2

Summer

− 16.7 ± 0.2

− 16.5

− 16.8

2

10.8 ± 0.4

11.1

10.6

2

♂ Spring

− 16.3 ± 0.0

− 16.3

− 16.3

1

11.6 ± 0.0

11.6

11.6

1

♂ Summer

− 16.8 ± 0.0

− 16.8

− 16.8

1

11.1 ± 0.0

11.1

11.1

1

♀ Spring

− 16.6 ± 0.0

− 16.6

− 16.6

1

10.9 ± 0.0

10.9

10.9

1

♀ Summer

− 16.5 ± 0.0

− 16.5

− 16.5

1

10.6 ± 0.0

10.6

10.6

1

S. acus

Pooled

− 16.1 ± 0.4

− 14.7

− 16.6

21

10.8 ± 0.7

11.9

9.1

21

Spring

− 16.2 ± 0.3

− 15.8

− 16.6

16

11.0 ± 0.7

11.9

9.8

16

Summer

− 15.6 ± 0.5

− 14.7

− 16.1

5

10.3 ± 0.8

11.2

9.1

5

♂ Spring

− 16.2 ± 0.3

− 15.9

− 16.6

8

11.1 ± 0.6

11.9

10.0

8

♂ Summer

− 16.0 ± 0.1

− 16.0

− 16.1

2

10.1 ± 1.5

11.2

9.1

2

♀ Spring

− 16.2 ± 0.3

− 15.8

− 16.6

8

10.9 ± 0.5

11.7

9.8

8

♀ Summer

− 15.3 ± 0.5

− 14.7

− 15.7

3

10.3 ± 0.2

10.5

10.2

3