The study compared the structure of mobile epifaunal assemblages associated with Mediterranean
Este estudio compara la estructura de la comunidad de macroinvertebrados móviles asociada a bosques mediterráneos de
Introduced seaweeds are responsible for severe worldwide biological invasions, with important effects on native macroalgal and animal assemblages (
In the Mediterranean Sea, species of genus
The present study aimed to compare the structure of mobile epifaunal assemblages associated with
The study was carried out around the Island of Pianosa, in the Tuscan Archipelago National Park (northwestern Mediterranean Sea) at 5 m depth (
Four areas of about 100 m2 were selected in
The number of taxa per sample and the abundance of organisms were detected by analyses of variance (ANOVA), with the same factors and levels used for multivariate analyses; Cochran’s C-test was utilised before each analysis to check for homogeneity of variance and data were transformed when necessary (
A total of 150 taxa were identified: 42 Polychaeta, 78 Arthropoda, 26 Mollusca and 4 Echinodermata (
May 2010 | Aug. 2010 | Nov. 2010 | May 2011 | |||||
---|---|---|---|---|---|---|---|---|
I | N-I | I | N-I | I | N-I | I | N-I | |
MOLLUSCA | ||||||||
Polyplacophora | ||||||||
7.5 | 0.0 | 7.5 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | |
Gastropoda | ||||||||
0.0 | 7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 17.5 | 5.0 | |
30.0 | 25.0 | 25.0 | 17.5 | 5.0 | 0.0 | 30.0 | 0.0 | |
0.0 | 5.0 | 7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 5.0 | 0.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 7.5 | 5.0 | |
430.0 | 82.5 | 45.0 | 205.0 | 0.0 | 50.0 | 362.5 | 55.0 | |
37.5 | 28.0 | 107.5 | 242.5 | 55.0 | 55.0 | 30.0 | 32.5 | |
12.5 | 12.5 | 5.0 | 0.0 | 12.5 | 0.0 | 7.5 | 17.5 | |
7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
5.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
5.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 0.0 | 5.0 | 0.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 7.5 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 12.5 | 0.0 | |
0.0 | 12.5 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 0.0 | |
0.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 0.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 17.5 | 0.0 | 0.0 | |
7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | |
12.5 | 17.5 | 5.0 | 50.0 | 20.0 | 32.5 | 0.0 | 0.0 | |
37.5 | 62.5 | 37.5 | 212.5 | 7.5 | 50.0 | 5.0 | 45.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 17.5 | 0.0 | |
5.0 | 0.0 | 5.0 | 0.0 | 7.5 | 0.0 | 0.0 | 0.0 | |
0.0 | 5.0 | 0.0 | 5.0 | 0.0 | 7.5 | 0.0 | 0.0 | |
0.0 | 0.0 | 5.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | |
ANNELIDA | ||||||||
Polychaeta | ||||||||
0.0 | 0.0 | 0.0 | 5.0 | 5.0 | 17.5 | 0.0 | 0.0 | |
7.5 | 5.0 | 0.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 5.0 | 0.0 | |
7.5 | 0.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
5.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
5.0 | 0.0 | 5.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | |
0.0 | 0.0 | 5.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
7.5 | 5.0 | 0.0 | 0.0 | 0.0 | 5.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 7.5 | 0.0 | 0.0 | 0.0 | 5.0 | 0.0 | |
0.0 | 7.5 | 5.0 | 7.5 | 0.0 | 0.0 | 7.5 | 0.0 | |
20.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
5.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 7.5 | |
0.0 | 0.0 | 7.5 | 0.0 | 17.5 | 0.0 | 0.0 | 0.0 | |
17.5 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | |
5.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | |
5.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 7.5 | |
0.0 | 0.0 | 7.5 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
12.5 | 5.0 | 5.0 | 32.5 | 0.0 | 5.0 | 5.0 | 0.0 | |
12.5 | 0.0 | 0.0 | 5.0 | 5.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 0.0 | 5.0 | 0.0 | 0.0 | 5.0 | 0.0 | |
7.5 | 0.0 | 0.0 | 0.0 | 32.5 | 5.0 | 0.0 | 7.5 | |
30.0 | 5.0 | 95.0 | 57.5 | 142.5 | 17.5 | 7.5 | 5.0 | |
220.0 | 37.5 | 12.5 | 5.0 | 7.5 | 0.0 | 57.5 | 45.0 | |
0.0 | 0.0 | 5.0 | 12.5 | 0.0 | 5.0 | 0.0 | 0.0 | |
0.0 | 30.0 | 0.0 | 0.0 | 0.0 | 5.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 5.0 | |
20.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 5.0 | |
0.0 | 0.0 | 7.5 | 5.0 | 0.0 | 0.0 | 7.5 | 0.0 | |
0.0 | 0.0 | 17.5 | 17.5 | 0.0 | 0.0 | 5.0 | 0.0 | |
5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 7.5 | 0.0 | |
17.5 | 0.0 | 0.0 | 0.0 | 37.5 | 7.5 | 0.0 | 5.0 | |
7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
17.5 | 0.0 | 7.5 | 7.5 | 20.0 | 0.0 | 0.0 | 0.0 | |
7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 0.0 | |
0.0 | 0.0 | 7.5 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
5.0 | 0.0 | 7.5 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
ARTHROPODA | ||||||||
Crustacea | ||||||||
Decapoda | ||||||||
25.0 | 0.0 | 112.5 | 12.5 | 17.5 | 7.5 | 37.5 | 0.0 | |
0.0 | 0.0 | 32.5 | 7.5 | 5.0 | 0.0 | 17.5 | 0.0 | |
5.0 | 0.0 | 50.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | |
12.5 | 0.0 | 105.0 | 120.0 | 20.0 | 57.5 | 0.0 | 12.5 | |
17.5 | 50.0 | 142.5 | 132.5 | 30.0 | 67.5 | 45.0 | 20.0 | |
0.0 | 17.5 | 0.0 | 0.0 | 0.0 | 0.0 | 17.5 | 25.0 | |
0.0 | 0.0 | 12.5 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 50.0 | 7.5 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 12.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 12.5 | 32.5 | 17.5 | 37.5 | 0.0 | 0.0 | |
0.0 | 0.0 | 25.0 | 0.0 | 32.5 | 20.0 | 0.0 | 7.5 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 17.5 | 7.5 | |
7.5 | 30.0 | 20.0 | 5.0 | 17.5 | 5.0 | 0.0 | 7.5 | |
0.0 | 5.0 | 20.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 7.5 | 0.0 | 0.0 | 0.0 | |
0.0 | 5.0 | 0.0 | 0.0 | 12.5 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 5.0 | 12.5 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
Isopoda | ||||||||
0.0 | 0.0 | 5.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | |
5.0 | 0.0 | 30.0 | 12.5 | 0.0 | 0.0 | 5.0 | 30.0 | |
0.0 | 5.0 | 5.0 | 17.5 | 7.5 | 0.0 | 12.5 | 12.5 | |
0.0 | 5.0 | 17.5 | 25.0 | 0.0 | 0.0 | 0.0 | 5.0 | |
0.0 | 7.5 | 32.5 | 12.5 | 5.0 | 30.0 | 0.0 | 5.0 | |
0.0 | 12.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
12.5 | 17.5 | 7.5 | 12.5 | 57.5 | 17.5 | 32.5 | 7.5 | |
0.0 | 0.0 | 5.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | |
Amphipoda | ||||||||
0.0 | 0.0 | 0.0 | 17.5 | 0.0 | 0.0 | 0.0 | 0.0 | |
55.0 | 12.5 | 12.5 | 17.5 | 0.0 | 0.0 | 175.0 | 155.0 | |
107.5 | 75.0 | 37.5 | 12.5 | 80.0 | 7.5 | 117.5 | 45.0 | |
0.0 | 5.0 | 0.0 | 0.0 | 12.5 | 0.0 | 175.0 | 220.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 20.0 | 0.0 | 0.0 | |
117.5 | 95.0 | 25.0 | 37.5 | 57.5 | 0.0 | 7.5 | 0.0 | |
0.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 42.5 | 237.5 | |
0.0 | 55.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
7.5 | 0.0 | 17.5 | 5.0 | 5.0 | 5.0 | 312.5 | 57.5 | |
0.0 | 0.0 | 7.5 | 7.5 | 5.0 | 0.0 | 5.0 | 0.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 5.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 17.5 | 0.0 | |
0.0 | 17.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
117.5 | 5.0 | 30.0 | 25.0 | 37.5 | 0.0 | 257.5 | 45.0 | |
120.0 | 5.0 | 30.0 | 17.5 | 0.0 | 0.0 | 0.0 | 0.0 | |
67.5 | 5.0 | 37.5 | 0.0 | 0.0 | 0.0 | 82.5 | 12.5 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 50.0 | |
0.0 | 5.0 | 82.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 0.0 | |
0.0 | 0.0 | 5.0 | 0.0 | 7.5 | 0.0 | 0.0 | 0.0 | |
157.5 | 112.5 | 0.0 | 0.0 | 0.0 | 0.0 | 82.5 | 155.0 | |
0.0 | 0.0 | 7.5 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 25.0 | |
5.0 | 5.0 | 20.0 | 5.0 | 5.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 25.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
17.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 7.5 | 12.5 | |
130.0 | 75.0 | 17.5 | 0.0 | 5.0 | 5.0 | 150.0 | 150.0 | |
5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 37.5 | 7.5 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 162.5 | 30.0 | |
37.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 12.5 | 0.0 | |
0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 25.0 | 0.0 | |
12.5 | 5.0 | 62.5 | 62.5 | 7.5 | 0.0 | 0.0 | 0.0 | |
5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 20.0 | 30.0 | |
5.0 | 20.0 | 0.0 | 0.0 | 0.0 | 0.0 | 50.0 | 132.5 | |
0.0 | 0.0 | 12.5 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
Pycnogonida | ||||||||
7.5 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 5.0 | 0.0 | |
5.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
12.5 | 7.5 | 5.0 | 5.0 | 0.0 | 0.0 | 0.0 | 20.0 | |
7.5 | 7.5 | 5.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
ECHINODERMATA | ||||||||
Ophiuroidea | ||||||||
0.0 | 20.0 | 137.5 | 30.0 | 42.5 | 0.0 | 7.5 | 0.0 | |
7.5 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | 0.0 | |
5.0 | 0.0 | 12.5 | 7.5 | 0.0 | 0.0 | 7.5 | 7.5 | |
Echinoidea | ||||||||
0.0 | 5.0 | 0.0 | 0.0 | 5.0 | 0.0 | 0.0 | 0.0 |
ANOVA analyses detected a significant difference among dates for the abundance of organisms (F=80.7, p=0.003) and the mean number of taxa per sample (F=20.6, p=0.001), while differences between conditions were not significant (F=2.6, p=0.120 and F=44.6, p=0.071 respectively). Both variables were higher on spring dates than on the others (
PERMANOVA detected a significant interaction between Date and Condition (
Source | df | MS | Pseudo-F | P(perm) | perms |
---|---|---|---|---|---|
Date=D | 3 | 15552.0 | 80.40 | 0.001 | 999 |
Condition=C | 1 | 7643.7 | 14.21 | 0.125 | 999 |
Area(C)=A(C) | 2 | 2047.2 | 10.58 | 0.388 | 999 |
D×C | 3 | 4692.5 | 2.42 | 0.002 | 997 |
D×A(C) | 6 | 1934.3 | 10.58 | 0.340 | 999 |
Residual | 32 | 1827.9 | |||
Total | 47 | ||||
PAIRWISE TEST (C×D) | |||||
Condition | P(MC) | Date | P(MC) | ||
Non-invaded | Invaded | ||||
May 2010 | 0.119 | May 10, Aug 10 | 0.068 | 0.036 | |
August 2010 | 0.056 | May 10, Nov 10 | 0.008 | 0.036 | |
November 2010 | 0.007 | May 10, May 11 | 0.077 | 0.093 | |
May 2011 | 0.175 | Aug 10, Nov 10 | 0.004 | 0.059 | |
Aug 10, May 11 | 0.019 | 0.044 | |||
Nov 10, May 11 | 0.005 | 0.014 |
The SIMPER test showed that the main differences between assemblages in November 2010 were the greater abundance of amphipods (
Taxa | Abundance | Abundance | Contribution |
---|---|---|---|
November 2010 | Invaded | Non-Invaded | % |
79.3 | 8.3 | 5.39 | |
29.3 | 66.8 | 5.32 | |
58.3 | 0.0 | 4.57 | |
0.0 | 50.0 | 4.46 | |
20.8 | 58.3 | 4.46 | |
58.3 | 16.8 | 4.35 | |
54.3 | 0.0 | 3.81 | |
142.8 | 18.3 | 3.63 | |
41.8 | 0.0 | 3.27 | |
37.5 | 0.0 | 3.12 | |
20.8 | 33.3 | 2.91 | |
18.0 | 36.8 | 2.78 | |
Non-Invaded | May 2010 | Nov. 2010 | |
179.3 | 54.3 | 8.01 | |
112.5 | 0.0 | 7.06 | |
95.0 | 0.0 | 5.08 | |
83.3 | 50.0 | 4.68 | |
75.0 | 8.5 | 3.99 | |
75.0 | 4.3 | 3.89 | |
50.0 | 66.8 | 3.64 | |
0.0 | 58.3 | 3.56 | |
54.3 | 0.0 | 3.52 | |
0.0 | 37.5 | 2.37 | |
Non-Invaded | May 2011 | Nov. 2010 | |
0.0 | 237.5 | 21.8 | |
0.0 | 220.8 | 8.51 | |
4.3 | 150.0 | 4.19 | |
0.0 | 133.3 | 3.54 | |
0.0 | 154.3 | 3.07 | |
66.8 | 20.8 | 2.47 | |
58.3 | 12.5 | 2.31 |
The main differences between spring sampling dates (May 2010 and May 2011) and autumn ones (November 2010) were a higher abundance of organisms in spring, especially the molluscs
Results of the study described the structure of epifaunal assemblages associated with
Epifaunal assemblages associated with
The sampling design of the study was not suitable for assessing the temporal dynamics of the assemblages. However, in non-invaded areas, epifaunal assemblages associated with
The seasonal development of
The main effects of the presence of
The results show that the effects of
Differences between invaded and non-invaded beds were not evident five months after the disappearance of
The effects of
We wish to thank the Italian National Research Council (CNR) for supporting the study and S. Oliva for the Spanish translation of the summary.