Meiofaunal Biodiversity on Hydrothermal Seepage
355
Table Z. Average densities ind.lO cm- 2 (SD) of the main taxa at each station
SlZH
S12M
Sl2C
S16H
S16M
S16C
Thrbellaria
Gnathostomulida
Nematoda
Polychaeta
Gastropoda
Ostracoda
Copepoda
Nauplii
Halacaridae
Total
7.9
58.5
7.9
0.4
7.5
91.5
0.4
0.4
174.7
4.6
38.3
7.7
1.0
8.5
47.5
1.0
1.0
81.3
3.5
147.8
8.8
0.4
0.9
222.6
0.4
3.1
387.6
3.7
153.7
7.8
1.0
2.0
214.0
1.0
3.3
375.1
9.2
0.4
10.1
7.0
0.9
198.4
1.8
227.9
performed for significance of all pairwise comparisons between stations.
Results
The two sites showed marked differences in their
sedimentary characteristics. Stations of the site
S 12 had fairly homogeneous sediments (Table 1)
classified as "moderately sorted coarse sand". In
contrast. all stations of the site S16 showed highTable 3. P-values from pairwise comparisons of total meiofauna, nematodes and copepods densities between stations of
the two sites using SNK test after ANOVA (F-values are
reported too). Underlined values indicate significant differences
Total meiofauna; F c s,z!ll=36.08; P S12M
S12G
S16H
S16M
S16G
0.40
0.49
0.001
0.001
0.06
S12H
0.55
ll.OOl
0.001
0.01
S12M
Nematodes; F(,,24l=17.8Sj P S12M
Sl2G
S16H
S16M
S16G
0.23
MID.
MID.
0.001
0.001
S12H
0.001
0.001
ll.OOl
0.01
S12M
Copepods; F(,,24)=28.90; P S12M
0.15
Sl2C
0.22
SI6H
MID.
S16M
ll.OOl
S16C
0.31
S12H
O.Bl
0.001
llJllll
0.06
S12M
0.001
~
0.03
Sl2G
QJM,
0.02
0.06
S12G
ll.OOl
llJllll
0.Q1
S12C
0.42
MID.
S16H
1.00
0.10
S16H
0.54
0.001
S16H
0.001
S16M
0.40
S16M
o.ool
S16M
9.8
1.0
5.7
7.2
1.2
97.4
1.8
97.5
1.8
0.4
4.0
0.4
6.6
2.9
1.0
1.8
1.0
4.9
1.8
2.6
0.4
4.8
2.9
1.0
1.0
4.8
4.4
4.8
61.2
70.4
6.4
10.8
38.2
29.4
Sl2H
S12H
S12H
812H
SI2H
' - - - S I 2 M
' - - - - - - - - \
812M
{ SI2M
i
S12M
~ 812M
r 8ne
rL[ SI2C
812C
SI2e
Sl2C
r - - - - S I 6 H
SI6H
S16H
SI6H
' - - - - - - Sl6H
' - - - S l l i M
' - - - - - - - - 1 , - - - SHiM
S16M
SHiM
Sl6M
SI6e
Sl6C
SI6C
SI6C
.... , _-+-----.,~_+_--+--+___-_+_--+-____', Sille
10
20
30
40
50
60
70
80
90
100
SI2~§x:
SI2C
SI2H
Sl21$f#I/
sm.lPZM
812MS12M
SI2M
Bray-Curtis similarity
MDS (stress=O.06)
Fig. 2a,h. Multivariate analysis on copepod assemblages: (a)
Dendrogram and (b) Two dimensional non-metric MDS plot
of all replicate samples at each station
a
b