Carrasson and Matallanas: Feeding ecology of Bathypterois mediterraneus 
269 
Table 2 
Composition of the diet of Bathypterois mediterraneus in the four groups (bathymetric and ontogenetic) established. IRI = index of 
relative importance; %IRI = percentage of IRI. Unid. = unidentified. 
1800-2250 m 
1000-1425 m 1425-1800 m 
Size 1 Size 2 
Diversity (H') 
No. of specimens with food 
Composition of diet 
(Sizes 1 and 2) 
2.69 
94 
IRI %IRI 
(Sizes 1 and 2) 
2.33 
95 
IRI %IRI 
2.87 (2.93) 
25 
IRI %IRI 
3.16 
68 
IRI %IRI 
Foraminifera 
— 
— 
0.3 
0.0 
— 
— 
— 
— 
Polychaeta 
75.0 
0.6 
4.6 
0.0 
29.4 
0.3 
42.4 
0.3 
Polychaeta unid. 
41.5 
0.4 
1.2 
0.0 
— 
— 
25.0 
0.2 
Aphroditimorfa 
4.2 
0.0 
1.1 
0.0 
29.4 
0.3 
4.2 
0.0 
Crustacea 
Crustacea unid. 
42.0 
0.4 
— 
— 
— 
— 
— 
— 
Copepoda 
9966.3 
77.4 
13195.5 
90.0 
5644.8 
52.2 
8550.2 
67.6 
Copepoda unid. 
— 
- 
8.4 
0.1 
- 
— 
— 
— 
Calanoid Copepoda 
9966.3 
88.7 
12531.0 
95.5 
5014.3 
56.3 
8550.2 
79.5 
Harpacticoid Copepoda 
— 
— 
— 
- 
37.3 
0.4 
— 
— 
Ostracoda 
20.0 
0.2 
3.8 
0.0 
— 
— 
3.4 
0.0 
Ostracoda unid. 
0.9 
0.0 
0.1 
0.0 
— 
— 
0.4 
0.0 
Cipridin a sp. 
— 
— 
1.0 
0.0 
— 
— 
1.5 
0.0 
Cipridinidae 
12.4 
0.1 
0.4 
0.0 
— 
— 
— 
— 
Amphipoda 
609.5 
4.7 
117.1 
0.8 
1651.2 
15.3 
516.5 
4.1 
Amphipoda unid. 
— 
— 
0.4 
0.0 
— 
— 
0.8 
0.0 
Amphipoda Gammaridea 
551.2 
4.3 
95.2 
0.7 
1651.2 
15.3 
477.5 
3.8 
Amphipoda Gammaridea unid. 
138.1 
1.2 
30.2 
0.2 
151.8 
1.7 
122.8 
1.1 
Orchomene humilis 
15.5 
0.1 
— 
— 
— 
— 
— 
— 
Orchomene sp. 
— 
— 
0.1 
0.0 
13.6 
0.2 
— 
— 
Lyssianasidae 
17.8 
0.2 
3.0 
0.0 
26.6 
0.3 
— 
— 
Harpini a sp. 
— 
— 
1.0 
0.0 
— 
— 
— 
— 
Bruzelia typica 
— 
— 
2.5 
0.0 
— 
— 
4.7 
0.0 
Pseudotiton bouvieri 
— 
- 
— 
— 
— 
— 
0.7 
0.0 
Rhachotropis caeca 
0.7 
0.0 
- 
— 
- 
— 
— 
— 
Rhachotropis sp. 
14.7 
0.1 
— 
— 
438.3 
4.9 
30.6 
0.3 
Monoculode s sp. 
0.9 
0.0 
— 
— 
— 
— 
0.9 
0.0 
Oediceridae 
— 
— 
— 
— 
— 
— 
3.9 
0.0 
Amphipoda Hyperiidea 
1.3 
0.0 
0.2 
0.0 
— 
— 
— 
— 
Isopoda 
13.1 
0.1 
5.0 
0.0 
22.6 
0.2 
8.8 
0.1 
Isopoda unid. 
1.3 
0.0 
2.2 
0.0 
5.7 
0.1 
2.9 
0.0 
Gnathi a sp. 
1.0 
0.0 
— 
— 
— 
— 
0.4 
0.0 
Anthuridae 
1.0 
0.0 
0.6 
0.0 
5.7 
0.1 
0.3 
0.0 
Ilyarachna sp. 
0.2 
0.0 
— 
— 
— 
— 
— 
— 
Tanaidacea 
0.9 
0.0 
7.7 
0.1 
2664.1 
24.6 
49.5 
0.4 
Tanaidacea unid. 
0.9 
0.0 
— 
— 
— 
— 
— 
— 
Tanaidae 
— 
— 
7.7 
0.1 
2664.1 
29.9 
41.7 
0.4 
Paratanaidae 
— 
— 
— 
— 
— 
— 
0.3 
0.0 
Cumacea 
15.8 
0.1 
194.6 
1.3 
751.8 
7.0 
1214.7 
9.6 
Cumacea unid. 
7.3 
0.1 
99.3 
0.8 
401.9 
4.5 
596.0 
5.5 
Cyclaspis longicaudata 
— 
— 
0.6 
0.0 
— 
— 
14.0 
0.1 
Leucon longirostris 
0.6 
0.0 
— 
— 
— 
— 
— 
— 
Campylaspis glabra 
0.2 
0.0 
— 
— 
— 
— 
— 
— 
Campylaspis sp. 
— 
— 
0.1 
0.0 
— 
— 
— 
— 
continued 
