364 
Fishery Bulletin 95(2), 1997 
fish of the families Engraulidae (Hubbs and Wisner, 
1953; de Sylva, 1962; Evans and Wares, 1972; Holts 
and Bedford, 1990), Clupeidae (Hubbs and Wisner, 
1953; Koga, 1968), Scombridae (Backer, 1966; Evans 
and Wares, 1972), Scomberesocidae (Morrow, 1952; 
Hubbs and Wisner, 1953), and Carangidae (de Sylva, 
1962; Backer, 1966; Evans and Wares, 1972), and 
some cephalopods (Morrow, 1952; Yabuta, 1953; La 
Monte, 1955; de Sylva, 1962; Williams, 1967; Eldrige 
and Wares, 1974). 
We also found that striped marlin feed on demer- 
sal species, such as M. productus and searobins, 
Prionotus spp, as well as on benthic species, such as 
mantis shrimp, Squilla spp. Other authors have 
found occasional prey from benthic or reef habitats 
in striped marlin (Morrow, 1952; Backer, 1966; Wil- 
liams, 1967; Evans and Wares, 1972; Eldrige and 
Wares, 1974); thus, it appears that striped marlin 
move to the bottom to prey on benthic organisms. 
Our results show the importance of seasonal prey 
availability off Cabo San Lucas. During spring 1988, 
S. caeruleus was the main prey of striped marlin, 
whereas in fall and winter, S. japonicus was more 
important. The latter is probably more abundant in 
Table 2 
Seasonal absolute values of the index of relative importance (IRI) of the stomach contents of striped marlin from Cabo San Lucas, 
B.C.S., Mexico (WI = Winter, SP = Spring, SU = Summer, FA = Fall). 
Species 
1988 
SP 
73 = 55 
1988 
SU 
73 = 34 
1988 
FA 
73 = 92 
1989 
WI 
73 = 56 
1989 
SP 
73 = 67 
1989 
SU 
73 = 11 
1989 
FA 
73 = 35 
Cephalopoda 
Abraliopsis affinis 
0 
0 
6.13 
160.62 
0.82 
0 
0 
DosicLicus gigas 
21.08 
2,637.22 
480.66 
59.48 
1,031.04 
0 
672.83 
Stenoteuthis oualaniensis 
12.21 
8.58 
24.28 
0.97 
1.79 
0 
0 
Octopus spp. 
1 
1.99 
0.31 
0 
2.49 
0 
0 
Argonauta spp. 
4.14 
42.34 
38.08 
2.04 
0 
0 
0 
Crustacea 
Amphipoda 
0 
0 
0 
0 
0 
0 
33.57 
Isopoda 
0 
0 
1.05 
0 
0 
0 
0 
Squilla spp. 
0 
0 
0 
0 
0.45 
0 
0 
Euphausiacea 
10.32 
21.49 
0 
0 
3.04 
0 
0 
Pleuroncodes planipes 
22.56 
3.09 
104.10 
16.99 
13.50 
628.17 
0 
Osteichthyes 
Clupeidae 
49.08 
27.96 
9.59 
18.31 
33.27 
0 
0 
Etrumeus teres 
368.43 
346.57 
357.95 
67.47 
369.22 
0 
51.76 
Sardinops caeruleus 
8,049.39 
30.58 
102.05 
473.74 
739.77 
644.94 
2,072.04 
Opisthonema libertate 
0 
0 
0 
0 
295.76 
0 
0 
Merluccius productus 
0 
0 
203.19 
855.85 
49.07 
0 
0 
Strortgylura spp. 
0 
0 
0 
2.27 
0 
0 
0 
Fistularia spp. 
0 
0 
83.03 
40.63 
0 
0 
51.76 
Prionotus spp. 
0 
0 
0 
0.50 
0 
0 
0 
Serranidae 
0 
0 
0.81 
0 
0 
0 
0 
Carangidae 
0 
74.97 
1.97 
27.56 
1.55 
0 
0 
Caranx caballus 
25.30 
27.81 
4.17 
0 
0 
780.10 
0 
Caranx hippos 
4.48 
0 
0.59 
2.86 
0 
0 
19.88 
Decapterus hvpodus 
54.50 
58.56 
1.62 
0 
0 
0 
1,036.23 
Selar crumenophthalmus 
1.60 
446.19 
28.31 
2.17 
0 
0 
0 
Coryphaena hippurus 
0 
0 
0 
1.41 
0 
0 
0 
Mugil spp. 
1.87 
0 
0 
0 
0 
0 
0 
Sphyraena ensis 
0 
0 
0 
0 
0 
586.04 
0 
Auxis spp. 
2.69 
8.76 
131.51 
22.63 
0 
0 
0 
Scomber japonicus 
1,299.15 
351.06 
1,957.42 
4,324.37 
2,117.20 
0 
1,073.73 
Balistes polylepis 
0 
0 
115.06 
0 
0 
0 
864.20 
Xanthichthys mento 
0 
0 
0.37 
0 
0 
0 
0 
Diodon spp. 
0 
2.09 
0 
0 
0 
0 
0 
Unidentified organic matter 
0 
0 
0.07 
0 
0.03 
0 
0 
