Marin-Enriquez and Muhlia-Melo: Environmental and spatial preferences of Coryphaena spp 
13 
Map of the spatial distribution of estimated incidental catch per unit of 
effort (ICPUE) of common dolphinfish (Coryphaena hippurus) and pom- 
pano dolphinfish (C. equiselis) for the period 2004-2013 in the eastern 
Pacific Ocean off Mexico. The scale indicates ICPUE measured in number 
of fish caught per set. An x indicates areas where fishing is prohibited. 
Arrows indicate the Gulf of California (GC), Baja California Peninsula 
(BCP), Cabo Corrientes (CC), and Gulf of Tehuantepec (GT). 
Month 
10,000 
8000 
6000 
4000 
2000 
0 
B 
i 
□ Small 
C Medium 
■ Large 
2004 2006 
III ru I. 
2008 
Year 
2010 2012 
1 
Figure 3 
Temporal variation in estimated number of dolphin¬ 
fish (Coryphaena spp.) caught per size class of fish by 
the purse-seine fleet for the period 2004-2013, (A) by 
month and (B) year. The 3 size classes are small (<30 
cm in total length [TL]), medium (30-60 cm TL), and 
large (>60 cm TL). 
ters with high (>1 mg/m 3 ) chl-a concentrations (Fig. 
4B). A similar result was found in respect to SSH pref¬ 
erences for the 3 size classes, with higher catch in wa¬ 
ters with positive SSH values (Fig 40. Relationship 
between logarithm of ICPUE and 
SST was significant only for medi¬ 
um- and large-size dolphinfish (F (4i 
306)-7-52, P<0.05 and F( 4 , 423) = 1®.02, 
P<0.05), whereas chl-a concentra¬ 
tion and ICPUE were significant 
of all 3 size classes (F, 4 92) =13.71, 
P<0.05, F l4 , 3 o 4 ) = 22 . 78 , P<0.05 and 
F (4 42 3)=46.68, P<0.05 for small, 
medium-size, and large fish). Rela¬ 
tionship of catch and SSH was not 
as clear (F=~l; P>0.22 for all 3 size 
classes). 
No apparent spatial segrega¬ 
tion due to size was observed, but 
some spatial patterns arose when 
an analysis per latitudinal bands 
was applied. Of the total fish in 
the small-size class, 33.39% (1719 
fish) were caught between 20°N 
and 22°N. On the other hand, for 
the medium-size class, 24.30 % of 
total fish (4893 fish) were caught 
between 10°N and 12°N. For the 
large-size class, there was a promi¬ 
nent mode at the southernmost 
latitudinal band (10-12°N), where 
27.30% of total fish (7177 fish) were 
caught (Fig. 5A). 
A total of 2090 fish (41.50% of total fish) in the 
small-size class were caught between 114° W and 
116°W. Fish for the medium-size class were distributed 
west of 113°W and the maximum number of fish (4708, 
23.50% of total fish) were caught between 117°W and 
120°W. The most important mode for the large-size fish 
(6242, 24% of total fish) was found between 114°W and 
117°W (Fig. 5B). 
The maximum and minimum SST values from quad¬ 
rants where at least one dolphinfish was caught were 
31.10° and 18.50°C. Despite this wide range, dolphin¬ 
fish showed a clear preference for warm waters. Al¬ 
most 40% (38.20%, 1926 fish) of total fish belonging 
to the small-size class were caught between 25°C and 
26°C. The main mode for the incidental catch of fish 
in the medium- and large-size classes was found be¬ 
tween 27°C and 28°C, with 38.60% (7755) and 36.82% 
(9711) of total fish caught for the medium- and large- 
size class, respectively (Fig. 5C). 
Chl-a concentration also showed a wide range (0.05- 
2.61 mg/m3) for those quadrants with positive sets. 
However, 82.90% of total fish, in all 3 size classes was 
caught in waters with concentrations of chl-a between 
0.05 and 0.25 mg/m 3 (3877, 75% of total fish, for the 
small-size class, 16,092, 80% of total fish for the me¬ 
dium-size class, and 22,764, 86% of total fish for the 
large-size class; Fig. 5D). 
Dolphinfish were caught incidentally in SSH values 
ranging from -0.13 to 0.32 m. Of total fish (2047) of 
the small-size class, 40% were caught in waters with 
SSHs from 0.05 to 0.1 m. For the medium-size class, 
