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Fishery Bulletin 115(1) 
Time (GMT -4 hrs) 
Figure 7 
Variability in daytime vertical movements of a longfin mako ilsurus paucus; LFM2) 
tagged off the northwestern coast of Cuba in 2015. (A) Temperature-depth profile dur- 
ing a week-long period in June showing limited temperature variability. (B) Tempera- 
ture-depth profile in early July showing movement through a temperature-stratified 
water column. (C) 39-h period beginning 8 June when the shark remained largely at 
depths of 300-400 m during the day within this relatively unstratified water column. 
(D) 31-h period beginning 3 July showing regular daytime forays from cold depths into 
warmer surface waters. GMT-4 h=4 hours behind Greenwich Mean Time. 
southwest Pacific indicated a comparable vertical move- 
ment pattern of shallower depths at night than those 
during the day, descents to 620 m, and a temperature 
range of 8.8-23.4°C (Stevens et ah, 2010). 
Similar DVM behavior has been observed in a num- 
ber of other pelagic shark species, including the bigeye 
thresher (Alopias superciliosus; Stevens et ah, 2010), 
white shark (Nasby-Lucas et ah, 2009), and porbeagle 
(Saunders et ah, 2011), as well as in pelagic teleosts 
such as the swordfish (Carey and Robison, 1981; Abas- 
cal et ah, 2010; Sepulveda et ah, 2010) and bigeye 
tuna {T. obesus; Musyl et ah, 2003), and it often has 
been suggested that this behavior is a response to the 
movement of their prey (Musyl et ah, 2003; Stevens 
et ah, 2010; Saunders et ah, 2011). Although the diet 
of the longfin mako has not been described fully, the 
presumed prey of this species includes schooling fish 
and pelagic squid species (Compagno, 2001). The lat- 
ter may be the more important dietary component 
because squid and squid beaks have been identified 
in the contents of stomachs of longfin makos (Dodril 
and Gilmore, 1979; Castro, 2011) and are similarly a 
known component of the shortfin mako diet (Stillwell 
and Kohler, 1982; Maia et ah, 2006). The stomach of 
a 310-cm-TL female longfin mako from the southeast- 
ern Pacific Ocean contained squid remains, most like- 
ly from jumbo squid (Dosidicus gigas; Bustamante et 
ah, 2009). Pelagic cephalopods also have been shown 
to be diel vertical migrators (Roper and Young, 1975). 
A distinct DVM pattern was observed for jumbo squid 
tagged with satellite tags: they spent most daylight 
hours at depths >250 m, rose toward the surface at 
dusk, and spent the majority of time at night at depths 
<150 m (Gilly et ah, 2006). This pattern is similar to 
