310 
National Marine 
Fisheries Service 
NOAA 
Fishery Bulletin 
established In 1881 •<?. 
Spencer F. Baird 
First U S. Commissioner 
of Fisheries and founder 
of Fishery Bulletin 
Food habits of the blue shark, Prionace glauca 
(Linnaeus, 1758), in waters off northern Peru 
Francisco Cordova-Zavaleta (contact author) 1 - 2 
Jaime Mendo 2 
Sergio A. Briones-Hernandez 3 
Nicolas Acuna-Perales 1 
Adriana Gonzalez-Pestana 1 - 4 
Joanna Alfaro-Shigueto 1 - 4 - 5 
Jeffrey C. Mangel 1 - 5 
Email address for contact author: fcordova@prodelphinus.org 
Abstract-— The blue shark (Prionace 
glauca) is the most landed shark 
species in Peruvian shark fisheries, 
representing 42% of total landings. 
Despite its importance for fisheries, 
the ecological role of the blue shark 
in Peruvian waters remains poorly 
understood. Therefore, in this study, 
we aimed to assess the food habits 
of blue sharks off northern Peru 
through stomach content analysis. 
Between February and December of 
2015, 143 stomachs were collected 
and 28 found to be were empty. In¬ 
dividuals measured from 110.0 to 
299.4 cm in total length. The results 
indicate that blue sharks have epi- 
pelagic and mesobathypelagic feed¬ 
ing habits, preying upon a wide 
number of prey taxa (42 species) 
but with a diet dominated by cepha- 
lopods, especially Argonauta spp. 
and Ancistrocheirus lesueurii. Diets 
differed by size class and location, 
suggesting that longitudinal move¬ 
ments are related to increments in 
body size. In addition, we propose 
that blue sharks scavenge for food 
on the basis of finding the cyprid 
larval stage and juvenile cosmopoli¬ 
tan duck barnacle (Lepas anatifera) 
associated with the prey item ‘un¬ 
identified cephalopods.’ The present 
study contributes new information 
on the diet of blue sharks. 
Manuscript submitted 14 December 2017. 
Manuscript accepted 16 August 2018. 
Fish. Bull. 116:310-322 (2018). 
Online publication date: 11 September 2018. 
doi: 10.7755/FB.116.3-4.9 
The views and opinions expressed or 
implied in this article are those of the 
author (or authors) and do not necessarily 
reflect the position of the National 
Marine Fisheries Service, NOAA. 
1 ProDelphinus 
Calle Jose Galvez 780-e 
15074 Lima, Peru 
2 Facultad de Pesqueria 
Universidad Nacional Agraria la Molina 
Avenida La Molina s/n 
15024 Lima, Peru 
3 Centro Interdisciplinario de Ciencias Marinas 
Instituto Politecnico Nacional 
Avenida Instituto Politecnico Nacional s/n 
Colonia Playa Palo de Santa Rita Apdo. 
23096 La Paz, Baja California Sur, Mexico 
In the southeastern Pacific Ocean, the 
area off northern Peru is an important 
area of convergence between temper¬ 
ate (Humboldt Current) and tropical 
(South Equatorial Current) waters 
(Spalding et al., 2007). This particular 
area hosts a diversity of marine spe¬ 
cies (Chirichigno and Cornejo, 2001), 
including a large number of sharks 
(Cornejo et ah, 2015). One of these 
is the blue shark (Prionace glauca), 
which is considered a key cosmopoli¬ 
tan pelagic species that exerts top- 
down control on community structure 
(Stevens et al., 2000). 
On a global scale, the blue shark 
is the most landed shark species (as 
target and nontarget catch) and the 
major component of the international 
shark fin trade (Clarke et al., 2006; 
Nakano and Stevens, 2008). It is also 
the most landed species by Peruvian 
shark fisheries, representing 42% of 
total landings (Gonzalez-Pestana et 
4 Facultad de Biologia Marina 
Universidad Cientffica del Sur 
Panamericana Sur Km 19 
15067 Lima, Peru 
5 Center for Ecology and Conservation 
College of Life and Environmental Sciences 
University of Exeter, Penryn Campus 
Penryn, Cornwall TRIO 9FE, United Kingdom 
al., 1 2016). Seventy percent of blue 
shark landings come from the small- 
scale longline fishery operating along 
the coast (Doherty et al., 2014), es¬ 
pecially off southern Peru where 
cold to temperate waters support 
higher abundances of pelagic sharks 
(Adams et al., 2016). Likewise, it is 
one of the most frequently species 
caught in Peruvian small-scale drift- 
net shark fisheries (Alfaro-Shigueto 
et al., 2010). However, despite its 
importance for fisheries, biological 
studies describing the ecological role 
of blue sharks in Peruvian waters 
are few. 
There have been several studies 
regarding the diet of blue sharks in 
1 Gonzalez-Pestana, A., C. Kouri, and X. 
Velez-Zuazo. In review. Shark fisher¬ 
ies in the southeast Pacific: a 61-year 
analysis from Peru. FlOOOResearch 
3:164. [Available at website.] 
