IMIS

Zooplankton samples were collected with oblique net tows in the upper 200 m (or from 10 m above the sea floor in shallow stations), using a Bongo net of 500 µm mesh width and mouth diameter of 0.7 m. Four cruises correspond to the four seasons of 2005 and the rest are summer cruises preformed during 2002-2008. Hyperiid amphipods were identified using mainly the taxonomic key for Hyperiidea of the world oceans (Vinogradov et al., 1996). The total number of samples analyzed were 482 but hyperiids were absent in 18. The positive samples were 75% of the oceanic stations collected during nighttime, and the rest were from neritic stations (11% nighttime and 14% daytime). The total number of species found are 125, with strong dominance of Vibilia armata, Lestrigonus schizogeneios, Primno brevidens, and Eupronoe minuta. The abundances of these and other common species changes seasonally as described by Lavaniegos & Hereu (2009), and interannually as observed in summer of the period 2002-2008 for the northern Baja California region (Lavaniegos, 2017) and the Gulf of Ulloa and offshore region (Lavaniegos, under review).