Abundance and distribution of the paralarval cephalopod community in the northern Gulf of Mexico

ABSTRACT The abundance and distribution of cephalopod paralarvae from the upper water column (0–130 meters) in the northern Gulf of Mexico (GOM) was studied using samples collected during six ichthyoplankton surveys between 2009 and 2012. A total of 2240 cephalopod paralarvae belonging to 21 families were examined. Thirty-three percent of the paralarvae could not be identified to family, highlighting a common issue in paralarval research. Octopodidae, Enoploteuthidae and Ommastrephidae were the most abundant taxa collected in the time series. Nine families and the entire Cephalopoda group were analyzed. Eight taxa had significantly different abundances between some sampling periods and two taxa had significantly different abundances between GOM regions. Most taxa were found deeper in the water column during the day, Ommastrephidae and Onychoteuthidae being the only exceptions. Five taxa were significantly more abundant in nighttime samples than daytime samples. Enoploteuthidae and Octopodidae showed evidence of diel vertical migration, with higher abundance between 20 and 100 meters during the day and 0–40 meters at night. These results provide insight into vertical paralarval movement, the timing and location of spawning, and potential effects of hydrographic features and circulation patterns dominated by the Loop Current on paralarvae in epipelagic waters of the northern GOM.