Lewis et al.: Integrating DNA barcoding of fish eggs into ichthyoplankton programs 
159 
45°N 
40°N 
35°N 
44°N 
40°N 
35°N 
Eggs/10 m' 
Atlantic Ocean 
Atlantic Ocean 
Eggs/10 m' 
Eggs/1 0 m‘ 
Atlantic Ocean 
Atlantic Ocean 
Figure 2 
Maps showing the locations of calculated egg abundances, reported as the number of eggs per 10 m 2 of water, based 
on sort counts and station haul factor values from ichthyoplankton samples collected along the northeastern U. S. 
continental shelf during 2002-2012 by the NOAA Northeast Fisheries Science Center during its 4 sampling sea- 
sons of (A) winter (January-February), ( B ) late spring (May-June), (C) late summer (August), and (D) late autumn 
( November-December ). 
respectively), and the singular eggs of Atlantic cut- 
lassfish ( Trichiurus lepturus ) and red drum ( Sciaenops 
ocellatus) were each collected at the highest recorded 
temperature of 26.84°C. 
Egg size also varied significantly between species; 
measured diameters of the successfully barcoded eggs 
ranged from 0.57 mm to 2.52 mm (Fig. 4). The eggs 
of blackcheek tonguefish ( Symphurus plagiusa), small- 
mouth flounder ( Etropus microstomus), and butterfish 
( Peprilus triacanthus) were smallest on average; each 
species had one egg with a measured diameter of 0.57 
mm. On the opposite end of the scale, eggs of margined 
snake eel ( Ophichthus cruentifer) were the largest, 
with an average egg diameter of 2.43 mm (N= 5) (Table 
1). The egg size range of Atlantic cod was the greatest 
with a difference of 0.56 mm separating the smallest 
and largest diameter measurements (N=47). Diameters 
for the various species of identified anchovies were 
based on long-axis measurements because eggs of these 
species are naturally ovoid in shape. 
For barcoded species that were identified from at 
least 15 stations, egg measurement and collection data 
were further analyzed to determine correlations be- 
tween egg size and SST. Of the 11 species that met the 
15-station requirement and were tested, 5 species dis- 
played significant trends (P<0.05 or 5%) between SST 
and average egg diameter (Table 2, Fig. 5, A-E), with 
yellowtail flounder ( Limanda ferruginea ) being the 
only species to illustrate a positive correlation between 
SST and egg diameter. 
Discussion 
One of the primary goals for this study was to com- 
pare our results from the molecular identification of 
