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Fishery Bulletin 106(2) 
ties associated with identifying Centropristis larvae 
prompted this work. The ITS region was chosen for 
assay development because it diverges rapidly during 
speciation and contains unique primer sites for dis- 
tinguishing species (Baldwin, 1992; Lu et al., 2002; 
Litaker et al., 2003). The divergence between Centro- 
pristis species was supported by the ITS phylogenetic 
analysis, which showed that C. striata, C. ocyurus, 
and C. philadelphiea were genetically distinct from 
each other and from another related serranid species, 
Diplectrum formosum (Fig. 3). The analysis further 
showed that C. ocyurus and C. philadelphiea are more 
closely related when compared to C. striata, which is 
consistent with the morphological characteristics of the 
adult fish. One of the goals of this study was to conduct 
the larval assays in a manner that would cause minimal 
damage to the preserved specimens. The method used 
in our study, where DNA was recovered from a single 
eye, made it possible to perform morphometric analyses 
on genetically identified fish and to evaluate whether 
species-specific characteristics exist that can be used 
to identify the larvae. 
The PCR assays were successfully validated by us- 
ing larvae that were collected on cruises ranging from 
Chesapeake Bay to southern Georgia during September 
2000, November 2000, and February through March 
2001 (Fig. 1). The peak spawning season for C. striata 
occurs between June and September in the Mid-Atlantic 
Bight (Able et al., 1995) and between March 
and May in the South Atlantic Bight (Wenner 
et al., 1986; Mercer, 1989; McGovern et al., 
2002). Data for spawning of C. philadelphiea 
comes from Miller (1959) who concluded that 
spawning occurs during May and June. Ma- 
nooch (1984) indicated that ripe females of C. 
ocyurus were collected in the South Atlantic 
Bight during March and April and that young 
fish appear in late April, suggesting that 
spawning occurs offshore in spring. Results 
from our study confirmed that spawning of 
C. ocyurus overlapped with that of C. striata 
and occurred in September and as early as 
February to March. The data from our study 
for C. philadelphiea are limited, making it 
difficult to determine whether the low abun- 
dance was due to spawning period, spawn- 
ing locations, or spawning stock biomass. 
Centropristis philadelphiea larvae may have 
been less abundant in the collections because 
most of the sampling was conducted in waters 
deeper than 10 m. Trawling studies off the 
southeastern United States indicate that C. 
philadelphiea is a year-round resident of shal- 
low coastal waters (<10 m) with sandy-mud 
substrates (Wenner and Sedberry, 1989) and 
is not present at greater depths over sandy- 
mud or hard bottoms (Wenner et al., 1979; 
Sedberry and Van Dolah, 1984). Furthermore, 
it is likely that the sampling of larvae did not 
occur during the peak spawning season for C. 
philadelphiea (Miller, 1959). 
Because PCR is a highly sensitive molecu- 
lar technique, care must be taken to avoid 
contamination. The data indicated that DNA 
cross-contamination occurred in three of the 
larval samples. We hypothesize that the DNA 
contamination occurred while the Centropris- 
tis larvae were stored collectively or during 
the sorting of the larvae. Field-collected lar- 
vae should therefore be preserved individually 
and utensils or tools used to process larvae 
should be decontaminated between larvae 
during the sorting process with a reagent that 
destroys DNA. 
a 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 
A jc 
246 bp mm 
123bp mm 
c 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 
Figure 4 
Results of cross-reactivity tests for (A) black sea bass (Centropristis 
striata), (B) bank sea bass (C. ocyurus ), and (C) rock sea bass (C. 
philadelphiea) polymerase chain reaction (PCR) assays. In each 
panel, the gels were loaded in the following order: lane 1, 123-bp 
ladder; lane 2, positive controls for A) C. striata, B) C. ocyurus, 
and C) C. philadelphiea ; lane 3, A) C. ocyurus, B) C. striata, C) 
C. philadelphiea ; lane 4, A) C. philadelphiea, B) C. striata, C) C. 
ocyurus\ lanes 5-14, sand perch ( Diplectrum formosum), spottail 
pinfish (Diplodus holbrooki), red grouper (Epinephelus morio), 
rock hind (Epinephelus adscensionis), speckled hind (Epineph- 
elus drummondhayi), butter hamlet (Hypoplectrus unicolor), gag 
grouper ( Mycteroperca microlepis), pygmy sea bass (Serraniculus 
pumilio), tattler ( Serranus phoebe), and belted sandfish (Serranus 
subligarius); lane 15, no DNA control. 
