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Fishery Bulletin 96(4), 1998 
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Alpheidae (F (I0 45) = 14.9; P< 0.001) 
A B C3 D3 E F Cl C2 C3 D1 D2 D3 D4 
Portunidae (F (10 45) = 6.5: P< 0.001) 
Down flow field 
Across flow field 
Stations 
Figure 4 
Density of three families of queen conch predators and total predators collected from 11 dredge stations 
located down and across the Shark Rock flow field. Total predators include alpheids, portunids, xanthids, 
as well as two mollusc families — olivids and marginellids (not shown individually). Stations C3 and D3 
are illustrated in both dimensions for comparison. Values are mean ±SE (n = 5 for all stations except C3, 
where n- 6). Note different y scale on each graph. F and P values are for 1-way ANOVAs made for each 
variable and flow-field dimension. Means that were not statistically different (P> 0.05) are designated by 
similar letters (Tukey multiple comparison test on log-transformed data). 
cussed below). This latter conclusion is supported by 
the fact that the modal size for dead conch was small 
(1-5 mm). Future studies should examine the inter- 
action of settling date with food quality and quan- 
tity, growth, and predation rates. Few data of this 
type exist for sediment-dwelling invertebrates. Third, 
the smallest postlarval conch were probably under- 
sampled. Despite the use of small mesh (1.2-mm), 
some of the smallest individuals may have passed 
through the dredge bags. Furthermore, shells of 
newly settled queen conch are frequently broken into 
fragments that would not be retained on a 1.2-mm 
mesh. Nevertheless, our study provides the first 
quantitative data on newly settled conch ( <45 mm 
SL, <6 months postlarval age) and important insights 
into their early life history. 
Role of settlement and habitat 
on conch recruitment 
In this study, large volumes of sediment had to be 
sorted to detect relatively low settlement densities 
(<12/m 2 ) of queen conch over the traditional nurs- 
ery. These densities were not surprising given that 
1- and 2-year-old queen conch typically occur in ag- 
gregations with just 0. 2-1.0 individual/m 2 (Stoner 
and Ray, 1993). The most intriguing findings are that 
settlement was concentrated in the traditional nurs- 
ery ground and that recruitment to early benthic 
stages was directly correlated with settlement den- 
sity over a large spatial scale. This is compatible with 
the prediction (Connell, 1985) that settlement will 
be most influential in predicting the recruitment of 
