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Figure 6 
Mean predicted probability of moving for Black Sea Bass ( Centropristis striata) 
at a reef in the mid-Atlantic Bight during periods of low (open circles, solid line) 
and high (crosses, dashed line) water temperatures at the bottom of the seafloor; 
temperatures <13°C are low, and those temperatures >13°C are high. Predictions 
are for 121 Black Sea Bass fitted with acoustic transmitters and tracked between 
late May and mid-November 2003. 
among social groups (and, therefore, exhibited larger 
home ranges [>100 ha]), but females that occupied the 
site for longer durations (>100 d) may have been more 
strongly associated with a specific group (and, there- 
fore, exhibited smaller home ranges [<60 ha] ). The mat- 
ing system of Black Sea Bass has not been observed in 
the wild, but on the basis of observations with captive 
fish (Nelson 7 ), these social groups are likely to be ha- 
rems. Some of the fish that exhibited larger home rang- 
es may have been fish undergoing transformation to 
males (see, e.g., Mercer, 1978). As such, these fish may 
display exploratory behaviors, searching for territories 
or joining spawning groups as “sneaker” males. Addi- 
tional studies on the reproductive strategies and social 
behavior of this species are needed to understand the 
mating system of Black Sea Bass and the role of sex- 
transitioning fish. 
On average, mature male Black Sea Bass exhibited 
smaller home ranges than did females and subordinate 
or transitional males, perhaps, because mature males 
establish territories only as large as they can success- 
fully patrol and defend. These sex-related differences 
in home-range size were similarly observed in anoth- 
er protogynous serranid, Pseudanthias squamipinnis 
(Shapiro, 1987). However, our study and that of Shap- 
iro (1987) contrast with results reported for other ter- 
7 Nelson, D. 2005. Personal commun. NOAA Fisheries Ser- 
vice, Northeast Fisheries Science Center, Milford, CT 06460. 
ritorial protogynous fishes, such as hogfishes ( Bodianus 
spp.), for which home ranges of males exceeded those 
of females (Hoffman, 1983). The difference we observed 
for Black Sea Bass may be due to the significantly larg- 
er home ranges (13.7-736.4 ha) of fish on inner-shelf 
habitats compared with those of fish using coral-reef 
habitats, where home ranges are typically on the order 
of a few' hundred square meters (0.01-0.05 ha; see e.g., 
Hoffman, 1983). 
Furthermore, if we assume that fish tagged and re- 
leased at a given time represented the population of 
available fish, then fish released early in the study may 
have arrived at the site earlier than those fish tagged 
and released later in the study period. Under this as- 
sumption, mature male Black Sea Bass that arrived 
early at the site (i.e., fish released in early June) estab- 
lished larger home ranges (>120 ha) than males arriv- 
ing later in summer (fish released in July), indicating 
that spawning territories may be limited on the inner 
continental shelf and that late-arriving males may be 
less likely to establish and maintain larger territories. 
The observed relationship between mean size of the 
home-range area of males and timing of release also 
was observed among the minimum and maximum size 
of the home-range area of these fish and the timing 
of their release. Whether home-range size is related 
to spawning success of males is unknown, but such 
knowledge could shed light on the importance of the 
timing of inshore migrations and the ability of males to 
