308 
Fishery Bulletin 109(3) 
Rockpool 
Figure 2 
Mean (±1 standard deviation) temperature and salinity at the 
beginning (B), middle (M), and end (E) of isolation of pools from 
the sea at Praia dos Castelhanos, Espirito Santo, Brazil. Differ- 
ences in these variables during the period of pool exposure to 
air were tested by repeated-measure ANOVA models with the 
Greenhouse-Geisser test (temperature in pools 2, 3, and 5) or the 
sphericity assumed test (all other models). In significant models 
(temperature for all pools, with P<0.001; salinity in pool 1 with 
P<0.05), results for contrast tests between the beginning and 
middle periods and the beginning and end periods are indicated 
above M and E, respectively. For all pools, n = 8 except for pool 
1, where n= 7. NS=not significant; *=P<0.01, **=P<0.001. 
being segregated by its physicochemical char- 
acteristics (Fig. 3B), pool 1 also differed from 
other pools (Fig. 3A; Table 1) on account of the 
smoothness of its bottom. This feature is prob- 
ably caused by high hydrodynamics and the con- 
stant sanding of the rocky substratum by virtue 
of the pool location in the breaker zone adjacent 
to the beach. Abrasion also severely limited 
growth of macroalgae and sessile invertebrates 
(Table 1). The five other pools separated into 
three categories: category 1 consisted of pool 3 
(very small and filled with gravel), category 2 
consisted of pool 5 (of large size with high rock 
and low sand covers), and category 3 consisted of 
the remaining pools 2, 4, and 6. The sandiness 
of pool 2, the depth, rugosity, algal and sand 
cover of pool 4, and the “graveliness” (coarseness 
of unconsolidated substrate) of pool 6 were insuf- 
ficient to differentiate them (Fig. 3A). 
Spatial distribution of fishes 
A total of 3448 individuals, representing 64 
taxa (58 species) and 27 families, was caught 
(Table 2). Sixteen of the 58 species, represent- 
ing 64% of the total number of individuals, 
were considered permanent residents (PR), 19 
(28%) were opportunists (O), and 23 (7.3%) were 
transients (T). Abundance, richness, diversity, 
and total wet weight of all fish differed among 
rockpools, but there were no significant differ- 
ences in Pielou's evenness or mean length (Fig. 
4). Abundance was very high at pool 5 due to 
Halichoeres poeyi, Stegastes fuscus, and Acan- 
thurus bahianus. Individual mean weight was 
very high at pool 4 because of rather large and 
abundant Labrisomus nuchipinnis and juveniles 
of Sparisoma axillare. The community indices 
for pool 1 were characteristic of environments 
with elevated stress level (e.g., estuaries): high 
abundance, low diversity, and dominance of few 
species. Permanent residents were the most 
representative pool users (above 40% of total) in both 
number and weight. Proportions of the three user cat- 
egories varied among pools. Pools 1 to 4 were dominated 
by permanent residents (above 60% in number and above 
80% in weight). In pools 5 and 6 (and in a smaller mea- 
sure, 2 and 4), although permanent residents remained 
dominant, the number and weight of opportunists and 
transients were very representative (Fig. 5). 
The ten most-abundant species were either permanent 
residents or opportunists and showed four different 
patterns of spatial distribution (Friedman test, Fig. 6). 
Pattern A, where species were most abundant at pool 
5 and rare elsewhere (except pool 6), was displayed 
by A. bahianus , H. poeyi, and S. fuscus. Species most 
abundant at pool 1 but rare in other pools, Bathygobius 
soporator and Ctenogobius boleosoma, were classified as 
displaying pattern B. Absence at pool 1 and low abun- 
dance at pool 3, as for Malacoctenus delalandei and S. 
axillare, characterized pattern C. The most abundant 
species overall, Bathygobius mystacium and L. nuchi- 
pinnis, displayed pattern D where abundance was most 
expressive at pool 5 but remained relatively high in 
the other pools. No obvious pattern of spatial distribu- 
tion was identified for Abudefduf saxatilis. Except for 
B. soporator and C. boleosoma (pattern B), there was 
no similarity between abundance and physicochemical 
characteristics of rockpools. The distribution patterns of 
mean individual weight (not shown) of these most-abun- 
dant species did not present much similarity with those 
of abundance (Fig. 6). The gobies C. boleosoma and (to a 
lesser degree) B. mystacium showed a pattern similar to 
pattern B detected for abundance. The mean individual 
weight of Abudefduf saxatilis was higher in larger pools 
(2 and 5) and that of B. soporator was lowest in pool 1 
which presented the highest abundance. Overall, six 
of the ten species displayed significant differences in 
