Harter et al.: Fish assemblages associated with grouper pits in the Gulf of Mexico 
425 
Table 2 
Annual mean abundances of all taxa, observed during video surveys conducted with a re- 
motely operated vehicle at Pulley Ridge, in the Gulf of Mexico, from 2012 through 2015. The 
overall mean is the average of the 4 annual values for each taxon. Taxa are listed in order 
from highest to lowest overall mean. Commercially or recreationally harvested species are 
noted in bold. 
Scientific name 
2012 
2013 
2014 
2015 
Overall mean 
Haemulidae 
124.09 
4.05 
0.00 
0.00 
32.04 
Haemulon striatum 
0.00 
64.86 
21.77 
12.15 
24.70 
Schultzea beta 
0.00 
13.51 
32.17 
33.00 
19.67 
Apogon spp. 
0.63 
31.24 
5.40 
32.73 
17.50 
Chromis scotti 
9.74 
2.46 
0.97 
26.25 
9.85 
Pterois volitans 
3.06 
4.70 
13.97 
6.65 
7.10 
Hemanthias vivanus 
0.00 
0.00 
26.37 
0.00 
6.59 
Chromis enchrysura 
2.50 
7.35 
10.51 
2.46 
5.71 
Serranidae 
0.05 
21.62 
0.00 
0.00 
5.42 
Chromis spp. 
2.73 
4.68 
0.00 
7.10 
3.62 
Chromis insolata 
2.48 
2.41 
4.63 
4.17 
3.42 
Anthiinae 
7.13 
4.05 
0.49 
1.92 
3.40 
Apogon affinis 
0.00 
0.00 
13.43 
0.00 
3.36 
Coranthias tenuis 
0.25 
0.00 
0.11 
11.54 
2.98 
Apogon maculatus 
4.44 
2.97 
0.71 
0.00 
2.03 
Holocentrus spp. 
0.50 
3.65 
2.34 
1.02 
1.88 
Bodianus pulchellus 
0.43 
0.38 
1.14 
1.10 
0.76 
Chromis cyanea 
1.81 
0.68 
0.17 
0.31 
0.74 
Chaetodon sedentarius 
0.35 
0.73 
0.71 
0.58 
0.59 
Equetus lanceolatus 
0.00 
0.24 
1.97 
0.04 
0.56 
Centropyge argi 
0.28 
0.57 
0.17 
0.87 
0.47 
Canthigaster rostrata 
0.08 
0.03 
1.29 
0.31 
0.42 
Epinephelus morio 
0.38 
0.49 
0.46 
0.35 
0.42 
Holacanthus tricolor 
0.38 
0.16 
0.26 
0.46 
0.31 
Serranus tortugarum 
0.06 
0.03 
0.00 
1.15 
0.31 
Mycteroperca phenax 
0.44 
0.05 
0.23 
0.52 
0.31 
Sparisoma atomarium 
0.13 
0.00 
0.49 
0.27 
0.22 
Liopropoma eukrines 
0.03 
0.19 
0.23 
0.37 
0.20 
Holacanthus bermudensis 
0.19 
0.11 
0.31 
0.10 
0.18 
Chaetodon ocellatus 
0.00 
0.11 
0.23 
0.29 
0.16 
Stegastes partitus 
0.06 
0.14 
0.00 
0.38 
0.15 
Pronotogrammus martinicensis 
0.00 
0.16 
0.26 
0.13 
0.14 
Apogon pseudomaculatus 
0.00 
0.14 
0.20 
0.08 
0.10 
Halichoeres spp. 
0.08 
0.00 
0.06 
0.25 
0.10 
Lutjanus spp. 
0.01 
0.00 
0.20 
0.15 
0.09 
Table Continued 
These pits represent the only areas of Pulley Ridge 
that provide a diversity of structural habitat. Whereas 
most of Pulley Ridge is relatively flat and consists of 
rubble and pavement and little rugosity, the grouper 
pits provide moderate relief (1-2 m), slopes of 5-30°, 
and high-rugosity habitat. Rugosity here is defined as 
a degree of ruggedness of the rock bottom in relation to 
the size of rock ledges, holes, and crevices, which tend 
to provide the most structurally complex habitat for 
reef fish. The grouper pits provide habitat for a large 
variety and density of small reef fish, and the exposed 
rock provides habitat for sessile benthic biota. Although 
rugosity of the grouper pits was not measured quanti- 
tatively, it differed visually only for those grouper pits 
that were not actively being maintained by a predator. 
These abandoned pits tended to be filled with sediment 
and lack exposed rock ledges. 
Overall, 66 fish taxa were observed in the grouper 
pits of Pulley Ridge, 16 of which are managed species 
(Table 2). Schooling species, such as bonnetmouths 
and the striped grunt, had the highest overall mean 
abundances (84.40 individuals/pit [SE 25.30]), but the 
species that composed the schooling category varied 
among years. Bonnetmouths dominated in 2012, but 
the striped grunt and the school bass were more abun- 
dant during 2013-2015. Of the small, benthic fish that 
