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Fishery Bulletin 1 14(2) 
Table 1 
Categorization of functional groups, based on taxonomy, ecological function, or importance to fisheries, used in our study of 
trends of fish biomass in data from shore-based creel surveys conducted around Guam during 1985-2012 
Functional group name 
Description and notes 
Example species 
Bait fishes 
Sardine-like species that periodically come to 
nearshore waters in large numbers 
Selar crumenophthalmus, Ellochelon vaigien- 
sis, Gerres longirostris, Crenimugil crenilabis 
Invertebrates 
The top shell (Tectus niloticus) was the domi- 
nant component in the total catch of inverte- 
brates as a result of very high landings of this 
single species of 30 t in 1985 and 16 t in 1991 
Crabs, lobsters, sea cucumbers, mollusks, octo- 
puses, urchins, and clams 
Nonreef-fish species 
Species that are pelagic, deepwater, freshwater, 
or associated with sandy bottoms 
Tuna, deepwater snappers (e.g., Etelis corus- 
cans), Kuhlia rupestris 
Macroalgae Planktivores 
Fish species that feed on particles from water 
column 
Soldierfishes (Holocentridae), some uni- 
cornfishes (e.g., Naso annulatus), chromises 
( Chromis spp.), cardinalfishes (Apogon spp.) 
Coral-consuming fishes 
Fish species that feed primarily on corals 
Mostly butterflyfishes ( Chaetodon spp.) 
Detritivores 
Fish species that feed primarily on detritus 
Surgeonfishes (Ctenochaetus spp.) 
Invertebrate-consuming 
fishes 
Fish species that feed on invertebrates, sepa- 
rated into exploited species and lightly or non- 
exploited species 
Exploited: emperors (Lethrinus spp.), snap- 
pers ( Lutjanus spp.), goatfishes (Mullidae), 
wrasses ( Cheilinus spp.); lightly or non- 
exploited; porcupinefishes (Diodon spp.), file- 
fishes (Aluterus spp.) 
Herbivore-browsers 
Fish species that browse on plants, separated 
into exploited species and lightly or nonex- 
ploited species 
Exploited: sea chubs ( Kyphosus spp.), rabbit- 
fishes ( Siganus spp.), unicornfishes (e.g., Naso 
unicornis)', lightly or nonexploited: milkfish 
(Chatios chanos) 
Herbivore-grazers 
Fish species that graze on plants, separated 
into exploited species and lightly or non-exploit- 
ed species 
Exploited: surgeonfishes (Acanthurus spp.); 
lightly or nonexploited: sergeants (Abudefduf 
spp.) 
Herbivore-scrapers 
Fish species that feed on plants and scrape 
hard substrate (including corals); all exploited 
species 
Small-bodied parrotfishes (e.g., most species 
of Scarus, Chlorurus sordidus ) 
Herbivore-excavators 
Fish species that feed on plants and excavate 
hard substrate (including corals); all exploited 
species 
Large-bodied parrotfishes (e.g., most species 
of Chlorurus, Scarus rubroviolaceus) 
Humphead parrotfish 
An exploited species 
Bolbometopon muricatum 
Humphead wrasse 
An exploited species 
Cheilinus undulates 
Benthic piscivores 
Fish species that feed primarily on other fishes 
and are mostly resident to a reef area separated 
into exploited species and lightly or nonex- 
ploited species 
Exploited: groupers (Epinephelus spp.); lightly 
or nonexploited: morays (Gymnothorax spp.) 
Mid-water piscivores 
Fish species that feed primarily on other fishes 
and are benthopelagic, all exploited species 
Leatherjacket (Scomberoides sp.), needle- 
fishes (Belonidae), reef cornetfish (Fistularia 
commersonii ) 
Roving piscivores 
Fish that feed primarily on other fishes and 
rove on reefs; all exploited species 
Jacks (Carangidae), barracudas (Sphyraena 
spp.) 
Rays 
All exploited species 
Stingrays (Myliobatiformes) 
Sharks 
All exploited species 
Reef-associated sharks (e.g., blacktip reef 
shark [Carcharhinus melanopterus ], grey reef 
shark [C. amblyrhynchos], and whitetip reef 
shark [Triaenodon obesus ]) 
