Marine Resources Assessment for the Marianas Operating ... - SPREP

AUGUST 2005 FINAL REPORT
crevices of rocky and coralline bottoms (spiny, slipper, and coral lobsters), and mud or sandy bottoms
in high littoral sands, crevices or burrows among subtidal rocks and coral heads, or on the surfaces of
marine plants and other invertebrates (true and hermit crabs) (Chan 1998a, 1998b; Manning 1999;
Ng 1998). The depth distribution of these different reef crustaceans (mantis shrimp, coral associated
shrimps, lobsters, and crabs) varies from 0 to more than 100 m (WPRFMC 2001). Some crustaceans
also provide symbiotic or commensal associations with other marine organisms (e.g., cleaner
shrimps, crabs: camouflage, protection, etc.) (Colin and Arneson 1995).
Life History—Stomatopods lay as many as 50,000 eggs which are joined together by an adhesive
secretion and held by the female in a small subchelate appendage where the eggs are constantly
turned and cleaned. Besides peneids which shed their eggs directly into the water, all other decapods
carry their eggs on their pleiopods (WPRFMC 2001).
♦ Echinoderms (Sea Cucumbers and Sea Urchins)
Status—Echinoderms include sea cucumbers (holothuroids), sea urchins (echinoids), brittle and
basket stars (ophuiroids), sea stars (asteroids), and feather stars/sea lilies (crinoids). This group is
managed in Micronesia as part of PHCRT (WPRFMC 2001). More than 200 echinoderm species (47
holothuroids, 53 echinoids, 47 ophuiroids, 35 asteroids, and 21 crinoids) have been reported from
CNMI and Guam (Kirkendale and Messing 2003; Paulay 2003d; Starmer 2003) and have EFH
designated within the boundaries of the study area (WPRFMC 2001; NMFS 2004c). At least 196 of
these species are known from Guam (Paulay 2003d). Some echinoderms have economic
importance, particularly the sea cucumbers which are prized for the dried muscular body wall.
Gonads of some species of sea urchins are edible (Conand 1998). However, outbreaks of the crownof-thorns
starfish (Acanthaster planci) since 1967 have had negative economic impacts; an
Acanthaster outbreak devastated Guam’s reefs in 1967 (Colgan 1987) and Tinian’s reefs in 1969-
1970 (Grigg and Birkeland 1997).
Distribution—The phylum Echinodermata is exclusively marine and distributed throughout all
oceans, at all latitudes, and depths from the intertidal zone down to the deep sea (Colin and Arneson
1995). Echinoderm fauna are widely distributed across several localities of the Indo-Pacific region
with few taxa being endemic (Pawson 1995).
Habitat Preferences—A small proportion of echinoderms form dense monospecific populations in
shallow reef zones and play important roles in trophodynamics and nutrient regeneration. The coral
reef habitat and associated environments inhabited by echinoderms include sandy bottoms of
lagoons, coral sand, and reef-flat rocks (sea urchins); hardbottom biotopes of reef flats, sublittoral and
patch reefs, outer reef slope, and cryptofaunal habitats (sea stars); under stones in trenches on reef
flats or on seagrasses (brittle stars); weak current areas in reef-flats and outer slope trenches and
caves (feathered stars); and coral slopes (passages), inner/outer lagoons, inner/outer reef-flats
covered with sand and rubble (sea cucumbers) (Sorokin 1995; Conand 1999; Miskelly 1968). Most
echinoderms (e.g., brittle and feathered stars) are nocturnal, hiding in the daytime and feeding at
nighttime (Sorokin 1995). They also have formed commensal relationships with small reef organism
(e.g., shrimps and fishes) (Colin and Arneson 1995).
Life History—The majority of echinoderms have separate sexes, but unisexual forms occur among
the sea stars, sea cucumbers, and brittle stars. Many species have external fertilization, which
produce planktonic larvae, but some brood their eggs, never releasing free-swimming larvae (Colin
and Arneson 1995).
♦ Annelids (Segmented Worms)
Status—Segmented worms or polychaetes are managed in Micronesia as part of PHCRT (WPRFMC
2001). At least 76 genera and over 100 species of polychaetes have been reported from Guam
(Bailey-Brock 2003) and have EFH designated within the boundaries of the study area (WPRFMC
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