Sea Stars
Luidia (Platasterias) latiradiata
Distribution
The living genus Platasterias is a surviving somasteroid and Luidia is a surviving
basal asteroid (Fell 1963). Luidia (Platasterias) latiradiata, based upon its skeletal
morphology, is considered a ‘‘living fossil’’ (Fell 1963; Caso 1970; Blake et al.
2000). The biogeographical distribution of this species has been extended to
Ecuador. It had been found close to the coast of México and Central America
(Caso 1970, 1976; Solís-Marín 1998). Villamar and Cruz (1983) found large
specimens on a sandy bottom in the intertidal zone at Playas, General Villamil, in
the mainland of Ecuador (Fig. 6.1). In México, this species have been reported by
incidental mortality due to shrimp fisheries, where this assumes an impact that can
cause a decrease in their populations. For more information, review the México
chapter.
Diet and Feeding Habits
Villamar and Cruz (1983) reported L. latiradiata fed on crustaceans (i.e. cumaceans, miscidaceans), gastropods (Olivella semistriata), and bivalves (Donax
mancorensis).
Phataria unifascialis and Pharia pyramidata
Distribution and Density
Distribution of sea star species in shallow waters along the mainland of Ecuador is
essentially unknown. Sonnenholzner and Lawrence (2002) conducted a brief
survey focused on two sea stars, P. pyramidata (Fig. 6.3h), and P. unifascialis
(Fig. 6.4 g–h) at Los Frailes, Machalilla National Park, Manabí. They made sixtyone transects (2 m wide 9 25 m long ‘‘double’’ quadrants, a total area of
3,100 m
2 ). The density of P. unifascialis and P. pyramidata was 0.017 ind m
-2
and 0.0006 ind m
-2 , respectively. These species were found mainly on open rocky
flat bottoms among the rocks, on or under boulders and dead coral.
Arm Size
Sonnenholzner and Lawrence (2002) measured P. unifascialis and P. pyramidata
in the southern and northern embayment at Los Frailes, Manabí. The arm radius of
P. unifascialis ranged from 40 to 80 mm, with most being 60–70 mm. The arm
radius of a small distinct cohort was 90–95 mm. The arm length of P. pyramidata
was between 93 and 121 mm.
6 Echinoderms of Ecuador
207
Luidia (Platasterias) latiradiata
Distribution
The living genus Platasterias is a surviving somasteroid and Luidia is a surviving
basal asteroid (Fell 1963). Luidia (Platasterias) latiradiata, based upon its skeletal
morphology, is considered a ‘‘living fossil’’ (Fell 1963; Caso 1970; Blake et al.
2000). The biogeographical distribution of this species has been extended to
Ecuador. It had been found close to the coast of México and Central America
(Caso 1970, 1976; Solís-Marín 1998). Villamar and Cruz (1983) found large
specimens on a sandy bottom in the intertidal zone at Playas, General Villamil, in
the mainland of Ecuador (Fig. 6.1). In México, this species have been reported by
incidental mortality due to shrimp fisheries, where this assumes an impact that can
cause a decrease in their populations. For more information, review the México
chapter.
Diet and Feeding Habits
Villamar and Cruz (1983) reported L. latiradiata fed on crustaceans (i.e. cumaceans, miscidaceans), gastropods (Olivella semistriata), and bivalves (Donax
mancorensis).
Phataria unifascialis and Pharia pyramidata
Distribution and Density
Distribution of sea star species in shallow waters along the mainland of Ecuador is
essentially unknown. Sonnenholzner and Lawrence (2002) conducted a brief
survey focused on two sea stars, P. pyramidata (Fig. 6.3h), and P. unifascialis
(Fig. 6.4 g–h) at Los Frailes, Machalilla National Park, Manabí. They made sixtyone transects (2 m wide 9 25 m long ‘‘double’’ quadrants, a total area of
3,100 m
2 ). The density of P. unifascialis and P. pyramidata was 0.017 ind m
-2
and 0.0006 ind m
-2 , respectively. These species were found mainly on open rocky
flat bottoms among the rocks, on or under boulders and dead coral.
Arm Size
Sonnenholzner and Lawrence (2002) measured P. unifascialis and P. pyramidata
in the southern and northern embayment at Los Frailes, Manabí. The arm radius of
P. unifascialis ranged from 40 to 80 mm, with most being 60–70 mm. The arm
radius of a small distinct cohort was 90–95 mm. The arm length of P. pyramidata
was between 93 and 121 mm.
6 Echinoderms of Ecuador
207