There are many doubts about the taxonomy of some Peruvian brittle stars like
O. kroeyeri. It probably includes at least two species that have not yet been
distinguished. More detailed studies are required.
8.3.2 Tropical Peruvian Eastern Pacific
Seventy five percent of the intertidal Peruvian echinoderm species are concentrated at the northern tip of Peru along less than 150 km of coastline. North of
Cabo Blanco (4°15
0 S; Fig. 8.1), all species are typical of the Tropical Eastern
Pacific, with the exception of C. gibbosus, Pentamera chierchia and P. chiloensis,
which are widely distributed. Pentamera spp. are even found in cold waters and
cannot be considered members of any given province.
On the other hand, Ophiothrix magnifica, a brittle star common at north Peru
(Fig. 8.4f), enters the Peru Current to Paracas and is successfully established in
enclosed shallow bays where warmer waters allow the temporary presence populations. This species is not considered widely distributed since it appears only in
refugia where environmental conditions differ from the surrounding areas. The
region between El Ñuro and Punta Sal is where the best example of the Tropical
Eastern Pacific echinoderm community is found in Peru. Rocky reefs are scarce in
northern Peru, represented mainly by flat strata of sedimentary rocks. In this area
some taller reefs appear, mainly at Punta Sal. Further north, the diversity is reduced
because of the sediment load and turbidity caused by the discharge of adjacent rivers.
In the intertidal, the most common species are Ophioderma panamensis,
Ophiocoma aethiops (Fig. 8.4d), O. magnifica, Arbacia incisa and Echinometra
vanbrunti, mainly in tide pools and below rocks. In the subtidal zone the most
abundant species are Eucidaris thouarsii (Fig. 8.5g), and Phataria unifascialis.
Pentaceraster cumingi used to be abundant, but it has become rare since it is collected to be sold as souvenirs. The most common sea cucumber is Cucumaria flamma
(Fig. 8.5f) which populates the higher portions of reefs. Under the rocks, Holothuria
arenicola and H. impatiens are frequent species, together with O. panamensis and
O. aethiops (Fig. 8.4d). Another common species, O. magnifica, may be found in all
available cryptic habitats, including rocks, algae, sponge, ascidians, and gorgonians.
Ophiothela mirabilis is a brittle star that is always associated with gorgonians, where
it is attached to their branches in large numbers (Fig. 8.4e).
Astropyga pulvinata (Fig. 8.4h), a large sized sea urchin, is a very rare species in
Peru. It has been reported in two localities: north of Punta Sal, where there is a rather
large population composed mostly by large adults, and at Lobos de Afuera, where a
large group of juveniles on a rocky reef were found (Hooker et al. 2005). Some other
rare species are Toxopneustes roseus, known in Peru only from scarce reports at El
Ñuro, Isla Foca, and Islas Lobos de Afuera. Paulia horrida is a rare seastar found
through its whole distribution, reported in Peru only from Punta Sal (Fig. 8.4c).
This differs from the status of the seastar Nidorellia armata, which was frequent
but has become close to extinction due to extraction for the souvenir market.
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Y. Hooker et al.
O. kroeyeri. It probably includes at least two species that have not yet been
distinguished. More detailed studies are required.
8.3.2 Tropical Peruvian Eastern Pacific
Seventy five percent of the intertidal Peruvian echinoderm species are concentrated at the northern tip of Peru along less than 150 km of coastline. North of
Cabo Blanco (4°15
0 S; Fig. 8.1), all species are typical of the Tropical Eastern
Pacific, with the exception of C. gibbosus, Pentamera chierchia and P. chiloensis,
which are widely distributed. Pentamera spp. are even found in cold waters and
cannot be considered members of any given province.
On the other hand, Ophiothrix magnifica, a brittle star common at north Peru
(Fig. 8.4f), enters the Peru Current to Paracas and is successfully established in
enclosed shallow bays where warmer waters allow the temporary presence populations. This species is not considered widely distributed since it appears only in
refugia where environmental conditions differ from the surrounding areas. The
region between El Ñuro and Punta Sal is where the best example of the Tropical
Eastern Pacific echinoderm community is found in Peru. Rocky reefs are scarce in
northern Peru, represented mainly by flat strata of sedimentary rocks. In this area
some taller reefs appear, mainly at Punta Sal. Further north, the diversity is reduced
because of the sediment load and turbidity caused by the discharge of adjacent rivers.
In the intertidal, the most common species are Ophioderma panamensis,
Ophiocoma aethiops (Fig. 8.4d), O. magnifica, Arbacia incisa and Echinometra
vanbrunti, mainly in tide pools and below rocks. In the subtidal zone the most
abundant species are Eucidaris thouarsii (Fig. 8.5g), and Phataria unifascialis.
Pentaceraster cumingi used to be abundant, but it has become rare since it is collected to be sold as souvenirs. The most common sea cucumber is Cucumaria flamma
(Fig. 8.5f) which populates the higher portions of reefs. Under the rocks, Holothuria
arenicola and H. impatiens are frequent species, together with O. panamensis and
O. aethiops (Fig. 8.4d). Another common species, O. magnifica, may be found in all
available cryptic habitats, including rocks, algae, sponge, ascidians, and gorgonians.
Ophiothela mirabilis is a brittle star that is always associated with gorgonians, where
it is attached to their branches in large numbers (Fig. 8.4e).
Astropyga pulvinata (Fig. 8.4h), a large sized sea urchin, is a very rare species in
Peru. It has been reported in two localities: north of Punta Sal, where there is a rather
large population composed mostly by large adults, and at Lobos de Afuera, where a
large group of juveniles on a rocky reef were found (Hooker et al. 2005). Some other
rare species are Toxopneustes roseus, known in Peru only from scarce reports at El
Ñuro, Isla Foca, and Islas Lobos de Afuera. Paulia horrida is a rare seastar found
through its whole distribution, reported in Peru only from Punta Sal (Fig. 8.4c).
This differs from the status of the seastar Nidorellia armata, which was frequent
but has become close to extinction due to extraction for the souvenir market.
290
Y. Hooker et al.