Ophionereis reticulata (Say) (family Ophionereididae) share nearly similar habitats with O. echinata, though they prefer sandy bottoms and hide under reef
overhangs and under rock and coral slabs. This is one of the most common species
of brittle stars across the Puerto Rican shelf, at depths ranging from nearly sea
surface to well beyond 30 m. it prefers sandy bottoms at the edge of coral reefs,
under coral overhangs or rubble.
There are also three ubiquitous brittle stars from family Ophiodermatidae,
which include Ophioderma rubicundum (Lütken), O. apressum (Say), and
Ophiothrix suensonii (Lütken). The first species can be typically found hidden
during the day under coral heads and reef crevices but foraging at night across
open areas of reef bottoms. During coral mass spawning events they become very
active and rapidly climb coral heads, sea fans (Gorgonia spp.) and other octocorals
approximately two minutes before mass spawning begins. This behavior can be
used as an indication of the beginning of spawning and could probably result from
some form of chemical reception of signals from corals. In the case of
O. apressum, its behavior and typical habitat range is fairly similar to that of
O. rubicundum, while O. suensonii is typically hidden during the day within
sponges but can be commonly seen active at night, often climbing different
octocoral species.
There is also an important species of basket star, Astrophyton muricatum
(Lamarck) (order Phrynophiurida). It can be commonly found across the region,
particularly in coral reefs with abundant sea fan populations and at least moderate
water circulation. They often coil into a tight rounded shape attaching to gorgonians or sponges, but open widely to filter plankton at night by orienting its body
and spreading its arms perpendicular to the prevailing current.
14.3.3 Echinoidea Distribution
The distribution and abundance of Echinometra lucunter and E. viridis were
examined on seven coral reefs near the southwest of Puerto Rico (McGehee 1992).
Urchin distribution was strongly correlated with patterns in water motion, depth,
and substrate size among the reefs. However, the two species of Echinometra
occupy different habitats. Echinometra lucunter was most abundant in the shallow
forereef zone while E. viridis was more common in habitats with less water
movement and smaller substrate particle sizes, such as deep forereef and nearshore
sites. McGehee (1992) observed that water movement may be the best variable to
predict abundance and distribution of the two urchins. As for depth, E. lucunter
was found in shallow water at depths of 2–3 m, and E. viridis was found at depths
greater than 3 m. Also, E. lucunter can be extremely abundant (e.g., 50–125 ind
m
-2 ) on subtidal emergent eolianite platforms along the northern coast (Hernández-Delgado, unpub. data).
As of 1940, Mellita lata was ranked the most common echinoderm of Puerto
Rico (Kenk 1944). The distribution of this species occurred in the uppermost
14 Review of Echinoderm Research in Puerto Rico
457
overhangs and under rock and coral slabs. This is one of the most common species
of brittle stars across the Puerto Rican shelf, at depths ranging from nearly sea
surface to well beyond 30 m. it prefers sandy bottoms at the edge of coral reefs,
under coral overhangs or rubble.
There are also three ubiquitous brittle stars from family Ophiodermatidae,
which include Ophioderma rubicundum (Lütken), O. apressum (Say), and
Ophiothrix suensonii (Lütken). The first species can be typically found hidden
during the day under coral heads and reef crevices but foraging at night across
open areas of reef bottoms. During coral mass spawning events they become very
active and rapidly climb coral heads, sea fans (Gorgonia spp.) and other octocorals
approximately two minutes before mass spawning begins. This behavior can be
used as an indication of the beginning of spawning and could probably result from
some form of chemical reception of signals from corals. In the case of
O. apressum, its behavior and typical habitat range is fairly similar to that of
O. rubicundum, while O. suensonii is typically hidden during the day within
sponges but can be commonly seen active at night, often climbing different
octocoral species.
There is also an important species of basket star, Astrophyton muricatum
(Lamarck) (order Phrynophiurida). It can be commonly found across the region,
particularly in coral reefs with abundant sea fan populations and at least moderate
water circulation. They often coil into a tight rounded shape attaching to gorgonians or sponges, but open widely to filter plankton at night by orienting its body
and spreading its arms perpendicular to the prevailing current.
14.3.3 Echinoidea Distribution
The distribution and abundance of Echinometra lucunter and E. viridis were
examined on seven coral reefs near the southwest of Puerto Rico (McGehee 1992).
Urchin distribution was strongly correlated with patterns in water motion, depth,
and substrate size among the reefs. However, the two species of Echinometra
occupy different habitats. Echinometra lucunter was most abundant in the shallow
forereef zone while E. viridis was more common in habitats with less water
movement and smaller substrate particle sizes, such as deep forereef and nearshore
sites. McGehee (1992) observed that water movement may be the best variable to
predict abundance and distribution of the two urchins. As for depth, E. lucunter
was found in shallow water at depths of 2–3 m, and E. viridis was found at depths
greater than 3 m. Also, E. lucunter can be extremely abundant (e.g., 50–125 ind
m
-2 ) on subtidal emergent eolianite platforms along the northern coast (Hernández-Delgado, unpub. data).
As of 1940, Mellita lata was ranked the most common echinoderm of Puerto
Rico (Kenk 1944). The distribution of this species occurred in the uppermost
14 Review of Echinoderm Research in Puerto Rico
457