14.3.4 Holothuroidea Distribution
There are only a few species of non-pelagic sea cucumbers that are known to
execute rapid movements. The species that are able to make rapid movements are
members of the order Apodida. Astichopus multifidus (Sluiter) is a member of the
order Aspidochirotida. Specimens of this group are characterized by dish-shaped
tentacles and respiratory trees. The genus Astichopus is easily recognized because
it is very large and soft and with tube feet uniformly covering both the dorsal and
ventral sides of the body. Astichopus was most abundant on the northwestern
coast, at Crashboat Landing, Puerto Rico. Specimens have been seen at depths of
20–40 m at different times near Isabela, Camuy and Arecibo, Puerto Rico. There
were a few individuals collected from La Parguera, Puerto Rico in areas of dense
turtle grass (Thalassia testudinum). Glynn (1965) stated that Astichopus possibly
breed in the late autumn or early winter in Puerto Rico. Astichopus is very active.
The most frequent means of progression when the animal was left undisturbed is a
slow crawl. Glynn (1965) examined the environmental effects on movements.
Sudden changes in sea water temperature (3–4 °C) resulted in walking, bounding
and rolling movements more effectively than other environmental changes
(salinity, oxygen availability, light regimes, etc.). Specimens were attracted to
natural and artificial light of low intensity (B5 foot-candles) and did not demonstrate any clear tendencies to geotactic or thigmotactic behavior. Increased activity
of this sea cucumber does not release any toxic substance.
Euapta lappa (Müller) can be also commonly found on shallow (3–10 m) to
moderately deep (20–25 m) reefs. They are soft-bodied and are commonly found
at the base of reef patches. They usually hide in reef crevices during the day and
emerge at dusk, moving around adjacent sandy and rubble bottoms. Several other
species in the family Holothuridae (Order Aspirochirotida) can be found across
seagrass, sandy and rubble bottoms in northern and eastern Puerto Rico, including
Holothuria mexicana, Holothuria (Thymiosycia) thomasi (Pawson and Caycedo)
and Actinopygia agassizzi (Selenka). Also individuals of Isostichopus badionotus
(Selenka) (family Stichopodidae) have been documented from Culebra Island.
14.3.5 Echinoderm Larval Distribution
Williams and García Sais (2010) described the temporal and spatial distribution
patterns of echinoderm larvae in La Parguera, Puerto Rico. Temporal variability of
echinoderm larval abundances was examined from a series of monthly tows
between Cayo Collado and Cayo San Cristobal in La Parguera. In this study
11,921 echinoderm larvae were collected. Echinoidea larvae were the numerically
dominant taxa, representing 52.5 % of the total. Amongst the sea urchin assemblage, 20 % were D. antillarum larvae. Ophiuroidea larvae represented 45.6 % of
the total. The combined abundance of Holothuroidea and Asteroidea larvae was
460
S. M. Williams et al.
There are only a few species of non-pelagic sea cucumbers that are known to
execute rapid movements. The species that are able to make rapid movements are
members of the order Apodida. Astichopus multifidus (Sluiter) is a member of the
order Aspidochirotida. Specimens of this group are characterized by dish-shaped
tentacles and respiratory trees. The genus Astichopus is easily recognized because
it is very large and soft and with tube feet uniformly covering both the dorsal and
ventral sides of the body. Astichopus was most abundant on the northwestern
coast, at Crashboat Landing, Puerto Rico. Specimens have been seen at depths of
20–40 m at different times near Isabela, Camuy and Arecibo, Puerto Rico. There
were a few individuals collected from La Parguera, Puerto Rico in areas of dense
turtle grass (Thalassia testudinum). Glynn (1965) stated that Astichopus possibly
breed in the late autumn or early winter in Puerto Rico. Astichopus is very active.
The most frequent means of progression when the animal was left undisturbed is a
slow crawl. Glynn (1965) examined the environmental effects on movements.
Sudden changes in sea water temperature (3–4 °C) resulted in walking, bounding
and rolling movements more effectively than other environmental changes
(salinity, oxygen availability, light regimes, etc.). Specimens were attracted to
natural and artificial light of low intensity (B5 foot-candles) and did not demonstrate any clear tendencies to geotactic or thigmotactic behavior. Increased activity
of this sea cucumber does not release any toxic substance.
Euapta lappa (Müller) can be also commonly found on shallow (3–10 m) to
moderately deep (20–25 m) reefs. They are soft-bodied and are commonly found
at the base of reef patches. They usually hide in reef crevices during the day and
emerge at dusk, moving around adjacent sandy and rubble bottoms. Several other
species in the family Holothuridae (Order Aspirochirotida) can be found across
seagrass, sandy and rubble bottoms in northern and eastern Puerto Rico, including
Holothuria mexicana, Holothuria (Thymiosycia) thomasi (Pawson and Caycedo)
and Actinopygia agassizzi (Selenka). Also individuals of Isostichopus badionotus
(Selenka) (family Stichopodidae) have been documented from Culebra Island.
14.3.5 Echinoderm Larval Distribution
Williams and García Sais (2010) described the temporal and spatial distribution
patterns of echinoderm larvae in La Parguera, Puerto Rico. Temporal variability of
echinoderm larval abundances was examined from a series of monthly tows
between Cayo Collado and Cayo San Cristobal in La Parguera. In this study
11,921 echinoderm larvae were collected. Echinoidea larvae were the numerically
dominant taxa, representing 52.5 % of the total. Amongst the sea urchin assemblage, 20 % were D. antillarum larvae. Ophiuroidea larvae represented 45.6 % of
the total. The combined abundance of Holothuroidea and Asteroidea larvae was
460
S. M. Williams et al.