Page 299 - Encyclopedia of Aquarium and Pond Fish, 3rd Edition

ECHINODERMS 297

Himerometra robustipinna Culcita novaeguineae Pseudocolochirus axiologus
Feather Starfish Bun Starfish Sea Apple

ORIGINS Off the coast of Southeast Asia, notably in the ORIGINS Widely distributed throughout the entire ORIGINS Found on coral reefs off Indonesia, and also on
vicinity of Singapore and parts of Indonesia. Indo-Pacific region. Australia’s Great Barrier Reef.
SIZE 7 in (18 cm). SIZE 10 in (25 cm). SIZE 6 in (15 cm).
DIET Brine shrimp and other small foods. Try to place DIET Mussel, clam, and shrimp meat. Offer small DIET Food particles in suspension. Use liquid foods. May
the food close to the starfish to encourage it to feed. amounts each day, removing any uneaten scraps. also take brine shrimp.
WATER Temperature 77–79°F (25–26°C); alkaline WATER Temperature 77–79°F (25–26°C); alkaline WATER Temperature 77–79°F (25–26°C); alkaline
(pH 8.1–8.3) with SG 1.020–1.024. (pH 8.1–8.3) with SG 1.020–1.024. (pH 8.1–8.3) with SG 1.020–1.024.
When Bun Starfish are mature, their bodies fill
out so much that their five legs are no longer
visible. One of the heaviest of all starfish, they
have spotted upperparts, but their markings and
coloration are highly variable. These predatory
starfish are best housed alongside nonaggressive
fish, rather than in a reef setup, because they will
attack sessile invertebrates, such as corals.

This placid, red starfish usually feeds after dark, The purplish-blue form of this echinoderm, which
waving its highly mobile, featherlike arms in the occurs on the Great Barrier Reef, is exceptionally
current to collect fine particles of food. Feather beautiful. Sea Apples of Indonesian origin are
Starfish can be kept in groups, providing retreats smaller, with grayish-pink bodies. The tentacles
for small, nonaggressive fish, such as gobies. As projecting from the body are used to extract fine
with other starfish species, if an arm breaks off, it food particles from the water. Tankmates for Sea
will usually regenerate. Good water conditions are Apples must be chosen carefully, because some fish
vital for the overall well-being of Feather Starfish. will try to bite off their feeding tentacles.

SPINELESS VERTEBRATES

Sea squirts, such as the striking blue variety
seen here (Rhopalaea crassa), consist of little
more than a baglike body known as a tunic.
These reef animals feed by drawing water
in through the large hole on the top of the
body, then filtering it for edible particles, and
finally passing it out through a smaller orifice
called the exhalant siphon. Like the other
species featured in this section, sea squirts
do not have a backbone, yet these creatures
are actually classified in the same phylum
as vertebrates. This apparent oddity of
classification comes about because when they
are free-swimming larvae, sea squirts possess a
well-developed nervous system. This includes a
stiff central support, called a notochord, which
is similar to the spinal cord. Once they have
matured, however, sea squirts adopt a wholly
sedentary lifestyle and lose these features.
Sea squirts can grow to a relatively large
size, with some species measuring up to 20 in
(50 cm) in length. Being highly vulnerable to
predators, they inhabit inconspicuous areas of
the reef, where they often associate in groups.
Like Turbo Snails (see p.295), sea squirts may
turn up unexpectedly in a marine aquarium,
being introduced accidentally when pieces of
live rock are added to the tank.

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