The volume contains 264 pages, illustrated
with hundreds of excellent color underwater identification photographs. It also contains as well clear accompanying line drawings of sclerites, critical for final taxonomic
determination. There is a bibliography and an index.
Marine biologist Katharina Fabricius,
Research Scientist at the Australian Institute of Marine Science and octocoral taxonomist
Philip Alderslade, Curator of Coelenterates at the Museum and Art Gallery of the Northern
Territory at Darwin, Australia, collaborated to author this handsome identification guide
to over 90 genera of the order Alcyonacae, belonging to 23 families. This order, along
with the orders Helioporacea (blue coral) and Pennatulacae (sea pens) -- groups this
volume does not cover -- form the Subclass Octocoralia, which is characterized by polyps
bearing eight (as the name implies) hollow tentacles, with both sides fringed by one or
more rows of pinnules. This differentiates them from the six tentacle based Hexacoralia,
which includes the sea anemones, hard corals, zoanthids and corallimorphs. The state of
taxonomy of the Alcyonacea, like that of other cnidarians, is currently under revision.
The goal of the book's authors is to provide "a tool which for the first time, should
give non-experts a comprehensive review of these 90 genera, and the means to correctly
identify them underwater and in the laboratory." We would add, ‘and in the
aquarium.’
Proud sponsor of this column
Many aquarists
are interested in maintaining organisms from this group, among them some that are often
considered the most beautiful inhabitants of coral reefs, in spite of the fact that some
of the most attractive and colorful species are azooxanthellate and therefore require
difficult, special feeding regimens. Charles Delbeek's report on Dendronephthya at
the Waikiki Aquarium, "Non-photosynthetic Corals" in the January 2002 premier
issue of Advanced Aquarist and Rob Toonen's "Discussion of the care of
gorgonians" in the March 2002 issue are indications of this interest. These authors
detail both the advances made in the husbandry of the group and the remaining critical
limitations in our knowledge.
This well illustrated field and laboratory
guide significantly adds to the project of solving the problems associated with improving
specimen viability by providing the information necessary for reliable identification of
90 genera known from the Central and Western Pacific, the Indian Ocean and the Red Sea,
along with some information on their natural habitats.
The volume begins with forty
valuable pages of basic material about the biology and ecology of reef-inhabiting soft
corals and sea fans, and explains the few technical terms used. The section starts with a
general overview of the classification of the phylum Coelenterata down to the order
Alcyonaria. This is followed by discussions of octocoral histology and anatomy and of
their growth forms. Aquarists will appreciate the information in the sections following on
reproduction, propagation, and on nutrition -- including feeding and photosynthesis. The
second half of this section discusses the ecology of octocorals, including important notes
on their physical environment, such as currents, light, salinity, temperature and
nutrients. This is followed by a fascinating discussion of "chemical ecology,"
covering protection and defense, anti-fouling and anti-predator substances, interactions
with other species ranging from symbiosis to allelopathy (chemical defense against space
competitors), internal sunscreens and complementary metabolites used in reproduction. This
opening section concludes with "Choice of Octocorals for a Coral Reef Aquarium,"
in which the authors recommend choosing zooxanthellate species and seek to discourage the
collection or acquisition of those that lack symbiotic algae, excellent general advice for
the time being, given our present state of knowledge.
The remaining 200 pages of the guide are
devoted to identification and associated information. The authors caution that
classification into suborders "is difficult to justify," and therefore allocate
families and genera into "groups." A summary survey of families, with
page-referenced photos of typical genera provides handy organization for the remainder of
the volume. The guide proper is profusely illustrated with excellent underwater
photographs and detailed line drawings of skeletal elements for each genus, along with
descriptions of colony shape, polyp structure, color, habitat and abundance, and
geographic distribution. Most important, the presence or absence of zooxanthellae is noted
for most genera. The photographs - averaging 6 to 8 per genus - cover the major growth
forms, including pictures of entire animals in their natural environment as well as
close-up photographs of characteristic details. The book is worth having for the beautiful
illustrations of these gorgeous organisms alone.
Proud sponsor of this column
The authors
allocate the families to three groups and two suborders. In the Stolonifera Group, they
place, among others, Clavularia, and Tubipora. The Alcyoniina Group contains
the Alcyoniina, among them the familiar genera Sinularia, Cladiella, Sarcophyton
and Lobophytum; the intriguing Nephtheidae, including Nepthea, Scleronepthya,
Dendronephthya and Lemnalia; Nidaliidae; Paracyoniidae and Xeniidae,
including Xenia, Cespitularia and Anthelia. The Scleraxonia Group
contains the families Briareidae, with its single genus Briareum (often called Pachyclavularia)
and Anthothelidae, Subergorgiidae, Melithaeidae and Parisididae, each containing very
colorful but usually azooxanthellate gorgonians. The suborder Holaxonia includes the
families Keroedidiiae, Acanthogorgiidae and Plexauridae, all of which also include many
beautiful red, purple or orange azooxanthellate gorgonians and the family Gorgoniidae
which contains both zooxanthellate and azooxanthellate genera. The final suborder,
Calcaxonia, contains the family Ellisellidae, also with highly colorful but
azooxanthellate genera; Ifalukellidae, with two zooxanthellate genera; Primnoidae and
Chrysogorgiidae, each with single azooxanthellate genera and the family Isididae, with
both zooxanthellate and azooxanthellate genera.
This volume is worth space on your bookshelf
for its value as an excellent, informative, beautiful, identification guide. It does not,
however, provide the detailed information needed to increase the potential for survival of
the azooxanthellate genera in aquariums. The current state of knowledge about the
husbandry of these organisms is limited, as is their life span in captivity. For advances
in that direction, articles such as those by Charles Delbeek on Dendronephthya and
Rob Toonen on nonphotosynthetic gorgonians in this publication are much more likely to
provide critical husbandry information
Periodicals
The February 2002 National Geographic
features "Cuba's Reefs," by Peter Benchley, with magnificent photographs by
David Doubilet (p. 50). Benchley reports that Cuba's reefs are almost pristine, compared
with other Caribbean reef areas. He says, "I...apparently slipped backward nearly
half a century into an underwater realm that had not existed, so far as I knew, since the
1950's." Cuba, with the largest submerged shelf in the Caribbean, has more than 3,000
miles of coastline containing four reef systems, each equal to or larger than the Florida
Keys. The "Garden of the Queen" Marine Sanctuary, containing about a thousand
square miles of reefs off Cuba's southeast coast, is strictly protected. As in many other
world areas, however, there is conflict between the value of commercial fishing areas and
the need for environmental protection to meet the demands of the thriving tourism
industry. Currently the balance is in favor of ecotourism. The dive operation was very
professional - several crewmembers had advanced degrees, including a veterinarian.
You can read the full article and see the
extraordinary photos at:
The May-June issue of American
Scientist includes "The Global Transport of Dust: An intercontinental river of
dust, microorganisms and toxic chemicals flows through the Earth’s atmosphere,"
by Dale W. Griffin, Christina A. Kellogg, Virginia H. Garrison and Eugene A. Shinn. The
authors, scientists at the USGS, suggest that bacteria and fungi have been hitching
trans-Atlantic rides on dust from the Sahara desert and settling into the warm waters of
the Caribbean, contributing to the deterioration of its coral reefs. The summary is
available at:
The Public Broadcasting System (PBS) has two
video presentations of interest to aquarists and other lovers of the seas.
The exciting series "Shape of Life"
is currently being aired on PBS stations nationally and internationally. The eight part
series on the evolution of life starts with "Origins," focusing on the sponges.
It then presents programs on the cnidarians, the flatworms, the arthropods, the mollusks
and the echinoderms. The final two programs are on the annelid worms and the chordates.
You can find extensive previews and scheduling information at:
"Empty Oceans, Empty Nets"
documents the crisis of marine fisheries as they are systematically fished down to the
point of collapse. The video, Item A5390, priced at $24.98 can be ordered from:
