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| This column, the first Media Review for Advanced Aquarist will cover two pieces on highly significant, related topics for advanced aquarists, and two short notes from Coral Reefs. The first book is on a subject that will be of increasing interest and importance - the aquaculture of organisms of value for marine aquarists. The second is a draft report of the U.S. Coral Reef Task Force subgroup on the trade in coral and coral reef organisms. As will be seen, conclusions from the task force report will certainly serve to focus more attention on the captive breeding of aquarium species.
The next section of the book is devoted to the larvae and their rearing. The author starts with a more detailed presentation on the stages of larval development and then discusses outfitting the nursery and caring for the larvae. The next step is a little more demanding. For example, to feed the larvae and bring them through their metamorphosis to adulthood, it is best to establish a brine shrimp hatchery. Kirkendoll gives excellent advice on establishing and maintaining these cultures. She also provides valuable tips on alternative foods, basing much of her work on the pioneering efforts of Martin Moe, as described in his Raising the Orchid Dottyback. A summary chapter concludes the main body of the book, with notes on issues in commercial breeding. Kirkendoll finishes by documenting her failed attempts to close the life cycle of L. amboinensis, the Striped Cleaner shrimp and L. debelius, the Flame shrimp. She was not able to bring them past the fourth week of larval development and offers suggestions to those who would attempt to breed these attractive species. I hope some of you will take up the challenge. This little book, with its casual and informal style will help you get up and running.
The opening Executive Summary of this report puts the commercial exploitation of coral reefs and coral reef in perspective, stating, "Many coral reef species and resources are harvested globally for commercial purposes, including food fish, the aquarium trade, live fish markets, construction materials, curios, jewelry, pharmaceuticals and traditional medicines. International trade in coral, reef fish, live rock and other coral reef animals are activities that contribute to the decline and degradation of reefs, primarily through the use of destructive collection practices and overexploitation of resources." Of these, of course, it is the danger to the aquarium trade organisms and the damage from destructive collection techniques that we must accept responsibility for, even as we recognize that other aspects of the exploitation of reefs are far more destructive. U.S. aquarists have a particular responsibility because we are the number one consumer of live coral and marine aquarium fishes (as well as the largest importer of coral skeletons and coral jewelry). Of an estimated 1.5 million marine aquarium hobbyists worldwide, 1 million are in the U.S. (p. 9)
The report lists other dangers and problems associated with collection: most collected species are herbivores that control benthic algae, mortality figures from source reefs to home aquaria have been found to be as high as 90%, some collected species have poor survival rates in captivity, and economic incentives lead to the collection of rare and difficult to capture species such as deep-water fishes. The Trade Subgroup makes a number of recommendations to the U.S. Coral Reef Task Force. With respect to other nations with coral reefs, these include: (1) continued active participation in international and regional organizations concerned with exploitation of coral reef species (2) expanded capacity to collect data, assess reef status, evaluate impacts of collection and enforce regulations (3) development and implementation of sustainable management, environmentally sound collection techniques and certification programs (4) establishment of alternatives such as aquaculture and coral farming. For the U.S., the report suggests: (1) improved enforcement of regulations regarding coral species trade, including certification that organisms were not taken through destructive practices (2) development of educational material to raise domestic consumer awareness to ensure that demand for marine organisms does not contribute to the decline of reef species and the degradation of coral reef ecosystems (3) encouragement of alternatives to wild collection (4) development, with the marine aquarium industry, of practices to reduce mortality rates and improve product quality to ensure survival in captivity (5) prohibition of domestic harvest and collection by defined destructive techniques.
From the Periodicals "Do color patters of Pocillopora damicornus reflect Zooxanthellae diversity?" by Jr-Kai Yu et. al. from Coral Reefs, March 2000, Vol 19, #1, pg 98-99. Analysis indicates no statistical differences in zooxanthellae gene types or density between pink and brown morphs. The depth distribution differed markedly, however, with the brown morph found predominantly in very shallow habitats. The pink morph possesses the pigment pocilloporin which is associated with slow growth rates and "superior competitor ability." On the basis of this finding, the authors question the taxonomic identity of the two P. damicornus morphs. "Coral crabs influence the feeding patterns of crown-of-thorns starfish" by M. Pratchett, E. Vytopil and P. Parks from Coral Reefs, March 2000, Vol 19, #1, pg. 36. Crabs of the genus Trapezia live in association with pocilloporid corals; Tetralia only in Acropora. "In feeding experiments where crabs were removed from all coral colonies we found that Acanthaster planci (crown-of-thorns starfish) consumed both Acropora nasuta and Pocillopora damicornis in equal numbers. When Tetralia and Trapezia crabs were present in their respective host species, A. planci consumed all the A. nasuta colonies but never consumed P. damicornis." The Trapezia crabs were more effective in their defense, breaking off thorns at the pedicle. The Tetralia crabs pinched at the starfish's tube feet, doing little damage. |
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