We are all familiar with shallow coral reefs. Growing in warm, clear waters, these colorful ecosystems are easily accessible to divers and snorkelers alike. What is less known is that coral reefs extend into deeper waters, up to almost 200 meters. In these gloomy depths, corals have adapted to low light levels, cold water and elevated nutrients.
Symbiodinium (AKA zooxanthellae) is the engine that spurs much of coral reef growth. From anatomy to clades, parasitic zoox to coral fidelity, Dana Riddle updates us on this powerhouse symbiont.
When we talk about the history of the marine aquarium, we often praise people such as Lee Chin Eng, Peter Wilkens and Jean Jaubert, who did pioneering work in the 20th century. Their innovations and vision helped give rise to the popular marine aquarium hobby we know today. What few people know, however, is that Victorian England saw an aquarium craze 165 years ago, when much ground-breaking work was done. Some of the pioneers of the marine aquarium from that time are George Johnston, Robert Warington, Anna Thynne, William Lloyd and Philip Henry Gosse. In this article, I will detail their work, including the trials and tribulations, which represents some of the early attempts to maintain a balanced marine aquarium.
The diversity of Tridacnid available to hobbyists has expanded in recent years, and so has the taxonomic confusion among aquarists and researchers alike. James W. Fatherree sheds light on the "new" giant clams.
Feature Study: Effects of rock preconditioning and irradiance on growth of crustose coralline algae in aquaculture
Due to its high commercial value, live rock is a promising candidate for aquaculture. This poses interesting challenges, as our knowledge of live rock development in aquaculture is limited. The current preliminary study investigated the effects of rock preconditioning and irradiance on the growth of crustose coralline algae (CCA), a desired group of benthic calcifying algae.
Reefs are tricky balancing acts of livestock largely learned through trial and error. Fortunately, we have successful aquarists to guide the way. James shares his experiences with stocking a large mixed reef.
Back in 2005 I first read about Dendronephthya corals, notorious for being difficult to maintain in aquaria. Lacking zooxanthellae, these corals require plankton to stay healthy. In the following years, I read up on the scientific literature, and toyed with the idea of setting up an aquarium specifically designed for Dendronephthya. This led to the launch of a crowd funding project on Indiegogo, to acquire funds for the development of a culture protocol for Dendronephthya corals. Although insufficient funds were gathered to fully develop an aquaculture system and culture protocol, two preliminary experiments were conducted. In this article, I will present the results of these experiments, and provide future directions for research. This may help aquarists to keep pushing the frontier of coral husbandry and aquaculture.
Myths are a part of life, and occur everywhere. So too in the aquarium hobby, where anecdotal observations and theories sometimes transform into facts, with little evidence to support them. We often make choices based on hearsay or "facts" presented by aquarists, who may dispense their advice with the best intentions. In some cases, unfortunately, we are misleading ourselves. In this article, we discuss some of the myths that still persist in the marine aquarium hobby today, and look at these from a scientific point of view. The take home message is that we should all keep an open mind, but remain critical towards claims that have no factual basis.
Aquarium water yellows over time due to organic decomposition. Dana Riddle analyzes the effects of this phenomenon on light attenuation and demonstrates why aquarists should strive for consistent maintenance practices.
Feature Article: Imitating Natural Light Quality, Intensity, and Dosage in a Reef Aquarium - Do We Really Want To?
When it comes to reef aquariums, Mother Nature has always been the de facto benchmark aquarists aspire towards. Dana investigates in great detail the quality and quantity of light over natural reefs in order to lay the groundwork to answer the age-old question: what is the best light for captive corals?
At present, several factors which influence the growth of scleractinian corals in aquaculture have been identified. These are known as light, water flow, water quality, and nutrition. This article will focus on nutrition, and describe the various ways in which corals feed. It will summarize the latest scientific findings about this topic, and present practical information on how to maximize coral feeding rates in the aquarium. This will promote efficient, sustainable coral aquaculture, and help the aquarist to maintain healthy corals at home.
Dana Riddle previously documented and discussed light intensity of a Hawaiian tidepool versus the home aquarium. Dana continues his light analysis by examining spectral data. What can nature teach us about coral care?
James journeys to Australia's Great Barrier Reef with full camera gear in tow. Join him as he surveys the world's largest living structure and witness its incredible beauty and fragility.
Can we possibly match the amount of natural light in an aquarium?
The mutualistic symbiosis between corals and zooxanthellae is a well-known fact amongst aquarists. To improve our understanding of zooxanthellae biology, scientists isolate these symbionts from the coral host under a variety of environmental conditions. This article will provide an overview of zooxanthellae biology, and how these dinoflagellates are isolated for scientific study. This will give aquarists more insight into, and hopefully appreciation for, the symbiosis between zooxanthellae and the corals they grow in their home aquaria.
Feature Article: Coral growth under Light Emitting Diode and Light Emitting Plasma: a cross-family comparison
With the advent of new technology, aquarists are able to customize light spectra with great flexibility. However, our knowledge of how light spectrum affects aquarium life, including corals, is still limited. Here, we show the effects of two light spectra, emitted by Light Emitting Diode (LED) and Light Emitting Plasma (LEP), on the growth of ten commercially important scleractinian corals. It appears that the effect of spectrum is highly species dependent, and that most efficient coral growth is invariably attained at low irradiance. The results from this study can be used to optimize sustainable coral aquaculture.
As LED lighting moves further into the mainstream, there is new effort being made to provide a fuller spectrum light that can be tuned by the aquarist to satisfy both the demands of the corals as well as the visual pleasure of the aquarist.
Flatworms are well-known in the aquarium hobby and research community. Both in the wild and in captivity, they hide between the tentacles of many corals. Despite their common appearance in aquaria, the nature of the symbiosis between corals and flatworms has long been unclear. New evidence strongly suggests that epizoic acoelomorph flatworms are parasitic. Next to suffocating coral tissue and feeding on coral mucus, flatworms have now been found to impair coral feeding.
Light is one of the main life-supporting resources on our planet. Being photosynthetic, many marine invertebrates require light to live; Their symbiotic zooxanthellae need light for photosynthesis to produce sufficient nourishment both for their own use and for the host coral.
Feature Article: Improved husbandry of marine invertebrates using an innovative filtration technology - part two: results with two 12 cubic meter DyMiCo systems
In part one of this article I discussed the growing incentive to aquaculture marine invertebrates to increase the sustainability of the global aquarium trade, and presented the DyMiCo technology as a possible solution. In part two, I will outline some of the results that have been obtained with the DyMiCo technology recently. More specifically, I will discuss the successful husbandry of invertebrates that depend on a live plankton population for their survival.