Articles by Jay Hemdal
The cherry anthias, also known as the Sakura anthias (a.k.a. Sakuradai (さくらだい) in Japan), is a large, attractive and very hardy member of the family Serranidae (groupers and their allies) and the sub-family Anthiinae (the anthias). Click on the PDF link on the right (or below on your phone)...
Rotifer Culture
C. Jay Hemdal
Brackish water rotifers, (Brachionus plicatilis) are a useful food source for certain invertebrate aquarium animals, have been used as bio-assay animals, and are a virtual necessity when raising larval clownfish (Amphiprion sp.). Many culture methods have...
Basic Captive Propagation of Marine Fishes
C. 2003 - 2022 Jay Hemdal
Few people would argue that breeding and raising marine fishes is a much more difficult undertaking than raising freshwater species. The primary reason is that most marine fish have tiny larvae with an extended...
Acclimating Animals to Aquariums
Jay F. Hemdal c.2020
Introduction to acclimation techniques
Most beginning aquarists hear that they must “acclimate” any new animals they add to their aquarium. Acclimation (sometimes termed “acclimatization”) is simply the process of gradually adapting...
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Sourcing Marine Fishes and Invertebrates
Experienced aquarists are aware that fishes from different regions of the world can have different levels of sustainability when acquired for their aquariums. The reasons for these differences may include collection technique (the use of cyanide for...
Salinity Measurements for Marine Aquariums
@Jay Hemdal
Introduction
The fundamental difference between freshwater and marine aquariums is of course, their respective salt content. The salt level is usually reported as either salinity (parts per thousand of salt in water) or specific gravity...
Filefish in Marine Aquariums
Jay Hemdal C. 2022
Filefish, (often called leatherjackets in Australia) have enjoyed a moderate level of popularity for many years as marine aquarium fish. As a group however, there is some variation as to their relative appropriateness for particular aquariums...
Evaluating Synthetic Sea Salts
C. Jay Hemdal 2016
Revised January 12, 2022
This is an update of my 2016 article that examines some testing methods to evaluate synthetic seawater, some of which can be done at home. A short history and list of sea salts is also given. Please note - this is NOT...
Basic Underwater Photography in Aquariums
@Jay Hemdal c.2021
Aquarists often have difficulty photographing animals in their aquariums. Not only do they have the same problems as other photographers (flash reflection off the glass, issues with white balance, fast moving subjects, etc.) they have...
Routine analysis of aquarium water for total bacteria in smaller public and private
aquariums is rarely performed. However, many large aquariums monitor their fish and
invertebrate water systems for this parameter, especially if they already have the required
techniques in place due to...
Our aquarium animals are wholly dependent on the care we give them for their continued good health. Proper environmental care is of course paramount; good water quality, excellent diet, proper aquarium size, compatible inhabitants, etc. Obviously, controlling disease is also a major factor...
Tube Feeding Techniques for Fish
Jay Hemdal
c. 2021
Syringe with catheter attached.
Here is an all too familiar scenario: an aquarist faced with trying to care for a new, expensive fish that tragically refuses to accept any food. Common sense dictates that fish need food in order to...
Hydrogen peroxide usage report
Jay Hemdal
April 3, 2021
Premise:
I use 7% hydrogen peroxide for my home water treatment system. Therefore, since I always have this material in the house, I wanted to explore other possible uses for it, including:
Disease control
Water sterilization
Bleaching...
Estimating the Need for Swimming Space for Aquarium Fishes
Jay Hemdal
For those not wishing to read the entire article, here is the basic formula for calculating the swimming space needs for active swimming species (tangs, wrasses, fusiliers, etc.)
Look up the maximum adult size of the...
Food for Thought
Or
Potential Pitfalls of Using Utility Organisms (CUC) in Aquariums
Jay Hemdal
Aquarists often add “utility organisms” (animals not just for use in a purely decorative sense) to their aquariums to serve some beneficial function. These are often called CUC (Clean Up...
Mucus: The Slime that Binds
Jay Hemdal C. 2020
This article examines the various causes of excess mucus coatings on fish, as well as fecal mucus issues.
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The mucus produced by the fish’s epidermal cells gives them their characteristic slimy feel. Mucus is produced by three...
Parasitic Crustaceans (Copepods, Isopods, and Sea Lice)
Jay Hemdal c.2020
This is an excerpt from my upcoming fish disease book - a section on arthropod parasites of fish; isopods and copepods.
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Cause
This disease problem is caused by a variety of very small crustaceans that...
This file is a PDF copy of the book, "Aquarium Careers" written by Jay Hemdal
It offers some advice to people interested in aquariums as a career. What is a “Job”, what is an “Occupation”, and how might they differ from a “Career”? To me, a job is something distasteful that you must do in...
Red Band Syndrome in Marine Fishes:
Caused by the Protozoan; Uronema sp.
Jay Hemdal
Introduction:
This moderately common disease of certain species of marine fish is so often misdiagnosed that most aquarists apply incorrect treatment methods when attempting a cure. Symptoms include the...
Aquarium Inventions
@Jay Hemdal C.2006
This article discusses aquarium inventions, a bit of history and future thoughts. It is offered just as a way to get DIYers thinking about expanding on their ideas. Includes an interview with John Kuhns, the person who invented Novaqua and Amquel. A...
