That Fish Blog – Aquarium Advice and Information

Hello, Frank Indiviglio here.  Marine aquarists and divers are well-aware of the mucous “sleeping bags” produced by Parrotfishes and certain Wrasses each night.  It was assumed that these cocoon-like structures discouraged eels, crabs and other nocturnal predators – perhaps the mucous hid the sleeper’s scent, or was bad-tasting or toxic.  A study at Australia’s Queensland University, however, has revealed that the mucous cocoon’s main purpose may be to deter external blood-sucking parasites – the first known example of such a phenomenon.

A Good Reason to Hide

Writing in the November 17, 2010 issue of the journal Royal Society Biology Letters, researchers have established that sleeping Parrotfishes suffer numerous parasite attacks when deprived of their mucous cocoons (I couldn’t determine how they removed the cocoons without waking the fish!).  Parrotfishes with intact cocoons sleep peacefully through the night, and were rarely bitten. Read More »

In our modern society, boys and girls are raised to be men and women and play equal roles in everything from defense to child-rearing. The animals kingdom isn’t as simple. With some animals, males and females have specific roles to play in their community and are nurtured for their positions. Many of the fish we keep in our aquariums have very different strategies. Weighing the balance between reproducing and surviving plays a huge part in their life history, right down to the most fundamental concepts of gender, size, and appearance.

A “hermaphrodite” is an organism that has both male and female reproductive abilities. While this is usually very rare in animals like birds and mammals, it is extremely common in plants and some invertebrates. Biologically speaking, if the chances of a plant or animal running across another of its kind are low, the chances of it finding another with the opposite sex as itself that it can reproduce with are even lower. Therefore, not having an assigned gender or being able to act as both genders can be beneficial. Many plants, animals and invertebrates use this strategy, but we’ll focus on fish in this blog.

Fish like wrasses, parrotfish, anthias and clownfish use “sequential hermaphroditism”, meaning that instead of having both sets of reproductive organs, the fish starts out as one gender and at some point is triggered to switch to another. There are two types of sequential hermaphroditism that we can witness in the aquarium trade:  protogyny and protandry. Read More »

Hello, Frank Indiviglio here.  Aquarists have long known that Discus Fish (Symphysodon spp.) produce mucus with which to feed their young.  However, recent studies revealed unexpected new parenting behaviors, leading some ichthyologists to compare them to mammals.  Just as surprising is the discovery that the European Eelpout (Zoarces viviparus), a commercially valuable marine fish, actually suckles it young with a milk-like secretion!

Weaning Behavior

The surprising new information about Discus appeared in the October 29, 2010 issue of the Journal of Experimental Biology.  While observing a breeding colony of the much-admired South American fishes, University of Plymouth (UK) biologists noticed that both parents avidly fed the young with mucus secretions for 2 weeks.  The fry were allowed to feed from an adult’s body for approximately 10 minutes, after which the ravenous little fellows were “flicked” onto the mate for more food.  Read More »

Many other blogs have discussed (and will continue to discuss, I’m sure) the importance of testing various levels in your water and its effects on the overall health of your aquarium. But, how can you actually test it? For anyone who isn’t able to bring a water sample into That Fish Place or their local fish store for testing or who wants monitor their water quality at home, there are lots of options for what tests to use. While what to actually test for is for another blog, there are lots of options when it comes to how the tests are actually done. Here we’ll look at the pro’s and con’s of the three most common aquarium testing methods: Test Strips, Liquid Test Kits, and Electronic Testing Equipment. Read More »

Nearly a month ago, I was able to represent That Fish Place for MACNA in Orlando, Florida. MACNA (Marine Aquarium Conference of North America), is one of the oldest and largest marine aquarium conferences in North America. Each year you will find new/advanced technology in the hobby, new companies, and of course, livestock. This year was all about LED technology, which seems to be the future of lighting in the hobby.

Amongst the chatter of LEDs was the talk of Papua New Guinea and the SEASMART program. Last year in Atlantic City, SEASMART attended MACNA in the attempt to raise awareness for the need to collect livestock sustainably with an all new approach. Dan Navin, a close friend of mine collected some information on the program while we were there. He made a side trip to Papua New Guinea while vacationing in Australia to check out the operation, a few weeks later. Needless to say he liked what he saw, and is now the SEASMART MAR (Mariculture, Aquaculture, Restoration) Division Manager. Read More »