That Fish Blog – Aquarium Advice and Information

Hello, Frank Indiviglio here. Damselfishes and Clownfishes are closely related, with all 325+ species being classified in the Family Pomacentridae. Among the most numerous and conspicuous fish on tropical coral reefs, a number make hardy marine aquarium inhabitants.

Range and Habitat

Damselfishes and Clownfishes are found throughout the world’s tropical and semitropical seas, with the greatest diversity occurring in the Indo-Pacific Region, especially off Australia; relatively few occur in the Atlantic and Eastern Pacific Oceans. They occupy a startling variety of habitats, with many species restricted to specific depths or specific areas of wave action. Several species can even enter brackish waters.

Identification in both the wild and pet trade is sometimes difficult, as their colors often vary from individual to individual; different populations of the same species may also exhibit unique color patterns.

Clownfishes and Sea Anemones

Clownfishes (aka anemonefishes) are well-known for their habit of living in close association with an invertebrate that is also an aquarium favorite, the sea anemone. Usually home to just one pair of clown fish, the host anemone forms the basis of their territory, and they rarely stray far from it.

Surviving Among Deadly Tentacles

Clownfishes were long thought to be immune to the anemone’s stinging tentacles, as they shelter right among them without being harmed (other small fishes would be killed if they attempted to do this). We now know, however, that the clownfish’s secret is not immunity at all, but an even more amazing adaptation.

Anemone tentacles fire their sting-bearing cells (nematocysts) upon contact with any organism that they come in contact with. The tentacles are coated with mucus which inhibits them from stinging one another. It seems that the clownfish secretes mucus which mimics that covering the tentacles of the anemone. Therefore, the anemone simply does not recognize the clownfish as prey, or even as a distinct organism!

In return for the protection offered by its host, the clownfish consumes parasites that might harm the anemone. By swimming about and fanning its fins, the clownfish may also increase the flow of oxygenated water through the anemone’s tentacles and about its base.

Do Anemones and Clownfishes “Need” One Another?

Aquarists often question whether clownfishes and anemones can survive without one other. It appears that the relationship might the best be described as “commensal”. By this we mean that each derives benefits from living in close association with the other, but they are not strictly limited to that situation.

The vast majority of anemones live without clownfishes. Clownfishes, however, seem somewhat more dependent upon the relationship. While they will live quite well “on their own” in the aquarium, experiments in the wild have shown that clownfishes without anemone hosts are quickly eaten by larger fishes.

Further Reading

The Florida Museum of Natural History has posted an interesting article and video on clownfishes here.

Next time we’ll take a closer look at the damselfishes and a favorite aquarium clownfish.

Please write in with your questions and comments.

Thanks, until next time,

Frank Indiviglio

Amphiprion sandaracinos image referenced from wikipedia and originally posted by Bricktop

We recently added a new line of Metal Halide light bulbs to our product selection here at That Fish Place, the Ushio Aqualite line of bulbs.  Ushio is an industry leader in lighting technology who manufactures their light bulbs in Germany, so you can be confident in the quality control and workmanship of their products.

The Ushio Aqualite bulbs are available in single ended (mogul base) style in 175 watt and 250 watt, and double ended (HQI) style in 150 watt and 250 watt.  Both types of bulbs are available in 10,000K, 14,000K and 20,000K color temperature ratings. 

Ushio takes the utmost care and inspection of their raw materials and maintains top standards in cleanliness during their  lamp production. USHIO Aqualite lamps utilize proprietary rare-earth mixtures to provide the most consistent lamp color over the entire lifetime of the lamp.

We are proud to offer these top quality bulbs to our marine aquarium enthusiast,  give them a try, I think that you will be very pleased with their performance.

Please let us know if you have any questions about this exciting new line.

Thanks,

Dave

Hello, Frank Indiviglio here.  This Southeast Asian fish’s slender, 3-inch- long body belies its reputation as a fearsome combatant.  However, in betting parlors from Thailand to the Sunda Islands, matches between male wrestling halfbeaks (Dermogenys pusilla/pusillus) rival those featuring the better-known bettas (Betta splendens) in popularity.  In contrast to bettas, battling halfbeaks rarely inflict any serious damage…other than to the billfolds of losing gamblers!

Description and Habitat

Halfbeaks sport a startling adaptation to surface feeding…their immobile lower jaw is more than twice the length of the upper.  This, along with their subtle beauty – a silvery body highlighted by hints of blue and green – renders them a most unique addition to one’s collection. 

Halfbeaks inhabit estuaries and other areas of fluctuating salinity, and, while sometimes kept in fresh water, are at their best in brackish water aquariums. 

Feeding Wrestling Halfbeaks

Halfbeaks are highly specialized surface feeders and rarely if ever swim to lower depths in the aquarium. They tend to be picky feeders and prefer tiny live invertebrates such as mosquito larva, brine shrimps, fruit flies and Daphnia. Chopped blackworms may be taken, but these sink quickly and so must usually be offered via forceps (tedious but effective!). 

Halfbeaks may be habituated to flake and frozen foods, but the progeny of such fishes rarely reproduce, most likely due to a nutritional deficiency.

The Halfbeak Aquarium

While visiting pet stores and aquariums in Japan, where halfbeaks are more commonly kept than in the USA, I was surprised to find that multiple males were often housed together.  I learned that males will co-exist in large, well planted aquariums if emergent and surface-dwelling plants are grown as sight barriers.  Watching the threat displays and interactions in such aquariums was most interesting, and cast these little fellows in a new light for me.

A unique habitat preference and feeding style dictates that halfbeaks be kept in long, shallow aquariums and, with few exceptions, in single-species groups.

Breeding Halfbeaks

Wrestling Halfbeaks are live bearers, with healthy females giving birth every 30 days or so; males may be distinguished by a bright red blotch located in front of the dorsal fin. 

Unfortunately, adults are quite cannibalistic, and the fry rarely survive.  Breeding traps are not recommended, as the birthing process takes several days and females become stressed by long confinement in small areas.  Thickly-planted aquariums, with much of the vegetation at the surface, offer the best chance of success. 

Further Reading

Detailed information on the natural history of these and related fishes is posted at ZipCodeZoo.com.

A book I’ve written, The Everything Aquarium Book, addresses the care of brackish water fishes in detail.

Please write in with your questions and comments. 

Thanks, until next time,

Frank Indiviglio

Halfbeaks image referenced from wikipedia and originally posted by Neale Monks
 

Living in the Edge is actually more like it, with Hagen’s new aquarium the Fluval Edge.  Unlike many of the other new nano or desktop aquariums that have come out in the last few years, the Edge is something different.  Difficult to describe, and easy on the eyes, this cool little 6 gallon aquarium gives the small aquarium a twist in design.

The tank is made of glass, and is filtered by Hagen’s proven Aquaclear filter technology.  The unique design of the aquarium has it “hanging”out in space around its base and top.  The top conceals an access opening for cleaning, feeding, and filter access.  It looks like it jumped out of a sketch book of Frank Lloyd Wright designs.  The Edge comes in 3 colors so that you can fit it in with whatever your décor or taste may be.  Check it out, I think you will find it really interesting.

We couldn’t resist setting one of these little wonders up on display, if you visit the store find the display on the info desk on the sales floor.

Thanks, Until the next blog,

Dave

Hello, Frank Indiviglio here. Plankton forms the base of the food chains in all the world’s fresh and marine waters. Comprised of innumerable species of tiny, often microscopic plants and animals, plankton is a very useful but overlooked food source for tiny fish fry, filter-feeding invertebrates and seahorses, pipefishes and other small live food specialists.

Collecting Plankton

Marine waters are undoubtedly the best sources of plankton for seahorses and such creatures, but do not hesitate to try fresh water plankton as well. Just bear in mind that fresh water creatures will perish rapidly in salt water, so don’t overload your tank.

Available through biological supply houses, plankton nets are the most effective means of harvesting this valuable food. Don’t forget to examine your catch with a hand lens or microscope – you won’t believe your eyes!

Using Plankton

When rearing Atlantic seahorse fry at the Staten Island Zoo, I often towed a plankton net behind a boat and by hand from a dock. My efforts were rewarded with an amorphous glob of “organic material”, but the seahorses sure knew what to do with it!  Their reactions were much more vigorous than when presented with their standard meal of brine shrimp, and they grew rapidly.  I have also noticed that northern pipefishes immediately begin feeding when fresh seawater is added to their aquarium…I usually cannot see anything that looks like food, but they do!

I consider plankton to be nearly indispensible for seahorse and pipefish fry, and for adult dwarf seahorses and similar species. But nearly all small fishes and invertebrates, including fresh water species, will eagerly accept plankton as well.  Its use will greatly improve your chances of success with a number of delicate organisms.

Useful Products

Fortunately, “plankton substitutes” are available for those unable to collect their own. “Reef Bugs” are living microbes that are eagerly accepted by corals and other invertebrates. A wide range of other foods for filter feeding invertebrates helps simplify the keeping of these fascinating creatures.

Newly hatched brine shrimp, while not a complete diet for seahorses and pipe fishes, may be nutritionally improved through the use of Artemia food.

Further Reading

The Monterey Bay Aquarium has posted an interesting article on plankton collecting here.

Please write in with your questions and comments.