That Fish Blog – Aquarium Advice and Information

Hello, Frank Indiviglio here.

With their ridiculously long “noses” (actually an extended jaw), secretive ways and unique feeding strategies, the elephant-nosed fishes have long been aquarium favorites.  All of the 200+ species discharge electrical pulses from specially-modified muscle cells near the tail. 

The most commonly kept species, Peter’s elephant nose, has been shown to vary the strength, frequency and duration of these discharges.  Doing so helps this nocturnal fish to navigate and hunt in the turbid West African rivers it inhabits.

Using Electricity to Choose a Mate

Recently, researchers at Germany’s Potsdam University have shown that a related species, Campylomormyrus compressirostris, identifies potential mates by the characteristics of their electrical discharges. 

In laboratory tests, gravid females responded to the signals of males of their own species, but ignored those of a closely related fish that shares their natural habitat.  In this way, they are able to locate a mate of the proper species, even when surrounded by similar fishes in murky water at night.

It is theorized that Peter’s elephant nose also uses electricity as a form of communication and mate recognition.  Certainly, watching them avoid obstacles and locate buried blackworms in an aquarium at night, it is easy to see how completely they rely upon their electric-generating system.

Keeping Elephant-Nosed Fishes

Although very popular, elephant-nosed fishes require special care and rarely do well in community aquariums.  I recently set up an exhibit housing a group along with some other of their interesting West African neighbors – butterfly fishes, giant filter-feeding shrimp and dwarf clawed frogs.  Please look for an article on this exhibit and their general care soon.

Please Note:  The “trunk-less” fish pictured with the elephant noses is not the victim of an unfortunate accident but rather a related species, the baby whale or stoneroller, Pollimyrus isidori.  They are also quite interesting and do, if you have an active imagination, somewhat resemble (very!) small whales.  I’ll address them in the article mentioned above.

Further Reading

Belgium’s Africamuseum has posted an interesting article on the Peter’s elephant nose (Note: the photo appears to be of a deceased fish…they are much more attractive than pictured here!): http://www.africamuseum.be/museum/treasures/gnathonemus%20petersii

Please write in with your comments and questions.  Thanks, until next time, Frank Indiviglio.

Brandon here. Many aquarists that come through our fish room will ask what we recommend as algae eaters for their reef.  The answer is usually the same: snails, hermit crabs, or maybe a lawnmower blenny.  One of the most efficient algae eaters found on the reef is usually overlooked, the sea urchin.

Sea urchins are relatives of starfish and sea cucumbers, belonging to the phylum Echinodermata.  They are generally covered in hard spines for protection, little clawed arms called pedicellariae which are used to remove debris and detritus from the urchins’ skin and can also aid in protection, and tube like feet used for moving across the substrate.  Their mouths are surrounded by a structure called Aristotle’s Lantern, which is used for scraping rock and breaking food apart.  The Aristotle’s Lantern is what makes some urchins such efficient algae eaters.

While not all sea urchins eat algae, and not all that eat algae are desirable for a reef tank, there are a few that would make a great addition to the aquarium.  The Variegated Green Urchin, Lytechinus variegates, stays relatively small and clears live rock of virtually all types of algae.  One urchin that we use in some of our display tanks here at the store is the Tuxedo Urchin, Mespilia globulus.  These urchins also remain relatively small and do a number on different types of algae.  Another extremely efficient, algae-eating urchin is the Longspine Urchin, Diadema setosum.  These can grow very large, and have spines capable of puncturing skin and leaving a painful injury.

 Here are some urchins to avoid in the reef tank.  Rock-boring Urchins, Echinometra lucunter, do little to clean up algae.  They spend most of their time chewing holes in live rock.  Priest Hat Urchins, Tripneustes gratilla, are generally considered reef safe, and will even do some scavenging, but they can also grab immobile fish and inverts for dinner.  One urchin that we do not carry here at That Fish Place, the Flower Urchin, Toxopneustes pileolus, is very beautiful but can inflict a potentially deadly sting.  It is covered in what appears to be little flowers, but are actually pedicellariae.  These specialized pedicellariae have three jaws on the tip, each of which is hollow and filled with venom.  Upon contact they snap shut and inject venom into the skin, which causes extreme pain and even muscle paralysis, which could drown an unsuspecting diver.

Urchins are not for everyone.  While they will clean up most types of undesirable algae, they can also scrape coralline algae from the rock work, leaving it white and bare.  They also require good water quality in respect to temperature, salinity, and other factors.  Always be sure of the urchins’ specific requirements and adult size before purchasing.  Whether you have a reef tank or not, urchins can make very interesting additions to the aquarium.

Hey folks Jose here, we are going to talk about one of my favorite bad boys (and girls), the Dovii, also known lovingly as the Wolf Cichlid. The Dovii  hails from Central America in Honduras, Costa Rica and Nicaragua. Males can reach sizes up to 28 inches, while females are much smaller at 15 inches. In the wild, the species is an opportunistic piscivore, feeding on smaller fish. This is an easy fish to keep, as long as you have the space and get a compatible pair.

In juveniles, sexing is tough but can be done.  When I picked out my pair at 2 inches, the male was a little larger and he had black dots below the lateral line where as the female had none. In the store’s aquarium, the male was tough on the female, but a week after they went into my 40 breeder, the roles were reversed. They were shy at first, hiding under the caves that I provided for spawns.

Feedings are a blast. They eat everything! The main diet I feed consists of a marine pellet food made by Pretty Bird called Color Up, Prime Reef flakes, and the occasional (once a week) feeding of live crayfish. Now let me tell you how fast they can grow.  The male was 2 inches long and about an inch and a half high when I got him. I have had him for about seven or eight months, and feed them 2 to 3 times a week, and now the male is about 6 inches in length and close to 3 inches in height! They can really fill out fast!

So now they’re spawning. The spawning was not as bad as I thought it would be. The female was almost gold-yellow with dark barring, and close to her vent she started to take on a black coloration. The male’s coloration became a lot more vivid, but the most striking feature setting him apart from the female (wow) was that his lips and fins turned blue!  The Wolf Cichlid’s courting and mating dances consisted of a lot of gill flaring, head shaking and jaw locking.

I provided caves and PVC pipe for them to spawn on, but the female decided  that she was going to lay the eggs on bare glass. OK with me, because they’re easy to spy on there.  I think I’m on batch number 7, and in each batch (laid like clockwork around the end of the month) she numbered close to 200 fry. Not bad for a 3 inch female, though adult females can produce up to 1000+ eggs at a time. The parents are very protective over the fry, even attacking my hands when I’m working on the tank. Oh, did I mention the Dovii live with two Synodontis catfish that happen love the taste of fry? I have not saved any of the prior batches because of space limitations, but my roommate let me borrow his 10 gallon planted aquarium this time, so I was able to net out 30 fry to grow out. The fry are fed crushed flakes, crushed freeze dried brine and crushed freeze dried mysis shrimp. As of right now, it looks like another batch of eggs is on the way!

Until next time,

Jose

Eileen here. Thanks to movies like Finding Nemo, Ocellaris and Percula Clownfish, Hippo Tangs, Yellow Tangs and starfish have become must-haves in many home aquariums and we all know that damsels are good hardy fish for aquarists of all levels. But what else is there? A LOT!! When customers ask for my opinion on good fish and invertebrates for their aquariums, I like to recommend something a little out of the norm. Clownfish and damsels are great, but there are a lot of other fish and inverts that deserve a little more respect! Here are a few of my favorites….

1. The “other” clownfish

Forget the standard orange-fish-with-three-white-stripes; there are a lot of other clownfish out there that don’t follow this pattern but are just as hardy and attractive. The Saddleback Clownfish is either brown or black with one white stripe over its eyes like a mask and another that covers its back like…you guessed it, a saddle. The Orange Skunk and Pink Skunk Clownfish are two more that break the mold. Each has a light, pastel body with a thin white stripe along their back. These two are more peaceful and stay smaller than other clownfish species – perfect for smaller or more docile tanks. Nemo is great, but give his “cousins” some attention too!

2.  Bannerfish

Bannerfish are closely related to butterflies but are in a category all their own. The most common type is the Longfin Bannerfish, also known as the Poor Man’s Moorish Idol. This fish looks a lot like but is a whole lot hardier (and cheaper) than the rare and touchy Moorish Idol (y’know, Gill from Finding Nemo?). They aren’t exactly “Reef Safe” and may nip at some polyps, but bannerfish are great for fish-only community aquariums.

3. Cardinalfish

Peaceful. Schooling. Reef Safe. Hardy. Might even breed in your aquarium. What more could you want? Most cardinals stay under about 4 inches and some barely reach two inches so they can be kept in even small aquariums. Most of them can also be kept in small groups so instead of having just one or two big fish, you can have the color and activity of a small school!

4. Hawkfish

Hawkfish earn their name by perching on rocks and corals, then swooping down on an unsuspecting meal (NOT good tankmates for shrimp or tiny fish), but most of the time they hop around the tank from perch to perch. Tons of personality, generally friendly towards anything too big to eat, and easy to feed. You can find hawkfish in lots of different colors and variety and with maximum sizes ranging from two to twelve or more inches.

5.  Rabbitfish and Foxfaces

These fish are some of the hardest-working but most overlooked fish in the trade! They graze on lots of different types of algae, including the notorious hair algaes and bubble algaes, and will feed on most other aquarium foods as well. They don’t bother inverts or smaller fish and most bigger fish will leave them alone. Just don’t touch their dorsal spines – they’re venomous.

6. Hamlets

Not many fish can get along in larger, more aggressive community tanks, but hamlets are one of them! These fish aren’t for community tanks with small tankmates, but they are interesting and unique additions to larger community tanks with fish like angels, tanks, groupers and triggers.

7. Jawfish

One of my personal favorites! Jawfish might not be the most visible fish for your aquarium but they may be the most fun to watch. Many jawfish will decorate the entrance to their burrow with larger pieces of substrate or shells and will spend their time guarding their little threshold while darting in and out for food. Might not be as flashy as other fish, but a whole lot more fun!

8. Polyps and Mushrooms

These are not so much overlooked as underappreciated. Sure, some hardcore collectors will pay $50+ per polyp of some rare zoanthid polyps, but most polyps and mushroom are just recommended as starter corals or as something for new aquarists to start with as they dabble in the reef side of the hobby. Polyps and mushroom can be so much more! They come in lots of different colors and varieties and will usually spread around your aquarium to form a living mat over the rocks and even on the glass. Polyps and mushrooms both are usually sold on various sizes of rocks with one or more types on a single rock. Easy to care for, undemanding, easy to propogate…polyps and mushroom deserve more respect than we give them!

9. Gorgonians

Aquarists with low light can be very restricted with what types of corals they can keep in their tank. Gorgonians are an excellent alternative. Some species like bright green Encrusting Gorgonians benefit for decent light, but most species are strictly filter feeders and do not need light to survive. The branching forms like the Yellow Deepwater Gorgonian or fancy Sea Fans have a recognizably “coral-like” appearance with soft branches that can move and sway in the flow of your tank.

10. Leather Corals

Leather corals aren’t as popular as their flashy stony coral counterparts but they can be just as dramatic in a reef tank. Like the polyps, mushroom, and gorgonians, most leather corals are undemanding and don’t need a lot of extra care. With the exception of the rare bright yellow or green leather, most leather are shades of tan, pink and purple and don’t need a lot of light or even pristine water to thrive.

Until Next Time,

Eileen

Melisa here. Well, it is that time of the year again. It’s a bit chilly these days. What better to do than snuggle with the one you love or find someone to love…right?

The Anglers and frogfish that are commonly kept in our aquariums have much less complicated rituals.  Just before mating (usually 8-12 hours before), the females of many common types will begin to fill with eggs, typically 40,000 to 180,000!  Their abdomens become distended, making them quite buoyant.  When the male comes along he nudges the female’s abdomen, stimulating her to move to the surface where spawning occurs.  The eggs are usually released as an egg raft or veil that drifts along for a few days before dropping to the sea floor after the embryos hatch.  Post-planktonic frogfish (1-2 months old) take on the appearance of a perfect tiny Frogfish, but often display bright defensive colors!

Some species actually tend to the eggs, protecting the clutch until they hatch. Lophiocharon trisignatus males attach the egg clusters to their bodies until they hatch.  Some species hold the eggs not only to protect them, but also to lure prey closer with the eggs as a prospective meal for the clueless prey!

Deep sea anglerfish of the superfamily Ceratioidea probably have the most interesting way to find the” love of their life,” to say the least.

When scientists first started studying ceratioid anglerfish they were confused why all they appeared to capture were female anglerfish. It was also noted that most of these anglerfish that were studied had some type of parasite attached to them. It was later revealed that the “parasite” was actually what remained of the male anglerfish. With some further investigation scientists were able to tap into the secret lives of these anglerfish.

At birth the males are programmed to detect scents in the water. They immediately begin their search for a female in the deep dark depths of the ocean. As they mature, the males digestive system shuts down, making the males incapable of feeding themselves. If he does not find a female he will die. Assuming he finds a female he takes a big comp and attaches himself for life. The male anglerfish releases an enzyme that fuses his body with hers. From the moment they are one the male becomes an autotroph living off the female. As time goes by the male begins to degenerate, leaving only lump with is gonads enclosed to release sperm when the female releases her eggs. This extreme mating ritual assures that when the female is ready to release eggs they will be fertilized. 

If you know of any other bazaar mating rituals in the fishy world I would love to hear about them.

Until next time,

Patty