Keeping the African Giant Filter Shrimp (African Fan Shrimp, Vampire Shrimp), Atya gabonensis, Part 2

Hello, Frank Indiviglio here. Please see Part I of this article for further information.

Feeding

Giant Fan ShrimpThe fan shrimp’s unique mode of feeding is very interesting to observe.  The first 2 appendages are lined with plume-like bristles which are waved about when food is detected.  Tiny organisms, organic detritus and algae are trapped in these and transferred to the mouth.  Fan shrimp will also pick food particles from the substrate, in more “typical shrimp” fashion, and I have several times observed them feeding on dead fish (at night).

If you keep fan shrimp with fish, it is important to introduce food at night, just before you turn out the lights…the shrimp will rarely get enough to eat otherwise.  I keep a few yo-yo loaches, Kuhli loaches and armored cats with mine, but beware of adding too many nocturnally-feeding fish.

Unlike many shrimps with specialized feeding adaptations, these accept nearly any pelleted or freeze dried food.  One of the few published reports on their feeding habits in the wild (please see below) established that fan shrimp are omnivorous, with algae forming a major part of the diet.  I therefore provide my shrimp with both plant and animal foods.  I use algae  and shrimp tablets as a basis of the diet, alternated with flake and freeze dried foods.  Liquid invertebrate food  may also be squirted into their hiding places.

African fan shrimp begin waving their feeding appendages about as soon as food is sensed.  I usually drop algae tabs or other foods right near them, after which they will move over it and begin waving away.  If you look closely, you’ll be able to see fine particles of food lodge in the brushes as the tablet dissolves.

My fan shrimp do not gravitate towards the filter outflow in order to trap food, as do the Singapore wood shrimp (Atyopsis moluccensis) which share their tank.  They will, however, filter fine food particles from whatever water currents pass by their lairs.  Some suggest keeping these shrimp in well-established tanks that house high populations of diatoms and other micro-organisms.  Certainly this is a good idea, but as we know little of their actual food intake needs, I would suggest that shrimp in these situations be fed as described above as well.

Social Grouping/Compatible Species

African fan shrimp do exceedingly well in same-species groups; I have also kept them with Singapore wood shrimp, Atyopsis moluccensis, Japanese marsh shrimp, Caridina japonica and cherry shrimp, Neocardina denticulate.  Small, peaceful community fish such as guppies, zebra danios, cherry barbs and so on are also fine, but please see the feeding cautions above.

Alternatively, you can house fan shrimp with fish that do not compete for food, i.e. live food specialists such as elephant-nosed morymids and butterfly fish (both of which are also native to West Africa, although not to the same habitat-types).

Small and large cichlids, carnivorous catfish and crayfish will attack fan shrimp.

Captive Longevity

Unpublished reports set captive longevity at just over 5 years.

Breeding

Anecdotal reports claim breeding success in heavily-planted outdoor ponds.  The young are said to be planktonic for a period of 2-3 weeks after hatching, which would certainly complicate matters in an aquarium.  I plan to look into this further and report back.

Miscellaneous

Giant Fan ShrimpFan shrimp are, as mentioned, very much oriented to a specific home cave, being more like crayfish than shrimp in this regard.  I imagine (but this has not been established) that such holds true in the wild as well.  I have observed them to become quite stressed if routed from their retreats.  In most cases, they wander about, often for days, before returning to the cave.

Be extremely careful when working around them, and avoid moving or re-arranging their caves.  I usually forego cleaning the glass directly in front of their caves, unless I happen to catch the shrimp “away from home” on rare foraging forays.  In those cases I’m always careful to return the rocks to their original position – a slight change in their shelter’s height or depth has seemingly caused my shrimp to seek “new accommodations”.

We have a great deal to learn about this and other freshwater invertebrates… please write in with your questions and comments. Thanks, Frank Indiviglio.

Very little has been published about this species in its natural habitat.  An interesting article concerning field research with fan shrimp in Nigeria is posted at:

http://www.wajae.org/papers/paper_vol13/Food_and_Feeding_Habits_of_Atya_gabonensis_from_Lower_River_Benue_in_Northern_Nigeria_full.pdf

Looking For an Unusual Aquarium Fish – Try a Toadfish

Brandon hOrange Toadfishere. One of my favorite types of fish is one that is often overlooked because it lacks the cute appearance that so many other saltwater fish brandish.  In fact, many people believe them to be one of the ugliest saltwater fish we import here at That Fish Place.  The orange toadfish and freshwater lionfish are just two of many different species that belong to an order of very odd looking fish.

All toadfish belong to the order Batrachoidiformes.  This order is home to around 80 different species of toadfish, most of which are saltwater and brackish species.  Toadfish are characterized by their scaleless bodies, extremely large mouths, powerful jaws, and drab color (with the exception of a few reef species).  They get their name from the croaking sound they produce from their swim bladder to communicate with one another and attract mates.  Caution should be taken when handling toadfish.  Many species have spines that can inflict painful wounds, and in certain species the spines are connected to venom glands.  Most species have very powerful jaws that, in a large individual, are even capable of breaking fingers!

In the aquarium, most toadfish are extremely hardy, although they are shy and tend to hide.  You can usually spot their faces poking out from under the rock work in your tank.  They can persist for extended periods of time without eating, but will gorge themselves when food is available.  Toadfish do well on a varied diet of frozen meats including shrimp, krill, squid, and fish.  Their food should be enriched with a vitamin supplement such as Vitachem to ensure that they are receiving proper nutrition.  Tank mates should be chosen carefully as toadfish will not hesitate to eat anything small enough to fit into their mouth, including each other.

Several classmates and I have been successful at breeding the Oyster Toadfish (Opsanus tau) in captivity.  In fact, they have been extremely easy to breed.  We placed seven individuals into a very large tank, fed them well, and the fish did the rest of the work.  A pair of toadfish would lay several dozen eggs on the roof and sides of a rock cave.  One of the parents would remain and stand guard.  The eggs were yellowish in color and about the size of a pea.  After about a week the eggs would hatch and the fry would stay bonded to the rock.  After a few more days the fry became free swimming and would go off in search of food.  They will not take frozen food, so live brine and ghost shrimp would be a better offering.

 While breeding the oyster toadfishes’ tropical cousins may not be as easy, they are still an interesting fish to keep in the home aquarium.  If you’re looking for a predator that is a little out of the ordinary, why not try a toadfish?

Acceptable Plants for Bettas – Common Aquarium Questions

Bettas have long been popular as beautiful, low maintenance pets.  They are visually appealing and easy to care for, a terrific option as a child’s first fish or someone on the go.  We’re happy to answer questions about these terrific little fish any time, as with this one sent to Marinebio@thatpetplace.com:

Nancy Wrote:

I am wondering which plants are okay for betta fish. I will be doing many bowls and would like variety if possible. I wasn’t seeing anything specific on your plant info and I certainly don’t want to harm the fish!

Marine Bio Wrote:

Plants are a great addition to any betta set-up, whether you choose plastic, silk, or live varieties.  They let the fish feel safe and secure by providing cover with their roots or foliage.  Bettas do not eat the plants, but some plants can be toxic. If you want to use a plant that comes out of the top of the bowl or vase, choose a Spathiphyllum sp., commonly known as a peace lily, “Lucky Bamboo” which is actually a Dracaena sp., or many types of vining philodendrons can work as well. You can find a wide variety of foliage shape and color in these plants. For example, there is a variegated from of peace lily called ‘Domino’, and several different philodendrons that should be safe and will root in the water.  If you want plants that are submerged, try a strand of anacharis or hornwort, or a small cluster of riccia or Java moss. The main issue with keeping aquatic plants vibrant would be making sure that they have enough light. The plants I listed above should work in lower light conditions fairly well. A well lit room with lots of natural light coming in from windows would be sufficient. Just remember that you do not want to keep the betta bowls in the window because sunlight coming through the window can actually heat the bowl up if it is lit directly by the sunlight. Also, at night, the window tends to be one of the colder spots in the house. So the fluctuating temperatures would be bad for the fish.

For more information on bettas and their care, please read these helpful articles in our archives:

http://www.thatpetplace.com/pet/displayArticle.web?Filename=../Article_archive/Fish/Betta_Basics.html

http://blogs.thatpetplace.com/thatfishblog/2008/06/26/carnival-fish-part-2-the-betta/

That Fish Place and NCPARS Frag Swap Event January 31st

Just wanted to announce That Fish Place’s first Frag Swap and event this January 31st at the That Fish Place/That Pet Place Retail Store

At this point, we’ve never tried such a hobbyist-centered event, and though many of us have been to swaps, we’ve never attempted one of our own.

The folks from NCPARS though (North Central Pennsylvania Reef Aquarium Society), crank them out all the time, so they’re helping us.

What intially was billed as just a frag swap, has since morphed into an extravaganza, as lots of vendors and top aquarium hobbyists have jumped on board to display products and give away stuff.

Entry fee is $10 for non-NCPARS members, and $5 for members. Entry fee also snags you a 20% off coupon for the store, as well as up to 25% off certain vendor products, including Marineland, Current-USA, Red Sea, Tetra, Instant Ocean, Aquatic Life, Brightwell Aquatics and others.

Experts like Anthony Calfo and Steven Pro will be on hand to give seminars and demonstrate products.

If you’re in the Lancaster, PA area, be sure to stop in.

If you need directions, check out here.

Check our further details here.

If you have any other questions, be sure to post them and we’ll get back to you.

It’ll also give you a chance to see our soon-to-be-expanded reef area in the fish room (Blog coming soon…)

Hope to see you there.

Keeping the African Giant Filter Shrimp (African Fan Shrimp, Vampire Shrimp), Atya gabonensis, Part I

Hello, Frank Indiviglio here.

The African fan shrimp is not well established in the aquarium trade, but interest is growing.  I have maintained a group for approximately 2 years, and have found them to be fascinating, if a bit challenging in some respects.  Their mode of feeding is particularly interesting, but requires a bit of attention as to “presentation”…I’ll write more about that in Part II of this article.

NATURAL HISTORY

This shrimp inhabits rocky streams along the west coast of Africa, from Senegal to Gabon.  It is also recorded from the east coast of South America; however, the genus is not well studied and these populations may represent a different species.  Their natural history is not well-documented.

African fan shrimp are heavily-built and reach 4 inches in length.  The first 2 appendages are equipped with feathery bristles which are swept back and forth when the animal is feeding.  Most in the trade are tan to dark brown in color, but blue, yellow, pink and red specimens show up on occasion.

CAPTIVE HUSBANDRY

Captive Habitat

The Aquarium

A well-filtered 10 gallon aquarium will comfortably house 4-5 shrimp.  They seem quite social; I have keep 12 in a 55 gallon aquarium.  The tank should be well covered, in case they decide to explore by climbing filter tubes or heaters.

Heat and Light

I keep my fan shrimp at 76 F; their temperature range is reported to be 74-88F.

African fan shrimp only leave favored retreats at night, and then infrequently.

A Night Glo bulb  or similar bulb will allow you to view their nocturnal activities.

Substrate

A rock or gravel substrate is preferable, as such is what would be found in their native habitat.  However, people keeping these shrimp on sand report no problems.  They do not negotiate bare-bottomed tanks well, and seemed stressed by the effort.

Physical Environment – Habitat Type and Terrarium Decorations

African fan shrimp are very shy and retiring, and require suitable shelters if they are to thrive.  Mine seem quite specific in their choice of a retreat – once they settle in, they remain within the same cave or shelter, even if others are available.  I have observed several shrimp to occupy the same small caves for 18 months.

They will utilize rock caves or artificial structures and ornaments.  Despite their need for privacy, the shrimp seem unconcerned about being on view through glass…caves positioned near the aquarium’s glass will allow easy observations.  They prefer a “tight fit” over a spacious cave, and many will remain within one shelter, usually in physical contact with one another, if able.  I’m not sure if they prefer to live in groups (field studies are in short supply) or not, but they certainly do well when provided with a cave that allows them to congregate.

Water

Hailing as they do from fast-flowing streams, fan shrimp likely have high oxygen requirements, so be sure that your tank is adequately aerated.

They should be maintained at a pH of 6.5-7.4.  I use soft water, but this is not based on field research (in fact, water in rocky streams tends to be hard).

Like many invertebrates, fan shrimp are extremely sensitive to ammonia, and to copper and other chemicals that are found in fish medications.

I’ll finish up with feeding and  pass along a few observations next week.

We have much to learn about these and other fresh water shrimp… please write in with your questions and observations. Thanks, Frank Indiviglio.

A video of an African fan shrimp in the process of feeding is below: