Upcoming Events at SDTFS

February 11, 2007- Monthly Meeting, Loricariidae, with Shawn Page. This program is all about the many species of the fish we generally refer to simply as the Plecostomus. Photos on screen will be of some of the most beautiful varieties. Identification, care, feeding and breeding will all be covered. Shawn Page is a yacht and boat captain who became fascinated by these fish a few years ago and has studied tham intensely ever since. He is the most knowledgable person about plecostomus that I know of. He recently maintained a large aquarium with over 80 different species. I think it almost broke his heart to give it up because he is taking a yacht to spend most of the rest of this year in Alaska. This is likely to be one our best programs of the year.

March 11, 2007- Spring Auction - Note: This is a change from April for 2007 only. This is because the April meeting is on the 8th, which is Easter, and we anticipate a lower turnout, so have moved the auction up a month.

See the main web site for meeting dates for the rest of the year.

Established Mutations in the Zebra Danio

by Bill Cline

This is a report taken from “The Zebrafish Exposed” by Ralf Dahm in the Sept/Oct of 06 issue of American Scientist (not to be confused with Scientific American). Knowing of my interests in tropical fish, my brother called my attention to this article after seeing it in a purchased issue. The article starts out talking about the uses the fish has in scientific research - being a vertebrate, it is much closer related to us than a fruit fly, and since it develops in a clear egg, we can watch its development. There are, for instance, heart problems in the zebra danio, which are very similar to certain problems in a human. A medicine or procedure which cures the fish may help a human.....or at least put us on track to find the cure. Because of this, scientists have developed many of their own mutations of the fish, which most of us haven’t heard of. The mutations in these genes have been mapped, and the names given to these varieties of fish can be hilarious. We aquarists can be familiar with the albino, long-finned, leopard, and golden mutations in these fish, but there are many, many more.

In the albino, the fish is missing an enzyme needed to produce black pigment.

The long-finned has abnormally long fins.

The leopard has spots rather than stripes.

The golden lacks some of its black pigment, resulting in a golden skin.

If Ikarus has pectoral fins (the ones on their side, behind the gills), they are tiny but may be absent. Some of you may remember from Greek mythology, that Ikarus was the character who lost his wax wings when he flew too close to the sun.

Macho is a variety which doesn’t react when touched.

Casanova has two hearts which, I suspect, allows it to be in love with two mates simultaneously.

Spock has pear-shaped ears.

Van Gogh has tiny ears (you remember he was the artist who cut off his ear to give to his girlfriend).

Rolling Stones - The otolith is a stone-like piece of calcium in the fish’s ear, the movement of which helps a fish hear. Scientists use otoliths to measure the age of wild fish, as though they were tree-rings. In this variety of zebra danio, the otoliths aren’t attached, so they lie in odd places.

Dracula will die if exposed to light, because their blood cells burst.

Odyseus - In normal fish, the germline cells (which eventually become sperm and egg cells for future adult fish) migrate through the embryonic fish to the site where the sex organs will eventually form. In Odyseus, the germline cells make long trips, without ever finding the right spot to land and end up in strange places. Odyseus, in Greek mythology, couldn’t find his way home either.

There are many mutations which result in low numbers of red blood cells (which results in lighter shades of blood). These all seem to get named after light-colored wines: Chablis, Cabernet, Chardonnay, Retsina, Riesling, Sauternes, & Weissherbst.

Pickwick has a weak heart, which contracts poorly, and soon dies of heart failure. This genetic mutation produces a fish heart very similar to that of a human suffering from dilated cardiomyopathy (mentioned in the first paragraph).

Its usefulness to science was first suggested by George Streisinger in a 1981 issue of Science, and there are now 4,000 scientists in 500 research laboratories around the world, working with the zebra danio.

The Neolebias Genus

by Bill Cline

This is a genus, which used to be well-known to American aquarists. In fact, it was described in that classic oldie, Exotic Aquarium Fishes, by William T. Innes. It was highly desirable at that time, but SOMETHING (I can only assume it was political situations) removed them from our markets between then and when I entered the hobby about “62. That’s only a guess - but even political situations wouldn’t explain why a spawnable, attractive fish would disappear from the market. I don’t ever remember even seeing it, while I was in the business. It was, however, written about in Europe occasionally.

The largest species I know of (N. Trewavasae, N. trilineatus, and N. unifasciatus) only reach 2 inches (Smith (5) says 2 ½ inches for Trewavasae) and they are exceedingly peaceful. They not only don’t like being kept with aggressive fish, they don’t even like being kept with fish which rush the food too aggressively. If kept with fish which behave like they were in a college fraternity, they will retreat to the plant thickets and lose their color out of fear. They like soft, acid water in heavily-planted, yet dimly lit aquariums. It is also said to prefer a dark, sandy substrate. Oddly, it is also recommended that they be kept in shallow (8 inches) aquariums. This reflects their natural micro-habitat - the shallows of the river, thick with plants. I know this sounds like a lot of trouble, but so many desirable fish from that kind of water seem to be tiny, that a small aquarium dedicated to tiny, beautiful, timid fish wouldn’t be a waste........heck, I’ve dedicated a 75 gallon aquarium to them (pencilfish, rasboras, hatchetfish, sparkling gouramis, Microsynodontis, cardinals, etc). I have a reverse-osmosis unit devoted to the cause, and by mixing the R. O. water with the tap water, I keep the hardness down about 6 degrees DH or 8 degrees GH. I’m told, however, that not all RO units are created equal. Several authors mention ansorgei as the most colorful in the genus, but trewavasi and axelrodi are also very colorful, when conditions are to their liking.

Some of the Neolebias have adipose fins and some do not. Some people have considered those which are missing it as African ‘tetras’ which are exceptions to the “adipose fin rule”*, but since the break-up of the Characids, they are now in the subfamily Distichodontinae, which itself is in the family Citharinidae, and the order Characiformes. This places them and the Distichodus in a completely different family than the tetras.

N. ansorgii (also formerly known as N. landgrafi), sometimes called the African Redfin, was first imported from central Africa in the 20's. In nature, N. ansorgii feeds on worms, crustaceans and insects, but in the aquarium, they will also eat prepared foods. Dawes (1) says they show no preference for any particular level of the aquarium (surface, bottom, in-between), Mills and Vevers (3) however, say they prefer the lower layers. He also says they prefer a temperature of 73-83 degrees F. Axelrod et al (4) mentions only two species and they are both the same (ansorgei and landgrafi), and in it, he says they almost look the same. One unusual feature they have is a square dorsal fin. Pictured in 2, 3, 4, 6,

N. unifasciatus (Steindachner, 1894) It was formerly known by several names; Neolebias unitaeniatus, N. univittatus, Nannaethiops angustolinea, and Nannocharax shariensis. Found from Gambia to Chad (except for the Senegal River), Cameroon, Gabon and the Central African Republic (in the Chad and Oubangui Basins), including Ghana, Nigeria, Togo, Mali and the Cote de Ivoire (Ivory Coast). It will reach 5.3 cm total length. pH from 6 to 7, 24-28 degrees C.

N. trewavasae (Poll and Gosse, 1963), sometimes called the three-lined Neolebias and sometimes Trewavas’ Neolebias, from the Nile and Congo Basins, from the Cameroon through the Republic of the Congo, the Democratic Republic of the Congo, Gabon. It comes from slightly harder water, of dH 12 and a temp of 24-28 degrees C. It is a browser from among the shallow fringes, consuming algae, plant fragments, rotifers, protozoans, small crustaceans and small insects. A brilliant red, with a bit of black. It reaches 5.3 cm in total length. This is the only species mentioned in Smith (5), who doesn’t mention the Nile as an origin, only creeks and small rivers of the Congo Basin. He also says water chemistry is unimportant, then later says it should be soft (dH 5) and acid (pH 6.5) for breeding. For breeding, he also suggests Java Moss or breeding mops, and feeding the fry infusoria, liquid fry food, and green water. Pictured in 5 and 6. Fishbase has a beautiful picture of this fish on their site at http://www.fishbase.org.ph/images/thumbnails/jpg/tn_Netre_u1.jpg although apparently they are taking their site out of public usage.

N. axelrodi, also known as Axelrod’s Neolebias

N. trilineatus (formerly Nannaethiops tritaeniatus), also known as three-lined, goldband or goldenline Neolebias. It is from the Zaire Basin of Africa. With this species, Baensch (7) suggests a few plants, with more of an emphasis on open space. Pictured in 7 and on this German page. This is a species which has an adipose fin.

N. powelli is found 3 km south of Isiokpo and at Rumuji, both in the New Calabar System, and near Ahoada in the Niger River delta, at Omoku, at Odieke on the Orashi River, at Rumuekpe, and in the Imo System of the Otamiri River.

N. philippei is said to come from Boende in Tshuapa, Ibembo and Marais des environs des Boende. It has no adipose fin. It reaches 3.7 cm total length.

N. lozii, is said to come from Kataba Creek in the upper Zambezi in Zambia and in the western part of the country.

N. bidentatus (formerly known as Dundocharax bidentatus) only reaches 2.4 cm total length and comes from the Congo and northern Angola.

N. bleheri formerly known as Nannaethiops bleheri, it reaches 2 1/4 cm standard length.

N. kerguennae is mentioned as coming from Lambarene and Libreville in Gabon. It reaches 3.3 cm total length.

N. gracilis from Yokolo Village on the Marais River. It reaches 3.9 cm standard length (the other measurements are total length, but standard length is measured to the base of the tail).

N. gossei formerly known as Hemigrammocharax gossei and only reaches 3.6 cm total length. Not found since the holotype, which came from a small river in the Gabon.

N. spilotaenia reaches 3.3 cm total length and comes from Chiloango and Kasai.

N. olbrechtsi used to be known as Hemigrammocharax olbrechtsi and reaches a grand total length of 3.7 cm total length and comes from lake Tumba, from Zaire, and from near Yangambi.

*A commonly accepted rule that all tetras have adipose fins.

References:

1. The Aquarium Encyclopedia by Gunther Sterba

2. Complete Encyclopedia of the Freshwater Aquarium by John Dawes

3. The Tetra Encyclopedia of Freshwater Tropical Aquarium Fishes by Mills and Vevers

4. Exotic Tropical Fishes by Axelrod et al

5. Tetras and Other Characins by Mark Phillip Smith

6. Dr. Axelrod’s Mini-Atlas of Freshwater Aquarium Fishes by Herbert Axelrod

7. Aquarium Atlas #2 by Baensch & Riehl