---   The Fishroom Library Archives ---

Articles on Conservation and Species Maintenance -- 1996-2005

An archived collection of articles, tips, and information about tropical fishkeeping in general, and killi-keeping in particular, from past issues of the G.C.K.A. Newsletter.  To read an article, please click on the title (in blue).

All material is copyright © G.C.K.A. or the authors, unless otherwise noted. Reproduction is permitted for non-commercial purposes only (i.e., club bulletins). We do request that you provide source credit, and send us a copy of the publication in which the article appears. Please forward to G.C.K.A., c/o Recktenwalt, 4337 Ridgepath Drive, Dayton, OH 45424.

A Few Guidelines for Keeping Genetic Diversity in a Strain - by Rui Carneiro-Martins.  
Aquarist as a Naturalist - by Robert Rice. We can and should play an active role.
Yes, there's a place for hobbyists in conservation!
Genetic Diversity in Captive Breeding - by Dr. Harry Specht. How to maintain genetic diversity in fairly small breeding populations.
Is There a Place for the Hobbyist in Captive Breeding Programs - species maintenance and the individual killikeeper/breeder.
It's Not Just for the Other Guy - exotic species and habitat protection.
Keeping Populations Pure - by Roger Langton. Why it's important to maintain the purity of strains.
Keeping Strains Pure - a British view.
The Nature Conservancy Buys a Mexican Oasis - protection for Cuatro Ciénegas (Four Mashes) and the Coahuilan Pupfish (Cyprinodon atrorus).
Species Maintenance -- Some Observations - on species maintenance and genetic diversity.
Species Maintenance - It's Not Just for Killifish - others are worried, too.
Species and Population in Killifish - by Rui Carneiro-Martins.
Vanishing Cyprinodons
Why are Names and Location Codes Important?  

A Few Guidelines for Keeping genetic Diversity in a Strain 
By Rui Carneiro-Martins
        One of the most important concerns of the intermediate/advanced breeder of killifish is how to keep the stain he has in good condition, generation after generation. This article will try to give a few hints on how to properly maintain (or at least to not excessively degrade) the genetic background of a strain. One should bear in mind, however, that in order to keep this article fairly simple, some basic genetic concepts have been trimmed in a manner that might not be considered satisfactory to the initiated.
        Usually the first thing you do when introduced to a new species is to keep the fish alive. You search all possible sources for information on the fish and if they last more than a month you become pretty confident that they are safe for the time being. However, after a while most species begin to breed. Then comes the problem: what should you do to keep the population/strain strong and viable?
        You have to remember that an organism is the result of the information that it carries on its genome. The genome is organized into packets of DNA, known as chromosomes. Most organisms have duplicates of each chromosome on its karyotype (the number of chromosomes a cell possesses), usually depicted as 2n; those organisms are said to be diploid, as opposed to haploid, which show only one set of chromosomes (n).
        Since killifish are diploid, their chromosomes are paired, each of them carrying a single gene for the same characteristic. Each inherited characteristic is determined (at least in part) by two genes, with each parent contributing one from the pair he or she has. Assuming that both parents carry two identical genes (homozygosity), it's obvious that the progeny will also have that characteristic.
        However, if the genes of a parent are different (heterozygosity), the offspring will receive either the characteristic shown by the parent (the dominant one) or a concealed characteristic that we know little about (the recessive one). Recessive genes can be wholly harmless; they can be undesirable; or they can be absolutely deleterious, resulting in visible or invisible deformities, and even death.
        If both parents are heterozygous, the progeny may become homozygous over time, expressing the undesirable characteristics and passing them on to the following generations. The risk of this happening increases immensely when we intercross generations, which is commonly done when trying to "fix" a strain.
        None of the above takes into consideration phenomena like the mutational rate, multiple allele genes, genetic drift, etc. However, these concepts may be important if you want to have a better insight on the reasons subjacent to the following guidelines.
       Optimally, you should choose the best examples of a strain for breeding purposes. The selection criteria, however, are difficult to establish, if only that most of the time we don't know what those should be. The simplest and most obvious gauges are the pecking order within a group of fish (the dominant ones are usually, but not always, the most fit) and their physical beauty, although this depends immensely on personal taste. If you can, choose at least two or three males: the leader, which should be the top breeder, and then one or two others you can use to help keep up the genetic diversity of the strain.
        Another important thing to keep in mind is that all fish, however healthy and sound they may appear to be, may be carriers of undesirable genes. We're not talking here about those responsible for such obvious problems as physical deformities and such; we're talking about the less conspicuous problem genes which gradually accumulate over time in a population and contribute to the depletion of genetic diversity.
        However, we can take a few simple measures to avoid the rapid genetic decay of captive populations (especially due to inbreeding), that homebred strains are subject to. The following information is not meant as a panacea, but will hopefully improve your chances of maintaining a sound population for many years.
        Never cross fish from different populations of the same species, or from different species. This is something the average breeder already knows, but that bears repeating. Resist the temptation to cross populations; they may look alike, but they may be genetically so far apart that they produce infertile offspring. In other cases it may take a few generations before problems occur; eventually the fish may be unable to produce viable eggs and fry, and the entire strain is lost. As killikeepers we need to strive to maintain genetic diversity, not contribute to its destruction.
        Keep a minimum number of individuals for breeding from each generation. There is no set rule for this, however some studies have pointed out that the risk of inbreeding grows exponentially when the breeding stock number less than seven. That number may vary with the species and may be affected by a number of exogenous factors-aggressive behavior, size, feeding habits, tank size, etc. The effort of keeping more than ten breeding individuals may not be compensated for by the genetic contribution received from the extra fish.
        Don't intercross generations. In the natural setups often favored for killifish, it is easy to let the fry grow to adulthood, freely breeding with their parents. This practice can quickly result in serious inbreeding, since genetic malformations increase exponentially. Remember that each parent shares half of its genome with its progeny (F1); most siblings share much less common genetic material (and sometimes none at all), making inbreeding problems less problematic. If you use a natural setup, it's best to move the parents before the fry reach breeding age.
        Try to breed more females than males. Males are usually more aggressive than females and tend to establish more strict hierarchies, although this varies considerably among species and among individuals. A consequence of this is that extra males will have less chance to breed, and may even become a nuisance to the breeders. Perhaps the best setup would be a tank full of females with a single top ranking male selected from a bachelor tank. This male should occasionally be rotated out and replaced for a time by a second or third rank male. Another possibility would be the use of two tanks, one solely for females and the other for males. Simply select the best individuals from each tank and pair them. Again, there are many choices. The emphasis on females is not mandatory to a successful breeding program, just practical.
        Don't look for "sports". Some aquarists breed fish solely to find and select for that particular morph (mutation) that makes a difference. In the context of genetic diversity, that's the wrong approach. Selection and breeding to "fix" a particular characteristic requires much inbreeding and artificial selection, making the possibility of strain depletion a real possibility. Even if the resulting "sport" is sound, it may be so different from the original wild form that the strain/population has become completely decharacterized.
        Be very careful when crossing fish from different sources. This may sound like heresy, but is in fact simply a precaution. The reason for frequent exchanges between two or more strains of the same population is obvious - improvement in overall genetic quality, as a direct result of the introduction of new genes. However, new genes may also be a synonym for trouble-sometimes the new strain carries a deleterious gene that only becomes apparent later. The end result of this may be the destruction and loss of both previously sound strains.
        In addition, a great deal of misidentification exists within the killifish hobby; you might inadvertently end up with a disaster. Unless you are completely confident about the genetic integrity of the second source, it's better to play safe for the first generation. Keep a number of specimens from both sources apart from the rest, just in case the crosses don't go the way you thought they should. Be alert for signs of problems: an increasing number of fungused eggs, anomalies in fry or juveniles, unhatched eggs, etc.
        Never use a fungicide. That sounds harsh, and flies against a rule of thumb, but it's paramount. Most viable eggs have some natural capacity to elude fungus attack. That defensive capacity is genetically determined (whether enhanced by environmental conditions or not). We should look for that important characteristic and try to preserve it. If you artificially protect eggs that lack this natural defense, you are in fact weakening the strain by selecting fish that will pass this lack on to the next generation. In time you may end up with a strain that is unable to produce fungus resistant eggs. In itself, that is an indicator of poor genetics, since in nature such fish (or eggs) would not have survived. Fungicides may have other undesirable effects as well, particularly mutagenic ones. Fungicides also are known to harden the outer layer of the egg (the chorion), making hatching difficult.
        There are a few more rules that could be added. However, the above list is fairly simple, the rules are fairly easy to follow, and they are effective.
        Finally, you must not forget that before applying any guidelines to maintain genetic diversity, you must first keep the fish alive and healthy (good husbandry), and correctly identified (don't mislabel, misspell, or modify the scientific names and codes). Good luck! -- GCKA Newsletter, August 1998                                                Return to top of page

The Aquarist as a Naturalist
By Robert Rice, Navarre, Florida

Yes, there’s a place for hobbyists in conservation!

        "The American Killifish Association has organized a Killifish Conservation Committee to try and keep species alive that are endangered or extinct in the wild," wrote Roger Langton in a message to the NANFA mailing list on February 12, 1999. Not all species are chosen, he continued, but instead a core group of species that are representative of a group or subgenera of killifish.
        All of this work is being done entirely by hobbyists.
        Several species of killifish have already become extinct in West Africa. In Cameroon extensive logging spells doom for the rainforest species that can only survive in small, shaded streams.
        Aphyosemion elberti (Ntui population) has been extinct for several years in the wild, although the species still exists in the hobby. Also extinct, and from the same area, are Fundulopanchax walkeri GH2 and Epiplatys chaperi schreiberi. The former, a core species of the KCC, is currently being propagated by aquarists.
        Again, in Cameroon, it is feared the several populations of Fundulopanchax fallax (formerly a distinct species under the genus Aphyosemion) are either extinct or at the critical stage. Nevin Aspinwall of the US and Wolfgang Eberl of Germany recently searched extensively for F. fallax Malende in its known locations; neither found them. Other species that now can’t be found include F. schwoiseri, and F. rubrolabiale. F. kribianum (south of Kribi) is also among the missing, and there is concern for Epiplatys esekanus and Aphyosemion raddai.
        At risk are the fishes of the Niger Delta in Nigeria, and many little-known species of South American annuals. These are only a few examples of what has been learned by dedicated killifish aquarists.
        None of these species are on the endangered species list, nor are any of them protected by any agency or government, although some countries are becoming more protective of their natural heritages. Many of these fishes are, however, being raised and maintained by dedicated hobbyists, with breeding schemes in place to help ensure as much genetic diversity as possible in the captive populations. The results may not be perfect, but in some cases the results have been remarkable. Some time ago, Paul Loiselle sent Roger Langton seven pairs of Pachypanchax sakaramyi from a named location in Madagascar. The resulting fish founded populations in the Denver Zoo (USA) and the Nice Aquarium (France).
        So conservation aquarists have already been making a contribution. But we can't stop now; there are no options with extinction. We should never surrender a species to extinction without a fight.
– G.C.K.A. Newsletter, February 2000                                                                                        Return to top of page

Genetic Diversity in Captive Breeding
By Dr. Harry Specht
Copyright by Dr. Harry Specht, 1996

        The subject of genetic diversity in fish was explored in detail by Gary Sutcliff's article, "Preserving Genetic Diversity in Killifish Species Maintenance," in JAKA, Vol. 23, 1992. In the article, he provided data which indicated that the minimum effective breeding population to preserve the maximum amount of the native gene pool should consist of 6 to 10 individuals, or five pairs.
        Genetic drift, or the loss of genes, occurs with each generation. Increasing the minimum population increases heterozygosity, or genetic diversity, and reduces the rate of loss. Assuming a base breeding pool of 10 individuals, the first generation offspring will retain 95% of the original genetic diversity. After five generations, only 77.4% of this original genetic material remains.
        Gary's is a most interesting and informative article, which can be utilized to set forth a practical long range species maintenance program.
        Start with as many fish as possible, with a minimum of five pairs. If possible, start with wild fish for heterozygosity, or secure fish from different sources for a diverse gene pool.
        Breed every fish in the group, using random selection to determine pairing. Cull fry only for obvious defects.
        Separate the eggs from each pairing and select 4-6 fry from each spawn for breeding the next generation. With problem species it is advisable to raise the fry from each spawn separately until they sex out, then select a male and a female from each for breeding.
        Breeding for all succeeding generations should involve a minimum of five pairs of fish.
        This procedure is being followed, roughly speaking, by the Killifish Conservation Committee of the AKA. The coordinators select representative species (Core Species), and then appoint a Keeper of the Studbook for each species to record the genetic background of the founding fish. Next it is necessary to find a number of aquarists willing to maintain those Core species. Upon direction of the Keeper of the Studbook, exchanges are made among the members maintaining a species, to assure maximum genetic diversity. This is the model for genetic diversity being followed by zoos all over the world as they cooperate in breeding their captive stock.
        This conservation activity is just commencing in the AKA, in an effort to prevent genetic drift among our captive populations of killifish. It is apparent that many killifish species are being lost in nature and that a number of species are now found only in captive populations, such as Cyprinodon alvarezi and Cynolebias whitei. We
        We hobbyists must make an effort to maintain our killifish, or many species will be lost forever. Insuring genetic diversity becomes vital with the loss of wild populations, as there may in the future be no wild fish to restore stocks or genetic diversity.
        I would encourage anyone interested in conserving killifish to join the AKA, and to participate in the Killifish Conservation Committee. -- G.C.K.A. Newsletter, January 1997                                                Return to top of page

Is There a Place for the Hobbyist In Captive Breeding Programs?
By Donna M. Recktenwalt       

        "Absolutely!" answers Harry Specht of the AKA, chairman of the species maintenance program for Aphyosemion australe (chocolate).
        Informally, every hobbyist who keeps, breeds, and distributes strong, healthy fish is a participant in species maintenance. Such individual efforts keep species in the hobby, and provide the opportunity for others to both enjoy and distribute them further.
        On the personal scale, species maintenance involves a personal commitment to keep and breed a given species over an extended period of time; to maintain as diverse a gene pool in your breeding stock as possible; and to distribute any extra resulting fry.
        On a larger scale, species maintenance involves participation in an organized group, such as the AKA's Species Maintenance Committee, where bloodlines are maintained and breeding stock is selectively exchanged among the participating members to maintain genetic diversity in the overall population. Individuals distribute their excess stock by regular means.
        There is no question that the topic of species maintenance and captive breeding is a timely one, or that it will continue to gain in importance as humankind irrevocably exerts continuing pressure on the natural world. With volative political and environmental conditions extant not only in Africa and South America, but also in many other places as well, numerous species are already disappearing entirely from the wild or becoming impossible to collect.
        As Roger Langton has pointed out, in northern Mexico Cyprinodon alvarezi, C. longidorsalis, C. veronicae, and Megupsilon apoues are already extinct in the wild. In West Africa by 1993 Fundulopanchax walkeri GH2 and Epiplaty chaperi schreiberi were probably extinct, and other F. walkeri populations along the Irovy Coast were probably in trouble.
       According to Wolfgang Eberl, Aphyosemion elberti (bualanum) N'tui is extinct due to land clearing, although it is being maintained within the hobby. The same is true of several of the Cynolebias species from Uruguay (Valizas), which are no longer found in the wild, including C. cheradophilius, C. viarius, C. melanotaenia and C. luteoflammumlatus. Epiplatys esethanus may be in serious trouble due to road construction in Cameroon, and Chromaphyosemion LEC 93/26 or 24 will likely disappear as the city of Libreville, Gabon expands.
        Of particular concern, according to Roger Langton, are "F. fallax (deltanensis), F. sjoestedti, F. powelli, F. arnoldi, and F. gulares. Many species of Aphanus are on the verge of extinction for much the same reasons as the U.S. desert pupfish."
        Al Anderson, who traveled to Brazil a year ago, reported that it was very disturbing to see the signs of overpopulation everywhere, with styrofoam cups. plastic bags, bottles, oil and scum in evidence along the banks of the Amazon River.
        But the problems are not only in foreign lands, or with "exotic" species. Here in the U.S., a number of species are listed as endangered and protected, either by the individual states, or by the federal government. Among these are nearly a dozen species and populations of Cyprinodon, half a dozen species of Fundulus, and several of Crenichthys. In northern Mexico, a number of the Goodeidae and Poeciliidae face the same problems.
        Some efforts are currently in place to maintain some of the threatened species, including participation by a number of zoos and universities, either in direct efforts at conservation, or in conjunction with ongoing research studies. But, as Harry Specht pointed out in the July/ August issue of the Journal of the American Killifish Association (JAKA), "the zoo breeding programs [especially for mammals] have been very successful, but their space and fund restraints limit the number of animals that can be handled in this fashion.... They are overwhelmed by [the] sheer numbers of fish and invertebrates that need to be managed."
        The individual killikeeper can make a differenceand should make the effort to do so. 
-- G.C.K.A. Newsletter, September 1997                                                                    Return to top of page

Exotic Species and Habitat Protection – It’s Not Just for the Other Guy
By Donna M. Recktenwalt

        As killikeepers, we often bemoan the loss of habitat faced by killifish species in Africa, South America, and Mexico, among other places. War, development, pollution, and burgeoning population growth all put pressures on native flora and fauna, to the extent that some species have already become extinct and others are at risk.
        In the southwestern United States and Mexico, several pupfish species have already been lost; in Africa, the survival of a number of species is problematical due to habitat loss.
        We tend to forget that some of our own native species (not only killifish) are facing similar problems. Although in some cases the problem is habitat loss, in many the problem is with competition from introduced species.
        "Many aquarium fish can be naturalized and take over local waters," reminds Wright Huntley. And they have. In southern Florida (the ideal location for a number of commercial fish farms) collectors can find any number of exotic species well established in the local waters. These exotics, including plecostomus, cichlids, tilapia, mouthbrooders, a number of catfishes, gouramis, platies and swordtails, among others, now occupy habitat previously occupied by native fishes, which they have preyed upon or driven out.
        "Around the San Francisco bay, most of our storm drains run through fresh, then brackish, then salt water," says Wright Huntley. "Any fish lost down those drains can possibly find a suitable habitat. Lucania parva are commonplace around the bay. As U.S. natives, they aren’t even regarded as introduced exotics, but they compete with our native 3-spine Sticklebacks, moving from one stream to the next. L. parva can tolerate brief (or even longer) seawater exposure."
        Introduced exotics are a major threat to native fauna both in the U.S. and worldwide. Few areas face the extent of the problem faced by Florida. But in a number of areas, introduced non-natives are causing great damage to local habitats. Native fishes in Nevada are a case in point. The Bay Area Killifish Association has long been working with the Tropical Fishkeepers Exchange, the Desert Springs Action Committee, the Native Fishes Association, the North American Native Fishes Association, and the Northern California K.C., to reduce the impact of natives in Nevada waters, removing mollies, Gambusia, tilapia and other species from the Ash Meadows Wildlife Refuge (home to several species of pupfish), and from the Moapa and Virgin Rivers.
        "The number of pupfish that one largemouth bass can eat is just staggering!" observes Wright Huntley.
        Closer to home, in Indiana, exotics are appearing too. In this case, they include such species as bighead carp, grass carp, and common carp, all "exotic" species for Indiana. Grass carp were introduced more than a century ago, with the bighead and grass carps more recent invaders. "Triploid grass carp have been stocked for several years in Indiana for aquatic vegetation control," reports Brant Fisher of the Department of Natural Resources, "but reproduction in the wild had never been documented" [until recent collections]…. The bighead carp and and silver carp have migrated from the Mississippi and Ohio Rivers and into the Wabash River system, and "are probably now found throughout the Wabash River system." All three species were brought from Asia for aquaculture uses. "We don’t know yet what long term effects … [they] will have on our native fauna, [but] they all compete directly with many of our native species."
        How do exotic fish get into native waters? Accidents happen. Storms flood fish farms, leading to escapes. Eggs get carried in on plants carelessly thrown away. Fishermen release bait fish, which thrive in the new waters. Fish from home aquaria are released (by intent or by accident). With the best of intentions, exotic species are knowingly introduced into native waters by wildlife experts, then outcompete the natives.
        "Much of the damage has already been done," Wright Huntley says. "But just a bit of common sense will help prevent further degradation. We must insist on responsible behavior of all aquarists, within our ability to do so. We must divert some of our hobby skill to planning and doing things that will keep our native species going." 
-- G.C.K.A. Newsletter, May 2000                                                                                Return to top of page

Keeping Populations Pure
By Roger Langton
Copyright 1996 by Roger Langton

        I have been keeping killies for 29 years now and have always kept populations, even if they went by the same species name, separate in terms of breeding. History has shown that this is the prudent thing to do.
        In the 1960s and 70s, many populations of Aphyosemion bivittatium came into the hobby. Many of them carried location names, such as Tiko, Kumba, Edea, Kribi, Lagos, etc. As time went on and the various populations were more carefully studied, hobbyists learned that several of these populations were, in reality, separate species. The subgenus Chromaphyosemion was designated to cover these several, related species.
        Hobbyists came to discriminate among A. bivittatium, A. loennbergii, A. splendopleure, A. bitaeniatum, A. poliaki, A. volcanum and A. riggenbachi. In other words, populations that carried the same name, A. bivittatium (the name used by many hobbyists at the time) turned out to be separate species.
        Other examples include the several populations called A. calliurum (Mesoaphyosemion) and A. elberti (Kathetys). In the latter case, several current populations kept by aquarists may turn out to be separate species as they are studied more carefully.
        Early on, the late Jorgen Scheel demonstrated that some of the populations that carry the same species name had different chromosomes. For example, among the A. calliurum populations, he found the following variations: (n=10-20, A=20-31). This considerable variation among these populations was brought to the attention of hobbyists and many responded by keeping each population separate, even when the fish looked almost identical. To do otherwise would risk an outcome that might result in hybrids and infertile offspring.
        When you obtain a species, such as A. aff. primiginium 88/10, it tells you that this is a population related to A. primiginium, and that it was collected in 1988 at location 10. Similar populations were collected at other locations, eg. 88/6. To cross them with the assumption that they are identical species could lead to the negative results mentioned previously.
        Many advanced killie hobbyists will not bring new fish into their breeding program unless all of the codes have been retained by the breeder. These hobbyists, for example, would not obtain a species with the name given only as Nothobranchius vosseleri.
        Why? Because the buyer does not know what he/she is getting. There are three available populations of N. vosseleri recently collected by Watters, Wildekamp and Sainthouse in 1995. If N. vosseleri is offered as N. vosseleri Karogwe north TAN 95/17, or N. vosseleri Karogwe south TAN 95/18 or N. vosseleri Mombo TAN 95/19, the hobbyists will know exactly which population he/she has and can be confident that no hybridization has taken place. We may learn, in future, that the three populations of N. vosseleri have some significant biological differences (chromosomes?) that makes cross breeding them unproductive, as it may weaken the long-term viability of the species.
        There are many more similar examples that could be used.
        While I have your attention, let me make an observation on the use of nomenclature, as it relates to Fundulopanchax gardneri. Here again it is important to keep populations separate and to use the correct nomenclature. The correct name to use for the "yellow" forms is F. gardneri nigerianus ("nigerianum" is not correct; when gardneri was moved from Aphyosemion gardneri nigerianum to Fundulopanchax gardneri nigerianus, a change in gender from masculine to feminine took place, which changed "nigerianum" to "nigerianus").
        In addition, it is important to include a location name, such as Jos Plateau, Makurdi, Akure, etc. If the location name is lost, the fist should be distributed as an "aquarium strain."
        The blue forms of gardneri are designated as F. gardneri gardneri N'sukka, and so on for location names.
        This is complicated by the fact that there are both blue and yellow forms of F. gardneri nigerianus Akure, which are found together in nature. In this case, the population is designated F. gardneri nigerianus Akure (yellow) or (blue).
        Because of these identification problems, the killie keeper needs to be informed of the importance of keeping track of all collecting codes and population data, in order to help ensure that problems are not caused by careless breeding practices.
-- G.C.K.A. Newsletter, December 1996                                                                        Return to top of page

        "Keeping strains pure is probably the most important function of killifish associations," states Guy Wren of Great Britain
        We all know that we should carefully retain complete information on the fish we keep – the full Latin name, properly spelled, with complete collection code information. Sometimes this data is lost. Sometimes it becomes incorrect over time, due to blurred labeling or poor handwriting. When this happens, the fish almost automatically become "aquarium strain." The fish are no less beautiful, but have less value to breeders, since their pedigree cannot be verified.
        How do people feel about aquarium strains?
        "My local aquatic shop (London) always keeps killies but is not always given full details of where they are collected," Guy says. In the U.S., more than one fishkeeper has found killifish that he sold to an aquarium store being sold under another name entirely – or by some completely "made-up" name that bears no relationship to the information the breeder provided. To many fishkeepers, these "aquarium strain" killifish are as welcome as those with a long string of alpha-numeric codes behind their names.
        As breeders, we usually prefer fish that have an accurate pedigree, especially with the constant rate of change in killifish taxonomy as scientists further clarify the relationships of species.
        Are we implying that aquarium strain fish should be avoided, or that they are inferior to fish with a string of letters and numbers behind their names?
        Not at all.
        But whether we’re distributing our excess stock through private or commercial channels, we need to be careful to always include whatever complete location/collection information we have for those fish. To our fellow breeders, this is important data. To others, it may be less so. Once the fish are out of our tanks, we no longer have control over what information goes with them. -- G.C.K.A. Newsletter, May 2003                                        Return to top of page

The Nature Conservancy Buys a Mexican Oasis

        Turquoise pools, streams and freshwater springs sparkle among the gypsum dunes and dried lake beds of the Chihuahuan Desert in Mexico.
        A mirage? No, it is the Cuatro Ciénegas (Four Mashes) Basin Wildlife Refuge, a roughly 500-square mile site located in north-central Mexico. Decreed a natural refuge by the Mexican government in 1994, Cuatro Ciénegas is The Nature Conservancy's first land acquisition in Mexico.
        An extreme rarity, Cuatro Ciénegas is one of only two remaining desert spring-fed wetlands in North America. The other is Ash Meadows National Wildlife Refuge in Nevada, which the Conservancy also helped save.
        Where there is water, so there are fish-in the lakes (lagunas), the pools (pozas) and the canals. Many of the pozas are natural aquariums, containing only a few hundred gallons of water; even the larger lagunas are seldom more than 250 ft. wide or 25 ft. deep. The area's salt marshes are alive with snakes, turtles, and fish.
        Cuatro Ciénegas has 77 unique native plant and animal species, including the threatened Coahuilan box turtle, grass shrimp and a variety of desert fish, including the threatened Coahuilan (Banded) pupfish, Cyprinodon atrorus, which can withstand conditions of especially high temperatures and salinity, and two varieties of Cichlasoma minckleyi.
        Naturalists have long expressed concern about the future of Cuatro Ciénegas, citing the falling water table (due to the pumping of aquifers for irrigation) and continued mining of the natural gypsum dunes, along with overgrazing and uncontrolled tourism.
        "We still don't understand the [dune formation] process very well," states Salvador Contreras Banderas, a biologist with the Autonomous University of Nuevo Leon (UANL). "In fact, we keep learning about the biology and geology of this region. New species are continually discovered in the valley," even as others are documented as becoming extinct.
        "What we've seen is that the water has been over-exploited," Contraras said. "The seasonal rhythms of the marshes are being overridden by human development, and the dunes are steadily being destroyed." Mining has reduced the once 50-foot gypsum dunes to 20 feet. Recently, however, due to extensive efforts by environmentalists and others, mining has been halted.
       Working with local partner DESUVALLE, The Nature Conservancy has protected a 450-acre site called La Poza Azul, so named for the turquoise pools found there. Unfortunately, in previous years the refuge as a whole had not been afforded the conservation protection it needed, but this is changing.
        The Conservancy"s Mexico program, Texas chapter, DESUVALLE and other partners are initiating a number of conservation projects at studying Cuatro Ciénegas, including studies of hydrology, environmental impact studies and the establishment of environmental education programs. At La Poza Azul, conservationists recently created a new visitors center to educate visitors about this true oasis in the desert. 
References
Aristy, Natalie, "Buying a Mexican Oasis," Nature Conservancy, May/June 1998, p. 28.
Grall, George, "Mexico's Desert Aquarium," National Geographic Magazine, October 1995, pp. 85-97.
Mader, Ron, "Endangered Treasure: Cuatrocienegas," October 1993, http:www.txinfinet.com/mader/
       exotravel/border/cienegas1.html.
-- GCKA Newsletter, August 1998                                                                                Return to top of page

        Most of us think of killifish populations as isolated and localized, often separated from their fellows by considerable distance. We tend to think that there is little chance of genetic mixing. Supposedly killies just stay in their own little pool and do not exchange genes, with fish in other pools.
        "I don’t believe it," says Bob Meyer. "All it takes is an animal walking between pools to carry an egg… it happens."
        Bob set up a new pond outside. "Within three days I had duckweed, frogbit, and toad eggs. I didn’t know any of these existed within a mile of my house. I did not have frogbit in any of my tanks, and the nearest neighbor with a pond is 5 miles away. The nearest neighbor is a mile. If plants can move, eggs can move."
        There is also possible cross contamination by high winds and flooding due to rain. "A 12-inch catfish was caught on the main street of our town," Bob reports. "The local pond, two miles away, had flooded and the catfish swam up the flood control lines. It was caught swimming on a major, flooded road." Small creeks often flood and expand across considerable landscape. Even if such flood water is shallow, it is often enough to connect small, normally isolated pools.
        "I believe that a population of 20 killies can go 100 years without new blood. But eventually that new blood comes in, or the species gets inbred and dies." In South America, collectors have found pools with lots of killifish, right next to pools with none. Perhaps one was fished out by the local birds, or perhaps one received some influx of new genetic stock, while the other died out of inbreeding.
        At the very least, it’s something to think about. -- G.C.K.A. Newsletter - October 2003        Return to top of page

Species Maintenance -- It's Not Just for Killifish

        Although AKA members and killifish breeders pride themselves on being involved in the efforts for species maintenance and captive breeding, they are hardly the only aquarists to do so. The subject is one that is gaining attention, and not only among tropical fish fanciers and zoologists.
        At the 1996 American Cichlid Convention, Dr. Paul Loiselle presented a program regarding the search for refuge areas where endangered Lake Victoria cichlids could be introduced and continue to exist as wild populations. The introduction of the Nile Perch into Lake Victoria has placed extreme survival pressure on many of the endemic cichlid species there.
        According to Dr. Loiselle, the most promising possibilities for reintroduction of some species are the man-made reservoirs near Lake Victoria. In most cases, these reservoirs have few native species that would be displaced by or compete with the Victorian cichlids that would be introduced.
        He further pointed out that some species are probably already extinct in the wild, but continue to exist as aquarium fish, such as the cherry and black ruby barbs. However, he cautioned, it is not certain that species that have been domesticated for generations could be used to reestablish wild populations. Also, certain species are not desirable as aquarium fish and would not survive if left to the vagaries of the aquarium trade.
        A number of zoos and commercial institutions are already involved in species preservation, concentrating on breeding and disseminating species that are threatened or already extinct in the wild. The AKA's species maintenance and captive breeding programs are designed to follow these same guidelines, preserving genetic diversity within select "core" species and distributing the fish within the hobby in the hopes that threatened species will not be lost as human encroachment and habitat destruction eliminate ever more of their native ranges. -- G.C.K.A. Newsletter, January 1998        Return to top of page

Species and Population in Killifish
By Rui Carneiro-Martins
© 1999 Rui Carneiro-Martins

        Species and population are two key words commonly used by killikeepers, but unfortunately, not always as accurately as they should be. The concepts seem easy enough to grasp, although further study reveals confusing nuances. Specialists are still battling over some of the definitions and consensus is far from achieved. These questions of detail are, however, unimportant for the layman.
        This article is written in the hope of helping clarify things. The approach chosen is a simplified one, in order to be readily understood, rather than a detailed account that would only be of interest to hardcore taxonomists.
Many hobbyists do not realize that the procedures for naming killifish follow the established rules for binomial nomenclature (scientific naming), as codified by the International Commission of Zoological Nomenclature (ICAN). These rules should not be ignored, or changed. The binomial classification system is based on a "tree" of descriptive descent, of which our major interests lie in the Genus and the Species, plus the added concept of Population. For usage, genus and species names are always given in italics, with the genus name capitalized.

Population
        Contrary to the beliefs of many, population does not equal a taxon, although it may have some taxonomic significance. In biology, population has a number of different meanings. In our case, it represents a group of animals belonging to a certain species that is reproductively isolated from similar groups of the same species. When individuals belonging to two different populations of the same species are allopatric (living in different geographical areas) and morphologically distinct, they can be designated as subspecies (a taxon), acquiring then the inherent taxonomic status.
        Population is a paramount concept when we talk about killis because of their habitat peculiarities; most inhabit small ponds or stretches of water that are usually sufficiently isolated from each other to prevent contact between them.
        Crosses between populations are therefore difficult, but not altogether impossible; eggs and fish can still be carried away to nearby habitats and if contamination between two adjacent ponds is frequent enough, they basically constitute a sole population, not two.
        Whether a cross occurs or not is a difficult situation to ascertain, even for experienced collectors, because there are many factors influencing this possible outcome: climate (e.g., floods and their frequency), fauna (e.g., birds and their aquatic habits), ground peculiarities, distance, etc., to name just a few. Thus collectors and knowledgeable hobbyists tend to consider population as a synonym of collection site, which is not only probably right but also the conservative approach.
        As a consequence, if collection sites are considered the same as populations, and if they in turn imply reproductive isolation in nature, then it becomes imperative for conscious killikeepers to never cross fish from different populations.
        To accomplish this, it is fundamental that we take great care when dealing with killifish identification. If taxonomic nomenclature–species and subspecies–is fairly well controlled by the ICZN, the same does not apply to the population and collector’s code add-ons. In fact, there are no formal rules whatever for collection codes. Although many (but not all) follow some recognizable pattern, often including the country where the collection was made, the year, and a location number, collection codes are wholly the responsibility of the collector, both to document and to assign.
        That doesn’t mean that the aquarist is free to discard this information. On the contrary, one must take extra care to accurately and completely retain the information. Misspellings or errors can change the name of the species or the population, thus losing it to the hobby. If someone loses the collection code information for a fish, or accidentally mixes two different populations, the fish become by default an "aquarium strain," with no population information recorded.
        Usually the describer name is dropped in common usage, although it is retained for more formal, scientific presentation.
        For example: Nothobranchius rachovii Ahl 1926 Beira 98 (full name); Nothobranchius rachovii Beira 98 (common usage); Nothobranchius rachovii (aquarium strain).
        From time to time, some fish appear in the hobby from unknown sources, often as "contaminants" in commercial imports. These fish may simply be considered aquarium strain, or they may be assigned a population/ collection code to differentiate them from fish already in the hobby.
        Finally, don’t worry too much about the correct name of a given species; whether one calls the fish Aphyosemion sjoestedti (Lönnberg, 1895) or Fundulopanchax sjoestedti (Lönnberg, 1895) is not that important as long as both scientific names are recognized by the community and by the ICNZ. The nomenclature issues are usually subjects of discussion for the specialists only and one should follow the proposed nomenclature that one feels is more adequate until a general consensus/majority between the scientific community is achieved; then one must abide by that, whatever one’s feelings on the subject (e.g. the Roloffia issue – since it has been considered invalid by the ICNZ in 1974, it should not be used anymore by anyone and this must not be subject to discussion).
References:
Huber, J.H. 1996. Killi-Data 1996. Updated checklist of taxonomic names, collecting localities & bibliographic references of oviparous Cyprinodont fishes (Cyprinodontoidei): in French, English, & German. Cybium, Soc. Fr. Ichtyologie, Ed. Paris, 366 pp.
Mayr, E. 1942. Systematics and the origin of species from the viewpoint of a zoologist. Columbia University Press, New York, 334 pp.
Seegers, L. 1997. Killifishes of the World–Old World Killis I. Aqualog. A.C.S. Verlag.
Seegers, L. 1997. Killifishes of the World–Old World Killis II. Aqualog. A.C.S. Verlag.
Wildekamp, R. H. 1993. A World of Killies. Atlas of the Oviparous Cyprinodontiform Fishes of the World. Vol. 1. Ed. Amer. Killifish Assoc.
Wildekamp, R. H. 1995. A World of Killies. Atlas of the Oviparous Cyprinodontiform Fishes of the World. Vol. 2. Ed. Amer. Killifish Assoc.
Wildekamp, R. H. 1996. A World of Killies. Atlas of the Oviparous Cyprinodontiform Fishes of the World. Vol. 3. Ed. Amer. Killifish Assoc.
-- G.C.K.A. Newsletter, January 2000                                                                            Return to top of page

        The Americas – particularly the American southwest and northern Mexico, as well as a few areas in the Caribbean – are home to a number of the pupfishes, Cyprinodon. Some species are healthy and secure. Many are threatened; a number are at high risk and classified "endangered;" and some species are already extinct due to loss of habitat.
        One extinct species, Cyprinodon arcuatus, the Santa Cruz pupfish, has only recently been described, according to an article by W. L. Minckley et. al. in Copeia. The last known population of this fish, which was found in the Monkey Spring system in southern Arizona (US) and northern Sonora (Mexico), was eliminated by introduced sport fish in 1971. Two other Mexican species, C. albivelus (Whitefin pupfish) from the Rio Yaqui basin, and C. pisteri (Guzman pupfish) from northern Chihuahua, were also described in the article.
        Despite the good intentions of some killikeepers, in the U.S. it is illegal for private aquarists to collect or to maintain any of the endangered or "extinct" species of pupfish. Government efforts are managing to maintain some species, while arguing over which groups have the right to manage the program for others.
        Earlier exports to Europe have assured that many of the endangered (and/or now extinct) species of pupfish from Mexico are still alive in the hobby.
        "Some [individuals] argue that you can never reintroduce aquarium-raised fish to the wild," says Wright Huntley. Those who spend time at places like Ash Meadows removing "tropical" exotics, have a different view, and work to maintain habitats so native species have at least a fighting chance to survive.
        Breeding and maintaining many of the Cyprinodon species can be a challenge, since their needs are very particular, usually involving high water temperatures and a diet based on algae and the microscopic life found in it. Although most desert species live in constant year-round temperatures, some seem to move to cooler areas during the winter and return to warmer water in the spring to spawn. This behavior may simply follow seasonal food availability, but it does provide the fish with a cool spell.
        Al Castro has observed that insufficient food or shelter often leads to cannibalism of fry and eggs in pupfish, thus serving as an effective population control. Tank size may be critical in keeping these fish, with crowding in too small aquaria a limiting factor in egg production. Giving them larger quarters may increase their fertility.
        Although private aquarists have had only limited success in maintaining endangered species of pupfish, non-governmental groups can contribute to conservation efforts.
Reference: Minkley, W., R. R. Miller and S.M. Norris, "Three New Pupfish Species, Cyprinodon (Teleostei, Cyprinodontidae), from Chihuahua, Mexico, and Arizona, USA." Copeia, 2002, No. 3, pp. 687-705.
-- G.C.K.A. Newsletter, September  2004                                                                Return to top of page

Why Are Names and Location Codes Important?
By Donna M. Recktenwalt

        It’s a common question among killikeepers, especially those fairly new to the hobby. "Why must I be so careful to keep all that information–locations and collection codes and such–for the fish I keep and breed?"
        "There are sound reasons, both from the scientific and the hobbyist points of view, for maintaining this unique identity," states Brian Watters. The purpose of such attached names and codes is not to confuse the hobbyist, but rather to provide a pedigree. Since numerous populations of a species may be collected from the same area, both the locality and the alpha-numeric codes are important. These various populations may, or may not, be capable of interbreeding. "Different populations should not, under any circumstances, be cross-bred," says Brian, since this would destroy their scientific value and might result in actual (and often infertile) hybrids. "The idea of crossing populations to ‘introduce new blood’ … may do more harm than good."
        Just to complicate the issue, sometimes the same population of a species is collected from the exact same location by different collectors at different times, thus carrying the same location name, but different codes. Only when the breeder is absolutely certain of the accuracy of these designations should such fish be interbred.
        The AKA Code of Ethics includes the following (specifically referring to the Fish and Egg Listings of the Business Newsletter, but equally applicable to breeders in general), "All nomenclature should be correct, location codes should be included if known." A fish that carries accurate location/collection codes has a known pedigree; fishes that do not must (by default) be assumed to be "aquarium strain." Since "aquarium strain" fish come from unknown backgrounds, they may or may not be capable of producing viable eggs and fry, or may be subject to gradual deterioration of the strain over several generations.
        The problem of correct usage of fish names has been worsening. Misspellings of species and location names is becoming more common, and we are seeing more incomplete location data and incorrect collection codes. As responsible hobbyists, we owe it to the fish we keep to ensure that the information on our fish is correct, especially if we are showing or distributing our fish.
        "Most hobbyists quite reasonably use the name that appeared on the bag or label when they first acquired the fish," adds Brian. However, the inadvertent errors that are appearing in the hobby (through smearing, poor handwriting, illegible labels, etc.) may mean that the hobbyist should question their accuracy in order to assure that previous errors aren’t perpetuated.
        How to do this?
        If possible, go to the source of the fish and ask.
        Then reach for Roger Langton’s Wild Collections of Killifish 1950-1995, which provides details of fish species names, location names and codes for most of the collections through 1995. For Nothobranchius, refer to Status of Nothobrancius species/populations in the hobby-past and present, accessible at the AKA web site (http://www.aka.org). Another good source of information is the KillieTalk e-mail List. A number of knowledgeable people regularly post information and answer questions there, including many experienced hobbyists.
        Other available useful data sources (although they may not include current or complete location or collection codes) include:

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