Species Maintenance, for Dummies

by Bill Forrest, CAS
Originally published in The Calquarium Volume 41, Number 6.
Aquarticles

Many species on this earth, including fauna and flora, are being threatened to the point of extinction by several
man-oriented causes. Habitat destruction is one of the major reasons why so many species are endangered,
although other contributing factors have played their role in decimating some species to the brink of extinction.

What can be done to try to ensure both fauna and flora species’ survival?

In natural habitats this would be difficult to accomplish because scientists and naturalists would have to try to
manipulate the proper environment to ensure success. Besides being too costly, this procedure would be too
difficult to control and most of the natural habitats belonging to these species have already been destroyed. So, an
alternate solution must be found.

In a quest to solve this problem, many public aquaria and zoos have adopted some form of Species Maintenance
Program that follows strict guidelines for the breeding of these species in captivity. Although this is not solving the
initial problem of habitat destruction, it is trying to maintain the continued existence of endangered species.

What can aquarium clubs and hobbyists do to preserve the existence of threatened and endangered underwater
flora and fauna species?

Some aquarium clubs, the Calgary Aquarium Society included, already have some form of a Species
Maintenance Program, however these programs are not set up with the same strict guidelines that are set and
enforced by the public aquaria and zoos. One of the strict captive breeding guidelines that is enforced by public
zoos and aquaria is not to allow any form of line breeding which is not enforced to my knowledge by aquarium
societies and hobbyists.

Why do public zoos and aquaria enforce the policy of no line breeding?

Line breeding can cause congenital deformities, weakened metabolisms and manipulated mutations that can
weaken the gene pool of any species. Congenital deformities and especially, weakened metabolisms can lead to
heredity diseases, birth defects, still-born fry, and the inability of fighting off contagious diseases from weakened
immune systems. So, therefore, the introduction of non-related individuals to the breeding stock is required to
maintain greater genetic diversity. These could be the reasons why public zoos and aquaria enforce the policy of
no line breeding.

There is no real evidence to support or contradict the issue that wild species populations are affected by line
breeding since wild populations are basically in an uncontrolled environment. Due to the possibility that line
breeding can weaken the gene pools in domestic populations it is unlikely that any wild populations are
propagated by this method. In natural environments it is more likely that wild populations propagate by natural
selection because it is governed by the survival of the fittest.

Has line breeding been a part of the aquarium hobby?

Line breeding has been a part of the aquarium hobby ever since its inception. This is why there are so many
different strains of goldfish (Carassius auratus), guppies (Poecilia reticulata), swordtails (Xiphophorus
helleri), platys (both Xiphophorus maculatus and Xiphophorus variatus), and the list goes on. Albinism and
any form of fin variation are all forms of manipulating a specific gene or genes. Line breeding does have its
specific uses in the aquarium hobby, however. The author believes that the preservation of endangered species in
their natural wild form should take precedence over the development of a new manipulated strain of the species.
The reason to preserve the wild form genetics of the species is because of the possibility of reintroduction of the
species to its natural habitat, if it still exists.

Why is it difficult for aquarium societies, their members, and in general hobbyists to embrace the policy of no line
breeding?

Quite simply, in most cases, the problem usually deals with acquiring non-related individuals or the lack of
resource information regarding acquisition of individuals of a specific species. This is why aquarium clubs should
have a Species Maintenance Program and a updated database of which species are being bred by which
members. This database should also include information pertaining to the lineage of species being maintained. If
the opportunity arises to obtain other non-related individuals it would offer greater genetic diversity to the existing
breeding stock. If all aquarium societies kept this database and exchanged this information through club
publications and/or their Internet sites the problem of resource information would be largely resolved. This
database information could also encourage the trading of non-related fry between tropical fish breeders and
hobbyists, introduction of a new species available to club members of your club, encourage other hobbyists to
keep endangered species, form a large world-wide database on the Internet pinpointing where exotic species are
being kept, and provide greater interaction between all of the aquarium clubs throughout the world.

Why do public aquaria and zoos enforce the policy of no hybridisation?

Hybridisation is produced by a cross breeding two different species. The results of hybridisation usually produce
sterile fry and like a rented mule are generally useless in today’s world. If the fry are fertile they pose a more
serious problem because they have the potential to pollute the gene pools of both involved species and those of
related species. This is the reason why public aquaria and zoos enforce the policy of no hybridisation.

Has the aquarium hobby been affected by hybridisation?

As with the horse and the donkey, some species can not keep their hooves, hands, and fins off of each other.
Aquatic species are no different. Many hybrids are even available for sale although some (such as the blood
parrot cichlid) have been proven mostly to be infertile while other hybrids (such as some of the livebearer
hybrids) have proven to be fertile and are definitely a threat to their related species’ gene pools. There are
several aquarium societies, such as the American Cichlid Association, that frown upon the creation of hybrids and
their creator.

The important thing to realise about a Species Maintenance Program is that the aquarist is trying to do just that,
maintain a species. The issues of hybridisation should not and will not be involved in a Species Maintenance
Program, especially in the cases of endangered species. That is why information about hybridisation was included
in this article, for the real DUMMIES.

In closing, I hope that the ideas in this article will not reach deaf ears or blind eyes because a lot of aquatic
species are counting on tropical fish hobbyists for their survival.