Little Fish With Big Names
By Larry Jinks
The two major groups of livebearers in the aquarium hobby are the Poeciliids and the Goodeids. Most hobbyists are familiar with the guppies, mollies, swordtails and platies so common in the hobby. I can remember raising green swordtails and black mollies when I first had tropical fish in the 1960’s. Raising livebearers and watching the babies being born were popular pre-Nintendo activities.
When I got back into the aquarium hobby in 1994, I began with a pair of green swordtails purchased at the NJAS spring auction. Some guy named Bob Larsen brought them into the auction.
My first entry into the NJAS Breeder Award Program was the fry of silver lyretail mollies in July of 1994. I followed these with guppies, platies and swordtails in the fall and was up to a whopping 20 points in the BAP standings. I had never even heard of a Goodeid in the fall of 1994 when George Savapolous brought in Xenoophorus captivus to an NJAS monthly auction. I would eagerly look forward to the NJAS meetings to find new species of livebearers to work with because “I can’t spawn cichlids.” (a story for another article) I asked people around the auction table what these fish were and were told they were Goodeid livebearers. What the heck, a livebearer’s a livebearer, right? I won the bidding and went home with my new prize.
With my little fish with a big name safely swimming in their own tank, I began to researchXenoophorus captivus. Oh my God! What did I get myself into? These fish don’t have the familiar gonopodium of the familiar livebearers and have a gestation period approximately twice as long as guppies. Their babies are how big when born?
It seems the Goodeid livebearers are all native to Mexico. The males have a notched anal fin called an andropodium to transfer the sperm to the female. These fish do not exhibit the superfoetation of the Poeciliids and the female must be fertilized for each brood of fry. The females have a gestation period of about eight weeks and produce about one to two dozen fry that average 1.5 to 2 centimeters long at birth. The fry are nourished in the female through extensions from their abdomen called trophotaenia (feeding ribbons). The embryos actually derive nourishment from the female with these structures and are not reliant on a yolk sac. In newly born fry you can still see the trophotaenia trailing form the abdomen, but they soon disappear.
My latest batch of Xenoophorus captivus came from ALA chairman Rit Forcier in a fish swap last October. I kept them in a 30 gallon tank with some crushed coral on the bare bottom. These fish are not particularly fussy and do best with slightly alkaline (pH 7.0 – 8.0) and moderately hard water. They feed on flake, pellet, live and frozen foods, but should have a vegetable component to their diet. I use a vegetable flake regularly and even throw in a piece of parboiled zucchini that I normally reserve for the albino Ancistrus.
I acquired some Zoogoneticus quitzeoensis at the Potomac Valley AS auction in October 2003. Jack Borgese, Frank Nell and I had gone down to their show and auction and had a great time. These Goodeids were donated to the auction by John Mangan, a noted Goodeid breeder in the PotomacValley club. I quarantined them in a ten gallon tank and later moved them to a 55 gallon by themselves. They quickly adjusted and produced by March of 2004. With the aid of some Java moss on the bottom and some floating plants at the surface, the fry develop without being eaten by the parents. I soon had a thriving colony which fed on a variety of foods including vegetable flake and turned in fry for points in June. Unfortunately, I arrived home from vacation in August and found the entire tank wiped out, probably due to poor water conditions.
I have also worked with Zoogoneticus tequila. I picked up my first trio at a Norwalk AS auction in October 2003 and had success with them in a twenty gallon setup with crushed coral. They didn’t produce many fry and I raised up only eight which I turned in to the North Jersey AS Breeders Award Program. The trio really didn’t produce any more young. As they were very large when I got them, maybe they were too old.
I obtained more Zoogoneticus tequila from both Rit Forcier and Tom Crane of the ALA in October 2004. These I had set up in a 10 gallon tank with crushed coral and Java moss (why mess with success?). They fed happily and produced fry which I brought in to the Jersey Shore AS Breeder Award Program in April 2005.
I currently maintain breeding populations of at least six different Goodeid livebearers and would like to see more people working with them. If anyone is interested they can see me at a meeting or contact me to obtain some of these fascinating livebearers.