Spawning Report: Xenotoca doadrioi (Redtail Goodeids)

04 June 2021

Submitted by Dave McGrew

Recently, fellow PVAS Club member John Mangan began inviting club members who were regular breeders to followup with him about the possibility of moving along stock to Chico’s Natural Pet Market in Falls Church, VA. We reached out, and brought a few fish along on trips to the area. We expressed an interest in some of his Goodeids. Xenotoca doadrioi have always been a fascinating, colorful species. John was happy to move along a starter breeding group of these from his collection. Being a C.A.R.E.S. species added interst to us.

The information John shared about their origin is this: His line were part of a group of Goodeids imported by the North American Goodeid Working Group for the 2014 American Livebearer Association Convention. John obtained his original stock at the convention in 2014. Their geographical source is near the town of Etzatlan, Mexico in the Ameca / Magdelana basin. The town is just west of Guadalajara, but not quite as far west as the better known collecting site San Marcos.

We got 8x Xentoca Doadrioi from John Mangan on December 12, 2020. They were of varying ages / sizes. Two males were brightly colored up, and at least two of the females were of matching size. They went into a 20 gal. long with black diamond blasting sand substrate, some shells from NC coast we’ve used for a few years now in aquariums, several cups of crushed coral in a mesh bio bag hidden inside a shell, and an odd assortment of plants, cuttings, and java moss. Two sponge filters run in the back corners. Lighting is just a cheap shop LED (5,000 K) that throws a reasonably balanced white light - usually muted by use of a cupboard liner to diffuse and limit lighting. Additional air comes by way of several air stones hanging in the back center. Throughout the six months since first recieving them, I have continued to add plant cuttings.

I keep these Goodeids at room temperature with no heater in our basement fishrom, which dips down barely below 70-degrees Farenheit in the winter, and lifts just above the same mark during the summer.

I water change the tank each week, and always add a broad spectrum liquid plant fertilizer (e.g. Aquarium Co-Op Easy Green). The Amazon Sword gets root tabs in the substrate now and then.

These Goodeids do well on a veggie diet. We ground their diet on Omega One Kelp Flakes, Bug Bites Spirulina Flakes, crushed Omega One Veggie Pellets, and broken up Algae Wafers. There is always duckweed in the tank as well, so if they want that, it's a free snack. Once fry appear, baby brine shrimp is added as well. Every other day, one of their feedings includes some added protein as well. They will try to eat just about anything.

The first spawn was discovered on January 7, 2021. Unfortunately, it was a light dropping, falling short of BAP by just a few fry. Still, it was so curious to observe their trophotaenia — umbilical cord-like appendiges that remian visible on fry for a few days after they are born.

Goodeids are livebearers, though not nearly as prolific as the better known livebearers — Guppies, Platys, Mollys, or Swordtails. Xenotoca doadrioi drop fry every few months, with reports of seasonal changes sometimes yielding higher fry production.

It was not until April 27, 2021 that we returned from vacation to find that the Goodeids had dropped fry while we were away at the beach. This time, more than 10x new fry were counted.

As long as things remain steady, with minor water changes, Goodeids are a very easy fish to keep. We have not observed them predating on their fry. They tend to be born larger than baby guppies or platys. Another fry drop was made (likely a different female) - evidenced by smaller fry with trophotaenia for a few days - but I did not try to make a firm count.

At the present moment, a proper colony is developed with multiple breeding adults and many young. It is about time to split the colony out, and allow a new one to develop in another tank. Eventually, we hope another aquarist interested in this C.A.R.E.S. species will show up to continue the process of “making more!”

Basic Water parameters were measured at the end of the BAP project:

20 gal.

68-72 degrees Farenheit

2x medium sponge filters

3-4x shells

Wisteria

Anacharis

Amazon Sword

Java moss

Java fern

Duckweed

Water lettuce

Valisneria

pH - 7.8-8.0

Ammonia - 0 ppm

Nitrite - 0 ppm

Nitrate - 10 ppm