Scientific Name of Fish: Xenotoca lyonsi Rio Tamazula
Hobby Name of Fish: Tamazula Redtail Splitfin
Method of Reproduction: Livebearer
Number and Gender Distribution of Parents: 2 male and 3 females
Origin of Parents: Tank raised, from PVAS auction several months ago
Some background information about the Goodeid Xenotoca lyonsi:
Goodeids. Goodeids are “named after the first known genus Goodea, that was described by David Starr Jordan in 1880 in honor of George Brown Goode” a “colleague and US American ichthyologist, who worked most of his time as a museum administrator.” http://www.goodeidworkinggroup.com/classification
According to the font of all knowledge Wikipedia, many Goodeids are referred to as splitfins. “The name "splitfin" comes from the fact that, in the male fish, the anterior rays of the anal fin are partly separated from rest of the fin.” “Goodeid fish have internal fertilisation, with males positioning themselves with a flexible part of the front anal fin, separated by a notch, which makes up the andropodium. Embryos hatch out of the egg within the ovarian follicle, and possess trophotaeniae, ribbon-like structures that emerge from the cloaca in front of the anal fin, on the ventral surface of the juvenile. These allow the absorption of nutrients within the ovary (matrotrophy), and are shed by juveniles shortly after birth. Female goodeids do not store sperm, and so a copulation event must precede each pregnancy.[6]” https://en.wikipedia.org/wiki/Goodeidae
Xenotoca lyonsi Rio Tamazula: There are currently five Xenotoca species I could discern: Xenotoca melansoma, Xenotoca eiseni, Xenotoca doadrioi, Xenotoca variata, and Xenotoca lyonsi. The latter species was named in 2015 after ichthyologist Dr. John Lyons at University of Wisconsin, Madison. Of these five species, four are listed on the CARES priority list. https://caresforfish.org/?page_id=336 Xenotoca lyonsi is listed as “CEN endangered” which is defined as “Species facing a very high risk of extinction in the wild in the near future”. https://caresforfish.org/?page_id=464
Xenotoca lyonsi Rio Tamazula originates in the Mexican state of Jalisco. Rio Tamazula was the collection point where these fish were obtained. Since some fish species have not been described or fully described by scientists, it is important to include the collection point. This information is valuable for the future if those fish turn out to be a distinct species or subspecies with particular geographic, genetic, or phenotypic characteristics. One should not interbreed fish from different collection points since that may inadvertently lead to hybridization between difference species or subspecies, resulting in a loss of the pure species or subspecies.
Why is Xenotoca lyonsi endangered? According to Lyons and colleagues, Xenotoca lyonsi is considered to be endangered/declining. “This species was recently separated from X. eiseni (Domínguez-Domínguez et al. 2016). It is known from the upper Coahuayana River basin and is endangered. Historically it was widespread, but lack of water and water pollution have eliminated most populations.” Lyons et al. ZooKeys 885:115-158.
“Xenotoca lyonsi is evaluated by the international union for the conservation of nature in the IUCN red list of threatened species as (CR) critically endangered (2018). Xenotoca lyonsi is known only from a few sites along its original distributional range, and is reported to have been extirpated from approximately 60% of the historical localities where it has been reported. All the areas where the species originally occurred are highly impacted by human activities, being totally modified for agricultural purposes, with sugar cane plantations demanding high water resources and discharging polluted water from the production process. Also, untreated urban waste into the river is a substantial ecological problem in the area. In several recent surveys for the species, it was never located downstream of the village waste water discharges and, when found, it was always upstream of the discharge sites. Also, the species is not abundant in the few localities from where it is currently known to exist (Domínguez Domínguez et al., 2016:93, Lyons et al., 2019:145, Köck, 2019).” https://mexfish.info/species.php?id=902
Approximate number of fry: 20
Date of Hatch or Birth: Dec 7, 2022
Date of Free Swimming If Hatched: N/A
Approx. Number of Fry at 60 Days: 20-ish
Aquarium Conditions:
pH: 7.2
General Hardness: 150 ppm
Average Temperature (72-76 F)
Salinity: none
Average Nitrate: < 40 ppm
Aquarium Size: standard 20 gallon
Water Source: Rockville MD tap water with Seachem Prime
Water Changes: 80% once a month
Filtration System: sponge filter
Additives: no crushed coral
Décor:
Live Plants: Multiple species of Cryptocoryne to keep nitrates down
Small flower pots to provide hiding spots
Substrate: bare glass
Lighting Type and Timing: Home Depot light, 12 hrs on/12 hrs off
Food Fed to Parents and How Often: Tetra Color Tropical Flakes morning and evening. Freshly hatched baby brine shrimp every other day.
Food Fed to Fry and How Often: Finely ground dry fry food (Aquarium Coop) morning and evening, freshly hatched baby brine shrimp every other day.
Additional comments: This batch of fry were raised using “Dean’s Fry System”. It is very convenient for feeding the fry and for keeping track of their growth. The fry are kept with the overhead lights off, so they only receive indirect lighting from nearby tanks. Also they have a little guppy grass for cover and to provide a structure for biofilm growth.
Spawning Report: Xenotoca lyonsi Rio Tamazula
Name: John Satterlee
Scientific Name of Fish: Xenotoca lyonsi Rio Tamazula
Hobby Name of Fish: Tamazula Redtail Splitfin
Method of Reproduction: Livebearer
Number and Gender Distribution of Parents: 2 male and 3 females
Origin of Parents: Tank raised, from PVAS auction several months ago
Some background information about the Goodeid Xenotoca lyonsi:
Goodeids. Goodeids are “named after the first known genus Goodea, that was described by David Starr Jordan in 1880 in honor of George Brown Goode” a “colleague and US American ichthyologist, who worked most of his time as a museum administrator.” http://www.goodeidworkinggroup.com/classification
According to the font of all knowledge Wikipedia, many Goodeids are referred to as splitfins. “The name "splitfin" comes from the fact that, in the male fish, the anterior rays of the anal fin are partly separated from rest of the fin.” “Goodeid fish have internal fertilisation, with males positioning themselves with a flexible part of the front anal fin, separated by a notch, which makes up the andropodium. Embryos hatch out of the egg within the ovarian follicle, and possess trophotaeniae, ribbon-like structures that emerge from the cloaca in front of the anal fin, on the ventral surface of the juvenile. These allow the absorption of nutrients within the ovary (matrotrophy), and are shed by juveniles shortly after birth. Female goodeids do not store sperm, and so a copulation event must precede each pregnancy.[6]” https://en.wikipedia.org/wiki/Goodeidae
Xenotoca lyonsi Rio Tamazula: There are currently five Xenotoca species I could discern: Xenotoca melansoma, Xenotoca eiseni, Xenotoca doadrioi, Xenotoca variata, and Xenotoca lyonsi. The latter species was named in 2015 after ichthyologist Dr. John Lyons at University of Wisconsin, Madison. Of these five species, four are listed on the CARES priority list. https://caresforfish.org/?page_id=336 Xenotoca lyonsi is listed as “CEN endangered” which is defined as “Species facing a very high risk of extinction in the wild in the near future”. https://caresforfish.org/?page_id=464
Xenotoca lyonsi Rio Tamazula originates in the Mexican state of Jalisco. Rio Tamazula was the collection point where these fish were obtained. Since some fish species have not been described or fully described by scientists, it is important to include the collection point. This information is valuable for the future if those fish turn out to be a distinct species or subspecies with particular geographic, genetic, or phenotypic characteristics. One should not interbreed fish from different collection points since that may inadvertently lead to hybridization between difference species or subspecies, resulting in a loss of the pure species or subspecies.
Why is Xenotoca lyonsi endangered? According to Lyons and colleagues, Xenotoca lyonsi is considered to be endangered/declining. “This species was recently separated from X. eiseni (Domínguez-Domínguez et al. 2016). It is known from the upper Coahuayana River basin and is endangered. Historically it was widespread, but lack of water and water pollution have eliminated most populations.” Lyons et al. ZooKeys 885:115-158.
“Xenotoca lyonsi is evaluated by the international union for the conservation of nature in the IUCN red list of threatened species as (CR) critically endangered (2018). Xenotoca lyonsi is known only from a few sites along its original distributional range, and is reported to have been extirpated from approximately 60% of the historical localities where it has been reported. All the areas where the species originally occurred are highly impacted by human activities, being totally modified for agricultural purposes, with sugar cane plantations demanding high water resources and discharging polluted water from the production process. Also, untreated urban waste into the river is a substantial ecological problem in the area. In several recent surveys for the species, it was never located downstream of the village waste water discharges and, when found, it was always upstream of the discharge sites. Also, the species is not abundant in the few localities from where it is currently known to exist (Domínguez Domínguez et al., 2016:93, Lyons et al., 2019:145, Köck, 2019).” https://mexfish.info/species.php?id=902
Approximate number of fry: 20
Date of Hatch or Birth: Dec 7, 2022
Date of Free Swimming If Hatched: N/A
Approx. Number of Fry at 60 Days: 20-ish
Aquarium Conditions:
pH: 7.2
General Hardness: 150 ppm
Average Temperature (72-76 F)
Salinity: none
Average Nitrate: < 40 ppm
Aquarium Size: standard 20 gallon
Water Source: Rockville MD tap water with Seachem Prime
Water Changes: 80% once a month
Filtration System: sponge filter
Additives: no crushed coral
Décor:
Live Plants: Multiple species of Cryptocoryne to keep nitrates down
Small flower pots to provide hiding spots
Substrate: bare glass
Lighting Type and Timing: Home Depot light, 12 hrs on/12 hrs off
Food Fed to Parents and How Often: Tetra Color Tropical Flakes morning and evening. Freshly hatched baby brine shrimp every other day.
Food Fed to Fry and How Often: Finely ground dry fry food (Aquarium Coop) morning and evening, freshly hatched baby brine shrimp every other day.
Additional comments: This batch of fry were raised using “Dean’s Fry System”. It is very convenient for feeding the fry and for keeping track of their growth. The fry are kept with the overhead lights off, so they only receive indirect lighting from nearby tanks. Also they have a little guppy grass for cover and to provide a structure for biofilm growth.
They are growing rapidly!
This CARES goodeid species spawned for me on Dec 7, 2022 with about 16 fry. I will write up a more detailed spawning report soon.