Allodontichthys tamazulae

Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
Allodontichthys tamazulae
English Name: 
Peppered or Tuxpán Splitfin
Mexican Name: 
Mexclapique (erronously: Mexcalpique) de Tamazula
Original Description: 

  TURNER, C. L. (1946): A contribution to the Taxonomy and Zoogeography of the Goodeid Fishes. Occasional Papers of the Museum of Zoology University Michigan No. 495: pp 1-15

Holotype: 

  Collection-number: University of Michigan Museum of Zoology, Cat. No. UMMZ-143022.

  The Holotype is an adult female of 27mm standard length, collected by C. L. Turner on April the 3rd, 1939.

Terra typica: 

  The Holotype was collected in the Río Tamazula, the uppermost section of the Río Coahuayana before it changes the name into Río Tuxpán, just above the town of Tamazula de Giordano in Jalisco.

Etymology: 

  The species is named for the town of Tamazula de Giordano in the state of Jalisco.

Synonyms: 

  none

Distribution and ESU's: 

  The Tuxpán Splitfin is endemic to the Mexican federal state of Jalisco, historically widely distributed in the upper sections of the Río Coahuayana (Miller et al., 2005), named ríos Tamazula and Tuxpán (downstream to about the town of San Marcos), and the upper Río El Tule drainage (ríos El Terrero and La Trampa), an affluent of the Río Naranjo, the name of the Río Coahuayana section following the Río Tuxpán. The historical extent of occurence included several affluents of the ríos Tamazula and Tuxpán, the ríos Contla, San Gregorio (San Jeronimo or Cobianes) and Atenquique, and the arroyos (creeks) Tecalitlán and Espanatica. Due to water pollution caused by sugarcane mills (e.g. Tamazula de Giordano), by sewage from the town of Tuxpán and by a huge paper mill in Atenquique can be inferred, that the main river nowadays is only scarcely populated with this species, and the Río Tamazula past the sugarcane mill in Tamazula de Giordano uninhabitable (Lyons and Mercado-Silva, 2000). However, it still inhabits the listed affluents and the Río Tamazula above the sugarcane mill and is known from about 10 collection sites. From the distribution in two distinct river systems, two subpopulations, the Río Tuxpán subpopulation (type subpopulation) and the Río El Tule subpopulation, can be inferred. The underlined names are the ones officially used by the Instituto Nacional de Estadística y Geografía; nevertheless, other ones might be more often in use or better known and therefore prefered.

 

  ESU ist short for Evolutionarily Significant Unit. Each unit expresses an isolated population with different genetic characteristics within one species. ESU's can be defined by Molecular genetics, Morphology and/or Zoogeography and help in indicating different phylogenetic lineages within a species. The abbreviation for an ESU is composed of the first 3 letters of the genus, followed by the first 2 letters of the species name and an ongoing number in each species.

   In Allodontichthys tamazulae, it is not possible to distinguish different ESU's, so there is only one recognized: Aldta1

 

  The Río Coahuayana subbasin on a Mexico map:

Río Coahuayana subbasin

  Within the Río Coahuayana subbasin, the Tamazula Splitfin occurs in two infrabasins: The Río Tuxpán infrabasin (TUX) in the Río Coahuayana headwaters and the Río Naranjo infrabasin (NAR) further downstreams. The bold red line encompasses the species' distribution, the thin red line separates the infrabasins. For a more detailed distribution, see the map for the Maximum Extent of Occurence (EOO):

Allodontichthys tamazulae infrabasins

     Maximum Extent of Occurence of Allodontichthys tamazulae:

Maximum EOO of Allodontichthys tamazulae

Status : 

  International Union for Conservation of Nature (IUCN): not assessed (assessment in process)

  Conservation status and population trends of Mexican Goodeids (Lyons, 2011): vulnerable/stable: "Historically know from throughout the Upper Coahuayana River basin (Miller et al., 2005). Pollution from a sugar cane mill near the town of Tamazula has made a portion of the former range of the species in the lower Tamazula River uninhabitable since the 1970’s (Lyons and Mercado-Silva, 2000). Since the 1980’s and 1990’s, A. tamazulae has been found at 10 locations, several of which are moderately large. Recent surveys indicate that all of these populations still persist."

  NOM-059-SEMARNAT-2010: Categoría de riesgo (Category of risk): P - En Peligro de Extinción (in danger of extinction)

Habitat: 

  The habitats are generally small, rocky streams and riffles over substrates of sand, rocks and boulders. The vegetation is typically green algae, sometimes sparse or none, especially in large rivers where the species is scarce. The currents are slight or moderate to swift, the water is turbid or clear. It can be found in depths of 1m, but usually it prefers depths of 0.5m or less. Like all known Allodontichthys-species, the Peppered Splitfin is a bottom-dwelling and riffle-inhabitating species.

 

  On a survey in 2016, a group of members of the GWG found this species together with Allodontichthys hubbsi and Ilyodon whitei close to the bridge at Contla in the Río or Arroyo Contla in very shallow (about 20cm deep) water in swift current. Both Allodontichthys species were easy to catch by lifting rocks, were the fish hided and put a handnet over the place. The river had a width of about three to four meters in this dry season, the broad stony river bank sugested a width of about eight to ten meters in the rainy season, which could be confirmed on a second survey in November 2018. The first survey revealed good stocks of this species with nearly the same number of individuals as of the Whitepatch Splitfin. The group was able to find this fish additionally in the Río Tamazula at the east end of the town of Tamazula de Giordano, together with the same species of Goodeids and "Xenotoca" lyonsi in sligthly deeper water and swift current. On the second survey of the Río Contla in November 2018, it was a murky fast flowing river, wide up to 8 or 10m and deep to 120cm at some places. Only few Peppered Splitfins could be found this time, including fry (and two female "Xenotoca" lyonsi). A survey of the Arroyo San José de Tule in the same month revealed the species together with A. hubbsi above the town of San José de Tule near the aquaeduct, whereas in the town, only Allodontichthys tamazulae could be found. All Allodontichthys at all surveyed locations in November were in poor health condition probably due to a higher pressure through parasites.

Río ContlaRío Contla

Río Tamazula

Río Tamazula

Río Tamazula

Río Tamazula

Arroyo San José de Tule

Arroyo San José de Tule

Biology: 

  Turner found no gravid females in April 1946, but Miller took individuals of 14–18mm SL between 24. February and 24. April. This suggests a reproduction during early winter.

Diet: 

  The conical and shouldered teeth and the short gut (2/3 to 3/4 of standard length) indicate carnivorous feeding habits. Turner found some large (5mm) insect larvae in the gut.

Size: 
The maximum known standard length is 73mm (Miller et al, 2005).
Colouration: 

  Turner described the colouration of preserved specimens in the following way: "In general the colouration of A. tamazulae is much lighter than of A. zonistius, and the entire portion above the lateral line is more lightly mottled with dark brown. About 12 heavy, dark, vertical bars extend in the females of A. zonistius from well above the lateral line to well below the lateral line, and a black comma-shaped patch is present just back of the pectoral fin. In A. tamazulae there are 18 to 22 very short dark bars along the lateral line. Only in the part anterior to the dorsal fin and behind the head is there any considerable extension of the bars below the lateral line. In this area 7 to 10 irregular bars extend downward upon the belly. The comma-shaped patch behind the pectoral fin is present in A. tamazulae, but is much lighter than it is in zonistius. Three light vertical bars occur upon the caudal fin in A. tamazulae. There are none in A. zonistius. All males are more heavily marked than the females, particularly in the vertical bars below the lateral line upon the belly."

Sexual Dimorphism: 

  At first appearance, males and females of the Peppered Splitfin are not as easy to distinguish from each other as sexes from other species of Goodeids, but easier than males and females from closer related species like Allodontichthys hubbsi or zonistius. The safest characteristic is the Splitfin in males, means the for Goodeinae typical mating organ formed by a notch after the first seven shortened rays of the Anal fin. Additionally, male Allodontichthys tamazulae have a bigger Dorsal fin than females, and it is usually more intensively coloured, dark blotched or even almost black. A third character is the colour: males are brighter coloured, mainly blue or bluish on the back, with the upper part of the body clearly separated from the lower part by a series of black blotches forming an irregular line while females are duller coloured and mainly yellow.

Allodontichthys tamazulae male 

Allodontichtys tamazulae female

Remarks: 

  In the 1980s, Miller & Uyeno postulated, that Allodontichthys hubbsi and tamazulae might be sister taxa, because they are distributed sympatrically and are of similar shape, but later phylogenetic results (Cytochrome c oxidase subunit I and mitochondrial control region, Webb, 2002) and morphological features (Rauchenberger, 1988, e.g. it differs from its congeners having only 3-3 versus 4-4 mandibular pores in the acustico-lateralis system, a longer base of the anal fin and the dorsal fin placed more anteriorly) heavily supported the position of Allodontichthys hubbsi at the basis of the genus as the most distinct representative. Latest phylogenetic studies (Cytochrome b gen, Domínguez-Domínguez et al., 2011) however place the Whitepatch Splitfin again next to Allodontichthys tamazulae as its closest relative. Nevertheless some inconsistencies remain: Why is it possible, that two closely related species of one genus are able to develop in one river system, and how can it happen, that both persist next to each other? Here the emergence of different sex chromosmomes in Allodontichthys hubbsi could be the answer. But how can the morphological distinct features between hubbsi and its three congeners be explained? Maybe the relationship is not that narrow and the Whitepatch Splitfin is really the most basic species of Allodontichthys, but former hybridisation processes between Allodontichthys hubbsi and tamazulae may be pretending narrow relationship in the cytochrom b gen, so for the moment, the position of the species in the genus Allodontichthys is not clearly resolved.

 

  The Whitepatched Splitfin occurs sympatrically with Allodontichthys tamazulae in the headwaters of the Río Tuxpán, but no more in the warmer parts of the river, where the Peppered Splitfin seems to be the only representative of the genus. Maybe this species is more tolerant against slightly higher temperatures or poorer water quality. However it is also possible, that both species have not clearly separated ecologocal niches and that Allodontichthys tamazulae is on the way to substitute Allodontichthys hubbsi in the future as this species is becoming absolutely rare. In some habitats, it seems to have disappeared throughout the decades and been replaced completely by Allodontichthys tamazulae

 

  Webb compared two populations of Allodontichthys tamazulae, one Aquarium strain from the Río Tamazula and one wild caught one from Río Contla, also from the Río Tamazula drainage. Surprisingly he found notably differences of the two samples (2.1% sequence divergence). That is nearly as much as he found between polylepis and the clade zonistius plus tamazulae (2.4%).

 

   J. Lyons and N. Mercado-Silva (2000) wrote, that in the field, the easiest possibility to distinguish A. tamazulae from thubbsi is by the colour of the back. While the Peppered Splitfin shows black or brown spots, the Whiteptach Splitfin doesn't have clear markings. Mary Rauchenberger (1988) described the dorsal body pigment of A. hubbsi as reduced in places, giving the fish a blotchy appearance. Additionally, she remarked pale fins in contrast to the other species.

Husbandry: 

  Looking on the biotopes of Allodontichthys tamazulae, they suggest the species may prefer a habitat with moderate to swift current, structured with gravel, rocks and boulders. It seems to be less aggressive than its congeners, nevertheless there is aggression between the adult fish, so the tank set up should prevent the fish from seeing each other all the time. Fry is eaten in most of the cases, but it may depend on the quantity and quality of food and on the number of places to hide. When several different stages of juveniles occur, fry may be neglected, so it makes sense to add separate brought up fry to the group with a size of 2 or 2.5cm to provide these stages and get a flock breeding colony.  

   The recommended tank size is at least 150 liters, bigger tanks with a generous base and little height (25cm are enough) are better for sure. With rocks well structured tanks combined with some roots and/or wood seem to do best with this species. The current should be moderate or swift, especially as the species is adapted to a high oxygene level (at least 8mg/l).

   In the wild, the species seems to feed from small or middle - sized invertebrates like bloodworms or insect larvae, so feeding with similar food, water fleas, Mysids and other food from animalistic sources will be best for this predatory fish. In aquarium, it feeds also well from flake food, granulate and even tablets, additionally given Nauplia of Brine Shrimps are eaten greedy and the species is not acting shy at all.  

   Concerning water quality, this species is in need of bigger water changes (60-80% every week) like most of the Goodeids, especially river inhabiting species, so an automatic water changing system can be helpful. Otherwise, in combination with constant temperatures higher than 24°C, fish may get sick, lose resistance against diseases and age too fast. So for keeping the strain healthy and strong, give the fish a rest during winter time with temperatures lower than 20°C for 2 or 3 months so they stop producing fry. In spring, when the temperature slowly increases, they will start spawning at 20 or 21°C and won't stop until it gets colder again or when it gets too warm (25°C).

  This species is doing very well when is kept in the open from spring to fall, starting when the water temperature by day exceeds 17°C and cold periods are no longer expected. Bring them out in the early afternoon, the time of the day with the highest water temperature. During the warm summer, reproduction will stop and may occur again in fall. Bring the fish in before the water temperature deceeds 17°C by day and keep them cool for the first days, then slowly raise the temperature but try to stay below 20°C over the winter time.

Locations