Subterranean Fishes of the World

The specific name was misspelled phreaticola by Vandel (1964, 1965).

Country

Types

Holotype: A female 54.6mm (SL/TL?). This specimen was reported to have been kept in the collection of Carranza and its present location (if still extant) is unknown. Paratypes: Sixty‑five specimens 33.5mm ‑ 54.7mm (SL/TL ?). Of these the whereabouts of only the following are known for sure: UMMZ 173788 (3 specimens, 35-45mm SL), UMMZ 223109 (5 specimens, 34-52mm SL), SU 48047 (3 specimens), TU 10810 (3 specimens, ex-Carranza collection), TU osteo 178, USNM 164169 (3 specimens). It was reported (Carranza, 1954:132) that each of the following institutions was sent three paratypes: BMNH, MNHN, IPN. Nineteen were retained alive in aquaria at the time of publication, 26 in the collection of Carranza, and 2 in the collection of C. Bolivar. The present location of these 47 (if still extant) is unknown. This species is the type species by original designation and monotypy of the cave‑restricted genus Prietella.

Distribution

Type locality: a dug‑out well called Pozo El Potrero de Dona Mariana, Municipio de Musquiz, Coahuila, Mexico (27^o10'N 101^o05'W).  Specimens of this species have now been collected from the Sotano de Amezcua (29^o20’N, 101^o30W) 200 km from the type locality (Sprouse, 1993; Elliott, 1994), and other sites (see Hendrickson, Krejca and Rodriguez Martinez 2001 for details). Ongoing research (Dean Hendrickson pers. comm.) will probably result in more locations being discovered. In 2016 fishes very like P. phreatophila were discovered in Amistad National Recreation Area near Del Rio, Texas. Dean Hendrickson is convinced that they are the same species.

Habitat

The type locality is “an artificially enlarged natural well fed by a deep crevice” (Reddell 1981:245). Hendrickson, Krejca and Rodriguez Martinez (2001) reports that the habitat of this species vary from deep ephemeral streams to perennial flows. All known habitats are subject to massive flooding.  In Sotano de Amezcua the animals have been collected from a sump pool which is probably not the real habitat.

Systematics

Taylor (1955, 1969) suggested that Prietella phreatophila is the sister group of the large and extensive genus Noturus. This was supported by Lundberg (1982) after a thorough anatomical study of many ictalurids. Further support was gathered by Amemiya, Kelsch, Hendricks and Gold (1986) who determined the karyotype of a single specimen. It has 2n=50 with a diploid are number of 80. This is not very distinct from a Noturus karyotype although  it was suggested that the presence of a single NOR (as opposed to multiple NORs in Noturus) may represent the ancestral condition for the Ictaluridae. Miller and Smith (1986:477) suggest that this species is of Oligocene or more recent origin.  The closest living relative is currently the hypogean Prietella lundbergi, though this is over 600km away.

Detailed studies the four North and Central American troglobitic ictalurids Satan eurystomus, Trogloglanis pattersoni, Prietella phreatophila and P. lundbergi  by Arce et al. (2016) suggest that they form a monophyletic group with fifteen synapomorphies: 1. Absence of eyes, 2. depigmentation, 3. Fifth vertebra, 4. Lateral line extent, 5. Mesethmoid cornua, 6. Anterior cranial fontanel, 7. Descending wing of frontal, 8. Supraoccipital posterior process, 9. Pterotic wings, 10. Parasphenoid and orbitosphenoid, 11. Abductor arcus palatine scars, 12. Anterior ceratohyal-ventral hypohyal joint, 13. Dorsal hypohyal, 14. Upper hypurals, 15. Transcapular ligament ossification. It would be highly valuable to compare these anatomical synapomorphies with those from molecular markers.

Museum Holdings

As above plus: USNM 164169, UMMZ 187684, and 173788, TNHC 12100, TCWC 5144-1 (karyotype slide preparation). Probably several specimens at the Instituto Mexicano de Recursos Naturales Renovables, Mexico (Taylor, 1969). More recent collections (including live animals) at Texas Natural History Collection, Texas Memorial Museum.