Prietella
Encyclopedia
Prietella is a small genus
of catfish
es (order
Siluriformes) of the family
Ictaluridae
. It includes two species, the phantom blindcat, P. lundbergi, and the Mexican blindcat, P. phreatophila.
and to be the sister group
of the Noturus. The karyotype
of P. phreatophila is indistinguishable from one of the genus Noturus; however, its diploid number of 50 chromosome
s differs from the proposed ancestral Noturus karyotype of 54–56 chromosomes. However, this relationship has not been supported by preliminary mitochondrial DNA
sequence data. Despite similarity to other cave-dwelling species of Ictaluridae, they are not closely related.
, Mexico
, very near the international boundary, to the southernmost Tamaulipas
, 750 kilometre
s (470 mi
) away to the southeast. The distribution of P. lundbergi is very restricted; P. lundbergi is known from two springs of the Tamesí River
drainage in the Tamaulipas state of Mexico. P. phreatophila has a greater distribution than P. lundbergi; P. phreatophila originates from the Bravo River basin, Coahuila, from near Múzquiz
northward to about 50 km (31 mi) southwest of Ciudad Acuña
and to near Allende
, Mexico. Both species occupy different Gulf of Mexico
drainages and are separated by about 600 km (370 mi).
P. lundbergi is a cave-restricted species. P. phreatophila occurs in wells. Most Phreatophila have been found well in habitats that likely have relatively little short-term fluctuation in environmental parameters. For the most part, they are found in still pools; they have never been seen in shallow running water. Often they are associated with a silt substrate.
. In Prietella, the lateral line is more reduced than in other members of the subfamily; after the gill opening, it is reduced to three or fewer pores. P. lundbergi differs from P. phreatophila by a number of characteristics including a reduced or absent swimbladder
, a more emarginate to weakly forked caudal fin, and a more deeply notched adipose fin. P. lundbergi grows to about 4.5 centimetre
s (1.8 in
) SL
.
P. phreatophila may lie motionless or drift in the current with their breathing slowed. Though they may be awakened by disturbances, this behavior is likely due to lack of predators in their habitat as this behavior would likely leave them extremely vulnerable to predation.
.
Both species of Prietella are on the IUCN Red List
. P. lundergi is a vulnerable species
, and P. phreatophila is an endangered species
. P. phreatophila is threatened by groundwater
pollution
and overfishing
. It has been noted that P. phreatophila should be considered a threatened species
due to being found in more localities than previously thought and recommended that P. lundbergi be considered endangered due to its extreme rarity.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of catfish
Catfish
Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...
es (order
Order (biology)
In scientific classification used in biology, the order is# a taxonomic rank used in the classification of organisms. Other well-known ranks are life, domain, kingdom, phylum, class, family, genus, and species, with order fitting in between class and family...
Siluriformes) of the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Ictaluridae
Ictaluridae
The Ictaluridae, sometimes called Ictalurids, are a family of catfish native to North America, where they are important food fish and sometimes as a sport fish. They include fish commonly known as bullheads, madtoms, channel catfish, and blue catfish....
. It includes two species, the phantom blindcat, P. lundbergi, and the Mexican blindcat, P. phreatophila.
Taxonomy
Prietella has been confirmed to be monophyleticMonophyly
In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...
and to be the sister group
Cladistics
Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...
of the Noturus. The karyotype
Karyotype
A karyotype is the number and appearance of chromosomes in the nucleus of an eukaryotic cell. The term is also used for the complete set of chromosomes in a species, or an individual organism.p28...
of P. phreatophila is indistinguishable from one of the genus Noturus; however, its diploid number of 50 chromosome
Chromosome
A chromosome is an organized structure of DNA and protein found in cells. It is a single piece of coiled DNA containing many genes, regulatory elements and other nucleotide sequences. Chromosomes also contain DNA-bound proteins, which serve to package the DNA and control its functions.Chromosomes...
s differs from the proposed ancestral Noturus karyotype of 54–56 chromosomes. However, this relationship has not been supported by preliminary mitochondrial DNA
Mitochondrial DNA
Mitochondrial DNA is the DNA located in organelles called mitochondria, structures within eukaryotic cells that convert the chemical energy from food into a form that cells can use, adenosine triphosphate...
sequence data. Despite similarity to other cave-dwelling species of Ictaluridae, they are not closely related.
Distribution and habitat
The distribution of Prietella now is known to extend from the very northern part of the state of CoahuilaCoahuila
Coahuila, formally Coahuila de Zaragoza , officially Estado Libre y Soberano de Coahuila de Zaragoza is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico...
, Mexico
Mexico
The United Mexican States , commonly known as Mexico , is a federal constitutional republic in North America. It is bordered on the north by the United States; on the south and west by the Pacific Ocean; on the southeast by Guatemala, Belize, and the Caribbean Sea; and on the east by the Gulf of...
, very near the international boundary, to the southernmost Tamaulipas
Tamaulipas
Tamaulipas officially Estado Libre y Soberano de Tamaulipas is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 43 municipalities and its capital city is Ciudad Victoria. The capital city was named after Guadalupe Victoria, the...
, 750 kilometre
Kilometre
The kilometre is a unit of length in the metric system, equal to one thousand metres and is therefore exactly equal to the distance travelled by light in free space in of a second...
s (470 mi
Mile
A mile is a unit of length, most commonly 5,280 feet . The mile of 5,280 feet is sometimes called the statute mile or land mile to distinguish it from the nautical mile...
) away to the southeast. The distribution of P. lundbergi is very restricted; P. lundbergi is known from two springs of the Tamesí River
Tamesí River
-References:*Atlas of Mexico, 1975 .*The Prentice Hall American World Atlas, 1984.*Rand McNally, The New International Atlas, 1993....
drainage in the Tamaulipas state of Mexico. P. phreatophila has a greater distribution than P. lundbergi; P. phreatophila originates from the Bravo River basin, Coahuila, from near Múzquiz
Múzquiz
Múzquiz is a one of the 38 municipalities of Coahuila, in north-eastern Mexico. The municipal seat lies at Santa Rosa de Múzquiz. The municipality covers an area of 8,128.9 km².As of 2005, the municipality had a total population of 62,710....
northward to about 50 km (31 mi) southwest of Ciudad Acuña
Ciudad Acuña
Ciudad Acuña, also known simply as Acuña, is a city located in the Mexican state of Coahuila, at and a mean height above sea level of 271 meters...
and to near Allende
Allende
Allende is a Spanish word of Latin origin meaning "beyond" or "besides". It is also a Basque surname.Allende may refer to:People*Salvador Allende, former President of Chile...
, Mexico. Both species occupy different Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...
drainages and are separated by about 600 km (370 mi).
P. lundbergi is a cave-restricted species. P. phreatophila occurs in wells. Most Phreatophila have been found well in habitats that likely have relatively little short-term fluctuation in environmental parameters. For the most part, they are found in still pools; they have never been seen in shallow running water. Often they are associated with a silt substrate.
Description
Like other cave species of catfish including the ictalurids Trogloglanis pattersoni and Satan eurystomus, Prietella species lack pigmentation and eyes and have a reduced lateral lineLateral line
The lateral line is a sense organ in aquatic organisms , used to detect movement and vibration in the surrounding water. Lateral lines are usually visible as faint lines running lengthwise down each side, from the vicinity of the gill covers to the base of the tail...
. In Prietella, the lateral line is more reduced than in other members of the subfamily; after the gill opening, it is reduced to three or fewer pores. P. lundbergi differs from P. phreatophila by a number of characteristics including a reduced or absent swimbladder
Gas bladder
The swim bladder, gas bladder, fish maw or air bladder is an internal gas-filled organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth without having to waste energy in swimming...
, a more emarginate to weakly forked caudal fin, and a more deeply notched adipose fin. P. lundbergi grows to about 4.5 centimetre
Centimetre
A centimetre is a unit of length in the metric system, equal to one hundredth of a metre, which is the SI base unit of length. Centi is the SI prefix for a factor of . Hence a centimetre can be written as or — meaning or respectively...
s (1.8 in
Inch
An inch is the name of a unit of length in a number of different systems, including Imperial units, and United States customary units. There are 36 inches in a yard and 12 inches in a foot...
) SL
Fish measurement
Fish measurement refers to the measuring of the length of individual fish and of various parts of their anatomy. These data are used in many areas of ichthyology, including taxonomy and fisheries biology.-Overall length:...
.
Behavior
Jaw-locking behaviors have been observed in P. phreatophila. Fish that have been presumed to be males when first coming in contact with each other will engage in this behavior that is thought to establish a social dominance hierarchy. Jaw-locking usually lasts less than 30 minutes but has been recorded to last for many hours. The dominance relationships are long-term; the same two fish usually do not engage in this behavior again.P. phreatophila may lie motionless or drift in the current with their breathing slowed. Though they may be awakened by disturbances, this behavior is likely due to lack of predators in their habitat as this behavior would likely leave them extremely vulnerable to predation.
Relationship to humans
Trade of P. phreatophila is restricted in GermanyGermany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
.
Both species of Prietella are on the IUCN Red List
IUCN Red List
The IUCN Red List of Threatened Species , founded in 1963, is the world's most comprehensive inventory of the global conservation status of biological species. The International Union for Conservation of Nature is the world's main authority on the conservation status of species...
. P. lundergi is a vulnerable species
Vulnerable species
On 30 January 2010, the IUCN Red List of Threatened Species identified 9694 Vulnerable species, subspecies and varieties, stocks and sub-populations.-References:...
, and P. phreatophila is an endangered species
Endangered species
An endangered species is a population of organisms which is at risk of becoming extinct because it is either few in numbers, or threatened by changing environmental or predation parameters...
. P. phreatophila is threatened by groundwater
Groundwater
Groundwater is water located beneath the ground surface in soil pore spaces and in the fractures of rock formations. A unit of rock or an unconsolidated deposit is called an aquifer when it can yield a usable quantity of water. The depth at which soil pore spaces or fractures and voids in rock...
pollution
Pollution
Pollution is the introduction of contaminants into a natural environment that causes instability, disorder, harm or discomfort to the ecosystem i.e. physical systems or living organisms. Pollution can take the form of chemical substances or energy, such as noise, heat or light...
and overfishing
Overfishing
Overfishing occurs when fishing activities reduce fish stocks below an acceptable level. This can occur in any body of water from a pond to the oceans....
. It has been noted that P. phreatophila should be considered a threatened species
Threatened species
Threatened species are any speciesg animals, plants, fungi, etc.) which are vulnerable to endangerment in the near future.The World Conservation Union is the foremost authority on threatened species, and treats threatened species not as a single category, but as a group of three categories,...
due to being found in more localities than previously thought and recommended that P. lundbergi be considered endangered due to its extreme rarity.