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41-462: Pterygoplichthys Pterygoplichthyini is a tribe of catfishes ( order Siluriformes) of the family Loricariidae . It includes two genera , Pterygoplichthys and the currently undescribed genus referred to as the Hemiancistrus annectens group, This group was earlier misspelled as Pterygoplichthini. Pterygoplichthyines are known from nearly the entire range of loricariids except for

82-529: A continuous series of lightnings that are almost continuous and silent. This makes Lake Maracaibo the place with the most frequent lightning on Earth. There are about 233 lightning strikes per square kilometer in a year on average. The nocturnal thunderstorms occur on average about 297 days per year. At its peak in September, the lake area can experience up to 280 lightning strikes per hour, approximately 28 lightning strikes per minute, lasting up to 9 hours, and

123-514: A five kilometer thick deposit of sediment on the bedrock. In the Pliocene , the depression of today's Lake Maracaibo reached what would be practically its current form. The numerous rivers that flow into the lake have been defining its banks, especially those that form the southern delta of the lake, where the Escalante , Catatumbo and Santa Ana rivers converge. Lake Maracaibo is located in

164-606: A member of Pterygoplichthys can range from about 50–70 cm. The stomach of Pterygoplichthys is greatly expanded with the posterior portion forming a long, thin sac that is highly vascularized. Pterygoplichthys' habitat is most common in sluggish streams, floodplain lakes , and marshes. They are known from the Orinoco , Amazon , Magdalena , Maracaibo , Paraná , Parnaíba and São Francisco systems. These fish have been introduced into many locations. Several species of Pterygoplichthys have been established in

205-888: Is also home to two endangered aquatic mammals, the West Indian manatee and the Amazon river dolphin . About 145 species of fish inhabit the lake, including many endemic species such as the Maracaibo half-hooked catfish ( Hypostomus maracaiboensis ), the Maracaibo hairy catfish ( Trichomycterus maracaiboensis ), the Maracaibo Lake Lamont catfish ( Lamontichthys maracaibero ), Lake Maracaibo tetra ( Bryconamericus motatanensis ), and Maracaibo wolf anchovies ( Lycengraulis limnichthys ) living in surface waters. The lake has been drilled about 14,000 times, and more than 15,000 miles of oil and gas pipelines criss-cross

246-405: Is capable of illuminating nighttime navigation. The aboriginal Añú  [ es ] people who lived on the banks of the lake refer to it as Coquivacoa. The tribes of Wayuu , Caquetíos , and Quiriquires also lived in the area. When Italian navigator Amerigo Vespucci and Spanish explorer Alonso de Ojeda 's fleet sailed here on August 24, 1499 (the first time Europeans entered this area),

287-525: Is connected to the Gulf of Venezuela to the north by a narrow spit . It is fed by numerous rivers, the biggest being the Catatumbo River . The fault in the northern section has collapsed and is rich in oil and gas resources. It is Venezuela's main oil producing area and an important fishing and agricultural producing area. Eutrophication caused by oil pollution is a major environmental problem facing

328-422: Is deep in the south and shallow in the north. The northern half of the lake, which looks like a bottleneck, is 55 kilometers long. The southeastern edge of the lake basin with a flat bottom is steep and the northwestern edge is gentle. The southern part is lighter due to river water injection, while the northern part is slightly salty due to tidal influence. The Catatumbo River forms a bird-foot-shaped delta in

369-578: Is established in Campeche , Chiapas , and other localities in central and western Mexico, while P. pardalis has been found in southeastern Mexico. In the Philippines , where these fish are known as janitor fish, P. disjunctivus and P. pardalis have been found, these fish are considered a threat to the freshwater fish population; they are found in the Marikina River , Laguna de Bay and

410-657: Is geographically a peninsula), while others like Toad have tectonic origins. The majority of the islands are located in the area of the Tablazo Bay and forms the Almirante Padilla municipality  [ es ] . The islands of Burro, Providencia, Hijacal, Pájaros, and the artificial islands are located at the neck of the lake and belong to other municipalities. Natural islands of Lake Maracaibo: Artificial islands of Lake Maracaibo: The 8,678 metres (28,471 ft) long General Rafael Urdaneta Bridge connects

451-521: Is plant matter. Their diet consists of algae , aufwuchs , general plant matter and possibly carrion . They are grazing animals or scavengers as opposed to predator fish. Pterygoplichthys are known for being kept out of water and sold alive in fish markets, surviving up to 30 hours out of water. Males excavate tunnels into mud banks where eggs are laid. P. gibbiceps has been bred commercially in fish farms in Florida and Malaysia for

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492-479: The Guyanas and coastal streams in southeastern Brazil . although later work by the same authority, and his co-authors, placed this group among the genus Hypostomus . Pterygoplichthyini is sister to the tribe Ancistrini , which shares the derived presence of an evertible patch of plates on the cheek. Pterygoplichthys and the H. annectens group differ most obviously in the number of dorsal fin rays (7 in

533-468: The H. annectens group and 9+ in Pterygoplichthys ). The two genera are supported as sisters by only one derived characteristic: a modified stomach that is attached to the abdominal wall by a net of connective tissue. This modified stomach allows these fish to breathe air. The stomach is vascularized. A white net of connective tissue surrounds the organ, leaving a circular area in the middle of

574-680: The Maracaibo lowland in the faulted basin between the Perija Mountains and the Merida Mountains of the Eastern Cordillera Mountains in northwestern Venezuela. The lake is in the shape of a vase. It is 210 kilometers long from north to south, 121 kilometers wide from east to west, covers an area of 13,512 square kilometers, the deepest is 35 meters, the shore length is about 1000 kilometers, and

615-479: The aquarium trade. P. multiradiatus and P. pardalis are both known as common plecos and are widely sold as algae eaters . However, most of them grow too large to be housed in an average home aquarium . In fact, in the wild, the Common Pleco can well exceed 2 feet in length, and, as well as growing large, they also produce a lot of waste that can pollute the water. Lake Maracaibo The lake

656-412: The carrying capacity of some fish communities. Moreover, none of the 30 professional water managers, engineers, lake management, and shoreline stabilization company owners contacted in 2004 by a particular study considered erosion caused by the burrowing activity of loricariid catfishes a major problem, except in some man-made lakes in the southeastern part of the state. In Mexico , P. multiradiatus

697-565: The stilt houses in which the Añú lived in reminded Vespucci of the Italian city of Venice , so he named the region Veneziola ( Venezuela in Spanish), or "Little Venice". Spain made two attempts to establish settlements around the lake in 1529 and 1569, but it was not until 1574 that the city of Maracaibo was successfully established. The Privateer Henry Morgan raided settlements on the lake in

738-585: The Andean mountains and lakes. The Lake District is home to a quarter of Venezuela's population, and with the influx of farmers from the nearby Andes, the population of the Lake District increased from about 300,000 in 1936 to over 3.62 million in 2007. Lake Maracaibo possesses highly oxygenated waters which makes it rich in algae, and in turn fish, making it very biologically diverse. It is home to clams, blue crabs , shrimp and other aquatic products, and

779-586: The Pasig River. P. multiradiatus has also been established in Puerto Rico and Taiwan . In 2022 Hungary the species was first discovered in Lake Hévíz . After catching an documenting several more specimens the species could be identified with certainty. It was also established that the species has successfully colonised the lake and has been declared an invasive species. Their primary food

820-599: The Spring of 1669 and defeated a Spanish squadron sent to intercept him. On July 24, 1823, Venezuela won the famous Battle of Lake Maracaibo on the lake during the Venezuelan War of Independence . The original depth of the lake mouth, which was only more than 4 meters deep, was increased to 8 meters after dredging in the 1930s, and the 3-kilometer-long stone breakwater was further increased to 11 meters after its completion in 1957, allowing ocean-going tankers to enter

861-614: The United States in Florida , Hawaii , Nevada , and Texas . Established species include P. multiradiatus in Florida and Hawaii, P. disjunctivus in Florida, and P. anisitsi in Texas. Sailfin catfish are one of the more successful established exotic fish in Florida in terms of their range extension and abundance, yet their presence has not had any measurable effect on native fishes, although they have contributed significantly to

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902-486: The aquarium trade. Pterygoplichthys is derived from the Greek πτέρυγ- ( pteryg- ), meaning "wing", ( hoplon ) - weapon and ἰχθύς ( ichthys ) meaning "fish". Pterygoplichthys has undergone much shifting in the past decades. Previously Liposarcus , Glyptoperichthys and Pterygoplichthys had been named as separate genera. Since then, these genera were recognized as synonyms of Pterygoplichthys by Armbruster, as

943-404: The body; the abdomen is almost completely covered in small plates. Other characteristics of members of this genus include an underslung suckermouth , evertable cheek plates, adipose fin present, and an enlarged stomach connected to the dorsal abdominal wall by a connective tissue sheet. P. anisitsi , P. disjunctivus , P. multiradiatus , and P. pardalis lack cheek odontodes , but still possess

984-461: The bottom of the lake to float to the surface of the lake, which in turn allowed the duckweed to rapidly multiply and triggered a bloom that lasted for up to eight months. The blooms were noted in June to have covered 18% of the lake, and the local government had to begin spending about $ 2 million per month on cleanup work. Numerous oil spills , at least partly attributed to deficient maintenance, and

1025-407: The city of Maracaibo, the lake water is contaminated with E. coli from feces, oil pollution, and eutrophication caused by agricultural sewage discharged into the lake, as well as domestic and industrial wastewater, resulting in the blooms of duckweed and green algae . The presence of large amounts of duckweed blocks the passage of sunlight, significantly affecting biological cycles, preventing

1066-504: The development of native algae and plant species. Additionally, duckweed residues accumulate at the bottom, generating a layer of organic elements that produces large amounts of ammonium, methane and other compounds whose saturation causes eutrophication of the waters. In the spring of 2004, heavy rains fell in the Lake Maracaibo basin, causing a large influx of fresh water into the lake. This caused nutrients originally deposited on

1107-461: The east of the lake. On the northwest coast is the capital of Zulia State , the second largest city in Venezuela and an important oil export port in the world. The lake area is also an important fishing and agricultural production area in Venezuela, supporting more than 20,000 fishermen, many of whom live in colorful traditional stilt houses built with iron sheets on the lake. The main crops on

1148-412: The evertible cheek plates; this was previously used as a trait to determine these fish as part of the genus Liposarcus . Species of the P. gibbiceps group (species formerly classified in the genus Glyptoperichthys ) are easily recognized by a large crest above the back of their skull. Color pattern is generally dark brown with either darker spots or lighter spots or vermiculations. The adult size of

1189-554: The few differences between the genera were not deemed great enough to validate Glyptoperichthys and Liposarcus , and that recognizing these separate genera would leave neither Pterygoplichthys nor Glyptoperichthys as monophyletic . There are currently 16 recognized species in this genus: Pterygoplichthys can be differentiated from most other loricariids due to their large dorsal fins with 9 or more (usually 10) dorsal fin rays, which gives them their common name "sailfin catfish". These fish have rows of armour plating covering

1230-463: The indiscriminate discharge of sewage without prior treatment, have significantly deteriorated the water quality, to the point that in some parts of the Zulia area, the water presents levels of contamination that are very dangerous for health. Within the existing polluting activities, the mining of mineral coal has started more recently, which further contaminates the basin with pollutants. Likewise,

1271-474: The lagoon. The area around the lagoon is inhabited by a quarter of the country's population and is also the place with the most frequent lightning on Earth. The famous Catatumbo lightning can illuminate nighttime navigation. Lake Maracaibo is located within the eponymous basin and is one of the oldest lakes on earth. It was formed 36 million years ago when the faults collapsed when the Andes were uplifted in

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1312-413: The lake area is 28 °C, the precipitation is more in the south and less in the north, and the average annual rainfall in the south is 1400 mm. The mountain wind from the Andes at night contacts the warm and humid air on the lake surface, forming an average of 297 mm per year. The meteorological phenomenon known as Catatumbo lightning takes place in southern part of the lake, characterized by

1353-437: The lake floor, but most of these pipelines are half a century old, with oil leaking from many aging underwater pipes. Before the 1950s, the lake water could still be used directly for domestic use, but then due to the intrusion of tidal salt water caused by the widening of the lake mouth channel, the salinity of the northern lake area increased by about 1,000%, and the south also increased by 300–500%. In lakeside towns such as

1394-415: The lake, At the same time, the northern part, which was originally fresh water, became brackish. The 8,678-meter General Rafael Urdaneta Bridge over the lake connecting Maracaibo and Santa Rita was completed in 1962. Lake Maracaibo is rich in oil and gas resources and is known as the "oil lake". The first Spaniards who arrived used tar seeping from the lake to fill ship cracks. The Maracaibo oil field

1435-484: The late Eocene . In the geological history, sea water and fresh water have alternated many times, and have flooded the area. At the end of the last glacial period , the sea level rose, connecting Lake Maracaibo directly with the Atlantic Ocean , and the lighter fresh water floated on the heavier salt water, causing nutrients to be deposited on the bottom of the lake, resulting in the accumulation of more than

1476-499: The so-called cañadas , which are random drainage courses, drag large amounts of garbage from the human settlements that are in their path to the lake. In addition to this, residential waste such as plastic bags and bottles are also added. These pollutants all eventually get carried into the lake. There are many islands in the lake. Some primarily consist of sedimentary rock , such as the Zapara, Pescadores, and San Carlos islands (which

1517-560: The south bank of the lake are bananas, peanuts, cocoa, coconut, sugar cane and coffee, the western shore of the lake developed dairy industry. Lake Maracaibo and the Catatumbo River are the main traffic lines for the transportation of commodities in the nearby area, and the city of Maracaibo is the transshipment center of coffee produced in the Andes. The waterway can pass through large sea-going ships and oil tankers, exporting crude oil and agricultural and livestock products from

1558-449: The southwest of the lake basin, and the surface lake water in the delta has a salinity of only 0.13%. However, the intrusion of seawater from the mouth of the lake makes the salinity of the bottom lake water higher, reaching 0.2–0.3%. The north is connected with the Gulf of Venezuela , and the spit at the mouth of the lake extends for about 26 kilometers. The annual average temperature of

1599-450: The stomach free; this connective tissue firmly holds the stomach to the body wall and is better developed in adults. It may also function as a hydrostatic organ, allowing the fish to remain buoyant midwater. Pterygoplichthys Pterygoplichthys , sometimes collectively known as janitor fish , is a genus of South American armored catfishes . These fish are commonly known as sailfin armoured catfish or sailfin plecs, especially in

1640-504: The volume is about 280 cubic kilometers. The largest river entering the lake, the Catatumbo River , enters the lake from west to east, providing 57% of the water entering the lake. In addition to the influence of the prevailing wind, the lake water circulates counterclockwise. There are also the Santa Ana River, Chama River , Motatán River , Escalante River , and about fifty other rivers which drain into it. Lake Maracaibo

1681-427: Was discovered in 1914, the first oil well was constructed in 1917, and large-scale exploitation began in 1922. The oil fields are concentrated in the northeast and northwest of the lake, and the oil-producing layers are mainly Tertiary sandstone and Cretaceous limestone, with a hydrocarbon-bearing area of 1,300 square kilometers, mainly concentrated in the coastal waters 105 kilometers long and 32 kilometers wide in

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