Доурада (Brachyplatystoma rousseauxii)

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Brachyplatystoma rousseauxii (CASTELNAU, 1855)

Dourada

Classification

Order: Siluriformes Family: Pimelodidae

Distribution

Widely-distributed throughout most of the Amazon and Orinoco river drainages plus other important fluvial systems in the Guianas and northeastern Brazil. The type locality is given simply as ‘Amazon River, Brazil’.

Habitat

Found in a number of habitat-types, though rarely in smaller tributaries, generally preferring deeper, flowing channels through which it travels for considerable distances at certain times of year. Like other large, migratory pimelodids these movements are typically associated with nutrient-rich, white water drainages rather than nutrient-poor black waters.

When the Amazon begins to rise at the start of the wet season, freshwater is pushed into its delta and the normally brackish waters recede, allowing juveniles and sexually-immature adults of several migratory catfish species, including B. rousseauxii, to enter the area and feed on polychaetes, bivalves, crustaceans, and other fishes.

This rich feeding ground is exploited until the sea water returns, at which point the catfishes begin to migrate upstream in massive numbers, moving up the Amazon and its tributaries. Sexually mature individuals are not normally recorded during these events so they’re thought related to feeding and dispersal rather than spawning. The fish are subject to intensive capture by commercial and artisanal fishing operations during this upstream movement.

Spawning occurs in often-distant headwaters and the fry are washed downstream to the delta, a process estimated to take 13-20 days. Juveniles then remain in the estuary region for around three years, entering the delta to feed when conditions permit. They then move into the lower and middle Amazon where they may remain for a further year as they continue to feed and grow.

Following this period of growth schools of adults begin to form and make their way into headwaters in order to spawn. There is no single spawning ground for a given species, rather there appear to exist distinct populations in different watersheds, and there exists ev >

Study of B. rousseauxii has revealed that sexually mature adults are found only in the western Amazon, with no mature individual ever recorded east of Manaus despite the intensive commercial fishery operating there. The total distance covered by some populations during migration from the delta was as much as 5500 km, making it the longest known in any freshwater fish species.

Maximum Standard Length

At least 1900 mm.

Aquarium SizeTop ↑

This species is suitable only for public aquaria plus a very small minority of private aquarists and as such we offer no recommended aquarium size.

Maintenance

The choice of décor is as much down to personal preference as anything else though a carefully-aquascaped, planted set-up is obviously out of the question. A sandy substrate with some large chunks of driftwood, or a completely bare arrangement are perhaps the most-favoured options in privately-owned aquaria, but provided water quality is maintained and lighting not too bright this species is relatively unfussy. An enormous, reliable filter system and rigorous maintenance regime should be considered mandatory.

Water Conditions

Temperature: 22 – 28 °C

Hardness: 18 – 357 ppm

Almost entirely piscivorous preying on loricariids and other bottom-dwelling fishes in nature but most specimens readily adapt to dead alternatives such as prawn/shrimp, mussel, squid, whitebait, strips of larger white fish, etc., in aquaria. Adults require a singe meal per week at most.

Behaviour and CompatibilityTop ↑

Only keep with species large enough to avoid predation.

Sexual Dimorphism

Reproduction

Unrecorded in captivity, perhaps unsurprising given its complex natural life cycle (see ‘habitat’).

NotesTop ↑

This species can be distinguished from congeners by the following external characters: colour pattern uniformly silvery-white in both adults and juveniles; caudal-fin in adults deeply-forked with narrow lobes which are equal in length or upper lobe slightly longer than lower; eye diameter fits approximately 5-7 times in length of snout; maxillary barbels in adults not reaching end of dorsal-fin, often shorter than head; caudal peduncle moderately compressed with greater depth than width; origins of adipose and anal fins approximately in line; base length of adipose and anal fins approximately equal; adipose-fin approximately twice as high as long; opercle subquadrangular; 19-21 anal-fin rays.

Brachyplatystoma spp. are distinguished from all other catfishes by two synapomorphies. The first comprises several morphological characters relating to the skull, specifically that the mandibular suspensorium (that which connects the lower jaw bone to the skull) is greatly expanded mediodorsally to form a large plate approaching the parasphenoid bone, with the hyomandibula and metapterygoid similarly enlarged.

The second is the presence of an elongate filament formed from a single, unbranched simple ray on both caudal fin lobes in juveniles and subadults. These become shorter or are lost in adult specimens of B. vaillantii, B. filamentosum, B. rousseauxii, and B. capapretum but retained in B. juruense, B. platynemum and B. tigrinum.

Brachyplatystoma

Brachyplatystoma

The fish at top is a Brachyplatystoma rousseauxii, and that below is an unidentified Brachyplatystoma
Scientific >
Kingdom:Animalia
Phylum:Chordata
Class:Actinopterygii
Order:Siluriformes
Family:Pimelodidae
Genus:Brachyplatystoma
Bleeker, 1862
Type species
Platystoma vaillantii

Synonyms
  • Piramutana
    Bleeker, 1858
  • Piratinga
    Bleeker, 1858
  • Taenionema
    Eigenmann & Bean, 1907
  • Goslinia
    Myers, 1941
  • Ginesia
    Fernández-Yépez, 1951
  • Merodontotus
    Britski, 1981

Brachyplatystoma is a genus of catfish from the family Pimelod >[1] As the occasionally used common name goliath catfishes indicates, this genus includes some of the largest species of catfish, including the piraíba, B. filamentosum, which reaches up to the region of 3.6 metres (12 ft) in length. Brachyplatystoma are found in the Amazon and Orinoco basins, and other tropical freshwater and brackish habitats in South America. Some species are migratory. These fish are important as food fish and, to some extent, aquarium fish.

Contents

Taxonomy [ edit ]

Brachyplatystoma originates from Greek brachys, platys, and stoma, which mean short, flat, and mouth respectively. This genus was described in 1862 by Pieter Bleeker. The type species is B. vaillantii. [1] The subgenus Malacobagrus is applied to B. capapretum, B. filamentosum, B. rousseauxii, and the extinct species B. promagdalena, which only is known from fossil remains. [2] [3]

Brachyplatystoma and its monotypic sister group Platynematichthys are the only genera in the tribe Brachyplatystomatini. These two genera are characterized by two synapomorphies; these include a gas bladder div >[3]

The genus Brachyplatystoma was previously not monophyletic; to correct this, the genera Merodontotus and Goslinia are now both included under Brachyplatysoma. Furthermore, a new species was described in 2005, which brings the species count to seven extant species. B. capapretum is sister to B. filamentosum. [3]

B. flavicans is not actually a species of Brachyplatystoma; this name is a commonly used synonym of Zungaro zungaro. [4]

Anatomy and appearance [ edit ]

Brachyplatystoma all exhibit long maxillary barbels that extend past the dorsal fin in all species, but may even extend to the caudal fin. The caudal fin of adult Brachyplatystoma fish is moderately to deeply forked. [3] Brachyplatystoma have specialized pelagic young with greatly elongated barbels and fin filaments, and strongly ornamented pectoral spines. [5]

This genus is characterized by two synapomorphies. One of these is modified jaw muscles. The other, more obvious trait, is only found in juveniles and subadults, in which the upper and lower rays of the caudal fin are extended into long filaments. [3] B. vaillantii is the sister species to all other Brachyplatystoma, marked by differences in the skull, jaw, and other bones. [3] The subgenus Malacobagrus is characterized by their derived lateral line, Weberian apparatus, a subquadrangular gill cover (as opposed to triangular in other species), and pectoral spine. [3]

As mentioned, one of the characteristics of this genus is caudal fin filaments on younger fish. In most of the species these filaments are lost in adulthood, though they are retained in B. tigrinum, B. juruense, and B. platynemum. [3] Many Brachyplatystoma exhibit countershading, in which the dorsal surface is darker, and then fades to a lighter belly. In most species, this is consistent throughout life, though there are some exceptions. Juvenile B. capapretum and B. filamentosum exhibit dorsal and lateral spots which mostly disappear in the adult form. Juvenile B. juruense and B. tigrinum exhibit lateral spots that expand to form vertical stripes as the fish matures. [3]

B. capapretum, described in 2005, was previously mis >[3]

Brachyplatystoma includes some of the largest species of Amazonian catfish, including the Piraíba, B. filamentosum, which reaches up to about 3.6 metres (12 ft) in length and 200 kilograms (440 lb) in weight. [6] Even the most modest species reach about 60 centimetres (24 in). [7] [8] [9] The other species range in size from about 1–2 metres (3.3–6.6 ft). [10] [11] [12]

B. filamentosum and B. rousseauxii have a mysterious “milk” gland at the anterior upper part of its pectoral fins. Its function is unknown, but in Colombia this fish is known as lechero, which means milkman. [13]

The world record recognized by IGFA for Brachyplatystoma filamentosum belongs to the Brazilian, Jorge Masullo de Aguiar with 155 kg. [ citation needed ]

Distribution and habitat [ edit ]

Fish of this genus are found in the Amazon, Orinoco, and The Guyanas in South America. [3] The genus does not occur west or north of the Andes or in the Venezuelan Coastal Range. [2] These fish generally inhabit areas that have a soft substrate, such as mud or sand. [6] [10] [7] The fossil catfish B. promagdalena has been found in Colombia in an area now drained by the Magdalena River, where Brachyplatystoma species are currently absent; during the Miocene, this area had been drained by the Amazon and Orinoco system. [2]

Ecology [ edit ]

These fish are mainly piscivorous. [13] Stomach contents of B. filamentosum have been claimed to sometimes contain monkeys and it may even prey on humans. [6]

Some of the species of Brachyplatystoma migrate long distances for reproduction. This is known in B. vaillantii, B. platynemum, and B. rousseauxii, but data about the migratory habits of other species are scant. [2] This migration is associated with white-water rivers, as black water does not contain enough food for migrating Pimelod >[14] Maturation is timed to the increase in river level. [13] Migration begins as the river level begins to rise with the coming of the rainy season. [14] [11] B. rousseauxii has the longest reproductive migration of any freshwater fish; from the mouth of the Amazon, migration may stretch 5,500 kilometres (3,400 mi), a trip which may last five to six months, before they spawn in the western tributaries of the Amazon. It is hypothesized that B. rousseauxii is homing, that is, it will return to the tributary in which it was born. [14] Before spawning, the stomachs of these fish are empty, due to high digestive efficiency. [13]

The young are carried downstream until they reach estuaries. [14] Juveniles and subadults are commonly found in these habitats. [10] They may even live in brackish waters at this time. [6] They will live in these estuaries and river mouths for about three years here before entering the lower reaches of the river. [14] At this still immature stage, they may form groups or school. This is the first record of young, migratory fish in the Amazon basin. [15]

Relationship to humans [ edit ]

Brachyplatystoma are important food fish. In the Amazon Basin, thousands of metric tons of fish from this genus are caught for both local consumption as well as exportation. [3] These fish are usually caught with the use of longlines or drift nets. [6] [10] They are also captured by harpoon as well as ropes with large fish hooks at the end. [13] B. filamentosum is a major fishery, and B. rousseauxii has become the most important species in the Amazon River basin. [13] B. rousseauxii and B. vaillantii constitute a significant percentage of Amazonian food fish. [14] Based on a review by IBAMA, B. vaillantii was by far the most caught fish by weight in the Brazilian Amazon in 1998, B. rousseauxii the fourth most caught and B. filamentosum the sixth (Semaprochilodus spp. second, Prochilodus nigricans third and Brycon spp. fifth). [16] The flesh of Brachyplatystoma is cons >[6] [10]

Human activities are a concern in that they may disrupt these fishes. Dams may impede the migration of these fish both to and from their spawning sites. [15] Gold prospecting may also frighten these large catfishes in the areas where they spawn. Deforestation can also affect the upriver spawning habitats. [13] Because these fish may migrate back to their original tributary, overfishing in a certain area may reduce a whole genetic group. [14] In some areas, catches have been diminishing due to overfishing. [3] B. rousseauxii is known to be overfished, and this same situation may apply to other Brachyplatystoma. [14] Catch rates of B. filamentosum have decreased drastically from 1977. [13]

Conversely, there have been recorded incidents where large B. filamentosum have preyed on humans. In one account documented on the television series River Monsters, a local fisherman was found having been swallowed head-first up to his waist by one of these catfish, though neither the fish nor the fisherman survived the encounter.

In the aquarium [ edit ]

Brachyplatystoma are generally uncommon in the fishkeeping trade. The large size of many of these fish prohibit them from being maintained in anything but the largest of aquaria, or in public aquariums. B. tigrinum is a highly prized fish in the fishkeeping hobby, and is one of the most expensive fish in this family. [17]

These fish should be kept in well-oxygenated aquarium with a high current. Due to their large size, the aquarium should also be spacious and any tankmates must be large enough not to be eaten. The aquarium should not be brightly lit, and h >[18] [19] Due to the similarity between B. tigrinum and B. juruense, the latter is often known as the False Zebra Shovelnose or False Tigrinus (as B. tigrinum was previously known as Merodontotus tigrinus). [17]

Species [ edit ]

There are currently seven recognized species in this genus (common name shown in second parentheses): [1]

ru.knowledgr.com

Brachyplatystoma – род зубатки от семьи Pimelodidae. Как иногда используемые зубатки голиафа общего названия указывает, этот род включает некоторые самые большие виды зубатки, включая Piraíba, B. filamentosum, который достигает о в длине. Brachyplatystoma найдены в бассейнах Амазонки и Ориноко и других тропических пресноводных и солоноватых средах обитания в Южной Америке. Некоторые разновидности миграционные. Эти рыбы важны как продовольственная рыба и, в некоторой степени, аквариумная рыбка.

Таксономия

Brachyplatystoma происходит из греческого brachys, меченосцев и устьица, которые означают короткий, плоский, и рот соответственно. Этот род был описан в 1862 Питером Блеекером. Разновидность типа – B. vaillantii. Подрод к Malacobagrus относятся B. capapretum, B. filamentosum, B. rousseauxii, и вымершие виды B. promagdalena, который только известен от окаменелости, остается.

Brachyplatystoma и его monotypic родственная группа Platynematichthys являются единственными родами в племени Brachyplatystomatini. Эти два рода характеризуются двумя synapomorphies; они включают газовый пузырь, разделенный на предшествующую часть и треугольную следующую часть, а также брюшной гребень под cleithrum, главная кость, поддерживающая грудные плавники.

Род Brachyplatystoma был ранее не монофилетическим; чтобы исправить это, рода, Merodontotus и Goslinia теперь оба включены под Brachyplatysoma. Кроме того, новая разновидность была описана в 2005, который приносит количеству разновидностей к семи существующим разновидностям. B. capapretum является сестрой к B. filamentosum.

B. flavicans не фактически разновидность Brachyplatystoma; это имя – обычно используемый синоним Zungaro zungaro.

Анатомия и появление

Brachyplatystoma вся выставка длинные верхнечелюстные усачи, которые простираются мимо спинного плавника во всех разновидностях, но могут даже распространиться на хвостовой плавник. Хвостовой плавник взрослой рыбы Brachyplatystoma умеренно к очень разветвленному. Brachyplatystoma специализировали морскую молодежь со значительно удлиненными усачами и финансовыми нитями, и сильно украсили грудные позвоночники.

Этот род характеризуется двумя synapomorphies. Один из них – измененные мышцы челюсти. Другой, более очевидная черта, только найден в подростках и подвзрослых, в которых верхние и более низкие лучи хвостового плавника расширены в длинные нити. B. vaillantii является родственными разновидностями ко всему другому Brachyplatystoma, отмеченному различиями в черепе, челюсти и других костях. Подрод Malacobagrus характеризуется их полученной боковой линией, аппаратом Weberian, подчетырехугольное покрытие жабр (в противоположность треугольному в других разновидностях), и грудной позвоночник.

Как упомянуто, одна из особенностей этого рода – нити хвостового плавника на младшей рыбе. В большинстве разновидностей эти нити потеряны во взрослую жизнь, хотя они сохранены в B. tigrinum, B. juruense и B. platynemum. Много Brachyplatystoma показывают защитную окраску, в которой спинная поверхность более темная, и затем исчезает к более легкому животу. В большинстве разновидностей это последовательно в течение жизни, хотя есть некоторые исключения. Подросток Б. capapretum и B. filamentosum показывают спинные и боковые пятна, которые главным образом исчезают во взрослой форме. Подросток Б. juruense и B. tigrinum показывают боковые пятна, которые расширяются, чтобы сформировать вертикальные полосы, поскольку рыба назревает.

B. capapretum, описанный в 2005, был ранее не распознан как B. filamentosum. Эти две разновидности тесно связаны. Однако эти разновидности отличаются по предверхнечелюстному прорезыванию зубов, юной и взрослой окраске, и взрослой верхнечелюстной длине усача и форме хвостового плавника. Эти две разновидности выставка определили юные стадии, хотя в B. capapretum эти пятна намного больше, чем глаз, в то время как в B. filamentosum эти пятна о том же самом размере как глаз. Кроме того, поперечное сечение хвостовой плодоножки округлено в этих двух разновидностях, в противоположность более глубокому, более тонкому поперечному сечению в других разновидностях Brachyplatystoma. У взрослого Б. capapretum есть очень темная или даже черная спина (ее имя разновидностей получено из португальского языка, что означает черный мыс), в противоположность более легкой спинной поверхности B. filamentosum.

Brachyplatystoma включает некоторые самые большие виды амазонской зубатки, включая Piraíba, B. filamentosum, который достигает о в длине и в весе. Даже самые скромные разновидности достигают о. Другие разновидности располагаются в размере от приблизительно.

B. у filamentosum и B. rousseauxii есть таинственная «молочная» железа в предшествующей верхней части ее грудных плавников. Его функция неизвестна, но в Колумбии эта рыба известна как lechero, что означает молочника.

Мировой рекорд, признанный IGFA за Brachyplatystoma filamentosum, принадлежит бразильцу, Хорхе Масульо де Агиару с 155 кг.

Распределение и среда обитания

Рыбы этого рода найдены на Амазонке, Ориноко и Guyanas в Южной Америке. Род не происходит к западу или к северу от Анд или в венесуэльском Прибрежном Диапазоне. Эти рыбы обычно населяют области, у которых есть мягкое основание, такое как грязь или песок. Зубатка окаменелости B. promagdalena была найдена в Колумбии в области, теперь истощенной рекой Магдалены, где разновидности Brachyplatystoma в настоящее время отсутствуют; во время миоцена эта область была истощена системой Амазонки и Ориноко.

Экология

Эти рыбы, главным образом, piscivorous. Содержимое живота B. filamentosum, как утверждали, иногда содержало обезьян, и он может даже охотиться на людей.

Некоторые разновидности Brachyplatystoma мигрируют большие расстояния для воспроизводства. Это известно в B. vaillantii, B. platynemum и B. rousseauxii, но данные о миграционных привычках к другим разновидностям скудны. Эта миграция связана с реками белой воды, поскольку черная вода не содержит достаточного количества еды для мигрирующего Pimelodids. Созревание рассчитано к увеличению речного уровня. Миграция начинается, как речной уровень начинает повышаться с тем, чтобы выйти из сезона дождей. У B. rousseauxii есть самая долгая репродуктивная миграция любой пресноводной рыбы; из устья Амазонки миграция может простираться, поездка, которая может продлиться пять – шесть месяцев, прежде чем они будут метать икру в западных притоках Amazon. Это предполагается, что B. rousseauxii возвращается, то есть, это возвратится к притоку, у которого это родилось в. Перед порождением животы этих рыб пусты из-за высокой пищеварительной эффективности.

Молодежь несут вниз по течению, пока они не достигают устий. Подростки и подвзрослые обычно находятся в этих средах обитания. Они могут даже жить в жестких водах в это время. Они будут жить в этих устьях, и устья рек в течение приблизительно трех лет здесь прежде, чем войти ниже достигает реки. На этой все еще незрелой стадии они могут сформировать группы или школу. Это – первый отчет молодой, миграционной рыбы в Бассейне Амазонки.

Отношения к людям

Brachyplatystoma – важная продовольственная рыба. В Бассейне Амазонки тысячи метрических тонн рыбы от этого рода пойманы для обоих местного потребления, а также экспортирования. Эти рыбы обычно пойманы с использованием ярусов или дрифтерных сетей. Они также захвачены гарпуном, а также веревками с большими рыболовными крючками в конце. B. filamentosum является главным рыболовством, и B. rousseauxii стал самыми важными разновидностями на Amazon River basin. B. rousseauxii и B. vaillantii составляют значительный процент амазонской продовольственной рыбы. Плоть многих из этих рыб, как полагают, имеет превосходное качество.

Деятельность человека – беспокойство, в котором они могут разрушить этих рыб. Дамбы могут препятствовать миграции этих рыб и к и от их нерестящихся мест. Золотая разведка может также напугать этих больших зубаток в областях, где они мечут икру. Вырубка леса может также затронуть вверх по реке мечущие икру среды обитания. Поскольку эти рыбы могут мигрировать назад их оригинальному притоку, истощающий рыбные запасы в определенной области может уменьшить целую генетическую группу. В некоторых областях выгоды уменьшались из-за истощения рыбных запасов. B. rousseauxii, как известно, истощен рыбные запасы, и эта та же самая ситуация может относиться к другому Brachyplatystoma. Ставки выгоды B. filamentosum уменьшились решительно с 1977.

С другой стороны были зарегистрированные инциденты, где большой B. filamentosum, охотились на людей. В одном счете, зарегистрированном на Монстрах реки телесериала, местный рыбак был найден, глотаясь головой вперед до его талии одним из них зубатка, хотя ни рыба, ни рыбак не пережили столкновение.

В аквариуме

Brachyplatystoma вообще необычны в торговле fishkeeping. Большой размер многих из этих рыб мешает им сохраняться в чем-либо кроме самого большого из аквариумов, или в общественных аквариумах. B. tigrinum является очень дорогой рыбой в fishkeeping хобби и является одной из самых дорогих рыб в этой семье.

Эти рыбы должны содержаться в хорошо окисленном аквариуме с током высокого напряжения. Из-за их большого размера, аквариум должен также быть просторным, и любой tankmates должен быть достаточно большим, чтобы не быть съеденным. Аквариум не должен быть ярко освещен, и укрытия должны быть доступными. О размножении не сообщают в неволе. Из-за подобия между B. tigrinum и B. juruense, последний часто известен как Ложная Зебра Shovelnose или Ложный Tigrinus (как B. tigrinum был ранее известен как Merodontotus tigrinus).

Разновидности

есть семь признанных разновидностей в этом роду (общее название, показанное во вторых круглых скобках):

  • Подрод Brachyplatystoma:
  • Brachyplatystoma juruense (Зубатка зебры, зубатка Juruense, Золотая Зебра Pim, Ложный Tigrinus)
  • Brachyplatystoma platynemum (Слюнявящий зубатку)
  • Brachyplatystoma tigrinum (зубатка Tigerstriped, Зебра shovelnose, тигр Руаяля shovelnose)
  • Brachyplatystoma vaillantii (зубатка Laulao, Piramutaba)
  • Подрод Malacobagrus

  • Brachyplatystoma capapretum

  • Brachyplatystoma filamentosum (Kumakuma, Piraíba, Filhote)
  • Brachyplatystoma rousseauxii (Dourada (litt. золотой на португальском языке. Имя, также используемое для нескольких других несвязанных разновидностей, например, золотистого морского карася Sparus))

Одна разновидность окаменелости известна:

  • †Brachyplatystoma promagdalena – только известный от окаменелостей миоценового происхождения.

Брахиплатисома (rousseauxii) – Brachyplatystoma rousseauxii вид

Классификация

Синонимы

Материалы

Количество видов в «сестринских» таксонах

видБрахиплатисома (rousseauxii)Brachyplatystoma rousseauxiiCastelnau1855
подрод(Malacobagrus)Malacobagrus
родБрахиплатисомаBrachyplatystomaBleeker1862
семействоПимелодовые (Плоскоголовые сомы)Pimelodidae
подотряд / подпорядок(Siluroidei)Siluroidei
отряд / порядокСомообразныеSiluriformes
надотряд / надпорядок(Ostariophysi)Ostariophysi
легионКостистые рыбыTeleostei
инфраклассНовоперые рыбыNeopterygii
подклассЛучеперыеActinopteriCope1871
классЛучеперые рыбыActinopterygiiKlein1885
надклассРыбыPiscesLinnaeus1758
подтип / подотделПозвоночные (Черепные)Vertebrata (Craniata)
тип / отделХордовыеChordata
надтипЦеломические животныеCoelomata
разделДвусторонне-симметричные (Трёхслойные)Bilateria (Triploblastica)
надразделЭуметазоиEumetazoa
подцарствоМногоклеточные животныеMetazoa
царствоЖивотныеAnimalia
надцарствоЯдерныеEukaryotaChatton1925
империяКлеточные

Пимелодовые – это сомы разной величины и формы, обладающие тремя парами усов (две из которых подбородочные). Пимелодовые подобны своим африканским родственникам из семейства Косатковых. Пимелодовые – богатое родами и видами семейство; среди них есть такие, что остаются маленькими, есть крупные (30 – 60 см), пригодные для содержания в аквариуме только в молодом возрасте.

Из числа пимелодовых сомов, обитающих в Центральной Америке, большинство принадлежит к роду рамдий (Rhamdia), и только по одному виду из родов пимелодов (Pimelodus) и пимелоделл (Рimelоdella) смогли распространиться до Восточной Панамы (Darien). Сомов этого семейства привозят в Европу уже многие годы. К самым популярным в аквариумистике рыбам принадлежат разные виды рода микроглянис (Microglanis), поскольку чаще всего их бурая или бежевая расцветка очень красива, а длина (8-12 см) позволяет содержать их в домашних водоемах. Самые известные виды – М. iheringi и М. parahybe. Только не надо путать эти виды с их родственниками из того же семейства, с родом Pseudopimelodus, последние достигают 18-25 см. Поскольку все плоскоголовые сомы с удовольствием едят мясо, в общем аквариуме при ночных поисках пропитания крупные их виды могут наделать больше вреда, чем более мелкие – например, микрограны (Microgranis). Среди представителей уже упомянутых родов пимелодов и пимелоделл есть известные аквариумные рыбы, в частности Pimelodus ornatus, P.albo fasciatus, P. maculatus и P. pictus, а также Pimelodella gracilis, которую мы часто видим в магазинах. У большинства из них имеются длинные усы, и этим они уже интересны многим аквариумистам. Тело у них серебристое, покрытое типичным для данного вида узором. Они вырастают до 26 см. Сорбиум веслоносый (Sorubim lima) со временем становится слишком большим для аквариума (60 см), но молодые особи длиной 10-12 см как питомцы очень любопытны. Молодь в аквариуме питается мелкими насекомыми, которые предлагаются в качестве корма, причем даже личинками, креветками и т.п. То же относится к другим видам из этого семейства. Представители родов Pseudostomatichthys, Pseudoplatystoma, Sorubirnichthys своим вытянутым вперед рылом напоминающие S. liта, как и Phractocephalus и Leiarius, сколь бы ни были хороши расцветкой, для обычных аквариумов не годятся: они слишком велики.

Плоскоголовые сомы как питомцы очень непритязательны. Импортируют чаще всего молодь (по поводу размножения в аквариуме информации нет), и она, хоть и жила в мягкой воде, скоро привыкает к среднежесткой. Сомы предпочитают мясную пищу, но “размеры” корма должны соответствовать размерам и возрасту рыб. Температура воды 22 – 26° С и по возможности не выше.

У вида Брахиплатисома (rousseauxii) еще нет первичных данных.

Зарегистрировавшись, Вы можете добавить фотографии, видеофрагменты, выдержки из научных или научно-популярных статей, отрывки из книг, ссылки на pdf-документы.

Другими словами – разместить здесь любую полезную информацию, имеющую отношение к данному таксону.

Brachyplatystoma

Brachyplatystoma

The fish at top is a Brachyplatystoma rousseauxii, and that below is an unidentified Brachyplatystoma
Scientific >
Kingdom:Animalia
Phylum:Chordata
Class:Actinopterygii
Order:Siluriformes
Family:Pimelodidae
Genus:Brachyplatystoma
Bleeker, 1862
Type species
Platystoma vaillantii

Synonyms
  • Piramutana
    Bleeker, 1858
  • Piratinga
    Bleeker, 1858
  • Taenionema
    Eigenmann & Bean, 1907
  • Goslinia
    Myers, 1941
  • Ginesia
    Fernández-Yépez, 1951
  • Merodontotus
    Britski, 1981

Brachyplatystoma is a genus of catfish from the family Pimelod >[1] As the occasionally used common name goliath catfishes indicates, this genus includes some of the largest species of catfish, including the piraíba, B. filamentosum, which reaches up to the region of 3.6 metres (12 ft) in length. Brachyplatystoma are found in the Amazon and Orinoco basins, and other tropical freshwater and brackish habitats in South America. Some species are migratory. These fish are important as food fish and, to some extent, aquarium fish.

Contents

Taxonomy [ edit ]

Brachyplatystoma originates from Greek brachys, platys, and stoma, which mean short, flat, and mouth respectively. This genus was described in 1862 by Pieter Bleeker. The type species is B. vaillantii. [1] The subgenus Malacobagrus is applied to B. capapretum, B. filamentosum, B. rousseauxii, and the extinct species B. promagdalena, which only is known from fossil remains. [2] [3]

Brachyplatystoma and its monotypic sister group Platynematichthys are the only genera in the tribe Brachyplatystomatini. These two genera are characterized by two synapomorphies; these include a gas bladder div >[3]

The genus Brachyplatystoma was previously not monophyletic; to correct this, the genera Merodontotus and Goslinia are now both included under Brachyplatysoma. Furthermore, a new species was described in 2005, which brings the species count to seven extant species. B. capapretum is sister to B. filamentosum. [3]

B. flavicans is not actually a species of Brachyplatystoma; this name is a commonly used synonym of Zungaro zungaro. [4]

Anatomy and appearance [ edit ]

Brachyplatystoma all exhibit long maxillary barbels that extend past the dorsal fin in all species, but may even extend to the caudal fin. The caudal fin of adult Brachyplatystoma fish is moderately to deeply forked. [3] Brachyplatystoma have specialized pelagic young with greatly elongated barbels and fin filaments, and strongly ornamented pectoral spines. [5]

This genus is characterized by two synapomorphies. One of these is modified jaw muscles. The other, more obvious trait, is only found in juveniles and subadults, in which the upper and lower rays of the caudal fin are extended into long filaments. [3] B. vaillantii is the sister species to all other Brachyplatystoma, marked by differences in the skull, jaw, and other bones. [3] The subgenus Malacobagrus is characterized by their derived lateral line, Weberian apparatus, a subquadrangular gill cover (as opposed to triangular in other species), and pectoral spine. [3]

As mentioned, one of the characteristics of this genus is caudal fin filaments on younger fish. In most of the species these filaments are lost in adulthood, though they are retained in B. tigrinum, B. juruense, and B. platynemum. [3] Many Brachyplatystoma exhibit countershading, in which the dorsal surface is darker, and then fades to a lighter belly. In most species, this is consistent throughout life, though there are some exceptions. Juvenile B. capapretum and B. filamentosum exhibit dorsal and lateral spots which mostly disappear in the adult form. Juvenile B. juruense and B. tigrinum exhibit lateral spots that expand to form vertical stripes as the fish matures. [3]

B. capapretum, described in 2005, was previously mis >[3]

Brachyplatystoma includes some of the largest species of Amazonian catfish, including the Piraíba, B. filamentosum, which reaches up to about 3.6 metres (12 ft) in length and 200 kilograms (440 lb) in weight. [6] Even the most modest species reach about 60 centimetres (24 in). [7] [8] [9] The other species range in size from about 1–2 metres (3.3–6.6 ft). [10] [11] [12]

B. filamentosum and B. rousseauxii have a mysterious “milk” gland at the anterior upper part of its pectoral fins. Its function is unknown, but in Colombia this fish is known as lechero, which means milkman. [13]

The world record recognized by IGFA for Brachyplatystoma filamentosum belongs to the Brazilian, Jorge Masullo de Aguiar with 155 kg. [ citation needed ]

Distribution and habitat [ edit ]

Fish of this genus are found in the Amazon, Orinoco, and The Guyanas in South America. [3] The genus does not occur west or north of the Andes or in the Venezuelan Coastal Range. [2] These fish generally inhabit areas that have a soft substrate, such as mud or sand. [6] [10] [7] The fossil catfish B. promagdalena has been found in Colombia in an area now drained by the Magdalena River, where Brachyplatystoma species are currently absent; during the Miocene, this area had been drained by the Amazon and Orinoco system. [2]

Ecology [ edit ]

These fish are mainly piscivorous. [13] Stomach contents of B. filamentosum have been claimed to sometimes contain monkeys and it may even prey on humans. [6]

Some of the species of Brachyplatystoma migrate long distances for reproduction. This is known in B. vaillantii, B. platynemum, and B. rousseauxii, but data about the migratory habits of other species are scant. [2] This migration is associated with white-water rivers, as black water does not contain enough food for migrating Pimelod >[14] Maturation is timed to the increase in river level. [13] Migration begins as the river level begins to rise with the coming of the rainy season. [14] [11] B. rousseauxii has the longest reproductive migration of any freshwater fish; from the mouth of the Amazon, migration may stretch 5,500 kilometres (3,400 mi), a trip which may last five to six months, before they spawn in the western tributaries of the Amazon. It is hypothesized that B. rousseauxii is homing, that is, it will return to the tributary in which it was born. [14] Before spawning, the stomachs of these fish are empty, due to high digestive efficiency. [13]

The young are carried downstream until they reach estuaries. [14] Juveniles and subadults are commonly found in these habitats. [10] They may even live in brackish waters at this time. [6] They will live in these estuaries and river mouths for about three years here before entering the lower reaches of the river. [14] At this still immature stage, they may form groups or school. This is the first record of young, migratory fish in the Amazon basin. [15]

Relationship to humans [ edit ]

Brachyplatystoma are important food fish. In the Amazon Basin, thousands of metric tons of fish from this genus are caught for both local consumption as well as exportation. [3] These fish are usually caught with the use of longlines or drift nets. [6] [10] They are also captured by harpoon as well as ropes with large fish hooks at the end. [13] B. filamentosum is a major fishery, and B. rousseauxii has become the most important species in the Amazon River basin. [13] B. rousseauxii and B. vaillantii constitute a significant percentage of Amazonian food fish. [14] Based on a review by IBAMA, B. vaillantii was by far the most caught fish by weight in the Brazilian Amazon in 1998, B. rousseauxii the fourth most caught and B. filamentosum the sixth (Semaprochilodus spp. second, Prochilodus nigricans third and Brycon spp. fifth). [16] The flesh of Brachyplatystoma is cons >[6] [10]

Human activities are a concern in that they may disrupt these fishes. Dams may impede the migration of these fish both to and from their spawning sites. [15] Gold prospecting may also frighten these large catfishes in the areas where they spawn. Deforestation can also affect the upriver spawning habitats. [13] Because these fish may migrate back to their original tributary, overfishing in a certain area may reduce a whole genetic group. [14] In some areas, catches have been diminishing due to overfishing. [3] B. rousseauxii is known to be overfished, and this same situation may apply to other Brachyplatystoma. [14] Catch rates of B. filamentosum have decreased drastically from 1977. [13]

Conversely, there have been recorded incidents where large B. filamentosum have preyed on humans. In one account documented on the television series River Monsters, a local fisherman was found having been swallowed head-first up to his waist by one of these catfish, though neither the fish nor the fisherman survived the encounter.

In the aquarium [ edit ]

Brachyplatystoma are generally uncommon in the fishkeeping trade. The large size of many of these fish prohibit them from being maintained in anything but the largest of aquaria, or in public aquariums. B. tigrinum is a highly prized fish in the fishkeeping hobby, and is one of the most expensive fish in this family. [17]

These fish should be kept in well-oxygenated aquarium with a high current. Due to their large size, the aquarium should also be spacious and any tankmates must be large enough not to be eaten. The aquarium should not be brightly lit, and h >[18] [19] Due to the similarity between B. tigrinum and B. juruense, the latter is often known as the False Zebra Shovelnose or False Tigrinus (as B. tigrinum was previously known as Merodontotus tigrinus). [17]

Species [ edit ]

There are currently seven recognized species in this genus (common name shown in second parentheses): [1]

Доурада (Brachyplatystoma rousseauxii)

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wikipedia.en / Page.B / Brachyplatystoma.md

Brachyplatystoma is a genus of catfish from the family Pimelodidae.[1] As the occasionally used common name goliath catfishes indicates, this genus includes some of the largest species of catfish, including the piraíba, B. filamentosum, which reaches up to the region of in length. Brachyplatystoma are found in the Amazon and Orinoco basins, and other tropical freshwater and brackish habitats in South America. Some species are migratory. These fish are important as food fish and, to some extent, aquarium fish.

Brachyplatystoma originates from Greek brachys, platys, and stoma, which mean short, flat, and mouth respectively. This genus was described in 1862 by Pieter Bleeker. The type species is B. vaillantii.[2] The subgenus Malacobagrus is applied to B. capapretum, B. filamentosum, B. rousseauxii, and the extinct species B. promagdalena, which only is known from fossil remains.[3][4]

Brachyplatystoma and its monotypic sister group Platynematichthys are the only genera in the tribe Brachyplatystomatini. These two genera are characterized by two synapomorphies; these include a gas bladder divided into an anterior portion and a triangular posterior portion, as well as a ventral crest under the cleithrum, the main bone supporting the pectoral fins.[5]

The genus Brachyplatystoma was previously not monophyletic; to correct this, the genera Merodontotus and Goslinia are now both included under Brachyplatysoma. Furthermore, a new species was described in 2005, which brings the species count to seven extant species. B. capapretum is sister to B. filamentosum.[6]

B. flavicans is not actually a species of Brachyplatystoma; this name is a commonly used synonym of Zungaro zungaro.[7]

Anatomy and appearance

Brachyplatystoma all exhibit long maxillary barbels that extend past the dorsal fin in all species, but may even extend to the caudal fin. The caudal fin of adult Brachyplatystoma fish is moderately to deeply forked.[8] Brachyplatystoma have specialized pelagic young with greatly elongated barbels and fin filaments, and strongly ornamented pectoral spines.[9]

This genus is characterized by two synapomorphies. One of these is modified jaw muscles. The other, more obvious trait, is only found in juveniles and subadults, in which the upper and lower rays of the caudal fin are extended into long filaments.[10] B. vaillantii is the sister species to all other Brachyplatystoma, marked by differences in the skull, jaw, and other bones.[11] The subgenus Malacobagrus is characterized by their derived lateral line, Weberian apparatus, a subquadrangular gill cover (as opposed to triangular in other species), and pectoral spine.[12]

As mentioned, one of the characteristics of this genus is caudal fin filaments on younger fish. In most of the species these filaments are lost in adulthood, though they are retained in B. tigrinum, B. juruense, and B. platynemum.[13] Many Brachyplatystoma exhibit countershading, in which the dorsal surface is darker, and then fades to a lighter belly. In most species, this is consistent throughout life, though there are some exceptions. Juvenile B. capapretum and B. filamentosum exhibit dorsal and lateral spots which mostly disappear in the adult form. Juvenile B. juruense and B. tigrinum exhibit lateral spots that expand to form vertical stripes as the fish matures.[14]

B. capapretum, described in 2005, was previously misidentified as B. filamentosum. These two species are closely related. However, these species differ in premaxillary dentition, juvenile and adult coloration, and adult maxillary barbel length and caudal fin shape. These two species exhibit spotted juvenile stages, though in B. capapretum these spots are much larger than the eye, while in B. filamentosum these spots are about the same size as the eye. Also, the cross section of the caudal peduncle is rounded in these two species, as opposed to a deeper, thinner cross section in other Brachyplatystoma species. The adult B. capapretum has a very dark or even black dorsum (its species name is derived from Portuguese which means black cape), as opposed to the lighter dorsal surface of B. filamentosum.[15]

Brachyplatystoma includes some of the largest species of Amazonian catfish, including the Piraíba, B. filamentosum, which reaches up to about in length and in weight.[16] Even the most modest species reach about .[17][18][19] The other species range in size from about .[20][21][22]

B. filamentosum and B. rousseauxii have a mysterious “milk” gland at the anterior upper part of its pectoral fins. Its function is unknown, but in Colombia this fish is known as lechero, which means milkman.[23]

The world record recognized by IGFA for Brachyplatystoma filamentosum belongs to the Brazilian, Jorge Masullo de Aguiar with 155 kg.

Distribution and habitat

Fish of this genus are found in the Amazon, Orinoco, and The Guyanas in South America.[24] The genus does not occur west or north of the Andes or in the Venezuelan Coastal Range.[25] These fish generally inhabit areas that have a soft substrate, such as mud or sand.[26][27][28] The fossil catfish B. promagdalena has been found in Colombia in an area now drained by the Magdalena River, where Brachyplatystoma species are currently absent; during the Miocene, this area had been drained by the Amazon and Orinoco system.[29]

These fish are mainly piscivorous.[30] Stomach contents of B. filamentosum have been claimed to sometimes contain monkeys and it may even prey on humans.[31]

Some of the species of Brachyplatystoma migrate long distances for reproduction. This is known in B. vaillantii, B. platynemum, and B. rousseauxii, but data about the migratory habits of other species are scant.[32] This migration is associated with white-water rivers, as black water does not contain enough food for migrating Pimelodids.[33] Maturation is timed to the increase in river level.[34] Migration begins as the river level begins to rise with the coming of the rainy season.[35][36] B. rousseauxii has the longest reproductive migration of any freshwater fish; from the mouth of the Amazon, migration may stretch , a trip which may last five to six months, before they spawn in the western tributaries of the Amazon. It is hypothesized that B. rousseauxii is homing, that is, it will return to the tributary in which it was born.[37] Before spawning, the stomachs of these fish are empty, due to high digestive efficiency.[38]

The young are carried downstream until they reach estuaries.[39] Juveniles and subadults are commonly found in these habitats.[40] They may even live in brackish waters at this time.[41] They will live in these estuaries and river mouths for about three years here before entering the lower reaches of the river.[42] At this still immature stage, they may form groups or school. This is the first record of young, migratory fish in the Amazon basin.[43]

Relationship to humans

Brachyplatystoma are important food fish. In the Amazon Basin, thousands of metric tons of fish from this genus are caught for both local consumption as well as exportation.[44] These fish are usually caught with the use of longlines or drift nets.[45][46] They are also captured by harpoon as well as ropes with large fish hooks at the end.[47] B. filamentosum is a major fishery, and B. rousseauxii has become the most important species in the Amazon River basin.[48] B. rousseauxii and B. vaillantii constitute a significant percentage of Amazonian food fish.[49] Based on a review by IBAMA, B. vaillantii was by far the most caught fish by weight in the Brazilian Amazon in 1998, B. rousseauxii the fourth most caught and B. filamentosum the sixth (Semaprochilodus spp. second, Prochilodus nigricans third and Brycon spp. fifth).[50] The flesh of Brachyplatystoma is considered to be of excellent quality.[51][52]

Human activities are a concern in that they may disrupt these fishes. Dams may impede the migration of these fish both to and from their spawning sites.[53] Gold prospecting may also frighten these large catfishes in the areas where they spawn. Deforestation can also affect the upriver spawning habitats.[54] Because these fish may migrate back to their original tributary, overfishing in a certain area may reduce a whole genetic group.[55] In some areas, catches have been diminishing due to overfishing.[56] B. rousseauxii is known to be overfished, and this same situation may apply to other Brachyplatystoma.[57] Catch rates of B. filamentosum have decreased drastically from 1977.[58]

Conversely, there have been recorded incidents where large B. filamentosum have preyed on humans. In one account documented on the television series River Monsters, a local fisherman was found having been swallowed head-first up to his waist by one of these catfish, though neither the fish nor the fisherman survived the encounter.

In the aquarium

Brachyplatystoma are generally uncommon in the fishkeeping trade. The large size of many of these fish prohibit them from being maintained in anything but the largest of aquaria, or in public aquariums. B. tigrinum is a highly prized fish in the fishkeeping hobby, and is one of the most expensive fish in this family.[59]

These fish should be kept in well-oxygenated aquarium with a high current. Due to their large size, the aquarium should also be spacious and any tankmates must be large enough not to be eaten. The aquarium should not be brightly lit, and hiding places should be available. Breeding is unreported in captivity.[60][61] Due to the similarity between B. tigrinum and B. juruense, the latter is often known as the False Zebra Shovelnose or False Tigrinus (as B. tigrinum was previously known as Merodontotus tigrinus).[62]

There are currently seven recognized species in this genus (common name shown in second parentheses):[63]

One fossil species is known:

  • Richter, Enrico: Groß – größer – am größten: Raubwelse der Gattung Brachyplatystoma
  1. Araujo-Lima, C.A.R.M.; and M.L. Ruffino (2003). Migratory Fishes of the Brazilian Amazon. Pp. 233—302 in: Carolsfeld, J.; B. Harvey; C. Ross; and A. Baer (editors). Migratory Fishes of South America.
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