Hoplosternum littorale
Encyclopedia
Hoplosternum littorale a species
of catfish
(order
Siluriformes) belonging to the Callichthyinae subfamily of the family
Callichthyidae
. It is known as tamuatá in Brazil
, atipa in French Guiana
, hassar in Guyana
, kwi kwi (or kwie kwie http://www.fao.org/docrep/field/003/ab490e/AB490E04.htm) in Suriname
, cascadu(ra) in Trinidad
, and busco or currito in Venezuela
.
.
Males grow to a larger average and maximum size than females and, during the reproductive season, develop fat deposits in the pectoral fin and an elongated recurved pectoral spine that often assumes a reddish colour. Males with recurved pectoral spines are not found outside of the reproductive period.
east of the Andes
and north of Buenos Aires
, including the Orinoco
, Trinidad, coastal rivers of the Guianas, Amazon River
drainage, Paraguay
, lower Paraná River
, and coastal systems in southern Brazil. It ranges from Venezuela and Guyanas to Argentina.
One single lot is known from the upper Paraná River and the São Francisco River
drainage; it has been suggested that these occurrences may represent introduced populations
. This species has also been introduced into the Indian River Lagoon
of Florida
.
H. littorale natively inhabits tropical standing waters or swamps. It is not found in rainforest creeks and clearwater rivers draining Precambrian Guyana and Brazilian Shields, where water is extremely poor in dissolved minerals. This species is restricted to swamps of (sub)tropical South America and the floodplains of Amazonian whitewater rivers originating in the Andes. Such environments are characterized by low levels of dissolved oxygen and markedly seasonal conditions caused primarily by fluctuations in rainfall.
H. littorale can breathe both with gills and through its intestines. However, intestinal respiration is not exhibited upon hatching, and the development of the respiratory intestine occurs throughout the juvenile period (up to 32 days old). Newly hatched larva
e do not have the ability to breathe air through their intestines; however, it is possible that they absorb oxygen through their skin at this point, before the armor plates have developed. Soon after, between about 12–23 days of age, young have the capacity to breathe air, but their respiratory intestine has not finished developing. The respiratory intestine is well-developed between days 24 and 32.
H. littorale has two types of hemoglobin
, anodic
and cathodic
; anodic hemoglobin has a relatively low oxygen affinity and has marked Bohr effect
s, while cathodic hemoglobin lack significant pH
effects. In H. littorale, cathodic hemoglobin has a pronounced reversed Bohr effect in which oxygen affinity increases with decreased pH. Cathodic hemoglobin has the purpose of safeguarding oxygen transport to tissues under hypoxic and acidotic conditions.
H. littorale diet varies by age. Immature fish feed primarily on small aquatic crustacean
s, especially Cladocera
, Ostracod
a, Copepod
a, and Eubranchipoda. Chironomid
larvae are important items in the diets of both juveniles and adults. The adult diet is dominated by mixed detritus, terrestrial insect
s, microcrustaceans, and aquatic beetle
s during the dry season, and mixed detritus and chironomid larvae during the wet season.
; among callichthyines, this species is reported to have the most complex nest structure. This dome-shaped nest is rich with oxygen; in the hypoxic
water conditions of tropical swamps, the main function of the bubble nest appears to be to provide oxygen to the developing eggs by lifting the eggs above the water surface while protecting them from desiccation. It may also serve to protect the brood against predators, regulate temperature, identify the center of the male's territory, and to synchronize reproductive activities. Nest-building activities usually lasted from 1,000 to 1,500 hours, but only on clear and warm days, particularly during the hottest hours. These activities are also reported to occur at night. Most nests are built in newly flooded swamps, especially in open water in the peripheral area of the swamp. A minimum distance of 10 metres between nests is observed. The nest is the centre of a territory that is vigorously defended by the male, using its enlarged pectoral spines. The diameter and height of the nest average 30 and 6 cm (12 and 2.36 in), respectively.
The beginning of nest building is preceded by a courtship
ritual. This pair formation consists of the male and female swimming parallel to each other, the male and female facing each other and contacting their barbels, the male stimulating the flanks of the female, the swimming to the surface by the male and female and production of the first bubbles at the nest site, and adding further bubbles to the nest under construction. The male produces most of the foam
. First, the male and female come to the surface and swim belly-up in small circles. The film of the air-water interface is swallowed and pumped out through the gill
s, where it gains mucus
. Movement of the pelvic fins stirs the water and mucus, captures air bubbles, and breaks these air bubbles into a foam. The female may add some bubbles to the nest under construction. Pelvic fin movement differs between sexes; males move their pelvic fins in a side-to-side fashion, while females open and close their pelvic fins. The male often dives to the bottom to retrieve plant debris; filamentous nest materials are preferred, which are knitted together in the nest by the male. The male creates an upward water current with its tail fin that lift plant materials up. Then, the male uses its developed pectoral fin spines to cary the plant materials to the nest. The male uses its mouth and pectoral fins to incorporate the plant material into the foam mass of the nest. Females neither have developed pectoral fin spines nor do they help in transporting plant debris. The end result is a dome-shaped nest made up of loosely interwoven plant material on top of tightly interwoven plant material, held up to the surface with a layer of foam; the eggs will be laid on top of this foam from below.
Spawning occurs during the daytime. There is indication that the female drinks the sperm and that fertilization takes place after the sperm has passed through her digestive tract. The male and female form the "T-position", where the female places its mouth over the male's genital opening and collects the sperm in the mouth. The female rests at the bottom for 30–60 seconds, and then swims to the nest, turns upside down, and lays the eggs in the nest. H. littorale is a multiple spawner. Investing in reproduction is high in females since they can spawn up to 14 times during a 7 month breeding season and each spawn consists of 6,000–9,000 eggs. On average, two to four females spawn simultaneously, resulting in an average number of 20,000 eggs per nest. The adhesive eggs are located in the centre of the nest under the plant debris above the surface of the water, and not in contact with the oxygen-depleted swamp water. The male guards the nest during incubation; incubation of the eggs takes two to three days depending on the temperature in the nest. The male also regularly supplies foam to the nest. Guarding and maintenance of the nest occurs day and night. Once spawning has been completed, the male attacks females that have deposited their eggs in the nest. Despite intense predation pressure on eggs and larvae, the male's guarding behavior extends for only one or two days after hatching. The male attacks with its large pectoral spines erect; the attack consists of rapid propulsion towards its target followed by a sharp lateral turn, which causes the rough outer edge of pectoral spine to drag across the target and cause abrasion.
H. littorale is now commercially cultured in Trinidad, Guyana and Suriname. It fetches a price of US$8/kg and there are local and foreign ethnic markets for
the fish.
H. littorale is also an aquarium
fish. It is a peaceful fish. It will eat any food that other fishes can eat.
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...
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...
(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) belonging to the Callichthyinae subfamily 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...
Callichthyidae
Callichthyidae
Callichthyidae is a family of catfishes , called armored catfishes due to the two rows of bony plates running down the length of the body. This family contains some of the most popular freshwater aquarium fish, such as the Corydoras.-Taxonomy:The family derives its name from the Greek words kallis...
. It is known as tamuatá in Brazil
Brazil
Brazil , officially the Federative Republic of Brazil , is the largest country in South America. It is the world's fifth largest country, both by geographical area and by population with over 192 million people...
, atipa in French Guiana
French Guiana
French Guiana is an overseas region of France, consisting of a single overseas department located on the northern Atlantic coast of South America. It has borders with two nations, Brazil to the east and south, and Suriname to the west...
, hassar in Guyana
Guyana
Guyana , officially the Co-operative Republic of Guyana, previously the colony of British Guiana, is a sovereign state on the northern coast of South America that is culturally part of the Anglophone Caribbean. Guyana was a former colony of the Dutch and of the British...
, kwi kwi (or kwie kwie http://www.fao.org/docrep/field/003/ab490e/AB490E04.htm) in Suriname
Suriname
Suriname , officially the Republic of Suriname , is a country in northern South America. It borders French Guiana to the east, Guyana to the west, Brazil to the south, and on the north by the Atlantic Ocean. Suriname was a former colony of the British and of the Dutch, and was previously known as...
, cascadu(ra) in Trinidad
Trinidad
Trinidad is the larger and more populous of the two major islands and numerous landforms which make up the island nation of Trinidad and Tobago. It is the southernmost island in the Caribbean and lies just off the northeastern coast of Venezuela. With an area of it is also the fifth largest in...
, and busco or currito in Venezuela
Venezuela
Venezuela , officially called the Bolivarian Republic of Venezuela , is a tropical country on the northern coast of South America. It borders Colombia to the west, Guyana to the east, and Brazil to the south...
.
Description
H. littorale is armor-plated and dorso-ventrally compressed. The fish will grow in length up to 24.0 centimetres (9.4 in) TLFish 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:...
.
Males grow to a larger average and maximum size than females and, during the reproductive season, develop fat deposits in the pectoral fin and an elongated recurved pectoral spine that often assumes a reddish colour. Males with recurved pectoral spines are not found outside of the reproductive period.
Distribution
H. littorale has the widest distribution of any callichthyid. It is present in all of South AmericaSouth America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...
east of the Andes
Andes
The Andes is the world's longest continental mountain range. It is a continual range of highlands along the western coast of South America. This range is about long, about to wide , and of an average height of about .Along its length, the Andes is split into several ranges, which are separated...
and north of Buenos Aires
Buenos Aires
Buenos Aires is the capital and largest city of Argentina, and the second-largest metropolitan area in South America, after São Paulo. It is located on the western shore of the estuary of the Río de la Plata, on the southeastern coast of the South American continent...
, including the Orinoco
Orinoco
The Orinoco is one of the longest rivers in South America at . Its drainage basin, sometimes called the Orinoquia, covers , with 76.3% of it in Venezuela and the remainder in Colombia...
, Trinidad, coastal rivers of the Guianas, Amazon River
Amazon River
The Amazon of South America is the second longest river in the world and by far the largest by waterflow with an average discharge greater than the next seven largest rivers combined...
drainage, Paraguay
Paraguay River
The Paraguay River is a major river in south central South America, running through Brazil, Bolivia, Paraguay, and Argentina...
, lower Paraná River
Paraná River
The Paraná River is a river in south Central South America, running through Brazil, Paraguay and Argentina for some . It is second in length only to the Amazon River among South American rivers. The name Paraná is an abbreviation of the phrase "para rehe onáva", which comes from the Tupi language...
, and coastal systems in southern Brazil. It ranges from Venezuela and Guyanas to Argentina.
One single lot is known from the upper Paraná River and the São Francisco River
São Francisco River
The São Francisco is a river in Brazil. With a length of , it is the longest river that runs entirely in Brazilian territory, and the fourth longest in South America and overall in Brazil...
drainage; it has been suggested that these occurrences may represent introduced populations
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
. This species has also been introduced into the Indian River Lagoon
Indian River Lagoon
The Indian River Lagoon is a grouping of three lagoons: Mosquito Lagoon, Banana River, and the Indian River, on the Atlantic Coast of Florida. It was originally named Rio de Ais after the Ais Indian tribe, who lived along the east coast of Florida....
of Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...
.
Ecology
Most activity of non-breeding H. littorale such as feeding and locomotor activity are mainly nocturnal. It has a maximum reported age of 4 years. The diet of H. littorale consists mainly of benthic invertebrates and detritus.H. littorale natively inhabits tropical standing waters or swamps. It is not found in rainforest creeks and clearwater rivers draining Precambrian Guyana and Brazilian Shields, where water is extremely poor in dissolved minerals. This species is restricted to swamps of (sub)tropical South America and the floodplains of Amazonian whitewater rivers originating in the Andes. Such environments are characterized by low levels of dissolved oxygen and markedly seasonal conditions caused primarily by fluctuations in rainfall.
H. littorale can breathe both with gills and through its intestines. However, intestinal respiration is not exhibited upon hatching, and the development of the respiratory intestine occurs throughout the juvenile period (up to 32 days old). Newly hatched larva
Larva
A larva is a distinct juvenile form many animals undergo before metamorphosis into adults. Animals with indirect development such as insects, amphibians, or cnidarians typically have a larval phase of their life cycle...
e do not have the ability to breathe air through their intestines; however, it is possible that they absorb oxygen through their skin at this point, before the armor plates have developed. Soon after, between about 12–23 days of age, young have the capacity to breathe air, but their respiratory intestine has not finished developing. The respiratory intestine is well-developed between days 24 and 32.
H. littorale has two types of hemoglobin
Hemoglobin
Hemoglobin is the iron-containing oxygen-transport metalloprotein in the red blood cells of all vertebrates, with the exception of the fish family Channichthyidae, as well as the tissues of some invertebrates...
, anodic
Anode
An anode is an electrode through which electric current flows into a polarized electrical device. Mnemonic: ACID ....
and cathodic
Cathode
A cathode is an electrode through which electric current flows out of a polarized electrical device. Mnemonic: CCD .Cathode polarity is not always negative...
; anodic hemoglobin has a relatively low oxygen affinity and has marked Bohr effect
Bohr effect
Bohr effect is a property of hemoglobin first described in 1904 by the Danish physiologist Christian Bohr , which states that an increasing concentration of protons and/or carbon dioxide will reduce the oxygen affinity of hemoglobin...
s, while cathodic hemoglobin lack significant pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
effects. In H. littorale, cathodic hemoglobin has a pronounced reversed Bohr effect in which oxygen affinity increases with decreased pH. Cathodic hemoglobin has the purpose of safeguarding oxygen transport to tissues under hypoxic and acidotic conditions.
H. littorale diet varies by age. Immature fish feed primarily on small aquatic crustacean
Crustacean
Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...
s, especially Cladocera
Cladocera
Cladocera is an order of small crustaceans commonly called water fleas. Around 620 species have been recognised so far, with many more undescribed. They are ubiquitous in inland aquatic habitats, but rare in the oceans. Most are long, with a down-turned head, and a carapace covering the apparently...
, Ostracod
Ostracod
Ostracoda is a class of the Crustacea, sometimes known as the seed shrimp because of their appearance. Some 65,000 species have been identified, grouped into several orders....
a, Copepod
Copepod
Copepods are a group of small crustaceans found in the sea and nearly every freshwater habitat. Some species are planktonic , some are benthic , and some continental species may live in limno-terrestrial habitats and other wet terrestrial places, such as swamps, under leaf fall in wet forests,...
a, and Eubranchipoda. Chironomid
Chironomidae
Chironomidae are a family of nematoceran flies with a global distribution. They are closely related to the Ceratopogonidae, Simuliidae, and Thaumaleidae...
larvae are important items in the diets of both juveniles and adults. The adult diet is dominated by mixed detritus, terrestrial insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s, microcrustaceans, and aquatic beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
s during the dry season, and mixed detritus and chironomid larvae during the wet season.
Reproduction
The first reproduction occurs after one year. Spawning is triggered by the first rains and occurs in the warm and rainy season. As a callichthyine, it builds a bubble nestBubble nest
Bubblenests, also spelled bubble nests or bubble-nests, created by some fish species, are floating masses of bubbles blown with an oral secretion, saliva bubbles, and occasionally aquatic plants, or an area for egg deposit attached at the bottom. Fish that build and guard bubble nests are known as...
; among callichthyines, this species is reported to have the most complex nest structure. This dome-shaped nest is rich with oxygen; in the hypoxic
Hypoxia (environmental)
Hypoxia, or oxygen depletion, is a phenomenon that occurs in aquatic environments as dissolved oxygen becomes reduced in concentration to a point where it becomes detrimental to aquatic organisms living in the system...
water conditions of tropical swamps, the main function of the bubble nest appears to be to provide oxygen to the developing eggs by lifting the eggs above the water surface while protecting them from desiccation. It may also serve to protect the brood against predators, regulate temperature, identify the center of the male's territory, and to synchronize reproductive activities. Nest-building activities usually lasted from 1,000 to 1,500 hours, but only on clear and warm days, particularly during the hottest hours. These activities are also reported to occur at night. Most nests are built in newly flooded swamps, especially in open water in the peripheral area of the swamp. A minimum distance of 10 metres between nests is observed. The nest is the centre of a territory that is vigorously defended by the male, using its enlarged pectoral spines. The diameter and height of the nest average 30 and 6 cm (12 and 2.36 in), respectively.
The beginning of nest building is preceded by a courtship
Courtship
Courtship is the period in a couple's relationship which precedes their engagement and marriage, or establishment of an agreed relationship of a more enduring kind. In courtship, a couple get to know each other and decide if there will be an engagement or other such agreement...
ritual. This pair formation consists of the male and female swimming parallel to each other, the male and female facing each other and contacting their barbels, the male stimulating the flanks of the female, the swimming to the surface by the male and female and production of the first bubbles at the nest site, and adding further bubbles to the nest under construction. The male produces most of the foam
Foam
-Definition:A foam is a substance that is formed by trapping gas in a liquid or solid in a divided form, i.e. by forming gas regions inside liquid regions, leading to different kinds of dispersed media...
. First, the male and female come to the surface and swim belly-up in small circles. The film of the air-water interface is swallowed and pumped out through the gill
Gill
A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...
s, where it gains mucus
Mucus
In vertebrates, mucus is a slippery secretion produced by, and covering, mucous membranes. Mucous fluid is typically produced from mucous cells found in mucous glands. Mucous cells secrete products that are rich in glycoproteins and water. Mucous fluid may also originate from mixed glands, which...
. Movement of the pelvic fins stirs the water and mucus, captures air bubbles, and breaks these air bubbles into a foam. The female may add some bubbles to the nest under construction. Pelvic fin movement differs between sexes; males move their pelvic fins in a side-to-side fashion, while females open and close their pelvic fins. The male often dives to the bottom to retrieve plant debris; filamentous nest materials are preferred, which are knitted together in the nest by the male. The male creates an upward water current with its tail fin that lift plant materials up. Then, the male uses its developed pectoral fin spines to cary the plant materials to the nest. The male uses its mouth and pectoral fins to incorporate the plant material into the foam mass of the nest. Females neither have developed pectoral fin spines nor do they help in transporting plant debris. The end result is a dome-shaped nest made up of loosely interwoven plant material on top of tightly interwoven plant material, held up to the surface with a layer of foam; the eggs will be laid on top of this foam from below.
Spawning occurs during the daytime. There is indication that the female drinks the sperm and that fertilization takes place after the sperm has passed through her digestive tract. The male and female form the "T-position", where the female places its mouth over the male's genital opening and collects the sperm in the mouth. The female rests at the bottom for 30–60 seconds, and then swims to the nest, turns upside down, and lays the eggs in the nest. H. littorale is a multiple spawner. Investing in reproduction is high in females since they can spawn up to 14 times during a 7 month breeding season and each spawn consists of 6,000–9,000 eggs. On average, two to four females spawn simultaneously, resulting in an average number of 20,000 eggs per nest. The adhesive eggs are located in the centre of the nest under the plant debris above the surface of the water, and not in contact with the oxygen-depleted swamp water. The male guards the nest during incubation; incubation of the eggs takes two to three days depending on the temperature in the nest. The male also regularly supplies foam to the nest. Guarding and maintenance of the nest occurs day and night. Once spawning has been completed, the male attacks females that have deposited their eggs in the nest. Despite intense predation pressure on eggs and larvae, the male's guarding behavior extends for only one or two days after hatching. The male attacks with its large pectoral spines erect; the attack consists of rapid propulsion towards its target followed by a sharp lateral turn, which causes the rough outer edge of pectoral spine to drag across the target and cause abrasion.
Relationship to humans
H. littorale is a valuable resource extensively fished in the deltas of the Amazon and Orinoco. In Guyana, French Guiana, Suriname, and Trinidad, this species is an extremely popular food fish.H. littorale is now commercially cultured in Trinidad, Guyana and Suriname. It fetches a price of US$8/kg and there are local and foreign ethnic markets for
the fish.
H. littorale is also an aquarium
Aquarium
An aquarium is a vivarium consisting of at least one transparent side in which water-dwelling plants or animals are kept. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, marine mammals, turtles, and aquatic plants...
fish. It is a peaceful fish. It will eat any food that other fishes can eat.