Hoplias aimara
Hoplias aimara
Hoplias aimara ( Syn: Hoplias macrophthalmus ), also Anjumara, Anjoemara, Guabina, Fasaco, in Portuguese or English Trairão Wolf Fish belongs to the family of Raubsalmler ( Erythrynidae ) and one of the major predators of South America.
Dissemination
Hoplias aimara occurs mainly in the rivers of tropical rainforest in the northern part of South America. The species is widespread in Brazil ( State of Amapa, in the rivers Tocantins, Xingu, Rio Tapajós and Rio Trombetas ), Colombia, Venezuela, Guyana, French Guiana and Suriname. The largest specimens of H. aimara occur in Suriname in Coppename River.
Description
Hoplias aimara with body lengths of 120 centimeters and weight of 40 kg, the largest species of the genus Hoplias. H. aimara has an elongated cylindrical shape. Along the sidelines, they have 32 to 47 scales. The pectoral fin has nine to 14 fin rays, the anal fin ten to 12 and the dorsal fin eight to 15 Your caudal fin has a rounded shape. At its palatine bone, they have pointed and very sharp fangs. Side of the gill cover, they have a characteristic black spot. The back is usually dark or light brown to golden brown in color, offset on the sides lighter with dark vertical stripes. His drawing may vary by geographical region of origin. With its characteristic pattern to H. aimara adapts to the stone base of the rivers.
Way of life
The species occurs in waters with a pH between 6.5 and 8 and water temperatures of 23 ° C to 30 ° C. Its habitats include both marshy shore regions, as well as plain water or black water rivers in the tropical rain forests. H. aimara holds also on behind waterfalls, rapids or in the opposite flow of rivers and streams. There he lurks in ambush for prey fish. Because of its hunting behavior, he is also known as wolf fish. While young fish make it even in small flocks prey to larger specimens become loners. It shows an opportunistic diet, for example by keeping the water falling eats small animals and insects. H. aimara is active mainly at dusk and at night. Its spawning season begins with the rainy season, which lasts from December to March. Depending on their size, a Rogner 6000-60000 eggs produce. They operate brood and defend the nest against predators spawning. In aquariums the type often shows very aggressive and cannibalistic behaviors.
Taxonomy
Scientists have long believed that there are two species of Giant Trahiras were: Hoplias aimara ( Valenciennes, 1846) and Hoplias macrophthalmus ( Pellegrin, 1907). Both were first described in French Guiana. Likely catches of H. aimara in the Orinoco and Rio Purus were errors. Subsequent morphometric studies showed that the holotype of H. aimara and H. macrophthalmus relates and belongs to a taxon. According to the International Rules for Zoological Nomenclature, the name Hoplias aimara has priority.
Species of the genus Hoplias
- Hoplias aimara ( Valenciennes, 1847)
- Hoplias australis Oyakawa & Mattox, 2009
- Hoplias brasiliensis ( Spix & Agassiz, 1829)
- Hoplias curupira Oyakawa & Mattox, 2009
- Hoplias lacerdae A. Miranda - Ribeiro, 1908
- Hoplias malabaricus ( Bloch, 1794) ( Trahira )
- Hoplias microcephalus ( Agassiz, 1829)
- Hoplias Patana ( Valenciennes, 1847)
- Hoplias teres ( Valenciennes, 1847)
Economic Importance
Due to its tasty meat, he is a popular food fish. In the Waiwai Indians in Guyana, he is one of the staple foods. Its occurrence has declined due to overfishing in some regions.
Hazardous situation
Studies on the biomagnification of mercury have shown that embed themselves in Hoplias aimara as Predator large amounts of pollutants into his flesh. They are also affected by the increasing nitrogen input into water bodies. After aquatic constructional measures the radius of action of Hoplias aimara limits. After the construction of the Petit- Saut dam in French Guiana, the fish exhibit greater site fidelity than in an unspoilt waters with flooding forests during the rainy season.