While normally dealing with commercial fisheries in the Oceans, once in a while I get the opportunity to do a “unusual job” and I really like them! Working in the Amazon river is not the “usual” deal for me, and Arapaima (paiche) is really an unusual fish.
Arapaima can reach lengths of more than 2 m (6 ft 7 in), in some exceptional cases even more than 2.5 m (8 ft 2 in) and over 100 kg (220 lb). The maximum recorded weight for the species is 200 kg (440 lb), while the longest recorded length was 4.52 m (15 ft).
As one of the most sought-after food fish species in South America, it is often captured primarily by handheld nets for export, by spearfishing for local consumption, and consequently, large arapaima of more than 2 m (6 ft 7 in) are seldom found in the wild today.
Commercial fishing of the arapaima has been banned, however is difficult to control this, furthermore it has a really delicate in flavour, and boneless. So there great incentives to farm them, but as you may see from the pictures, is not an easy task.
The arapaima is torpedo-shaped with large blackish-green scales and red markings. It is streamlined and sleek, with its dorsal and anal fin set back near its tail. Its local name, paiche, derives from the indigenous words for "red" and "fish".
To make him more unusual, it has a fundamental dependence on surface air to breathe. In addition to gills, it has a modified and enlarged swim bladder, composed of lung-like tissue, which enables it to extract oxygen from the air. This is an adaptation to the often hypoxic conditions of the Amazon floodplains, but requires the arapaima to surface for air every 5 to 15 minutes. This tendency to come at the surface makes it more vulnerable to be catch by spear fishermen.
Not just because the size, and the fact that there is no sexual dimorphism (male and females looks the same), hence the sexing is done by measuring hormone levels in blood; but also because the animal's life cycle is greatly affected by the seasonal flooding and this need to be imitated.
The arapaima lays its eggs during the months when the water levels are low or beginning to rise. They build a nest about 50 cm wide and 15 cm deep, usually in muddy-bottomed areas. As the water rises, the eggs hatch and the offspring have the flood season to prosper, during May to August. Therefore, the yearly spawning is regulated seasonally.
The arapaima male is supposed to be a mouthbrooder, like his relative, the Osteoglossum, meaning the young are protected in his mouth until they are older.
So what this has to do with me? Well the swiss government programme I’m working with, is evaluating this operation as to support the creation of employment via increase of exports possibilities, in function of a set of environmental and social practices. In the case of this farm, they are eliminating the use of fish meal based feeds, and farming some of the local small fish that are the natural diet of paiche, which besides being much better from a general "sustainability" perspective, has increased conversion ratios (kg food given vs kg gain in body weight), so a win win situation.
Again life keeps surprising positively me with the opportunities it put in from of me.