Estudos biológicos e ecológicos de pinctata sp. (bivalvia: mytillidae) na região do delta do rio Tocantins, município de Limoeiro do Ajuru

Abstract

Reports from 1924 indicate the presence of pearl-producing bivalves in the Tocantins River, thirty years after this narrative there was a certain international interest on the subject. The municipality of Limoeiro do Ajuru, located in the delta of the Tocantins River, is today one of the strongest shell extracting municipalities in Pará, although there is no legal record of this activity. Using data from an excursion to the municipality of Limoeiro do Ajuru in October 1997, the fishermen, usually young men between 17 and 25 years old, leave in small canoes at the beginning of the ebb tide to go fishing; They dive to the bottom of the river and there they palpate, collect the shells and put them in a small basket; after 30 to 50 seconds on the bottom they come back up to the surface to breathe and transfer them to the canoe; the commercialization of these shells was also verified. A couple of fishermen in small boats are capable of removing from the river about 30 kg of shells of a single species, i.e. about 200 shells; in a warehouse of a local dealer we found 30,000 shells, the production of only 30 days of work by 20 fishermen. This type of activity only occurs from July to December and only at low tide. Studies on the biology of this species should be carried out in order to prevent it from disappearing from the area, as happened in the municipalities of Bujaru and Igarapé-Miri.