Distribuição e abundância do ictioplâncton na região do Porto do Pecém, Ceará

Abstract

The ichthyoplankton is the fraction of the plankton comprising the fish eggs and larvae. The research on ichthyoplankton is of utmost relevance to the fisheries biology and to fully understand the marine ecosystems functioning. Although such studies are frequent in many regions of the planet, there is no information about the ichthyoplankton for the coast of Ceará. In order to change this situation, the distribution and abundance of fish eggs and larvae from the coastal zone waters of Pecérn were studied. A total of 28 samples were collected in four different campaigns during 2006. The samples from February and April represented the rainy season, while the collection in July and September comprised the dry season. The samples were collected through subsurface horizontal trawling during 5 min with a 30011m mesh net. Temperature, salinity, dissolved oxygen and pH were also recorded for each station. The samples were sorted and identified in the laboratory, totaling 4.320 eggs and 1.410 larvae of fish. 1.395 larvae were identified pertaining to 13 inferior taxa (genera or species), three orders and nine families. The ichthyoplankton from the studied area comprised three categories of families: pelagic, reef associated and demersal, with a prevalence of the first. Fish eggs were most abundant during the rainy season, while larvae numbers were larger during the dry months. The families Engraulidae and Serranidae were the most representative throughout the studied period. As to the frequency, the Serranidae were present in all samples, whereas the Gobiidae were collected in a single campaign.