Search Results

You are looking at 1 - 2 of 2 items for

  • Author or Editor: Farhana S. Ghory x
  • Search level: All x
Clear All

Abstract

The northern Chilean coast is characterized by its high productivity and diversity due to the presence of the cold, nutrient-rich water of the Humboldt Current. In this scenario, the rocky shore provides many microhabitats for invertebrates such as crustaceans. The aim of the present study was to analyse potential species interactions using probabilistic models and contingency tables. In this particular case we analysed the potential interactions between two sympatric intertidal decapods, Cyclograpsus cinereus and Petrolisthes granulosus, on the rocky shores of Cifuncho Bay, an isolated bay in the north of Chile. The results revealed that both species had a uniform pattern, that was adjusted to a binomial distribution for C. cinereus, and a Poisson distribution for P. granulosus. These results are probably due to territorial behaviour, and this was corroborated by the results of the contingency table, which denoted the independence of both species. These results would not coincide with classical observations of intertidal decapods on rocky shores of continental Chile, as those denoted a gregarious pattern. However, on the other hand, the present results do not explain any details about potential interactions between the two species here analysed.

In: Crustaceana

Abstract

The decapod fauna of Chile’s intertidal shores in inner seas south of 40°S has relatively low diversity because of the presence of low-salinity waters due to river inputs and glacial smelts; nevertheless it is possible that the same decapods species are found as on the northern and central Chilean coast. The aim of the present study was to determine the spatial distribution patterns of lower intertidal decapods on Pelluhuín beach, a small beach south of Puerto Montt, northern Patagonia. Data were obtained by counting individuals from random quadrants in intertidal zones; to the obtained data the variance/mean ratio was applied to determine if the specimens have a random, aggregate or uniform distribution, which are associated with Poisson, negative binomial or positive binomial distributions respectively. Among four of the species observed, a uniform distribution (positive binomial) was reported, and one had an aggregated pattern (negative binomial). The sites correspond to rocky shores in semi-urban zones, and in a protected zone. Our results on the interpretative probabilistic models of aggregated distribution patterns agree with previously reported observations of decapods on the rocky shores of Northern and Central Chile, specifically in interpretative probabilistic models.

In: Animal Biology