Diversity, Distribution and Composition of the Bivalvia Class on the Rocky Intertidal Zone of Marine Priority Region 32, Mexico

Abstract

The Bivalvia Class, is widely represented in marine ecosystems and is economically important; this research focused on this class and was carried out by sampling the rocky intertidal zone of seven sites located in the Marina Region Priority No. 32, Guerrero, Mexico, where the National Commission for the Knowledge and Use of Biodiversity reported lack of knowledge on marine species living there. The objectives were to examine species richness associated with the rocky intertidal zone, determine how the community is composed by the representation of families based on species richness and abundance, know the distribution of the species, analyze the structure sizes of populations and estimate the diversity index. Sampling was conducted at seven sites; the sampling unit was one square meter and the sampling area was 10 m2. 32 species were identified. Four species are new records for the Mexican Pacific Transitional: one for the state of Guerrero and one for Marine Priority Region 32. Arcidae and Mytilidae Families were better represented in species richness and Chamidae Family was the best represented in abundance. Chama coralloides was considered to be the representative species of the area; Striostrea prismatica showed the greatest size. The diversity index was estimated (H' = 3.65 bits/individuals). Species richness is high and corresponds to that expected in a tropical area.