Pedro Flores-Rodríguez

Mollusc community from a rocky intertidal zone in Acapulco, Mexico

The state of Guerrero, Mexico, has approximately 470 km of seashore but the marine fauna is not well known. The coastline has three marine areas for priority conservation of coastal and oceanic biodiversity, for which Comisión Nacional para la Conservación y Uso de la Biodiversidad (CONABIO) notes a distinct lack of knowledge in these areas. This study was carried out in a rocky intertidal middle zone from Playa ‘Majahua’, Acapulco, located south of Bahia de Puerto Marques. The objectives were to study: the species richness for classes Gastropoda, Bivalvia and Polyplacophora; the community structure from the representation of classes, families and genera; estimate density and species composition within a community; analyse size and structure of populations in the mollusc community; and estimate the diversity index. Three samplings were made in the intertidal middle zone in 2009. Ten square metres were sampled at each visit. Ninety-nine mollusc species were found to be represented, corresponding to 36 families. From all of these species, no record in Acapulco was found for 21 Gastropoda, 5 Bivalvia and 8 Polyplacophora species recorded. Gastropoda was the best represented; 1737 organisms were analysed with an estimated density of 86.8 organisms/m2 and 31 species were dominant. Crucibullum umbrella was the largest sized species. The diversity and equity index estimate in Majahua was the highest found for the rocky coast of Guerrero, indicating a mega-diverse area with great uniformity.

Riqueza, composición y diversidad de la comunidad de moluscos asociada al sustrato rocoso intermareal de playa Parque de la Reina, Acapulco, México

El conocimiento de la biodiversidad marina en el Estado de Guerrero, Mexico es escaso, lo que es senalado por la Comision Nacional para la Conservacion y Uso de la Biodiversidad. Para avanzar en este conocimiento, se trabajo en el intermareal rocoso de Playa Parque de la Reina, Acapulco, que se encuentra ubicada en la region marina prioritaria para la conservacion y uso de la biodiversidad numero 32. El objetivo fue determinar la riqueza de especies de moluscos, conocer la composicion de la comunidad, la densidad, el grado de aparicion de las especies, la composicion por tallas y la diversidad. El area de muestreo fue de 10 m-2 y la unidad de muestreo fue 1 m-2. Se identificaron 58 especies, 4 nuevos registros para el intermareal rocoso de Acapulco. Las familias mas representadas fueron: Muricidae, Ischnochitonidae, y Mytilidae. La densidad fue de 207,55 organismos m-2. Fueron dominantes 21 especies. Macrocypraea cervinetta presento la mayor talla. La riqueza de moluscos fue alta, coincidiendo con lo esperado en una zona tropical. Las especies dominantes y constantes representaron el 55,16%, y se consideran representativas de la comunidad. La densidad encontrada es la mas alta que se ha reportado para Guerrero, Mexico y el tipo de sustrato es uno de los factores determinantes que define la riqueza de especies y la abundancia.

Biocenosis de Bivalvia y Polyplacophora del intermareal rocoso en playa Tlacopanocha, Acapulco, Guerrero, México

The State of Guerrero, Mexico, has priority marine areas for conservation of its biodiversity, but information concerning diversity of mollusks is limited, so it is convenient to carry out species inventories, studies of populations and community ecology. This study was conducted in the intertidal rocky beach Tlacopanocha. The objectives were to determine richness, density and species diversity, analyze the species composition and size structure. The sampling area was 10 m and the sampling unit was 1 m. 35 species were identified of which three are new records for the intertidal rocky shores of the State of Guerrero. The best represented families in species richness were Ischnochitonidae and Arcidae, and Chamidae, and Chitonidae in abundance; species density was 31.60 ind m. Polyplacophora showed 42.9% of dominant species and Bivalvia 19.0%. Chama corallina showed the greatest length and Chama sordida the greatest width. Species richness of mollusks recorded is considered high and in agreement with tropical rocky substrates. Polyplacophora showed high species composition, which could be the result of adaptation of organisms to the dynamic conditions of the rocky intertidal. New records indicate the importance of species inventories and knowledge of the populations and community’s dynamics of the Guerrero marine fauna.The State of Guerrero, Mexico, has priority marine areas for conservation of its biodiversity, but information concerning diversity of mollusks is limited, so it is convenient to carry out species inventories, studies of populations and community ecology. This study was conducted in the intertidal rocky beach Tlacopanocha. The objectives were to determine richness, density and species diversity, analyze the species composition and size structure. The sampling area was 10 m 2 and the sampling unit was 1 m 2 . 35 species were identified of which three are new records for the intertidal rocky shores of the State of Guerrero. The best represented families in species richness were Ischnochitonidae and Arcidae, and Chamidae, and Chitonidae in abundance; species density was 31.60 ind m -2 . Polyplacophora showed 42.9% of dominant species and Bivalvia 19.0%. Chama corallina showed the greatest length and Chama sordida the greatest width. Species richness of mollusks recorded is considered high and in agreement with tropical rocky substrates. Polyplacophora showed high species composition, which could be the result of adaptation of organisms to the dynamic conditions of the rocky intertidal. New records indicate the importance of species inventories and knowledge of the populations and community’s dynamics of the Guerrero marine fauna.

Helminth communities of two species of piscivorous birds, Ardea alba (Linnaeus) and Nyctanassa violacea (Gmelin) (Ciconiiformes: Ardeidae), in two coastal lagoons from Guerrero state, Mexico

The composition and species richness in helminth communities of two species of heron, Ardea alba and Nyctanassa violacea, in two coastal lagoons from Guerrero, Mexico were examined. Nineteen species of helminth (7,804 individuals) were identified in 43 adult birds: 15 digeneans, 1 acanthocephalan, 1 cestode, and 2 nematodes. Eight species co-occurred in herons of both species and lagoons. The prevalence values of seven species and the mean abundance of five species varied significantly between species of birds and between lagoons. The heterophyid, Ascocotyle (Phagicola) longa, was the helminth numerically dominant in the helminth community of A. alba in both lagoons, while the cestode, Parvitaenia cochlearii, dominated the community of N. violacea. At the component community level, species richness varied significantly: 10 species in A. alba from Coyuca to 16 in N. violacea (Tres Palos). All of the birds examined were infected with helminth parasites: three to seven species per host in A. alba from Coyuca, and two to eight species in A. alba and N. violacea from Tres Palos. The results indicate that even though species composition was similar between both species of heron, the structure of their communities was not the same. Differences in the feeding behavior of the birds (day/night habits), as well as local differences in the abundance of species of fish, and infection levels of helminths in each lagoon are suggested as being responsible for the variations registered in the structure of the helminth communities.

Diagnóstico pesquero de Chiton articulatus (Mollusca: Polyplacophora) en Acapulco, México

Chitons are marine mollusks morphologically composed of a large muscular foot which allows them to conform to irregular surfaces. Few species as Chiton artic...

Composition of Prosobranchia-Pulmonata (Mollusca: Gastropoda) in rocky intertidal zone in the Marine Priority Region 32, Guerrero, Mexico

The aim of this research was the description of the taxocoenosis of Prosobranchia and Pulmonata subclasses (Gastropoda) associated with the rocky intertidal zone of the Marine Priority Region 32, Guerrero, Mexico. Based on known species richness, we examine the composition of the community based on the representation of families, assess abundance, the geographic distribution of species, estimate descriptive statistics of size, and estimate diversity. Sampling was conducted at 7 sites, the sampling unit was 1 m-2 and the sampling area was 10 m-2. One hundred and four species of subclass Prosobranchia and 4 species of subclass Pulmonata were identified. Columbellidae and Muricidae families showed higher species richness, meanwhile family Muricidae was the most abundant. Acanthais triangularis was the most representative species of the study area, and Macrocypraea cervinetta showed the greatest size. Twenty three species were found with broad distribution, 27 taxa with frequent distribution and 54 taxa with restricted distribution. Twenty eight species were represented by a single organism and 6 species with 2 organisms, these species were considered rare and were found in sites whose characteristic wave exposure is low to medium. Species richness was high and corresponds to that expected in the tropics.El objetivo de esta investigacion fue la descripcion de la taxocenosis de las subclases Prosobranchia y Pulmonata (clase Gastropoda), asociados a la zona intermareal rocosa de la Region Marina Prioritaria 32, Guerrero, Mexico. Basada en la riqueza de especies, la composicion de la comunidad a partir de la representacion de las familias, se evaluo la abundancia, distribucion geografica de las especies, se estimo los estadisticos descriptivos de las tallas (en largo) de las poblaciones y la diversidad. El muestreo se llevo a cabo en 7 sitios, la unidad de muestreo fue de 1 m-2 y el area de muestreo de 10 m-2. Se identificaron 104 especies de prosobranquios y 4 de pulmonados. Las familias Columbellidae y Muricidae fueron las mejores representadas en riqueza de especies y la familia Muricidae en abundancia. Acanthais triangularis se considero como la representativa de la zona, la especie Macrocypraea cervinetta mostro la mayor talla. Ademas, 23 especies presentaron amplia distribucion, 27 distribucion regular y 54 distribucion restringida. Veintiocho especies estuvieron representadas por un unico organismo, y 6 especies por 2 organismos, estas especies son consideradas raras. Las especies raras se encontraron en las estaciones cuya caracteristica de exposicion del oleaje es de bajo a medio. La riqueza de especies fue alta y corresponde a lo esperado en una zona tropical

Diversidad, especies de mayor importancia y composición de tallas de los moluscos en la pesca ribereña en Acapulco, Guerrero, México

Fishing of marine mollusks in Acapulco de Juarez, Guerrero, is intense and diverse and there is little knowledge about this resource. Therefore, for most of species subject to fishing there is no regulation. Due to this, the aims of this study were update inventory of mollusks that are fished for human consumption, determine species that are most important and analyze composition of catch sizes. Biological samples were taken from 2011 to 2014, directly from catches of fishermen. 72 interviews were conducted. 48 species were identified and 16 were the most important. In most species, organisms that did not reach size that would allow them to participate in renewal of reproductive stock were captured. Fishery biological studies are necessary to contribute to regulation of coastal fishing of mollusks.

Gasterópodos con potencial económico asociados al intermareal rocoso de la Región Marina Prioritaria 32, Guerrero, México

Resumen es: Los gasteropodos tienen numerosas especies de importancia comercial, de ellos se utilizan la carne y concha, ademas del uso potencial de sus toxinas para...

Socioeconomic Aspects for Coastal Mollusk Commercial Fishing in Costa Chica, Guerrero, México

An important part of the fishing activity in Mexico is carried out in the coastal strip and has a strong social, economic and ecological importance. In the state of Guerrero, mollusks fishing is coastal and craftwork activity focused on a small number of species and without information on biology and reproductive or ecological aspects for most species caught. This research was carried out in the Costa Chica region, Guerrero, Mexico and the aims were: 1) To analyze the socioeconomic features of cooperative societies of fishing production; and 2) To know the diversity of mollusks caught by coastal fishing and the species that have the greatest importance in fishing. From February to April 2013-2015, seven fish coop units, four piers and places where seafood is sold were visited. For the socio-economic analysis and the determination of the species that have more importance in the coastal fishing, a total of 67 surveys were applied. In order to determine the cast of species, the specimens captured by the fishermen were used, which were identified and counted. A total of 67 interviews were analyzed and an average of

Geographic range extension of gastropods in the coast of Guerrero, Mexico

1806.00 was estimated as weekly economic income just as a product of fishing, it was also estimated that on average the fishermen work 4.3 days a week. Fisheries cooperatives market most of their produce directly to restaurateurs and locals on the piers. Replacement of older adults by young fishermen from the same region was observed, most are adults between 22 and 39 years old. 25 species of mollusks of economic importance were registered for the coastal fishermen of the Costa Chica. Six species were identified as the main target for catching fishermen. The fishing of mollusks in Costa Chica is not subject to any type of control, which has led to overfishing reflected in the decline sizes and banks in populations of commercial importance.