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Enrique Morsan – One of the best experts on this subject based on the ideXlab platform.
local scale variation in the reproductive pattern of the southern geoduck panopea Abbreviata bivalvia hiatellidae in patagoniaRevista De Biologia Marina Y Oceanografia, 2016Co-Authors: Paula C. Zaidman, Marina A. Kroeck, Silvina Van Der Molen, Gabriela Noemi Williams, Leilen Graciavillalobos, Erica Oehrenskissner, Enrique MorsanAbstract:
espanolDurante el 2007 se realizaron estudios para explorar la variabilidad espacial a escala local, del ciclo reproductivo de Panopea Abbreviata en 3 poblaciones presentes en los golfos Nord-patagonicos (El Sotano y Puerto Lobos, en el Golfo San Matias, y Punta Conos en el Golfo San Jose), Argentina. Estudios previos determinaron que P. Abbreviata presenta un patron reproductivo, en ambos sexos, caracterizado por una continua proliferacion y evacuacion de gametos durante todo el ano. Sin embargo, el uso de indicadores cuantitativos (distribucion de frecuencia de diametros ovocitarios, ovocitos por campo ocular y area ovocitaria relativa) para las hembras permitio observar una ligera estacionalidad. Las variaciones en el ciclo reproductivo fueron relacionadas con el regimen anual de temperatura de cada sitio. Las hembras de El Sotano y Puerto Lobos muestran una estacionalidad similar en el patron reproductivo: las fases de proliferacion y maduracion predominan cuando la temperatura disminuye durante otono (marzo-mayo); este patron se revierte, cuando las temperaturas comienzan a aumentar durante primavera (septiembre-noviembre). Mientras que, en Punta Conos este patron es mas irregular. Sin embargo, en todas las poblaciones se encontraron individuos de ambos sexos en estadio de madurez durante todo el ano, evidenciando la ausencia de un periodo de inactividad gonadal. En las 3 poblaciones ambos sexos se caracterizan por multiples pulsos cortos de evacuacion de gametos. Este mismo patron se encontro en otras poblaciones de P. Abbreviata y es unico para el genero Panopea. Los 3 sitios estudiados presentaron un patron reproductivo similar. EnglishDuring 2007 was carried out studies to explore local scale spatial variability in the reproductive cycle of Panopea Abbreviata in 3 sites of the northern Patagonian gulfs (El Sotano and Puerto Lobos, in San Matias Gulf, and Punta Conos in San Jose Gulf), Argentina. Previous reports have revealed that P. Abbreviata exhibits a reproductive pattern characterized, in both sexes, by continuous proliferation of gametes and spawning throughout the year. However, the use of quantitative indicators for females has shown a slight seasonality to this pattern. Local spatial variability in the reproductive cycle of P. Abbreviata was observed at 3 sites and related to variation in the annual temperature regime at each locality. The females of El Sotano and Puerto Lobos showed similar seasonality in the reproductive pattern: proliferation and maturation phases prevailed over spawning stages when temperature decreased during autumn (March-May); this pattern was reversed when temperatures began to increase during spring (September-November). At Punta Conos this pattern is more irregular. However, at all localities, mature individuals of both sexes were present throughout the year, without a resting period during the reproductive cycle. The reproductive pattern is similar in the 3 sites with many small pulses in reproductive activity that are difficult to detect and characterized by year-round spawning. The same pattern was found in other localities of P. Abbreviata and is unique in the genus Panopea.
Growth variability in a metapopulation: The case of the southern geoduck (Panopea Abbreviata)Fisheries Research, 2015Co-Authors: Paula C. Zaidman, Enrique MorsanAbstract:
Abstract Oceanographic conditions modulate the growth of bivalves. In Northern Patagonia, Argentina , seasonal thermohaline fronts define 3 oceanographic domains in the San Matias Gulf (SMG) and the San Jose Gulf (SJG), which create different environmental conditions for growth. We studied the variability of the growth pattern in a metapopulation of the geoduck clam Panopea Abbreviata within and between oceanographic domains. P. Abbreviata forms spatially disjunct subpopulations in the SMG and the SJG. Growth patterns were determined using size-at-age data from counts of inner shell layers for two subpopulations in each oceanographic domain. We used a multimodel inference approach to describe the growth pattern, fitting five candidate growth models (von Bertalanffy, logistic, Gompertz, Richards, and Schnute-Richards). Growth was fast during the first 8–10 years and slowed in later years. This pattern was consistent with the pattern described in studies for other Panopea species. Larger individuals of P. Abbreviata were more abundant in mud-sandy places (Punta Conos and Playa Fracasso, SJG’s eastern coast) than in locations with sand sediment (Punta Colorada and Puerto Lobos, SMG’s western coast). Multimodel inference is a robust way to estimate growth parameters for this species. We found differences among locations, independent of the domains. The results suggest that local environmental conditions are greater growth modulators than general oceanographic conditions. The differences in growth observed among locations should be considered when developing biological reference points specific for each location.
Reproductive pattern of Southern geoduck, Panopea Abbreviata, at El Sótano (San Matías Gulf, Patagonia, Argentina)Marine Biology Research, 2012Co-Authors: Paula C. Zaidman, Marina A. Kroeck, Erica M. Oehrens Kissner, Enrique MorsanAbstract:
Abstract The reproductive cycle of the southern geoduck (Panopea Abbreviata) in a northern Patagonian population was studied throughout a 24-month period (April 2006–April 2008) using standard histological techniques and quantitative indicators (oocyte diameter distribution, oocytes per ocular field and relative oocyte area). P. Abbreviata exhibits a reproductive pattern characterized, in both sexes, by a continuous proliferation and spawning throughout the year. This is similar to that described in southern geoduck populations and is unique to this genus. Quantitative indicators allowed us to elucidate a slight seasonality in the reproductive cycle: a more pronounced spawning during warm months and gamete accumulation during could months. This article describes the first record of hermaphroditic individuals (n = 4) for P. Abbreviata.
Samuel Narciso – One of the best experts on this subject based on the ideXlab platform.
tasa de depredacion de coralliophila Abbreviata neogastropoda coralliophilidae sobre algunas especies coralinas del parque nacional morrocoy venezuelaRevista Biología Tropical; 2008: Vol. 56 (Suplemento 1), 2014Co-Authors: Samuel Narciso, Estrella Villamizar, C Del MonacoAbstract:
Coralliophila Abbreviata is a tropical gastropod of the Caribbean Sea. This gastropod is an important corallivore. The objective of this work was to estimate the predation rate of C. Abbreviata on some coral species in the coral reefs of Morrocoy National Park, Venezuela. The localities were Cayo Sombrero and Cayo Peraza. We evaluated the rate on five coral species: Montastraea annularis, Colpophyllia natans, Diploria strigosa, Diploria labyrinthiformis and Agaricia agaricites. We used three experimentals treatments. In treatment 1 we marked colonies with buoys that had been predated by C. Abbreviata. In treatments II and III we used exclusion cages. Treatment II included the colony with its predators and treatment III was the control (only the colony). The injuries of the colonies were measured every 4 days for at least a month. The predation rate in treatment I varied depending on the coral species. The highest rate was on C. natans (3.70 cm2/Ind/day), while D. strigosa, D. labyrinthiformis and M. annularis did not register any predation rate (0 cm2/Ind/day). In treatment II we only detected predation activity in 1 colony of M. annularis with 0.15 cm2/Ind/day. The main effect generated by C. Abbreviata on the Morrocoy National Park’s coral reefs could be a decrease in the colonies reproduction and growth rate due to energetic use in tissue regeneration of injuries.
nota sobre la densidad y tasa de depredacion de coralliophila Abbreviata y coralliophila caribaea sobre colonias jovenes de acropora palmata en un arrecife deteriorado de cayo sombrero parque nacional morrocoy venezuelaLatin American Journal of Aquatic Research, 2011Co-Authors: Carlos Del Monaco, Nicida Noriega, Samuel NarcisoAbstract:
The coral reefs of Morrocoy National Park are currently deteriorated. After the massive mortality of 1996, Acropora palmata has shown some signs of recovery, a process that could be hampered by Coralliophila. We observed only three colonies of A. palmata in an entire reef in Cayo Sombrero. In July 2005, these colonies registered Coralliophila Abbreviata densities of 4, 0, and 2 ind/col and Coralliophila caribaea densities of 22, 14, and 0 ind/col; in January 2006, said densities were 8, 0, and 4 ind/col (C. abbreviate) and 22, 14, and 0 ind/col (C. caribaea). Four sites of damage (two per predator) were observed in the three colonies. In one colony, C. Abbreviata caused a loss of tissue of 66.14 to 162.85 cm 2
Selectividad de presas de Coralliophila Abbreviata y C. caribaea en arrecifes coralinos del Parque Nacional Morrocoy, Venezuela: una aproximación experimentalLatin American Journal of Aquatic Research, 2010Co-Authors: Carlos Del Mónaco, Estrella Villamizar, Samuel NarcisoAbstract:
Coralliophila Abbreviata and C. caribaea are tropical gastropods of the Caribbean Sea. These gastropods have shown to be important corallivores. The objectiv…
Margaret W Miller – One of the best experts on this subject based on the ideXlab platform.
Assessment of Host-Associated Genetic Differentiation among Phenotypically Divergent Populations of a Coral- Eating Gastropod across the Caribbean, 2016Co-Authors: Lyza Johnston, Margaret W Miller, Iliana B. BaumsAbstract:
Host-associated adaptation is emerging as a potential driver of population differentiation and speciation for marine organisms with major implications for ecosystem structure and function. Coralliophila Abbreviata are corallivorous gastropods that live and feed on most of the reef-building corals in the tropical western Atlantic and Caribbean. Populations of C. Abbreviata associated with the threatened acroporid corals, Acropora palmata and A. cervicornis, display different behavioral, morphological, demographic, and life-history characteristics than those that inhabit other coral host taxa, indicating that host-specific selective forces may be acting on C. Abbreviata. Here, we used newly developed polymorphic microsatellite loci and mitochondrial cytochrome b sequence data to assess the population genetic structure, connectivity, and demographic history of C. Abbreviata populations from three coral host taxa (A. palmata, Montastraea spp., Mycetophyllia spp.) and six geographic locations across the Caribbean. Analysis of molecular variance provided some evidence of weak and possibly geographically variable host-associated differentiation but no evidence of differentiation among sampling locations or major oceanographic regions, suggesting high gene flow across the Caribbean. Phylogenetic network and Bayesian clustering analyses supported a hypothesis of a single panmictic population as individuals failed to cluster by host or sampling location. Demographic analyses consistently supported a scenario of population expansion during the Pleistocene, a time of major carbonate reef development in the region. Although further study is needed to full
Variation in life-history traits of the corallivorous gastropod Coralliophila Abbreviata on three coral hostsMarine Biology, 2006Co-Authors: Lyza Johnston, Margaret W MillerAbstract:
Coralliophila Abbreviata (Lamarck) is a corallivorous gastropod that lives and feeds on several species of scleractinian coral in the Western Atlantic and Caribbean. Previous studies of C. Abbreviata have revealed that snails on branching acroporid corals are larger and consume more tissue than those on massive and plating corals. To ascertain whether snail life-history and fitness are differentially affected by the coral host, an analysis of the age structure and female reproductive output of snail populations on three coral host taxa (Acropora palmata, Diploria spp., and Montastraea spp.) was conducted at four shallow (2–7 m depth) reef sites off Key Largo, Florida in June through August, 2004. Snails were, on average, almost twice as large on A. palmata than on Diploria spp. and Montastraea spp., averaging 30.3 mm shell length, compared to 17.2 and 17.6 mm, respectively. Brood size increased as a power function with female shell length. Females on A. palmata were significantly larger than females on the other two hosts and, therefore, produced more offspring per female. The number of growth striae on the inner surface of the operculum was used to estimate snail age. Estimates of growth rate were obtained by fitting the Gompertz growth function to size-at-age plots and mortality was estimated using growth parameters and size-frequency data. The data suggest that C. Abbreviata inhabiting A. palmata are larger than on alternative hosts due to a combination of a faster growth rate and longer life-span. The species is believed to be a protandrous hermaphrodite. The timing of sex change varied among hosts; snails on A. palmata changed sex later at larger sizes relative to those on the other two hosts. Based on these results, it seems probable that C. Abbreviata has developed reaction norms for life-history traits, allowing snails to adjust and maximize fitness in the different environments associated with various coral hosts.
Ecology of a corallivorous gastropod, Coralliophila Abbreviata, on two scleractinian hosts. II. Feeding, respiration and growthMarine Biology, 2003Co-Authors: Iliana B. Baums, Margaret W Miller, Alina M. SzmantAbstract:
Coralliophila Abbreviata is a corallivorous gastropod that has been observed to cause large feeding scars on reef-building corals on Floridian and Caribbean reefs. We detected differences in the population structure (length-frequency distribution and sex ratios) of C. Abbreviata populations living on two coral host taxa, Acropora palmata and Montastraea spp., in the Florida Keys in a previous study. We hypothesize that diet (host) has a major influence on snail population structure and, thus, we characterize metabolism, feeding and growth for snails residing on these coral taxa. Here, we present results of a reciprocal transplant experiment demonstrating that the taxon of the host influences snail growth rates, as indicated by changes in shell and body tissue weight. Regardless of the host from which they were drawn, snails resident on A. palmata grew faster than those resident on Montastraea spp. Thus, diet influences snail population structure. However, the tissue of Montastraea spp. provides more N and C per area of tissue than that of A. palmata. Respiration rates and tissue composition of snails collected from the two host taxa did not differ. Therefore, snails feeding on Montastraea spp. should have to consume less tissue per day to satisfy their metabolic requirements compared to snails feeding on A. palmata. Feeding rates for snails on A. palmata were measured in the laboratory over 48 h (1–9 cm2 coral tissue snail−1 day−1) and estimated from feeding scars observed in the field (weekly mean rate of 1.07 cm2 coral tissue snail−1 day−1). The lack of definition of snail feeding scars on Montastraea spp. required the calculation of coral tissue consumption rates based on estimated minimum carbon requirements. Calculated feeding rates for C. Abbreviata were 0.13–0.88 cm2 coral tissue day−1 snail−1, when feeding on Montastraea spp., and 0.44–3.28 cm2 coral tissue day−1 snail−1, when feeding on A. palmata. The calculated range for the latter is consistent with measured rates. Thus, C. Abbreviata exhibits high variation in growth parameters in response to environmental variability and/or food source. At mean levels of snail density on reefs off Key Largo, Fla., 20% of A. palmata colonies lose between 1.32 and 9.84 cm2 tissue day−1, while 50% of Montastraea spp. colonies lose between 1.04 and 7.04 cm2 tissue day−1. Together with published coral tissue regeneration rates, these results suggest that if sustained, such rates of predation could have a serious effect on the viability of these coral populations on Florida’s reefs.