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During the period June 2019 to February 2020, a comprehensive siphonophore and cnidarian community survey was conducted at three stations near Anconcito, 1, 5, and 10 miles offshore. A total of 15 siphonophore species were identified and seasonal and spatial patterns in their abundance and diversity were highlighted. Muggiaea atlantica emerged as a dominant species, especially during the wet season, evidencing its relevance in low temperature waters. At the 1 mile station, five siphonophore species were recorded during the wet season, with Muggiaea atlantica reaching a significant density of 39 ind.(100m³)-1 in November 2019. At 5 miles, cnidarian diversity was notable, with Chelophyes contorta and Diphyes dispar as dominant species, reaching 80 ind.(100m³)-1 in February 2020. The 10-mile fixed station showed high diversity during the wet season, with Agalma elegans, Diphyes dispar and Sulculeolaria chuni as the most abundant, reaching 88 ind.(100m³)-1 in February 2020. During the dry season, the fixed station at 10 miles recorded nine cnidarian species, with Abylopsis tetragona, Diphyes dispar and Muggiaea atlantica as the most relevant, reaching a density of 826 ind.(100m³)-1. In the water column at 5 miles, Chelophyes contorta, Diphyes dispar, Lensia multicristata and Muggiaea atlantica were the most abundant species, with 219 ind.(100m³)-1 during the wet season and 1031 ind.(100m³)-1 during the dry season. At 10 miles, during the wet season, 20 species of cnidarians were recorded, with Agalma okeni, Diphyes dispar and Sulculeolaria chuni being the most representative, with a density of 163 ind.(100m³)-1 in february 2020. In the dry season, 14 species were observed with Diphyes dispar, Lensia fowleri and Muggiaea atlantica as dominant, reaching significant densities statistical analyses, such as NMDS, ANOSIM and SIMPER, revealed significant associations and differences between study areas and fixed stations, highlighting the importance of environmental factors in species distribution. The ACC showed significant correlations between the presence of cnidarians and environmental variables such as temperature, dissolved oxygen, salinity and pH. [ABSTRACT FROM AUTHOR]

The studies carried out in extreme environments are of vital importance to know the variability of plankton in low temperature conditions, during the Southern summer, during the XVIII Ecuadorian Antarctic Expedition, between January and February 2014, the study area was located in the Guayaquil Cove and Chile Bay (Greenwich Island), plankton samples were collected at surface and vertical level using simple cylindro-conical-conical nets of 335µ and 50µ respectively, in order to determine the distribution of phytoplankton and zooplankton. Ten sampling stations were carried out in Guayaquil Inlet and 8 stations in Chile Bay in both strata. Nineteen phytoplankton species were identified at surface level and Thalassiosira sp. 60.3%, Cyclotella sp. 12.4% and Corethron criophylum with 12.7% were observed as dominant and 9 species in the water column, being dominant Thalassiosira sp. 52%, Cyclotella sp. 25% and C. criophylum with 11%, observing a 68.12% of dissimilarity between both zones, registering as dissimilar species Thalassiosira sp, Cyclotella sp., Limnophora abreviata, Synedra ocus and Diploneis coffeif.ormis. In Chile Bay, 19 species were recorded at surface level, with two dominant species, Cyclotella sp. 36% and C. criophylum with 28%, while 10 species were recorded in the water column, with Cyclotella sp. 45% and C. criophylum 25%. Zooplankton was represented in Guayaquil Cove by 11 groups, with copepods and amphipods as dominant, in the vertical there were 7 groups represented mostly by copepods, in Chile Bay in both strata an average of 6 groups were recorded and copepods were the dominant ones. Within the Ecological indexes in the phytoplankton recorded a Shannon value of 1.3 bits/cel at the surface level and 1.2 bits/cel in the vertical, Simpson of 0.4 bits/cel in both strata and Pielou recorded an average of 0.75 bits/cel, in Guayaquil Inlet, in Chile Bay at surface level a H value of 1.5 bits/cel and 1.2 bits/cel in the vertical was observed, Simpson with an average of 0.35 bits/cel in both strata and Pielou with 0.70 bits/cel at surface level and 0.9 bits/cel in the vertical. [ABSTRACT FROM AUTHOR]

The rocky intertidal zones of Capaes and Punta Blanca in the province of Santa Elena (Ecuador) present several communities of macroinvertebrates, therefore the objective of the research was to analyze and compare the distribution and abundance of nine stations established in the two study areas. Seventeen samples were collected in quadrats of 1 m each in an area of 160 m² in the two study areas. Five classes of macroinvertebrates were identified, Gasteropoda with 4 orders and 12 species, Crustacea with 1 order and 3 species, Bivalvia with 1 order and 1 species, Malascostraca with 1 order and 1 species, Polyplacophora with 1 order and 1 species. It was observed in both zones that the substrate is made up of interstratified sandstones. In the rocky intertidal zone of Capaes, 2234 ind/m² were recorded, with the Gasteropoda class being the most abundant with 1403 ind/m², showing Thais brevidentata as dominant, while the Malacostraca class had a relative abundance of 4.38%, evidenced by Pachygrapsus marmoratus and an index of 2.52 bits. In the Punta Blanca area, 2224 ind/m², the most abundant Gasteropoda class with 1153 ind/m², evidenced by Thais brevidentata as the dominant species, the Bivalve class with 15 ind/m², with 0.67% of relative abundance, the only species being Brachidontes adamsianus and an index of 2.53 bit. The homogeneity in Capaes was maintained with a value of 0.966 and in Punta Blanca with a value of 0.920. The observations made at the Capaes and Punta Blanca stations made it possible to determine the distribution and abundance of the benthic macrofauna present, most of which were of the Gasteropoda class with 62.8% relative abundance and Malacostraca, with 4.39% abundance, thus achieving the objectives set in little-known areas for the development of research work. [ABSTRACT FROM AUTHOR]

The amount of Pollicipes elegans distributed in the rocky area was evaluated in port Engabao during the months of May to October 2015, on the coast of Playas Canton, Guayas Province. Applying the quadrat method, the amount of organisms per square meter was determined in three stations, A, B and C. Working with each tidal stratum present in the study area, where the colonies counted in the low sea predominated with average temperatures of 31.5°C, salinity of 33 ups and 5.59mg/L of dissolved oxygen, parameters that influence their growth. In the first month, about 10246 organisms were recorded at point A (low sea), a number that decreased during the study period, reaching about 7521 organisms at the same point in October. Ninety specimens were collected within the study area and their rostral carina length, wet weight (g) and length (mm) were taken. In addition, Pearson's correlation was applied where the coefficient of determination weight-height was 88.25%. The rostral carina length was also related to the total wet weight, by means of a bar chart where the juvenile population had a percentage of 4.44% of those ≤ 17mm and the adult population had a percentage of 95.56% of those ≥ 17mm in length. In the frequency table, 61.1% of the population has a rostral carina length of 30 mm, considering that the entire population registered from May to October is adult according to the empirical table proposed by Samamé and Quevedo. In addition, the number of organisms collected in three in situ samplings was estimated, where the organisms extracted were counted, with an average of 272 organisms per sampling. [ABSTRACT FROM AUTHOR]