The community associated to the kelp Macrocystis pyrifera from Beagle Channel (54°00´S; 68°20´W) was studied. Sixty-eight taxa including Algae (5), Porifera (indet.), Bryozoa (7), Nemertea (2), Annelida (10), Mollusca (22), Crustacea (15) and Echinodermata (7) were recognized. A seasonal sampling during one year showed differences in composition when comparing (a) two different environments; (b) spring-summer period autumn-winter period; (c) parts of alga (fronds holdfast).

BackgroundCell-cell interactions are a basic principle for the organization of tissues and organs allowing them to perform integrated functions organize themselves spatially temporally. Peptidic molecules secreted by neurons epithelial cells play fundamental roles in cell-cell interactions, acting as local neuromodulators, neurohormones, well endocrine paracrine messengers. Allatotropin (AT) is neuropeptide originally described regulator Juvenile Hormone synthesis, which plays multiple...

Intertidal communities from rocky shores of the southwestern Atlantic are dominated by two small-sized mussels genus Brachidontes, B. rodriguezii (d'Orbigny, 1846) and purpuratus (Lamarck, 1819). Their generic placement, separation specimens based on external conchological characters geographic distribution problematic. We conducted a comparative study extensive collections observations at 14 sites along coasts Atlantic, complemented materials museum collections. Well-preserved species...

Mussels are important components of rocky shore assemblages throughout the world. Several mytilid species found as multilayered beds in intertidal along coasts south-western Atlantic. However, contrast to north communities Pacific and Atlantic, those Atlantic dominated by small size, locally named mejillines. These mid-intertidal attached consolidated substrates virtual monocultures two small-sized Brachidontes: B. rodriguezii (d'Orbigny, 1842) (Perumytilus) purpuratus Lamarck, 1819,...

The use of rocky intertidal assemblages in paleoecology and conservation paleobiology studies is limited because these environments have low preservation potential.Here, we evaluate the fidelity between living mussel bed communities (life or LAs) mollusk shell accumulations (death DAs) from environmentally harsh Patagonian Atlantic Coast.LAs were sampled mid-intertidal mussel-dominated habitats while DAs collected high water mark at beaches close proximity to community assess live-dead...

Communities of the rocky mid-intertidal zone South-western Atlantic are uniform in appearance, dominated by dense monocultures small-size mussels (Brachidontes rodriguezii and Perumytilus purpuratus). To explain this, two hypotheses have been advanced literature: environmental harshness due to high potential evaporation historical contingency after Last Glacial Maximum. In this study Uruguayan Argentine shores, we address implications predictions these from a biogeographic perspective...

The effects of grazing activity by the limpet Siphonaria lessoni Blainville, 1824 (Gastropoda) on Brachidontes rodriguezii (d'Orbigny, 1846) (Bivalvia) community. Understanding how biodiversity influences and modifies ecosystem processes depends our knowledge roles individual species. In intertidal rocky shore communities, molluscs are main grazers among them found pulmonate lessoni. Here it was used a manipulative field experiment to test community responses deletion from mid-intertidal...

Previous studies demonstrated complex architecture of the muscular system Macrostomum species, especially in rostrum area and pharynx. However, little is known about differences pattern between species genus. This study examines compares systems specimens belonging to three freshwater (M. quiritium, M. tuba velastylum), labeled with phalloidin-rhodamine studied by confocal microscopy. Our results agree previous descriptions, confirming that patterns for body wall, area, pharynx caudal region...

Une nouvelle espèce de Gieysztoria Ruebush & Hayes, 1939 (Platyhelminthes, Rhabdocoela, Dalyelliidae) d'Argentine, avec une discussion sur la répartition du genre en région néotropicale. provenant des environnements limniques Argentine est décrite. La disposition son système musculaire génital décrite utilisant phalloïdine marquée à rhodamine et microscopie confocale balayage laser (CLSM), approche méthodologique pour l'étude ce genre. reta n. sp. diffère ses congénères dans sa morphologie...

The genus Macrostomum (Platyhelminthes: Macrostomorpha) is a group of cosmopolitan free-living flatworms that occurs in wide range habitats. In our study, individuals velastylum were collected from the Sagastume stream (33°38ʹ34ʺS; 58°49ʹ63ʺW) Entre Ríos Province, Argentina, during 2016. They kept laboratory at room temperature order to study population parameters (1, fecundity; 2, hatching rate and time; 3, male sexual maturation 4, longevity). results show this species laid 1.5 eggs per...

Free-living microturbellarians are a part of lentic and lotic aquatic assemblages play an important but underestimated role in ecosystems. Consequently, they not included studies on the dynamics freshwater invertebrate communities. We report eight new records from Suquía River (Córdoba, Argentina): Catenula lemnae Dugès, 1832, Stenostomum arevaloi Gieysztor, 1931, aff. amphotum Marcus, 1945, Macrostomum quiritium Beklemischev, 1951, platensis Adami,...